New Physics Directions in the LHC era and beyond

Europe/Zurich
Max Planck Institute for Nuclear Physics, Heidelberg, Germany

Max Planck Institute for Nuclear Physics, Heidelberg, Germany

Saupfercheckweg 1 69117 Heidelberg Germany
Florian Goertz (Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany)
Description

The objective of this meeting is to bring together scientists working on various aspects of beyond the Standard Model physics. A particular focus will be placed on a critical assessment of the current status, which features long-standing puzzles while little experimental guidance exists in the form of discoveries of new particles. Various approaches to making progress will be discussed and confronted, including the naturalness criterion, the 'agnostic' bottom-up approach, considerations related to the interplay of Standard Model puzzles, and the exploration of synergies between earth-based experiments and astro/cosmological observables. New ideas and paradigms are essential for the continued progress of fundamental physics toward a better understanding of nature. 

Main topics of the workshop include:

  • Status of Naturalness 
    Composite Higgs, SUSY, New Paradigms, …
  • Interplay of SM Puzzles 
    Flavour, ALPs, GUTs, …
  • Astro-Cosmo-Collider Synergy 
    Dark Matter, Phase Transitions, GWs, …
  • Bottom-Up Approach 
    EFTs, Simplified Models, …

     

We particularly welcome and encourage the participation of early-career researchers. 

The workshop "New Physics Directions in the LHC era and beyond" will be hosted in-person at the Max-Planck-Institut für Kernphysik (MPIK, Max Planck Institute for Nuclear Physics) in Heidelberg, Germany. 

 

Participants
    • 08:45
      Shuttle Bus from Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz
    • 09:10
      Registration
    • Morning: Session 1
      Convener: Dr Florian Goertz (Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany)
      • 1
        Opening Remarks
        Speaker: Dr Florian Goertz (Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany)
      • 2
        Naturalness as a Method of Theoretical Particle Physics

        For decades naturalness and finetuning considerations have been important factors in the work of theoretical particle physics. I explain how such considerations fit into the broader scheme of methods of theoretical particle physics. I then formalize the intuitions of particle physicists over the decades within effective field theory language and justify several assertions along the way: the Standard Model (SM) is natural; the next standard theory is likely to also be natural; it is justified to include naturalness as a criteria for status ranking beyond the Standard Model (BSM) theories; and finally, finding and identifying high-status BSM theories is important for the advancement of science.

        Speaker: James Daniel Wells (University of Michigan (US))
      • 3
        S-matrix and naturalness
        Speaker: Georgi Dvali
    • 11:00
      Coffee Break
    • Morning: Session 2
      Convener: Prof. Manfred Lindner (Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany)
      • 4
        First order phase transitions with utra fast bubble: dynamics and applications

        In my talk I will discuss the first order phase transitions with fast bubbles. Particular attention will be paid to the heavy fields production and its applications for the non thermal Dark Matter production and baryogenesis.

        Speaker: Aleksandr Azatov (INFN - National Institute for Nuclear Physics)
      • 5
        Applications of the Tunneling Potential Formalism

        The Tunneling Potential formalism offers an alternative to the Euclidean bounce approach for calculating tunneling actions, which govern the exponential suppression of metastable vacua decay in quantum field theory. In this talk, I will discuss how this formalism elegantly describes gravitational effects on vacuum decay, bubble-of-nothing decays, domain walls, and more.

        Speaker: Jose Espinosa (Departm.of Physics & Astronomy)
      • 6
        Flavoured Dark Matter and its Phenomenology

        After introducing the general concept of flavoured dark matter, in this talk I will focus on a specific model of flavoured Majorana dark matter. I will provide a review of the constraints coming from flavour physics and direct and indirect detection constraints. I will then focus on different possible scenarios for dark matter freeze-out and their implications for collider phenomenology.

        Speaker: Monika Blanke (Karlsruhe Institute of Technology)
    • 13:00
      Lunch Break
    • Afternoon Session: Session 1
      Convener: Aqeel Ahmed (Max-Planck-Institut für Kernphysik, Heidelberg)
      • 7
        CP violation with ALPs and singlet scalars

        Novel bounds on CP-odd fermionic couplings of ALPs (axion-like-particles) and of a general singlet scalar are presented and compared. In both cases, we improve present constraints by several orders of magnitude. The impact of an additional Peccei-Quinn symmetry will be discussed as well.

