Numerous models of particle dark matter have been proposed, many of which remain viable given current experimental and observational constraints. Minimal dark matter is an extremely attractive option since it envisions the addition of a single SU(2) multiplet to the standard model, rather than a complicated array of particles and interactions. However, experimental limits already rule out a...
I'll discuss the conversion of relativistic axion dark radiation into terahertz electromagnetic radiation via a novel resonance that is only accessible in a neutron star magnetosphere thanks to the strong magnetic field. Based on 2408.04551 with Enrico Schiappacasse.
Theoretical physicists describe nature by i) building a theory model and ii) determining the model parameters. The latter step involves the dual aspect of both fitting to the existing experimental data and satisfying abstract criteria like beauty, naturalness, etc. We use the Yukawa quark sector as a toy example to demonstrate how both of those tasks can be accomplished with machine learning...
We introduce a field-theory framework in which fields transform under the little group, rather than the Lorentz group, specific to each particle type. By utilizing these fields, along with spinor products and the x factor, we construct a field-theory action that naturally reproduces the vertices of the constructive standard model (CSM). This approach eliminates unphysical components,...
We investigate the flavour sector of the supersymmetric SU(5) Grand Unified Theory (GUT) model using machine learning techniques. The minimal SU(5) model is known to predict fermion masses that disagree with observed values in nature. There are two well-known approaches to address this issue: one involves introducing a 45-representation Higgs field, while the other employs a higher-dimensional...
Self-interacting dark matter (SIDM) provides an intriguing alternative to collisionless dark matter, especially when it comes to resolving small-scale structure problems. I will present our preliminary findings on gravothermal collapse in SIDM halos using an extended version of the GravothermalSIDM code, now capable of incorporating velocity-dependent cross sections from the CLASSICS...
On generic (non-stationary) curved backgrounds, the link between Euclidean and Lorentzian signature QFT via a Wick rotation is not fully understood. In this talk, I will present a generalization to curved spacetimes of a variant of Wick rotation originally due to Zimmermann. This construction interpolates between Lorentzian and Riemannian metrics on the same underlying smooth real manifold,...
Model building in particle physics relies heavily on the intuition of theorists to select appropriate symmetry groups, particle content, and representation assignments. However, the space of viable models is vast. Exploring the space is usually computationally expensive. The challenge lies in the combinatorial complexity of symmetry and representation choices and the computational effort...
I will discuss the blue loop stage of intermediate mass stars as a type of ``magnifying glass'', where even seemingly small effects in prior stages of evolution, as well as assumptions about stellar composition, rotation, and convection, produce discernible changes. As such, blue loops, and especially the existence and properties of Cepheids, can serve as a laboratory where feebly connected...
Blazars are a subclass of active galactic nuclei (AGN), the brightest continuously emitting sources in the Universe, powered by accreting supermassive black holes (SMBH). Their defining characteristic is the presence of powerful, back-to-back relativistic jets of protons and electrons, with one jet closely aligned in the direction of Earth. This offers a unique opportunity to probe physics...
The lack of direct detections for weakly interacting massive particles has led theorists to think about more exotic scenarios for producing DM in the early Universe. One viable alternative is gravitational particle production i.e. the creation of particles through due to the presence of a sufficiently strong gravitational field. In this talk, I will go over how this mechanism can be used to...
The bias-variance tradeoff is a well-recognized phenomenon in statistics and machine learning. In this talk, I will discuss an extension, dubbed the bias-variance-correlation tradeoff. Roughly speaking, as the flexibility of a model decreases, the correlations in the outputs of a trained model for different inputs increases. Such correlations have implications for several applications of...
“New” physics can potentially be witnessed in two ways: firstly, by making familiar experiments more precise, and secondly, by looking for phenomena outside the familiar domain. Even though quantum mechanics (QM) has been extremely well-tested, there is room for novel, although necessarily tiny, effects.
In this talk, I will describe a framework that modifies QM slightly, using parameters...
Some of the most stringent constraints on axions arise from considerations of it's emission from astrophysical plasmas. However, many studies assume that particle production occurs in an isotropic plasma environment. This condition is rarely (if ever) met in astrophysical settings, for instance due to the ubiquitous presence of magnetic fields. The effects of the magnetic fields are only taken...
Macroscopic, composite, and ultraheavy dark matter remains one of the most intriguing dark matter candidates. Along with primordial black holes, this includes quark nuggets, Fermi balls, Q-balls, and more. I will motivate these candidates and discuss their formation mechanisms, before discussing here my recent work which places constraints on a wide and previously unconstrained area of the...
This talk reports recent measurements of jet production cross-sections and the sub-structure properties inside jets in ATLAS. These measurements provide important inputs to understand Quantum Chromodynamics at the high energy regime.
Sterile neutrinos are compelling dark matter candidates, yet the minimal Dodelson-Widrow (DW) production mechanism is excluded by astrophysical observations. We propose a scenario where heavy scalar-mediated non-standard interactions (NSI) between active and sterile neutrinos not only alter the DW mechanism but also generate new production channels, such as $\nu_a \nu_a \to \nu_s \nu_s$. This...
Theoretical understanding of deep learning remains elusive despite its empirical success. In this study, we propose a novel "synaptic field theory" that describes the training dynamics of synaptic weights and biases in the continuum limit. Unlike previous approaches, our framework treats synaptic weights and biases as fields and interprets their indices as spatial coordinates, with the...
Due to the inclination for forward gauge radiation, lepton colliders beyond a few TeV are effectively electroweak boson colliders, suggesting the treatment of electroweak bosons as constituents of high-energy leptons. In this talk, we summarize the status of electroweak boson parton distribution functions, present new theoretical progress on their implementation, and give a brief outlook for...
It has been known since the 1950's that an unstable particle is associated with a complex pole in the propagator. This had to be rediscovered twice: in the early 1970's in the context of hadronic resonances, and in the early 1990's in the context of the $Z$ boson. The physical mass of the particle is the real part of the pole in the complex energy plane. In hadronic physics, this replaced the...
We propose $w_i f_i$ ensembles, a novel framework to obtain asymptotic frequentist uncertainties on density ratios in the context of neural ratio estimation. In the case where the density ratio of interest is a likelihood ratio conditioned on parameters, for example a likelihood ratio of collider events conditioned on parameters of nature, it can be used to perform simulation-based inference...
In this work, we investigate the dependence of dark matter (DM) direct detection results, specifically single phonon scattering observables, on the astrophysical properties of the local DM halo. We analyze the impact of uncertainties in DM halo velocity distributions on both total cross-sections and daily modulation in single phonon excitation rates. Employing the Standard Halo Model (SHM),...
Studying heavy-flavour hadron properties provides a extensive tests for various QCD predictions as well as a means to probe the Standard Model validity. ATLAS experiment, being a general-purpose detector at LHC, is particularly successful in such measurements with final states involving muons, thanks to large collected integrated luminosity and precise muon reconstruction and triggering. This...
Stellar binaries have historically provided a rich target in the search for exotic compact objects such as primordial black holes (PBHs) or MACHOs. In a three-body interaction involving a PBH and a binary star system, the binary can either lose or gain a significant amount of energy from the PBH, leading to a change in its orbital period. A standard lore has been that if the perturber velocity...
We consider weakly interacting massive particle (WIMP) dark matter in a parity solution to the strong CP problem. The WIMP phenomenology is drastically affected by the presence of parity partners of WIMP and electroweak gauge bosons. We focus on a parity extension of $SU(2)_L$-doublet fermion dark matter, identify the viable parameter space, and derive the predictions of the theory. We find...
One of the fundamental difficulties in the Lagrangian formulation of effective field theories (EFTs) is that one can redefine the fields in a theory without changing the physical predictions, e.g. scattering amplitudes. The freedom to perform field redefinitions to change the form of the Lagrangian can often obscure the physical content of an EFT. This is in fact a familiar situation in any...
We investigate dark gauge-mediated supersymmetry breaking with an unbroken $U(1)_D$ symmetry and a massless dark photon. Messengers charged under both Standard Model and dark gauge groups generate new soft SUSY-breaking terms via gauge kinetic mixing. Large mixing significantly alters superpartner spectra compared to standard GMSB, reduces the μ parameter, and predicts a relatively light...