        Speaker: Belen Gavela Legazpi (Universidad Autonoma de Madrid (ES))
      • 8
        GUTs - how common are they?

        The individual fermion generations of the Standard Model fit neatly into a representation of a simple Grand Unified Theory gauge algebra. If there is nothing to Grand Unification, this would be appear to be a coincidence. We attempt to quantify how frequent this coincidence is among theories with group structure and fermion content similar to the Standard Model. This bottom-up theory-space investigation may contribute to shaping our expectations for what lies beyond the Standard Model.

        Speaker: Johannes Herms (Max-Planck-Institut für Kernphysik)
      • 9
        Charting Strong New Physics

        TBD

        Speaker: Alvaro Pastor Gutierrez
      • 10
        Probing a dark sector with collider physics, direct detection, and gravitational waves

        We assess the complementarity between colliders, direct detection searches, and gravitational wave interferometry in probing a scenario of dark matter in the early universe. The model under consideration contains a $B-L$ gauge symmetry and a vector-like fermion which acts as the dark matter candidate. The fermion induces significant a large dark matter-nucleon scattering rate, and the $Z^\prime$ field produces clear dilepton events at colliders. Thus, direct detection experiments and colliders severely constrain the parameter space in which the correct relic density is found in agreement with the data. Nevertheless, little is known about the new scalar responsible for breaking the $B-L$ symmetry. If this breaking occurs via a first-order phase transition at a TeV scale, it could lead to gravitational waves in the mHz frequency range detectable by LISA, DECIGO, and BBO instruments. The spectrum is highly sensitive to properties of the scalar sector and gauge coupling. We show that a possible GW detection, together with information from colliders and direct detection experiments, can simultaneously pinpoint the scalar self-coupling, and narrow down the dark matter mass where a thermal relic is viable.

        Speaker: JACINTO NETO
      • 11
        From Dark Matter to Neutrino Masses via a Late Phase Transition

        We present a model which addresses two open questions of the Standard Model (SM): the origin of neutrino masses and the nature of dark matter. To achieve this, the SM is extended by two keV-mass right-handed neutrinos as well as a Froggatt-Nielsen-like mechanism, under which only the non-SM fields are charged.

        The sterile neutrinos form a 2-component dark matter candidate. We assume the mass term of the new flavon-like scalar field $S$ to be negative, but a non-minimal coupling to curvature causes the effective mass to become tachyonic only in the recent universe, which triggers a late phase transition.

        Throughout the early universe and before the phase transition, the left-handed neutrinos are massless. Then, the non-zero expectation value$\langle S \rangle$ leads to small effective neutrino Yukawa couplings and a seesaw mechanism becomes efficient which results in two active neutrinos getting masses, while the third remains massless. The phase transition proceeds slowly, and the changing $\langle S \rangle$ introduces a time dependence to neutrino masses and mixings with potentially interesting phenomenological consequences. Additionally, $S$ can potentially act as thawing quintessence therefore solving another puzzle of the SM.

        Speaker: Maya Hager (Max-Planck-Institut für Kernphysik)
      • 12
        Dark Matter Direct Detection in t-channel mediator models

        We propose a comprehensive study of the Direct Detection phenomenology of singlet Dark Matter t-channel portal models. For that purpose, we present a complete computation of the loop induced direct detection cross-section for both scalar and fermionic Dark Matter candidates. We complete the study by comparing the results with current and future bounds from Direct Detection experiments and requiring the correct Dark Matter relic density.

        Speaker: David Cabo Almeida (University of Messina (Italy))
      • 13
        Hunting minimal dark matter quintuplet

        This study investigates the sensitivity of the Cherenkov Telescope Array (CTA) and Fermi Large Area Telescope (Fermi-LAT) to dark matter (DM) annihilation in γ-ray lines. We focus on observations of the Galactic Center (GC), dwarf Spheroidal galaxies (dSphs), and galaxy clusters (GCls). Specifically, we compare the reach of the GC with that of dSphs, considering the poorly known putative core radius of the DM distribution. Surprisingly, we find that the currently best dSph candidates present a more promising target than the GC, especially for core radii ranging from one to a few kiloparsecs.