Field redefinitions in effective field theories (EFTs) can involve derivatives, introducing redundancies that cannot be captured by the traditional geometry of field space based solely on two-derivative terms in the Lagrangian. To accommodate these derivative-dependent transformations, we present a geometric framework that extends beyond conventional field space to the functional manifold....
Score based and consistency diffusion models are presented for generating jet images, focusing on high-fidelity synthesis for high energy Physics applications. Using the JetNet dataset, the diffusion models are trained to learn the visual representation of jet kinematics. The results demonstrate that consistency models achieve significantly lower Fréchet inception distance measures compared...
Signatures of new physics at the LHC are varied and, by nature, often very different from those of Standard Model processes. Novel experimental techniques, including dedicated data streams, are exploited to enhance the sensitivity of the CMS Experiment to search for such signatures. In this talk, we highlight the most recent CMS results, obtained using the data collected at the LHC Run-2 and...
We are considering a minimal $U(1)_B$ extension of the Standard Model (SM)
by promoting the baryon number as a local gauge symmetry to accommodate a
stable dark matter (DM) candidate. The gauge theory of baryons induces non-
trivial triangle gauge anomalies, and we provide a simple anomaly-free solution
by adding three exotic fermions. A scalar S spontaneously breaks the $U(1)_B$...
How the supermassive black holes form has been an enduring puzzle. Recent discoveries of active galactic nuclei near cosmic dawn by James Webb Space Telescope suggests that SMBHs may have formed as early as $z ∼ 10$. We propose a mechanism that SMBHs form naturally near the cosmic dawn if the dark matter is axion or ALPs. Axion dark matter thermalizes by gravitational self-interactions and...
Dark matter (DM) - neutrino interactions will necessarily lead to a time-delayed flux of neutrinos from transient sources. Considering Milky Way supernovae, we find scattering with DM can lead to neutrino time delays on the order of thousands of years. Multiple supernovae are expected to occur on such timescales, meaning we expect a nearly continuous diffuse neutrino flux. We call this the...
The decays B->PP, where the pseudoscalar P is a pi or K, have been studied under the assumption of flavor SU(3) symmetry. The global fit reveals a 3.6 sigma discrepancy with the Standard Model. Separate fits for Delta S = 0 and Delta S = 1 decays find parameter sets that differ by a factor of 10, indicating a flavor SU(3) breaking of 1000%, significantly larger than the 20% breaking expected...
The observation of an exploding black hole would provide the first direct evidence of primordial black holes, the first direct evidence of Hawking radiation, and definitive information on the particles present in nature. However, indirect constraints suggest that direct observation of an exploding Schwarzschild black hole is implausible. We introduce a dark-QED toy model consisting of a dark...
We consider a simplified model of dark matter which contains a scalar dark matter candidate $\chi$ and a coloured scalar mediator $\phi$. The model parameter space contains dark matter mass $m_\chi$, mediator mass $m_\phi$, the dark matter coupling with the mediator $\lambda_d$ and the color representation $r$ of the mediator $\phi$. In this model, we investigate the phenomenology of...
The anomalous magnetic moment of the muon, i.e. ($g-2$), is one of the versatile and promising probes of new physics at the GeV scale, particularly for $Z^{\prime}$ gauge bosons that couple to both leptons and quarks. Due to inputs from experiments, lattice QCD as well as theory collaborations, one can constrain such BSM theories using various combinations of these inputs. Based on this idea,...
We present a framework to model microlensing signatures of novel compact object populations beyond the traditional stellar evolution path. A compelling model to investigate is the dissipative dark matter scenario, in particular, the atomic dark matter model, which can form dark black holes (DBHs) from the gravitational collapse of fragmented dark hydrogen gas. DBHs have unique mass ranges and...
I will review developments in applying Anomaly Mediated SUSY Breaking (AMSB) as a theoretical tool for understanding the dynamics of strongly coupled gauge theories. After reviewing the general properties of AMSB, I will show what we have been able to learn when applying it to a variety of examples. Many non-trivial consistency conditions are satisfied. In the case of QCD, I will show how we...
The electron and muon anomalous magnetic moment (g–2) are among the most precisely tested quantities in nature. But what about tau-leptons? Long overlooked, tau g–2 is so poorly constrained it cannot even test Schwinger's landmark $\alpha/2\pi \simeq 0.0012$ prediction from 1948. This leaves striking room for new physics where taus enjoy 280 times greater sensitivity than muons. Creative...
We present the first complete two-loop calculation of the electric dipole moment of the
electron, as well as the rates of the lepton-flavor violating decays μ → e + γ and τ → e/μ +
γ, in the unconstrained two-Higgs doublet model. We include the most general Yukawa
interactions of the Higgs doublets with the Standard Model fermions up to quadratic order,
and allow for generic phases in the...
Magnetic levitation technology offers force and displacement sensitivities at the quantum frontier, making it an attractive platform for probing the feeble interactions expected of beyond the Standard Model physics. Despite its promise, the case for magnetic levitation in fundamental physics applications is only just being built. In this talk, I will demonstrate how a setup based on the...
Recent years have seen growing interest in exploring quantum information principles within particle scattering processes, both in theoretical and experimental physics. Magic, a resource that quantifies computational advantages in quantum systems, offers a distinct measure of quantumness beyond conventional metrics like entanglement. As researchers investigate the role of magic in scattering...
We explore a conformal dark matter model based on the gauge group $SU(N_{c}) \times U(1)_{D}$, from which we can obtain confinement of bound-state dark matter at a dark QCD scale, and a WIMP and self-interacting dark matter at a higher energy scale, around $1$ TeV, along with the possibility of gravitational wave (GW) production from strong first-order phase transitions at both scales. We...
In this talk, we revisit motivation from String Theory for new phases of cosmology – prior to inflation. Cosmic inflation offers a causal way to predict initial conditions for the growth of structure and density fluctuations in the cosmic microwave background and large scale structure formation. However, asymptotic deSitter space possesses a past cosmological (physical) singularity implying...
As the heaviest known fundamental particle, the top quark plays a pivotal role in the search for new physics. Many beyond-the-Standard-Model theories predict interactions between the top quark and yet undiscovered particles. With the LHC becoming a top quark factory, it offers unprecedented opportunities to study top quark properties and explore potential signs of new physics. In this talk,...
The Gallium Anomaly (GA) currently stands at a global significance of greater than $5\sigma$. Most viable BSM solutions quickly run into strong tensions with reactor and solar neutrino data. In this talk, I'll argue that the GA resolution requires the ability to probe spectral features and oscillation behavior, therefore requires a new detection strategy for low-energy neutrinos. Firstly, I'll...
The recent demonstration of laser excitation of the 8 eV isomeric state of thorium-229 is a significant step towards a nuclear clock. The low excitation energy likely results from a cancellation between the contributions of the electromagnetic and strong forces. Physics beyond the Standard Model could disrupt this cancellation, highlighting nuclear clocks' sensitivity to new physics.
It is...
Indirect CP violation in kaon decays is measured with a precision at the permil level. In this talk, I briefly review the status of the standard model prediction, including current efforts to calculate the four-loop QCD corrections using the MaRTIn code.
Discovering that neutrinos have mass has left question regarding their origin. One possible model of their origin are Left-Right models, which add a SU(2) group with a right handed neutrino and a new heavy charged boson W'. Searches at the LHC for this heavy boson have not been successful, meaning that larger and more energetic colliders are needed. This analysis searches for the W' at 6.5 TeV...
The high center-of-mass energy of proton-proton collisions and the large available datasets at the CERN Large Hadron Collider allow the study of rare processes of the Standard Model with unprecedented precision. Measurements of rare SM processes provide new tests of the SM predictions with the potential to unveil discrepancies with the SM predictions or provide important input for the...
We discuss possible consequences of a manifestly non-commutative and T-duality covariant formulation of string theory on dark energy, when the correspondence between short distance (UV) and long distance (IR) physics is taken into account. We demonstrate that the dark energy is dynamical, time-dependent, and we compute the allowed values of w_{0} and w_{a} given by w(a)=w_{0}+(1-a)w_{a}, which...
We study the interactions between light axion-like particles (ALPs) and the Standard Model electroweak gauge bosons at future lepton colliders. In the long-lived ALP regime, mono-photon and mono-$Z$ production channels are exploited, while for ALPs with shorter lifetimes, non-resonant vector boson scattering processes are used. Our combined analysis shows that future lepton colliders can...