        In addition to CTA prospects, we extend our analysis to incorporate Fermi-LAT data. Recent advancements in computations have highlighted the impact of Sommerfeld enhancement and bound-state formation on the annihilation cross section of Minimal Dark Matter (MDM) multiplets. Exploring this new paradigm, we examine Fermi-LAT data to assess its capability to detect or rule out a potential line arising from bound-state formation processes. Our findings reveal that the Fermi-LAT data effectively rules out the MDM 5plet at a significance level of 2σ, demonstrating the importance of considering enhanced cross sections and new annihilation signatures in the quest to unravel the mysteries of dark matter.

        Speaker: Mr Mohammad Aghaie (University of Pisa)
      • 14
        Exploring Dark Sectors Using Dilepton Resonances

        Exotic decays with high multiplicity lepton final states are important indicators of SM interactions with dark sectors and have low observational backgrounds at the LHC. In order to explore hidden valleys/dark sectors (HV/DS), we have recast a recent ATLAS study searching for least two pairs of leptons with equal invariant mass: hep-ex/2306.07413. We have reproduced the results of this study, recast the study in order to put limits on an exotic Higgs decay to 4 dark photons, and explored the sensitivity of the ATLAS search to HV/DS scenarios with dark jets to see whether it has sensitivity to these models.

        Speaker: Ms Rabia Husain (Harvard University)
      • 15
        Energy-dependent Boosted Dark Matter from Diffuse Supernova Neutrino Background

        Diffuse neutrinos from past supernovae in the Universe present us with a unique opportunity to test dark matter (DM) interactions. These neutrinos can scatter and boost the DM particles in the Milky Way halo to relativistic energies allowing us to detect them in terrestrial laboratories.
        Focusing on generic models of DM-neutrino and electron interactions, mediated by a vector or a scalar boson, we implement energy-dependent scattering cross-sections and perform detailed numerical analysis of DM attenuation due to electron scattering in-medium while propagating towards terrestrial experiments. We set new limits on DM-neutrino and electron interactions for DM with masses in the range $\sim (0.1, 10^4)~$MeV, using recent data from XENONnT, LUX-ZEPLIN, and PandaX-4T direct detection experiments. We demonstrate that consideration of energy-dependent cross-sections for DM interactions can significantly affect constraints previously derived under the assumption of constant cross-sections, modifying them by multiple orders of magnitude.

        Speaker: Tim Herbermann (Max-Planck-Institut für Kernphysik)
      • 16
        Insights into the highest natural scale

        We apply the criterion of finite naturalness to the limiting case of a generic heavy sector decoupled from the standard model. The sole and inevitable exception is represented by gravitational interactions. We demonstrate how gravity can couple the Higgs to the heavy scale well before the three-loop diagrams mediated by the top quark discussed in previous literature. As an application, we illustrate how the criterion of finite naturalness disfavors large-field inflationary models with super-Planckian field excursions.

        Speaker: Pier Giuseppe Catinari (Sapienza)
      • 17
        Accidentally light scalars from large representations

        In models with spontaneous symmetry breaking by scalar fields in large group representations, we observe that some of the scalar masses can be loop-suppressed with respect to the naive expectation from symmetry selection rules. We present the most minimal model — the SU(2) five-plet — with such accidentally light scalars, featuring compact tree-level flat directions lifted by radiative corrections. We sketch some applications, from stable relics and slow roll in cosmology, to hierarchy and fine-tuning problems in particle physics.

        Speaker: Mr Giacomo Ferrante (LUPM)
      • 18
        A new framework for electric charge breaking

        I break the U(1)$_\text{EM}$ of the standard model by introducing new general scalar fields that obtain vacuum expectation values in their non-neutral components.
        This is realised with either minicharged particles or with scalars that allow for new renormalisable interactions, which I will illustrate at the example of fermion-fermion-photon interactions.
        Finally, I show how non-trivial behaviour can lead to strong limits by considering electron decay.

        Speaker: Manuel Salewski
      • 19
        Quantisation Across Bubble Walls and Friction

        We employ first principles to quantize field theories living on a bubble wall background in the planar limit, focusing on spontaneous gauge symmetry breaking. Utilizing these principles, we compute the average momentum transfer resulting from transition radiation—soft emissions during the traversal of an energetic particle across the wall, particularly focusing on longitudinal polarization. Our findings reveal comparability between longitudinal and transverse polarizations in symmetry-breaking transitions with mild super-cooling, with the former dominating in broken-to-broken transitions with thin walls. Our results bear phenomenological implications for bubble expansion during first-order phase transitions. Our versatile framework facilitates the computation of diverse particle processes in translation-breaking backgrounds. If time permits some concrete applications (e.g. emission of NGBs, symmetry restoring PT, ...) will be presented.

        Speaker: Giulio Barni (SISSA - Scuola Internazionale Superiore di Studi Avanzati)
      • 20
        Electroweak Baryogenesis from Composite Higgs Models

        Electroweak Baryogenesis (EWBG) is a very promising avenue to generate the observed Baryon Asymmetry in the Universe (BAU). Making use of elektroweak sphalerons as a baryon number violating process, one seeks to enhance the EW phase transition to be strongly first order and introduce more CP violation. Oftentimes, this is achieved by minimally extending the Standard Model (SM) with an additional particle, such as a scalar singlet in a bottom-up approach.
        Top-down, one can take Naturalness as a guiding principle: Can a theory that is constructed to solve the EW hierarchy problem and explain the structure of the SM incidentally also explain Baryogenesis? Several Composite Higgs models, for example, lend themselves readily to this cause.
        Recently, Angelescu et al. proposed a Gauge-Higgs-GUT scenario that – assuming a compact warped extra dimension – unifies not only all the Standard Model (SM) gauge bosons, but also the Higgs, in an SU(6) gauge field while reproducing the correct CKM and PMNS matrices. Due to the symmetry structure, the mass spectrum also contains a relatively light scalar singlet and leptoquark. Using the scalar potential obtained from solving the 5D equations of motion, we analyze if a baryogenesis mechanism is realizable in this scenario.

        Speaker: Aika Marie Tada (Max-Planck-Institut fuer Kernphysik)
      • 21
        Leptogenesis via Bubble Collisions

        We study a non-thermal realization of leptogenesis from the decays of sterile right-handed neutrinos (RHNs) produced via runaway bubble collisions at a generic first order phase transition. We explore the parameter space opened up by this new mechanism, which can accommodate RHN masses of several orders of magnitude heavier than the scale of the phase transition, while avoiding strong washout effects that conventional thermal leptogenesis would suffer from. Moreover, our framework can achieve the natural scale for neutrino mass generation with type-I seesaw (with $M_N\approx 10^{14}$ GeV). Preliminary studies seem to indicate that a promising correlation with high-frequency gravitational wave signals is possible.

        Speaker: Martina Cataldi (University of Hamburg)
      • 22
        EFT of supercooled phase transitions

        We present an analysis of the first-order supercooled phase transition associated with symmetry breaking in the early Universe in a classically scale-invariant model. We analyze the role of higher order thermal corrections for these transitions, and to what extent they can be computed using dimensionally reduced effective field theory (3D EFT). This framework requires high temperature (HT) expansion to be valid, which seems challenging due to the presence of supercooling. We show how to reliably use the HT expansion in dimensionally reduced theory for the calculation of bubble nucleation rate.
        We compare the obtained results to the results of the most common scheme based on the so-called daisy resummation.
        We further compute all of phase transition characteristics, discuss various scenarios of completing the transition and predict resulting gravitational-wave spectra and their observational prospects in future experiments such as LISA.

        Speaker: Mr Maciej Kierkla (University of Warsaw)
      • 23
        Impact of theoretical uncertainties on model parameter reconstruction from gravitational wave signals sourced by cosmological phase transitions

        Different thermal resummation techniques impact the gravitational wave (GW) spectra from cosmological first-order phase transitions predicted in a given particle physics model. To investigate this effect, we perform the first large-scale parameter scan of the electroweak phase transition (EWPT) in the dynamical real-singlet extension of the Standard Model (SM) using three different perturbative approximations of the effective potential. While predictions of the GW amplitudes from the common, 4D Daisy-resummed potentials are unreliable compared to state-of-the-art dimensionally reduced potentials, I will demonstrate that the overall detectable parameter spaces are robust up to a few percent in uncertainty. Regarding the reconstruction of the model parameters given a GW signal, I will illustrate that theoretical uncertainties however remain dominant over the experimental ones when using four-dimensional standard techniques. Three-dimensional effective theory, on the other hand, is accurate already at one-loop order, therefore providing the most promising route towards robust predictions.