In this talk I will focus on the study of the leptonic $B\rightarrow \ell \nu$ decay at next-to-leading order in QED. The future improvements of experimental measurements of this channel require a reliable theory prediction, hence a careful theoretical estimate of QED corrections. The multi-scale character of this process requires an appropriate effective theory (EFT) construction to factorize...
Supersymmetry (SUSY) provides elegant solutions to several problems in the Standard Model, and searches for SUSY particles are an important component of the LHC physics program. The direct production of electroweak SUSY particles, including sleptons, charginos, and neutralinos, is a particularly interesting area with connections to dark matter and the naturalness of the Higgs mass. Naturalness...
The sterile neutrino interpretation of the LSND and MiniBooNE neutrino anomalies is currently being tested at three Liquid Argon detectors: MicroBooNE, SBND, and ICARUS. It has been argued that a degeneracy between $\nu_\mu \to \nu_e$ and $\nu_e \to \nu_e$ oscillations significantly degrades their sensitivity to sterile neutrinos.
Through an independent study, we show two methods to eliminate...
The exceptionally large dataset collected by the ATLAS detector at the highest proton-proton collision energies provided by the LHC enables precision testing of theoretical predictions using an extensive sample of top quark events. Measurements of the inclusive top quark production rates at the LHC have reached a precision of several percent and test advanced Next-to-Next-to-Leading Order...
We propose a simple, well-motivated, and robust model of slow-roll thawing quintessence, which is consistent with current observations of dark energy and naturally satisfies the conjectured swampland constraints.
TBA
We investigate the impact of quenching factor uncertainties on the Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS) cross section measurements. From the recent results of Dresden-II, CONUS+, and COHERENT, we present that no choice of quenching factor can bring these three data sets into mutual agreement. We further present the quenching factor dependence on sensitivity of these...
We predict the expected flux of anti-electron flavor neutrinos in the diffuse supernova neutrino background (DSNB) with the inclusion of both failed and successful supernovae and binary stellar systems. Using simulations from the Garching Core-collapse Supernova Archive of single star progenitors and their neutrino energy spectra for a variety of explosion models, we determine an optimal...
Determination of the nature of dark matter is one of the most fundamental problems of particle physics and cosmology. This talk presents recent searches for dark matter particles from the CMS experiment at the Large Hadron Collider.
New electroweak states with masses below the TeV scale can still be discovered at the LHC. We show that motivated electroweak particles that are confined by a new gauge group could have masses as low as $100~{\rm GeV}$ and still be consistent with LHC searches. Additionally, we introduce a new search strategy to discover such particles at the high-luminosity LHC.
In the coming age of precision neutrino physics, neutrinos from the Sun become robust probes of the conditions of the solar core. Here, we focus on $^8$B neutrinos, for which there are already high precision measurements by the Sudbury Neutrino Observatory and Super-Kamiokande. Using only basic physical principles and straightforward statistical tools, we calculate projected constraints on the...
The top-quark mass is one of the key fundamental parameters of the Standard Model that must be determined experimentally. Its value has an important effect on many precision measurements and tests of the Standard Model. The Tevatron and LHC experiments have developed an extensive program to determine the top quark mass using a variety of methods. In this contribution, the top quark mass...
The COmpact DEtector for EXotics at LHCb (CODEX-b) is a particle physics detector dedicated to displaced decays of exotic long-lived particles (LLPs), compelling signatures of dark sectors Beyond the Standard Model, which arise in theories containing a hierarchy of scales and small parameters. The CODEX-b detector is a cube with 10m per side with two internal sections, planned to be installed...
The Lyman-alpha forest enables the study of cosmic structure on scales much smaller than those probed by baryon acoustic oscillations (BAO). While the BAO feature appears at 150 Mpc, the Lyman-alpha forest can resolve structure down to 1 Mpc, limited primarily by spectrograph resolution. This sensitivity makes it a powerful probe of small-scale clustering, which is influenced by the mass of...
For many spin-dependent dark matter-electron couplings, the DM's scattering rate in a target material can be written in terms of its dynamical magnetic susceptibility. This quantity can be inferred from neutron scattering data, without requiring a microscopic model of the material. As a proof of principle, I will show that an existing dataset can be used to find the DM scattering rate in...
Light exotics effective field theory (LEX-EFT) focuses on the idea that there may be light BSM particles that are so far undiscovered. This talk will focus on a specific portal to new physics, the quark-lepton portal. This portal encompasses all possible interactions, up to dimension six, that a quark, lepton, and LEX field (with or without additional SM fields) can have. Within this portal,...
The transition magnetic moment between active and sterile neutrinos is theoretically well-motivated scenario beyond the Standard Model, which can be probed in cosmology, astrophysics, and at terrestrial experiments. In this talk, we focus on the latter by examining such an interaction at proposed lepton colliders. Specifically, in addition to revisiting LEP, we consider CEPC, FCC-ee, CLIC, and...
We perform the first high-throughput search for materials that can serve as excellent low-mass dark matter detectors. Using properties of over one thousand materials from the Materials Project database, we project the sensitivity in dark matter parameter space for experiments constructed from each material, including both absorption and scattering processes between dark matter and electrons....
We study the physics potentials of heavy QCD axions at 3/10 TeV muon colliders (MuC). These heavy QCD axions differ from typical ALPs as they solve the Strong CP puzzle, and their phenomenology is driven by the $aG\tilde G$ couplings. Different realizations of heavy QCD axions have different implications, and we show comprehensively how muon colliders can uniquely probe them with a huge...
We investigate the potential of evaporating primordial black holes (PBHs) as unique astrophysical sources of high-energy neutrinos originating from the decays of heavy beyond-Standard-Model (BSM) scalars. In their final stages, PBHs can attain temperatures sufficient to emit CP-even (H2), CP-odd (𝐴), and charged Higgs bosons (𝐻±). In specific regions of parameter space, 𝐻2 and A predominantly...
The origin of large scale magnetic fields in the Universe is widely thought to be from early Universe processes, like inflation or phase transitions. These magnetic fields evolve via magnetohydrodynamic processes till the epoch of recombination. When structures begin to form in the later Universe, the conservation of magnetic flux amplifies the magnetic fields via the adiabatic collapse of...
As neutrino experiments become more precise and explore a wide range of en-
ergies, studying how neutrinos interact with matter has become an important
way to test the Standard Model and search for new physics. In this talk, I will
present our work on neutrino interactions at both low (MeV) and high (GeV)
energy scales. At low energies, we consider coherent elastic...
We present results from searches for resonances with enhanced couplings to third generation quarks, based on proton-proton collision data at a center-of-mass energy of 13 TeV recorded by CMS. The signatures include single and pair production of vector-like quarks and heavy resonances decaying to third-generation quarks. A wide range of final states, from multi-leptonic to entirely hadronic is...
The latest measurements of branching ratios, related to hadronic decays of B mesons to charm and pseudo-scalar final states (DP), showed disagreements with theoretical predictions based on QCD factorization. Meanwhile, SU(3) symmetry-breaking was found in recent studies to exceed the Standard Model threshold of 20% (in B decays to two pseudo-scalars). In the light of these results, an analysis...
Neutrinos produced by interactions between ultra-high-energy (UHE) cosmic rays and the cosmic microwave background can help trace the origins of these particles and investigate the mechanisms driving their extreme acceleration.
The detection of neutrinos above the PeV scale requires instruments capable of monitoring several cubic kilometers of dense material, as the neutrino flux drops...
A high-energy muon collider provides a wide variety of mechanisms for the production of new heavy particles. In this talk, I will first show how the PDFs for quarks, gluons and photons can be applied on muon collider, and then present production cross sections for a large variety of colored particles, including color triplet fermions and scalars and color sextet diquarks, leptoquarks,...
A general two Higgs doublet model is adopted to study flavor changing neutral Higgs (FCNH) interactions in $pp \to t \phi\to t(tc)$ at the Large Hadron Collider, where $\phi$ is either the CP-even Higgs scalar ($H$) or the CP-odd Higgs pseudoscalar ($A$). We considered two final states, (i) single lepton: $ttc \to bjj cb\ell\nu$, and (ii) same sign di-lepton: $ttc \to bbc \ell\ell \nu\nu$...