        Speaker: Daniel Schmitt (Goethe University, Frankfurt)
      • 24
        Riding the dark matter wave: Novel limits on general dark photons from LISA Pathfinder

        I demonstrate the possibility to perform a parametrically improved search for gauged baryon ($B$) and baryon minus lepton ($B-L$) Dark Photon Dark Matter (DPDM) using auxiliary channel data from LISA Pathfinder. In particular I point out the use of the measurement of the differential movement between the test masses (TMs) and the space craft (SC) which is nearly as sensitive as the tracking between the two TMs. TMs and SC are made from different materials and therefore have different charge-to-mass ratios for both $B-L$ and $B$. Thus, the surrounding DPDM field induces a relative acceleration of nearly constant frequency. For the case of $B-L$, I show that LISA Pathfinder can constrain previously unexplored parameter space, providing the world leading limits in the mass range $4\cdot 10^{-19}\,\text{eV}

        Speaker: Jonas Frerick
      • 25
        CMB spectral distortions from dark sector anisotropies

        We introduce a novel approach to investigate sectors solely gravitationally coupled, characterized by significant anisotropies. These anisotropies undergo damping through gravitational interactions with the baryon-photon fluid, inducing heating in the process. The resultant injected heat leads to observable distortions in the cosmic microwave background spectrum. We provide analytic estimates for the magnitude of these distortions and outline a method to calculate them from first principles. The application of these methods extends to anisotropies arising from a domain wall/cosmic string network, a first-order phase transition, or scalar field dynamics. Our findings indicate that this method holds the potential to explore substantial regions of previously unconstrained parameter space, serving as a valuable complement to upcoming searches for gravitational waves originating from such dark sectors.

        Speaker: Nicklas Ramberg (Johannes gutenberg universität Mainz)
      • 26
        Froggatt-Nielsen Models Meet the SMEFT

        The Froggatt-Nielsen (FN) mechanism is one of the oldest and simplest attempts at explaining the striking hierarchies observed in the fermion masses and mixings. Given that FN models give rise to the correct fermion masses and mixings by construction and that the new particles predicted by the models are typically assumed to be heavy, it is not clear if the models are experimentally falsifiable. In this talk, we try to shed light on the question of falsifiability by analysing the infrared features of FN models whilst staying agnostic about the fine details of the model. We achieve our goal by writing down a FN effective field theory, capturing all the local interactions allowed in the ultraviolet, and matching it to the Standard Model effective field theory (SMEFT) at the tree- and 1-loop-level. Our results indicate a rich and non-trivial signature of FN models on the SMEFT Wilson coefficients, leaving us with falsifiable predictions that could be studied at current and future colliders.

        Speaker: Eetu Loisa
      • 27
        Domain Walls in extended Higgs sectors

        In several models of extended Higgs sectors discrete symmetries play an important role. For instance, in order to avoid flavor changing neutral currents, a discrete Z2 symmetry is imposed on Two-Higgs-Doublet-Models. This can lead to the formation of domain walls as the Z2 symmetry gets spontaneously broken during electroweak symmetry breaking in the early universe. In this case, where the disconnected sectors of the vacuum manifold are 3-Spheres, the domain walls can have non-trivial structures localized inside their core.
        In this talk, I discuss the possibility of having electric charge breaking and CP-violating vacua localized inside the domain walls. I also discuss the possibility of inducing electroweak symmetry restoration inside the domain walls in the case of next-to-two Higgs doublet models.

        Speaker: Mohamed Younes Sassi (2.Institute for theoretical Physics Hamburg)
      • 28
        A global analysis of the SMEFT under the minimal MFV assumption

        The Standard Model Effective Field Theory (SMEFT) stands as a crucial tool in exploring physics beyond the Standard Model. As New Physics (NP) signals remain elusive, there is a growing importance to derive constraints on SMEFT Wilson coefficients. This investigation confronts the complexity arising from a high number of parameter space directions to be constrained, making global analyses particularly challenging. In this talk, I present comprehensive global fits of the SMEFT under the minimal Minimal Flavour Violation (MFV) hypothesis, i.e. assuming that only the flavour-symmetric and CP-invariant operators are relevant at the high scale. The considered operator set is determined by theory rather than the used datasets. Global limits on these Wilson coefficients are established using leading order and next-to-leading order SMEFT predictions for electroweak precision observables, Higgs, top, flavour and dijet data as well as measurements from parity violation experiments and lepton scattering. This investigation reveals an intriguing crosstalk among different observables, underscoring the importance of combining diverse observables from various energy scales in global SMEFT analyses.