Recently, the James Webb Space Telescope (JWST) has found early galaxies producing photons from more efficient ionization than previously assumed. This may suggest a reionization process with a larger reionization optical depth, $\tau_{reio}$, in some mild disagreement with that inferred from measurements of cosmic microwave background (CMB). Intriguingly, the CMB would prefer larger values of...
The traditional quark model accounts for the existence of baryons, like protons and neutrons, which consist of three quarks, as well as mesons, composed of a quark and antiquark pair. Only recently has substantial evidence started to accumulate for exotic states composed of four or five quarks or antiquarks. In this study, the CMS Collaboration investigates the recently discovered family of...
We present the first detailed study of Standard Model neutrino tridents involving tau leptons at the near detectors of accelerator neutrino facilities. These processes were previously thought to be negligible, even at future facilities like DUNE. However, our full $2\to 4$ calculation, including both coherent and incoherent scatterings, reveals that
the DUNE near detector will actually get a...
The age of WIMP-like dark matter direct detection is drawing to a close due to their non-detection at exquisitely sensitive liquid-noble detectors. However, models where the dark matter is lighter than the mass of a proton remain largely inaccessible to existing probes. Recently, molecular targets have emerged as particularly well-suited detector materials to look for this sub-GeV dark matter....
Higgs couplings are essential probes for physics beyond the Standard Model (BSM) since they can be modified by new physics, such as through the Higgs portal interaction $|H|^2\mathcal{O}$. These modifications influence Higgs interactions via dimension-6 operators of the form $ \left(\partial |H|^2\right)^2$ and $|H|^6$, which are generally expected to be of comparable size. This talk discusses...
The long-standing discrepancy between late and early-time measurements of the Hubble parameter has given rise to a tension that has been resistant to a satisfactory theoretical explanation, even as the statistical tension has grown to about 4-6$\sigma$. In this work, we present a novel idea designed to alleviate this tension. Taking dark matter to consist of a population of primordial black...
At upcoming neutrino oscillation experiments, a precise understanding of the neutrino flux is imperative for oscillation studies with sub-percent precision, even with a near detector. Current uncertainties on the neutrino flux are dominated by hadron production uncertainties, making their precise determination crucial. We propose a novel approach to investigate hadron production using near...
Dark matter continuously accumulates at the Earth’s core through DM–nucleon scattering as Earth traverses the Milky Way’s dark matter halo. With higher dark matter density in the Earth’s core, potential annihilations of these dark matter particles into Standard Model particles, like tau neutrinos and tau leptons, offer an intriguing observational target for indirect dark matter searches....
We propose a novel method to study the ultra-light bosons, where compact rotating objects undergo the phenomenon of quenched superradiance to create gravitational waves and neutrino flux signals. The neutrino flux results from appropriate coupling between the ultra-light bosons and the neutrinos. We consider a heavy sterile neutrino generation from ultralight scalar, which later results in...
Theoretical predictions for hadronic decays are extremely challenging due to the non-perturbative nature of QCD. The SU(3) approximate flavor symmetry of QCD can be used to derive relations between hadronic decay amplitudes. We perform a systematic study on how the SU(2) flavor symmetry amplitude sum rules can be used to give predictions for physical observables. In particular, we show a...
Tensor Networks, originally developed for quantum many-body systems, offer powerful representations of high-dimensional data. When applied to discriminate top quark signals from QCD backgrounds, the entanglement entropy of the tensor network model can give us insight into the correlations it has learned. Moreover, our study shows tensor network model is more resilient to detector effects and pile-up.
The Electron-Ion Collider (EIC) will have the capability to collide various particle beams with large luminosities in a relatively clean environment, surrounded by a large angular coverage detector. Our analysis focuses on the EIC’s sensitivity to Axion-like particles (ALPs) that are created via photon fusion and promptly decay to photons. We explore this predominantly through coherent...
Testing new interactions in the neutrino sector, both in current and upcoming experiments, is essential for uncovering the nature of neutrinos. In many extensions of the Standard Model (SM), active neutrinos may engage in self-interactions via the exchange of a new light particle, often motivated by the need to explain empirical puzzles such as the origin of neutrino mass. Cosmological data...
We show how the axion quality problem resulting from the violation of global symmetries by quantum gravity can be solved in presence of a gauged $U(1)_F$ flavor symmetry in a class of models. The gauged $U(1)_F$ explains the hierarchical structure of fermion masses and mixings via the Froggatt-Nielsen mechanism. The axion is realized as a byproduct of an accidental $U(1)$ symmetry with a QCD...
The Standard Model of Particle Physics explains many natural phenomena yet remains incomplete. Many new physics models (such as leptoquarks, W'/Z', or heavy neutral leptons) could manifest in final states involving multiple leptons. This talk will summarise the latest results from ATLAS in searches involving final states with leptons.
Experiments with directional sensitivity are ideal for discovering a dark matter signal even in the presence of irreducible backgrounds. Crystalline trans-stilbene ($C_{14} H_{14}$) is an excellent first example, with O(10%) amplitudes in its daily modulation signals. In this talk, I present a simple, universal measure for quantifying the statistical power of a directionally sensitive counting...
The growth of large-scale structure in the early universe remains unexplained to this day. Originally proposed by Alan Guth, inflation, which posits a brief period of rapid cosmological growth, stands as a potential explanation to this puzzle. Inflationary models use “slow roll parameters” to align predictions with cosmological constraints fixed by data from the CMB and other such experiments....
We study the one-loop model of a pair of charged scalars with chemical potential mechanism in cosmological collider physics. We evaluate the one-loop amplitude analytically using spectral decomposition in de Sitter. Compared to previous analysis, our result predicts the correct power dependence on scalar masses and the chemical potential for both the signal and the background. Using these...
A favored scenario for axions to be dark matter is for them to form a cosmic string network
that subsequently decays, allowing for a tight link between the axion mass and relic abundance.
We discuss an example in which the axion is protected from quantum gravity effects that would
spoil its ability to solve the strong CP problem: namely a string theoretic axion arising from gauge
symmetry...
Solar neutrinos provide crucial insights into the Sun’s fusion processes and neutrino oscillations in matter. However, detecting them requires effective suppression of backgrounds. One of these is spallation backgrounds—beta decays of unstable isotopes produced by cosmic-ray muons— which pose a major challenge above 6 MeV. We show that neutron tagging, made possible by the recent addition of...
Realistic grand unified theories based on the exceptional group $E_6$ will be presented and their phenomenological implications explored. These include fermion masses, neutrino oscillations, proton decay and a GUT-stabilized dark matter candidate.
We present NomAD (Nanosecond Anomaly Detection), an unsupervised machine learning algorithm developed for real-time anomaly detection in the ATLAS Level-1 Topological (L1Topo) trigger during Run 3. Combining a Variational Autoencoder with Decision Tree Regression, NomAD identifies rare and unconventional events in FPGA-based trigger hardware with low latency. Applied to dimuon events, the...
The discovery of the Higgs boson with the mass of about 125 GeV completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many measurements, it is not capable of explaining some observations by itself. Many extensions of the Standard Model addressing such shortcomings introduce beyond-the-Standard-Model couplings to the Higgs...
Stasis is a cosmological phenomena in which the abundances of the different energy components in the universe (such as matter, radiation, etc.) remain fixed for an extended period even though they are affected differently by expansion. Many of the mechanisms that lead to stasis revolve around a tower of states, which emerge in many BSM theories. In this talk, I will describe a realization of...
We discuss unusual θ terms that can appear in field theories that allow global vortices. These "Cheshire θ terms" induce Aharonov-Bohm effects for some particles that move around vortices. For example, a Cheshire θ term can appear in QCD coupled to an axion and induces Aharonov-Bohm effects for baryons and leptons moving around axion strings. We point out a potential experimental signature...
The KM3NeT collaboration recently reported the observation of KM3-230213A, a neutrino event with an energy of 220 PeV, nearly an order of magnitude more energetic than the highest-energy neutrino in IceCube’s catalog. Despite its larger effective area and longer data-taking period, IceCube has not observed similar events, leading to a tension quantified between ~2$\sigma$ and 3.5$\sigma$,...