        Speaker: Riccardo Bartocci
      • 29
        Radiative corrections to $B\rightarrow\ell\nu$

        In this talk I will focus on the study of the leptonic $B^- → \ell^- \bar{\nu}_\ell$ 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 the different contributions. In the first part of this talk, I will discuss the EFT description of the process at the partonic level, which is based on Heavy Quark Effective Theory and Soft Collinear Effective Theory. I will show how the inclusion of QED corrections demands a generalisation of the hadronic decay constant $f_B$. In the second part of the talk, I will discuss the EFT description below the confinement scale using a point-like description for the B-meson. I will show that depending on the cut on final state radiation and on the lepton flavor the contribution from excited states of the B meson can become important.

        Speaker: Max Ferré
      • 30
        $\mathcal{Z}_{\rm N} \times \mathcal{Z}_{\rm M}$ flavour symmetry

        $\mathcal{Z}_{\rm N} \times \mathcal{Z}_{\rm M}$ flavour symmetry presents a novel discrete symmetry based framework that effectively address the flavour problem of the Standard Model. Employing current as well as future projected sensitivities of the quark and leptonic flavour observables, the flavour phenomenology of the two different realizations of this framework, including the minimal $\mathcal{Z}_{\rm 2} \times \mathcal{Z}_{\rm 5}$ and a non-minimal realization $\mathcal{Z}_{\rm 2} \times \mathcal{Z}_{\rm 9}$, has been thoroughly investigated. It turns out that future projected sensitivities of the high-luminosity phase-\rom{1} and \rom{2} of the LHC as well as projected sensitivities for upcoming series of leptonic flavour experiments such as MEG-\rom{2}, Mu3e, and PRISM/PRIME will play a decisive role in constraining the parameters of the $\mathcal{Z}_{\rm N} \times \mathcal{Z}_{\rm M}$ flavour symmetry.

        Speaker: NEELAM SINGH Research Scholar, Physics, IIT(BHU) (Indian Institute of Technology, BHU, Varanasi)
      • 31
        Searching for lepton-number violation in rare meson decays

        The observation of a lepton-number violating (LNV) process would have far-reaching consequences for our understanding of fundamental physics. It would have implications on the viability of leptogenesis scenarios, and point toward a Majorana nature of neutrinos. In this talk, we will point out the possibility of searching for a hint of LNV in the rare meson decays $K\to\pi+$ invisible and $B\to K(K^*)+$ invisible through detailed measurements of kinematic distributions in the missing energy. Although our focus is on LNV, we highlight that our framework can also be used to search for other types of new physics. In particular, we show to what extent one can distinguish between new physics contributions from a dark sector and LEFT through dedicated measurements of kinematic distributions only. Finally, we point out that the observation of LNV in rare meson decays would have implications for flavor structures in the UV, and could put high-scale leptogenesis under tension.

        Speaker: Martin Mojahed
      • 32
        A Cosmological Solution to the DoubletTriplet Splitting Problem

        We propose a model that can solve simultaneously the doublet-triplet splitting problem of grand unified theories, the electroweak hierarchy problem and the strong CP problem. The mechanism is based on the dynamics of two light scalars that can crunch the universe at the QCD phase transition if triplets are light or if the doublets are heavy or do not have a vev. The same mechanism was previously discussed as an explanation for the small value of the weak scale and of the QCD θ-angle. The two problems are solved also in our context by the same dynamics that explains the splitting between Higgs doublets and triplets. The only traces left at low energies are two light axion-like particles weakly coupled to the Standard Model.

        Speaker: Pablo Sesma
    • 16:00
      Coffee Break
    • Afternoon Session: Poster Session
    • 17:30
      Welcome Reception
    • 19:00
      Discussions and lab tours
    • 20:00
      Shuttle Bus to Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz
    • 08:45
      Shuttle Bus from Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz
    • Morning: Session 1
      Convener: Georgi Dvali
      • 33
        Directions in Composite Dynamics: From Composite Higgs to a Natural Dual Magnetic Standard Model.
        Speaker: Francesco Sannino
      • 34
        Phenomenology of Composite Higgs Models with a fermionic UV completion
        Speaker: Werner Rudolf Porod (Julius Maximilians Universitaet Wuerzburg (DE))
      • 35
        Composite Higgs cosmology & the dilaton at the LHC
        Speaker: Geraldine Servant (Deutsches Elektronen-Synchrotron (DE))
    • 11:00
      Coffee Break
    • Morning: Session 2
      Convener: Belen Gavela Legazpi (Universidad Autonoma de Madrid (ES))
      • 36
        Searching for charming ALPs
        Speaker: Adrian Carmona Bermudez (Universidad de Granada (ES))
      • 37
        Semisymmetries in 2HDM

        The Two Higgs Doublet Model invariant under the gauge group SU (2) × U (1) is known to have six additional global discrete or continuous symmetries of its scalar sector. We have discovered regions of parameter space of the model which are basis and renormalization group invariant to all orders of perturbation theory in the scalar and gauge sectors, but correspond to none of the hitherto considered symmetries. We therefore identify seven new symmetries of the model and discuss their phenomenology.

        Speaker: Bohdan Grzadkowski
      • 38
        BSMPT v3: A Tool for Phase Transitions and Primordial Gravitational Waves in Extended Higgs Sectors
        Speaker: Milada Muhlleitner
    • 13:00
      Workshop Group Photo + Lunch Break
    • 14:00
      Open Discussions
    • Afternoon Session: Session 1
      Convener: Prof. Jan Pawlowski (ITP, Heidelberg)
      • 39
        Where to Look and how to Look for High-Frequency Gravitational Waves

        I will discuss a simple unified formalism for GW detectors that captures the sensitivity of widely different apparatuses (PTAs, LIGO, Weber bars, cavities and more). This allows to estimate the ultimate reach on GWs from a specific detector and to identify the best detection strategies for particular frequency intervals. Interestingly, a few existing detector proposals violate our simple scaling rules, casting doubts on their feasibility, and a number of motivated signals seem well beyond the reach of our species.

        Speaker: Raffaele D'Agnolo
      • 40
        Directions for particle physics beyond asymptotic freedom
        Speaker: Daniel Litim (University of Sussex (GB))
      • 41
        UV/IR Mixing and Physics Beyond the Standard Model

        UV/IR Mixing is an umbrella term for phenomena in which high and low energy physics does not decouple as expected, for example as a consequence of the fact that QFT does not respect holographic scaling.
        Based on how UV/IR mixing has been employed in the Cohen-Kaplan-Nelson (CKN) bound and advocated as a solution to the cosmological constant problem, we explore possible consequences of UV/IR mixing for particle physics phenomenology, from the hierarchy problem to neutrino mass generation and the anomalous magnetic moments of electrons and muons.

        Speaker: Heinrich Paes
    • 16:00
      Coffee Break
    • Afternoon Session: Session 2
      Convener: Prof. Evgeny Akhmedov (Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany)
      • 42
        News from extended scalar sectors

        Models with additional scalars pose interesting new physics scenarios. Apart from additional matter content, such models can also provide solutions to other open problems of the SM, as e.g. vacuum stability or dark matter. I discuss various new physics scenarios, their current constraints as well as discovery potential at current and future colliders.

        Speaker: Tania Natalie Robens (Rudjer Boskovic Institute (HR))
      • 43
        Discovery prospects for quasi-stable multiply charged BSM particles at the LHC

        Exotic searches for long-lived BSM particles at the LHC have attracted more attention in the recent years. In the talk, I will provide a comprehensive and model-independent investigation of prospects to detect quasi-stable charged LLPs. I will discuss particles with spin 0 and 1/2, with electric charges in range 1 ≤ |Q/e| ≤ 8, which are either singlet or triplet under SU(3). Such BSM particles might be produced as particle-antiparticle pairs and propagate through detectors, or form a positronium (quarkonium)-like bound state. I will discuss both possibilities and present lower mass bounds on new particles that can be provided by ATLAS, CMS and MoEDAL experiments at the end of Run 3 and HL-LHC phases.

        Speaker: Rafal Maselek
      • 44
        Spin correlations of bottom and charm quark pairs at the LHC for SM and BSM physics

        Spin correlations have been studied in detail for top quarks at the LHC, but have not yet been explored for the other flavors of quarks. Utilizing the partial preservation of the quark spin information in baryons in the jet produced by the quark, we present possible analysis strategies for ATLAS and CMS to measure the spin correlations in $b\bar b$ and $c\bar c$ samples. We find that some measurements are feasible with existing datasets while others will become possible at the HL-LHC. The proposed measurements can provide new information on the polarization transfer from quarks to baryons and might even be sensitive to physics beyond the Standard Model.