We present a method to suppress pileup and calibrate hadronic jet energy at L1 triggers using boosted decision trees for regression and classification. The fwX platform is used for implementation of BDTs on FPGA within the necessary timing and resource constraints. The in-situ pileup suppression can improve trigger performance in the high pileup environment of the HL-LHC.
Axion-like particles are currently among the most popular dark matter candidates. Considerable theoretical efforts have gone into expanding the parameter window of the quantum chromodynamics (QCD) axion beyond the narrow QCD band. The $Z_\mathcal{N}$ QCD axion model is the only such model which reduces the QCD axion mass naturally. The $Z_\mathcal{N}$ model invokes a discrete $Z_\mathcal{N}$...
We analyse the formation criteria for PBH formation via the Israel-Junction conditions. We find that the usual overdensity condition is a weaker condition when compared to the more fundamental junction conditions. In addition, we look into the PBH formed in fermi-ball scenarios and compare it with known results in the literature.
This talk reports recent precision measurements of diboson production and the study of anomalous Gauge boson self couplings (and constraints on EFT wilson coefficients) in ATLAS. These results offer further insights into the structure of electroweak interactions and provide greater sensitivity to new physics effects with improved measurement precision.
The existence of relic neutrino background is a strong prediction of the Big Bang cosmology. But because of their extremely small kinetic energy today, the direct detection of relic neutrinos remains elusive. On the other hand, we know very little about the nature of dark matter. In this work, we are putting constraint on the overdensity of the cosmic neutrino background by using them as the...
Spinor helicity formalism and modern amplitude techniques are powerful tools receiving strong attention. In this talk, we will show that the discrete symmetries, parity and charge conjugation, can be applied and determined completely within the spinor helicity language. We will further apply it to the production amplitude of magnetic monopoles by annihilating electric particles. On-shell...
If dark matter is ultralight, the number density of dark matter is very high and the techniques of zero-temperature field theory are no longer valid. The dark matter number density modifies the vacuum giving it a non-negligible particle occupation number. For fermionic dark matter, this occupation number can be no larger than one. However, in the case of bosons the occupation number is...
Cosmological stasis is a phenomenon wherein the abundances of multiple cosmological energy components with different equations of state remain constant for an extended period despite the expansion of the universe. This stasis phenomenon can give rise to cosmological epochs in which the effective equation-of-state parameter $\langle w \rangle$ for the universe is constant, but differs from the...
An excess of gamma rays from the Galactic center is observed by the Fermi Space Telescope. The two leading hypotheses for the cause of this excess are millisecond pulsars or dark matter. Generically, we expect the statistics of these two sources to differ. We train a graph convolutional neural network (NN) to accurately determine the relative flux contribution of point sources to the...
Driven by the increasing interest in probing spin structure and quantum entanglement in diboson processes, we study polarization and spin correlations in Higgs → VV decays. We show that higher-order electroweak corrections are crucial for accurately determining these coefficients and discuss their impact on proposed entanglement measurements.
The event rates and kinematics of Higgs boson production and decay processes at the LHC are sensitive probes of possible new phenomena beyond the Standard Model (BSM). This talk presents the most recent results in the measurements of Higgs boson production and decay rates, obtained using the full Run 2 and partial Run 3 pp collision dataset collected by the ATLAS experiment at 13 TeV and 13.6...
The symmetry breaking of a scalar particle (axion-like particle) in the early Universe produces a rich cosmology. In this cosmology, different patches of the Universe with different energies are separated by a network of domain walls. When the Universe cools, the domain walls annihilate as the lowest-energy patches become dominant. The annihilation process ("catastrogenesis") produces...
This talk reports recent differential measurements of single W boson in ATLAS for both on-shell and off-shell scenarios, which provide sensitive inputs to improve the constraints on PDFs and relevant EFT wilson coefficients.
We study the applicability of the usual finite temperature effective potential in the equation of motion of a homogeneous "misaligned" scalar condensate , and find important caveats that severely restrict its domain of validity: i:) the assumption of local thermodynamic equilibrium (LTE) is in general not warranted, ii:) a direct relation between the effective potential and the thermodynamic...
We present the first study of anti-isolated Upsilon decays to two muons (Υ→μ+μ−) in proton-proton collisions at the Large Hadron Collider. Using a machine learning (ML)-based anomaly detection strategy, we "rediscover" the Υ in 13 TeV CMS Open Data from 2016, despite overwhelming anti-isolated backgrounds. We elevate the signal significance to 6.4σ using these methods, starting from 1.6σ using...
We consider new contributions of lepton and nucleon EDM, which are
given by background effects of ultralight bosons. We calculate EDM contributions up to two loop diagram for CP-violating ALPs interactions with photon, lepton and nucleon. These new contributions will give new constraints on couplings, and constraints would be stronger if ALP mass is smaller than $10^{−11}$ eV.
The neutrinoless double beta decay experiments not only give great prospects for us to understand the nature of neutrinos, but also a efficient way to test the dark matter – neutrino interactions. We analyze the double beta decay data at PandaX to probe the dark matter – neutrino interaction. We compute the nuclear matrix element with the presence of this new interaction. We found that the...
The interpretation of multi-particle spin systems produced at colliders as quantum states has shown the potential to obtain quantum information at colliders. For instance, top quark or lepton pairs produced at colliders exhibit correlated spin states. Fermion pair production at lepton colliders presents an ideal source for comprehensive quantum tomography of the production process, enabling...
The conservation of baryon number in the Standard Model originates from an empirical symmetry and does not derive from first principles. Any discovery of a phenomenon that indicates that this symmetry is broken would have far-reaching consequences for our understanding of the universe, in particular the origin of the matter-antimatter asymmetry. A proposed process that can violate baryon...
While dark matter does not interact strongly with the standard model, for some models, this darkness can be attributed to a low population of a critical participant of a standard model active interaction. This ultimately leads to the formation of a bottleneck which prevents a discernible signal from being produced. On the other hand, small black holes produce all particles, whether in the...
Cosmological first order phase transitions proceed via the random nucleation and expansion of bubbles throughout space. This inherently stochastic process leads to statistical fluctuations across causally disconnected patches from which super-horizon curvature perturbations emerge. I will discuss how such phase transitions generate scalar perturbations that follow a universal power-law scaling...
We study the kinetic cooling (heating) of old neutron stars due to coherent scattering with relic neutrinos (keV sterile neutrino dark matter) via Standard Model neutral-current interactions by taking into account coherent enhancement, gravitational clustering, neutron degeneracy, Pauli blocking and weak potential. We find that the anomalous cooling of neutron stars due to relic neutrino...
The anomalous magnetic dipole moment ($g-2$) of the electron is one of the most precisely measured quantities in the world. To push precision beyond the current record, we can no longer assume the electron is in free space. We calculate $g-2$ for an electron in a cylindrical cavity and demonstrate that the boundary correction can be measured in a near-future experiment.
We discuss systematic limitations of entanglement measurements in particle production processes at collider experiments. Using the example of $pp\to ZZ$ production at the Large Hadron Collider, we study the distinct contributions that arise at leading and higher orders, which can affect the interpretation of the system as a two-qutrit $ZZ$ system.
This talk reports recent measurements of vector boson scattering and triboson processes in ATLAS. These results provide stringent tests of the Higgs mechanism, as well as the Gauge sector of the electroweak theory (through studying anomalous Gauge boson couplings), and offer a new avenue for precision tests of the SM as well as MC modelling. In addition, the investigation of boson...
While the nature of fast radio bursts (FRBs) remains unknown, population-level analyses can elucidate underlying structure in these signals. In this study, we employ deep learning methods to both classify FRBs and analyze structural patterns in the latent space learned from the Blinkiverse FRB Survey dataset. We adopt a Supervised Variational Autoencoder (SVAE) architecture which combines the...
We consider 2-to-2 scatterings of Higgs bosons in a CP-conserving two-Higgs-doublet model (2HDM) and study the implication of maximizing the entanglement in the flavor space, where the two doublets $\Phi_a$, $a=1,2$, can be viewed as a qubit: $\Phi_1=|0\rangle$ and $\Phi_2=|1\rangle$. More specifically, we compute the scattering amplitudes for $\Phi_a \Phi_b \to \Phi_c \Phi_d$ and require ...
In the Standard Model, the ground state of the Higgs field is not found at zero but instead corresponds to one of the degenerate solutions minimising the Higgs potential. In turn, this spontaneous electroweak symmetry breaking provides a mechanism for the mass generation of nearly all fundamental particles. The Standard Model makes a definite prediction for the Higgs boson self-coupling and...
Supercooled first-order phase transition (FOPT) can lead to the formation of primordial black holes (PBHs). This scenario imposes stringent requirements on the profile of the effective potential. In this work, we use the singlet extended Standard Model (xSM) as a benchmark model to investigate this possibility at the electroweak scale. The PBHs formed during a supercooled FOPT have a narrow...
A new neutrino-matter interaction can potentially affect neutrino propagation through matter. In this work, we explore the impact of a flavor-conserving scalar-mediated non-standard neutrino interaction in the supernova neutrino flux. We observe that the presence of scalar interaction involving muon and tau neutrinos (parameterized as $\eta_{\mu\mu}$ and $\eta_{\tau\tau}$, respectively) can...
Recursive constructions in amplitudes are a strong feature that requires careful analytic continuation with momentum shift to yield the full, correct, physical amplitudes. If not done systematically, an undetermined contact term would arise. We study the All-Line Transverse (ALT) shift, which we developed for on-shell recursion of amplitudes for particles of any mass. Our method allows for a...
I will discuss the Sommerfeld enhancement of scattering cross sections due to quantum forces. Quantum forces are forces which arise only at loop level. Since they are subject to corrections from a background with finite temperature or number density, there will also be an important contribution to the Sommerfeld enhancement in the presence of a background. In particular this can be applied to...
We establish a first principles, systematic framework for determining the bubble wall velocity during a first order cosmological phase transition. This framework, based on non-local Kadanoff-Baym equations, incorporates both macroscopic fluid dynamics and microscopic interactions between the bubble wall and particles in the plasma. Previous studies have generally focused on one of these two...
Cosmic neutrino background (CνB) is notoriously difficult to detect due to its low energy. We investigate the scenario in which CνB is scattered off by energetic cosmic rays throughout the history of the Universe, yielding a diffuse flux boosted to higher energies. The non-observation of this flux with current high-energy neutrino experiments already excludes an average cosmic neutrino...
We revisit the phenomenology of dark matter (DM) scenarios within radius-stabilized Randall-Sundrum models. Specifically, we consider models where the dark matter candidates are Standard Model (SM) singlets confined to the TeV-brane and interact with the SM via spin-2 and spin-0 gravitational Kaluza-Klein (KK) modes. We compute the thermal relic density of DM particles in these models by...
Dark photons are dark massive vector gauge bosons that are one of the simplest extensions of the Standard Model. Through a kinetic mixing term, visible photons resonantly convert into dark photons when the plasma mass of an ionized gas is equal to the dark photon mass $m_{A'}$. This disappearance of Standard Model photons leaves a striking signature in a map of the 21-cm signal and enhances...
Though the Standard Model (SM) of particle physics has been a very successful theory in explaining a wide range of measurements, there are still many questions left unanswered such as incorporation of gravity into SM, neutrino masses, matter-antimatter asymmetry, supersymmetry, or existence of dark matter candidates. One of the possible solutions to address these challenges is the extension of...
Recent SMEFT studies emphasize the consistent inclusion of $\frac{1}{\Lambda^4}$ terms in SMEFT predictions. In this presentation, we explore SMEFT up to $\frac{1}{\Lambda^4}$, incorporating renormalization group evolution (RGE) effects from the running of SMEFT Wilson coefficients (WCs), including dimension-8 contributions. We discuss the current status of dimension-8 renormalization and...
We consider the possibility that gravity is mediated by “continuous spin” particles, i.e. massless particles whose invariant spin scale ρg is non-zero. In this case, the primary helicity-2 modes of gravitational radiation on a Minkowski background mix with a tower of integer-helicity partner modes under boosts, with ρg controlling the degree of mixing. We develop a formalism for coupling...
We investigate dark matter and gravitational wave production in a type II 2HDM with the addition of an inert complex singlet. A $Z_2^\prime$ symmetry is imposed under which the doublets are even and the singlet is odd to ensure the stability of the dark matter candidate. Before the first order phase transition, finite temperature effects provide a window where thermal bath interactions produce...
We perform a model-independent analysis of the dimension-six terms that are generated in the low energy effective theory when a hidden sector that communicates with the Standard Model (SM) through a specific portal operator is integrated out. We work within the Standard Model Effective Field Theory (SMEFT) framework and consider the Higgs, neutrino and hypercharge portals. We find that, for...
This talk presents precise measurement of the CP properties of the Higgs boson using the full dataset collected in pp collisions at 13 TeV during Run 2 and at 13.6 TeV during Run 3 of the LHC. The measurements are performed in various Higgs boson production and decay modes, as well as their combinations. Observation of deviations between these measurements and Standard Model (SM) predictions...
The Leggett-Garg Inequality (LGI) offers a way to test for the
violations of classicality in a system by studying how its measurements
are correlated over time. Long-baseline neutrino oscillation experiments
provide some of the longest distances over which the quantum behavior of any system can be tested.
In my talk, I will present comprehensive results on LGI in connection to 3 existing...
Future observations of the sky-averaged 21-cm signal during the cosmic dawn promise unprecedented measurements of the gas temperature in this epoch. Such measurements can place extremely strong constraints on the lifetime of dark matter. We revisit the projected bounds on minimal decaying dark matter scenarios and present new constraints for theoretically motivated non-minimal dark sectors,...
I will review the importance of Big-Bang Nucleosynthesis to cosmology and the search for new physics, and explain how to perform parameter inference with LINX, a fast and differentiable BBN code package.
Superradiance offers a unique link between particle and black hole physics. Through this process, a cloud of light particles can build up around a spinning black hole that resembles the hydrogen atom. If the black hole is part of a binary system, the cloud can be disrupted and the particles transition from one state of the atom to another. In this talk, I will analyze a new gravitational...
The exchange of a pair of neutrinos can mediate a long-range force. This "neutrino force" is a unique quantum force predicted by the Standard Model; it is also sensitive to the nature of the neutrino mass. Yet, this force is too weak to be detected so far. In this talk, I will introduce our recent progress in detecting the neutrino force from two aspects.
(1) At the microscopic scale,...
I will demonstrate a general photon proliferation effect from N-body ultralight dark matter (DM) annihilation in the early Universe, which can induce a drastic photon-temperature shift after neutrino decoupling. For pseudoscalar DM mass below the eV scale, I will show that the photon proliferation effect becomes significant as the mass approaches the ultralight end, presenting the leading...
Light new particles could be emitted in nucleon decays if they have baryon-number-violating couplings. Even though they usually leave the detector as missing energy, interesting signatures can arise in such decays in underground detectors such as Super-Kamiokande and DUNE. In the particularly simple case of light sterile neutrinos, nucleon decays can even be an efficient production mechanism...
Many theories beyond the Standard Model (SM) have been proposed to address several of the SM shortcomings. Some of these beyond-the-SM extensions predict new particles or interactions directly accessible at the LHC, but which would leave unconventional signatures in the ATLAS detector. These unconventional signatures require special techniques and reconstruction algorithms to be developed,...
We show for the first time that warm inflation is feasible with Standard Model (SM) gauge interactions alone. Our model consists of a minimal extension of the SM by a single scalar inflaton field with an axion-like coupling to gluons and a monomial potential. The effects of light fermions, which were previously argued to render warm inflation with the SM impossible, are alleviated by Hubble...
Baryon number violation is our most sensitive probe of physics beyond the Standard Model, conveniently encoded in higher-dimensional effective operators. Operators involving derivatives are usually ignored in phenomenological analyses since they are generically suppressed compared to non-derivative operators. We will study exceptions to this statement and explore scenarios in which derivative...
We explore the big-bang nucleosynthesis (BBN) constraint on heavy neutrino that is a mixture of gauge singlet fermion and active neutrinos in the Standard Model. We work in the minimal model with only two parameters, the heavy neutrino mass $m_4$ and the mixing parameter $|U_{a4}|^2$, where $a=e$, $\mu$, or $\tau$ stands for the active neutrino flavor. We show that both the early universe...
Ultra-light bosonic dark matter (ULDM) is an interesting dark matter candidate. While the wave-like nature of ULDM has been widely studied in the literature, we explore another distinctive feature
of ULDM as Bose-Einstein Condensate (BEC) in this paper: the emergence of vortices in rotating BEC-ULDM halos. Using numerical solution of the GPP equation, we demonstrate that a vortex lattice...
The Belle and Belle II experiments have collected a 1.1 ab$^{-1}$ sample
of $e^+ e^-\to B\bar{B}$ collisions at a centre-of-mass energy
corresponding to the $\Upsilon(4S)$ resonance. These data, with low
particle multiplicity and constrained initial state kinematics, are an
ideal environment to search for rare electroweak penguin and radiative
$B$ decays. Results include those related to...
The Standard Model predicts a long-range force mediated by a pair of neutrinos, commonly referred to as the "neutrino force". This force scales as $G_F^2/r^5$, where $G_F$ is the Fermi constant. However, this scaling breaks down at distances $r \lesssim \sqrt{G_F}$, where the four-Fermi approximation becomes invalid. In this talk, I present a complete expression for the neutrino force that is...
We study a novel leptogenesis scenario with the temperature-dependent mass of heavy Majorana neutrino by the wave dark matter to explain the matter-antimatter asymmetry of the Universe. The leptogenesis happens twice in this scenario: the first leptogenesis occurs above the electroweak scale, while the second leptogenesis occurs below it. The sphaleron process converts the lepton asymmetry to...
An accurate description of the scalar potential at finite temperature is crucial for studying cosmological first-order phase transitions (FOPT) in the early Universe. At finite temperatures, a precise treatment of thermal resummations is essential, as bosonic fields encounter significant infrared issues that can compromise standard perturbative approaches. The Partial Dressing (or the tadpole...
In this talk, we look at some cosmological constraints on majoron dark matter in the singlet Majoron model. We consider two scenarios: pre-inflationary and post inflationary spontaneous lepton number symmetry breaking, while simultaneously demanding thermal leptogenesis to happen, and neutrino masses being generated by the type I seesaw mechanism. We derive the constraints and future prospects...
We propose an $E_6$ inspired Pati-Salam (PS) model that naturally accommodates multi-TeV leptoquark gauge bosons, X, with a softly broken discrete $Z_2$ symmetry. Standard Model (SM) fermions are $Z_2$-even in this framework, whereas exotic fermions are $ Z_2$-odd. An interesting feature of the model is that the PS gauge bosons are $Z_2$-odd, enabling them to couple exclusively between...
We construct the thermal bounce solution in holographic models that describes first-order phase transitions between the deconfined and confined phases in strongly-coupled gauge theories. This new, periodic Euclidean solution represents transitions that occur via thermally-assisted tunneling and interpolates between the $O(4)$-symmetric vacuum bubble at zero temperature and the high temperature...
Is the Standard Model Charge-Parity (CP) violation ever enough to generate the observed baryon asymmetry? Yes! In this talk, I will discuss our most recent work: baryogenesis together with a dark matter production mechanism that can generate the entire observed baryon asymmetry of the universe using only the CP violation within the Standard Model. We introduced baryogenesis along with a dark...
I will present some preliminary results from our study on Axion-Like Particles (ALPs) production from electromagnetic showers in beam dump experiments, focusing on SHiP as a relevant benchmark example. Existing projections for SHiP’s sensitivity to ALPs have focused on production from either the primary photon beam or the (high-energy) photons produced by π0 → γγ. In this work, we study the...
The Project 8 experiment seeks to determine the electron-weighted neutrino mass via the precise measurement of the electron energy in beta decays, with a sensitivity goal of $40\,\mathrm{meV/c}^2$. We have developed a technique called Cyclotron Radiation Emission Spectroscopy (CRES), which allows single electron detection and characterization through the measurement of cyclotron radiation...
Many models beyond the standard model predict new particles with long lifetimes. These long-lived particles (LLPs) decay significantly displaced from their initial production vertex thus giving rise to non-conventional signatures in the detector. Dedicated triggers and innovative usage of the CMS detector are exploited in this context to significantly boost the sensitivity of such searches at...
Project 8 is designed to directly measure the electron neutrino mass using cyclotron radiation emission spectroscopy (CRES). Using cyclotron frequency as a proxy for kinetic energy, the $\beta$-decay electron endpoint spectrum for magnetically-trapped electrons produced by a gaseous tritium source can be measured with high precision using CRES. Following the successful demonstration of CRES...
This talk reviews recent measurements of multiboson production using CMS data at sqrt(s) = 13 and 13.6 TeV. Inclusive and differential cross-sections are measured using several kinematic observables.
We discuss the Domain-Wall Standard Model formulated in five-dimensional spacetime. In this framework, all Standard Model (SM) particles are localized within a finite region (domain) along a non-compact extra spatial dimension. This scenario predicts the existence of a Nambu-Goldstone (NG) boson associated with the spontaneous violation of translational invariance in the extra dimension. The...
Optically levitated quantum sensors have recently been increasingly popular in proposals to detect ultralight dark matter and gravitational waves due to their world-leading sensitivities to forces. Although historically less optimized to search for many DM couplings than e.g. magnetic traps, optical traps can reach much higher frequencies (kHz-to-GHz). After outlining the necessary concepts in...
We introduce and investigate the effects of a light scalar interacting with the
short-lived kaon and the $K_S → μ^+μ^−$ decay. We use the results of searches performed at
kaon factories as well as the Standard Model predictions for this decay to constrain the
couplings of a ϕ particle with a mass $m_ϕ$ of the order of MeV. We also examine the time evolution of the kaon beams with the full...
In massive gravity, we expect a modification to the dispersion relation for gravitational waves and the angular correlation in pulsar timing arrays (PTAs) due to the five polarization modes that arise. We consider the lower bound for graviton mass constraints from the dispersion relation for future PTA observations and scrutinze the possibility of detection via the effective overlap reduction...
Leptogenesis provides a compelling explanation of the baryon asymmetry of the Universe. It uses lepton-number-violating (LNV) decays of heavy right-handed neutrinos, which also generate neutrino masses. These neutrinos can, in fact, be light enough to be produced in low-energy processes. If their LNV decays can be observed, this would directly constrain the parameter space of leptogenesis...
Recent observations from pulsar timing-array collaborations have provided compelling evidence for the existence of a stochastic gravitational wave background (SGWB). While astrophysical sources such as mergers of supermassive black hole binaries are likely contributors, additional signals may arise from early-universe phenomena or modified gravity theories. These different origins are expected...
In models of warm dark matter, there is an appreciable population of high momentum particles in the early universe, which free stream out of primordial over/under densities, thereby prohibiting the growth of structure on small length scales. The distance that a dark matter particle travels without obstruction, known as the free streaming length, depends on the particle's mass and momentum, but...
More evidence of New Physics (NP) has been observed in charged current decays of $\bar{B} \to {D^*} \ell \bar{\nu}$, as measured by the BaBar, Belle, and LHCb experiments. Curiously, the observable $R_{D^*}$ has been found to exceed Standard Model (SM) expectations, with a combined significance of $3.4\sigma$. Moreover, there is further motivation for NP in the muon sector due to persistent...
Baryogenesis is a dynamical out-of-equilibrium process generating the baryon asymmetry of the Universe. Focusing on the mechanism of electroweak baryogenesis, where baryon number is generated through CP-violating scattering of the fermions with the bubble wall during a first-order electroweak phase transition, perturbative calculations for the relevant processes are known to suffer from...
We explore the possibility that the right-handed neutrino Majorana mass originates from electroweak symmetry breaking. Working within an effective theory with two Higgs doublets, nonzero lepton number is assigned to the bilinear operator built from the two Higgs fields, which is then coupled to the right-handed neutrino mass operator. In tandem with the neutrino Yukawa coupling, following...
The Belle and Belle II experiment have collected samples of $e^+e^-$
collision data at centre-of-mass energies near the $\Upsilon(nS)$
resonances. These data have constrained kinematics and low
multiplicity, which allow searches for dark sector particles in the mass
range from a few MeV to 10 GeV. Using a 426 fb$^{-1}$ sample collected
by Belle II, we search for inelastic dark matter...
We explore how recent advancements in the manipulation of single ionic wave packets open new avenues for detecting weak magnetic fields sourced by ultralight dark matter. By leveraging the entanglement between the ion's spin and motional degrees of freedom, proposed trapped-ion matter-wave interferometers enable the measurement of the dynamical Zeeman phase shift accrued by the ion over its...
We present a methodology to streamline implementation of massive-quark radiative contributions in calculations with a variable number of active partons in proton-proton collisions. The methodology introduces subtraction and residual heavy-quark parton distribution functions (PDFs) to implement calculations in the Aivazis-Collins-Olness-Tung (ACOT) factorization scheme and its simplified...
We propose a novel method to obtain sensitivity to dark mediators and dark sectors at the LHC with masses of $\sim 10 \text{ MeV} - 10 \text{ GeV}$, providing complementarity with beam dump experiments. For this talk, we consider dark photons, which can be produced at the LHC by neutral meson decays, bremsstrahlung off baryons, or directly produced in correlation with a jet. We then consider...
Increasing attention has been given recently to the theory and phenomenology of portal matter (PM) models — a BSM framework in which the standard model (SM) local gauge symmetry group is augmented by a local dark group $U(1)_D$, of which the mediator is the dark photon, and kinetic mixing between $U(1)_D$ and the SM hypercharge is generated at one loop by the PM fields. The case in which the...
The Galactic-Center Excess, a surplus of gamma rays at the Milky Way’s core, has sparked debate
over its origins, with two main theories suggesting either dark matter annihilation or emissions from mil-
lisecond pulsars as potential sources. This study utilizes data from the Laser Interferometer Gravitational-
Wave Observatory (LIGO) to explore the presence of millisecond pulsars in the...
I will discuss the possible imprints of high-scale non-thermal leptogenesis on cosmic microwave background (CMB) from the measurements of inflationary observables such as spectral index ($n_s$) and tensor-to-scalar (r) ratio, which otherwise is inaccessible to the conventional laboratory experiments. I will argue that non-thermal production of baryon (lepton) asymmetry from subsequent decays...
We propose a novel strategy to probe heavy neutrinos with non-universal fermion couplings at the Large Hadron Collider (LHC) using vector boson fusion (VBF) processes. Focusing on proton-proton collisions at $\sqrt{s} = 13\,\mathrm{TeV}$, we investigate final states characterized by a muon, missing energy, and two forward/backward jets, originating from a virtual heavy neutrino. Unlike...
We explore flavored resonant leptogenesis embedded in a neutrinophilic 2HDM. Successful leptogenesis is achieved by the very mildly degenerate two heavier right-handed neutrinos~(RHNs) $N_2$ and $N_3$ with a level of only $\Delta M_{32}/M_2 \sim \mathcal{O}(0.1\%-1\%)$. The lightest RHN, with a MeV–GeV mass, lies below the sphaleron freeze-out temperature and is stable, serving as a dark...
We show that, in a $U(1)_{R-L}$-symmetric supersymmetric model, the pseudo-Dirac bino and wino can give rise to three light neutrino masses through effective operators, generated at the messenger scale between a SUSY breaking hidden sector and the visible sector. The neutrino--bino/wino mixing follows a hybrid type I+III inverse seesaw pattern. The light neutrino masses are governed by the...
The Belle and Belle~II experiments have collected a 1.1~ab$^{-1}$ sample
of $e^+ e^-\to B\bar{B}$ collisions at a centre-of-mass energy
corresponding to the $\Upsilon(4S)$ resonance. These data allow
measurements of $CP\!$ violation and the Cabibbo-Kobayashi-Maskawa
matrix elements in $B$-meson decay. In particular, we measure the
$CP$-violating phase $\phi_1/\alpha$ and...
In this talk, I will present bounds on the variation of fundamental constants from the cosmic microwave background (CMB). In our theoretically motivated model, the variation is modulated by a scalar field that behaves as an ultralight dark matter (ULDM). We self-consistently compute the effects of the variation of constants on big bang nucleosynthesis (BBN) and propagate those effects to the...
Electroweak Baryogenesis is a commonly studied mechanism to explain the baryon asymmetry of the universe. By introducing a real scalar singlet to the Standard Model, the electroweak phase transition can become strongly first order and satisfy the out-of-equilibrium Sakharov condition. Additionally, contributions from the scalar to the top quark mass term can provide the necessary CP violation....
In this work, we focus on the 2-to-3 scattering process between dark matter (DM) and nuclei, mediated by the Standard Model (SM) photon and a scalar particle with its mass spanning from 10 keV to 100 GeV. This process provides an efficient channel for producing energetic photons in the final state. These photons serve as a powerful probe in multiple contexts: they investigate unexplored...
We employ a gauge-invariant perturbative framework to analyze the next-to-leading order (NLO) effective action of the SU(2)-Higgs model at finite temperature. This involves utilizing a specific power counting scheme, which allows us to compute gauge-invariant observables for primordial gravitational waves arising from a thermal first-order electroweak phase transition. Finally, we then compare...
The addition of a heavy charged vector gauge boson $\mathrm{W}^\prime$ to the Standard Model (SM) with negligible quark couplings ("quarkophobic") and triple gauge couplings can address issues with the SM, such as the B-meson anomalies and recent discrepancies in the W boson mass measurements. Such a model featuring a large $\mathrm{W}^\prime$ decay width has not yet been explored at the LHC...
Type-I seesaw scenario is arguably the simplest scenario to generate the observed neutrino oscillation data and the observed baryon asymmetry in the universe via leptogenesis. Based on the Casas–Ibarra general parametrization, we derive analytic expressions for the CP asymmetry parameter in the leptogenesis with two and three generations of right-handed Majorana neutrinos, reproducing the...
We propose new solutions to accommodate both the MiniBooNE electron-like and MicroBooNE photon low-energy excesses, based on interactions involving light dark matter and/or neutrinos. The novelty lies in the utilization of a photon arising from 2-to-3 scattering processes between a nucleus/nucleon and a neutrino and/or dark matter ($\nu/\chi + N\to \nu/\chi + N + \gamma$) via exchanges of...
We perform a global extraction of the $\rm^{12}C$, $\rm^{40}Ca$ and $\rm^{56}Fe$ longitudinal (${\cal R}_L$) and transverse (${\cal R}_T$) nuclear electromagnetic response functions from an analysis of all available electron scattering data on these nuclei. The response functions are extracted for energy transfer $\nu$, spanning the nuclear excitation, quasielastic (QE) scattering with...
We investigate the non-zero temperature dynamics of a sub-GeV dark matter scenario
freezing-out via self-interactions. As a prototype, we take up the case of a scalar dark matter species undergoing $3 \to 2$ number changing annihilations catalysed by another scalar. We study the shape of the thermal potential of this scenario in a parameter region accounting for the observed relic abundance....
Since the discovery of the Higgs Boson at the Large Hadron Collider, much progress has been made in characterizing its couplings to the Electroweak bosons and the third generation of fermions. In this talk, I will discuss the LHC constraints in the leptonic sector of a flavor-violating 2HDM, a well-motivated model which is also constrained by precision measurements. I will also characterize...
Multi-Higgs-doublet models (NHDMs) has been gaining increasing popularity in beyond Standard Model (BSM) research, and people have been using it to address problems like dark matter, fermion mass hierarchies, and neutrino mass. Among these, there is steady growing literature (reaching a hundred) discussing the Four-Higgs-Doublet Model (4HDM). Finite symmetries play a pivotal role in NHDMs, yet...
Inflaton couplings during warm inflation result in the production of a thermal bath. Thermal friction and fluctuations can dominate the standard de Sitter analogues, resulting in a modified slow-roll scenario with a new source of density fluctuations. Due to issues with back-reaction, it is advantageous to consider inflaton couplings with the thermal bath that are pseudo-scalar in nature,...
This work presents advancements in model-agnostic searches for new physics at the Large Hadron Collider (LHC) through the application of event-based anomaly detection techniques utilizing unsupervised machine learning. We discuss the advantages of Anomaly detection approach, as demonstrated in recent ATLAS analysis, and introduce ADFilter, a web-based tool designed to process collision events...
Although protons are baryons with an overall vanishing lepton number, they possess a non-trivial leptonic content arising from quantum fluctuations which can be described by lepton parton distribution functions (PDFs) of the proton. These PDFs have been recently computed and can be used to define lepton-induced processes at high-energy colliders. In this article, we propose a novel way to test...