        Speaker: Yevgeny Kats (Ben-Gurion University)
      • 45
        Indications for New Higgses at the Electroweak Scale

        Differential top-quark distributions are in strong disagreement with their Standard Model predictions. I discuss a model that can explain these tensions with new Higgses whose masses are in agreement with the hints for narrow resonances at 95GeV and 152GeV,

        Speaker: Andreas Crivellin (University of Zurich (CH))
    • 18:00
      Shuttle Bus to Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz
    • 08:45
      Shuttle Bus from Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz
    • Morning: Session 1
      Convener: Joerg Jaeckel (ITP Heidelberg)
      • 46
        Wormholes in the Axiverse
        Speaker: Luca Vecchi (INFN)
      • 47
        Dark Matter Heating of Neutron Stars: Advantages and Challenges
        Speaker: Koichi Hamaguchi (University of Tokyo)
      • 48
        The role of impurities in cosmological phase transitions

        Topological defects can play an important role in cosmology. In this talk I will discuss a less explored effect that arises in the context of first order phase transitions, by which defects can act as local impurities catalysing the decay of the false vacuum. This dynamics takes place in one of the simplest extensions of the Standard Model, the xSM, where domain wall configurations associated to the new singlet scalar are shown to enhance the tunneling rate. This dramatically changes the way the electroweak phase transition proceeds, with implications for the corresponding spectrum of gravitational waves. I will finally discuss a similar mechanism involving QCD axion strings at the time of the electroweak phase transition.

        Speaker: Dr Simone Blasi (DESY)
    • 11:00
      Coffee Break
    • Morning: Session 2
      Convener: Hooman Davoudiasl
      • 49
        Partial compositeness at LHC and on the Lattice

        We review models of partial compositeness constructed using ordinary four-dimensional gauge theories with fermionic matter. We show that they give rise to a set of collider signatures of interest for the high luminosity run of LHC (mostly light scalars with low production cross-sections). We also discuss some observables that need to be computed on the lattice in order to establish the viability of these theories.

        Speaker: Gabriele Ferretti
      • 50
        Vacuum Stability in the Standard Model and Beyond

        We revisit the stability analysis of the Standard Model Higgs potential, using both the highest theoretical precision and the most accurate determination of input parameters to date. The stability of the electroweak vacuum is found to be subject to the top mass and the strong coupling constant, and we discuss the impact of their central values and uncertainties in detail.
        We further investigate vacuum stability for a variety of singlet scalar field extensions. We identify the cutoff-free BSM parameter spaces for stability and find sizable room for new physics. Phenomenological implication such as modified Higgs trilinear, the Higgs-to-electroweak-boson, and the Higgs quartic couplings are studied in the light of the HL-LHC upgrade and future colliders such as the FCC-hh.

        Speaker: Tom Steudtner
      • 51
        Exorcizing a Model of Fuzzy Electroweak Interactions

        Inspired by tower truncation in string field theory, weakly nonlocal (WNL) quantum field theories (QFT's) have been proposed to soften the UV behavior in particle physics for naturalness and quantum gravity. Pseudo-differential form factors preclude the appearance of pathological ghosts in the particle spectrum, contrary to local higher-derivative field theories à la Lee-Wick. However, when spontaneous symmetry breaking occurs, these string-inspired QFT's generally develops an infinite tower of ghosts in the physical vacuum at tree-level. In this talk, I will discuss a class of fuzzy QFT's (with a new covariant star-product of fields) that naturally avoids this problem. Then, I will use this formalism to define the Fuzzy Standard Model: a WNL deformation of the Standard Model, where electroweak symmetry breaking is realized without ghosts. The talk is based on arXiv:2307.11741 and arXiv:2311.08311

        Speaker: Dr Florian NORTIER (CNRS - IP2I Lyon)
      • 52
        Phenomenology of the 2HDM+a

        I will discuss phenomenological aspects of the 2HDM+a model complemented wth a fermionic Dark Matter candidate. I will show how the model complies with Dark Matter Phenomenology, can provide an interpretation of some recent experimental anomalies and, finally, can account for GW signals from a First Order Phase Transition in the Early Universe.

        Speaker: Dr Giorgio Arcadi (University of Messina (Italy))
      • 53
        The principle of global relativity

        I present a new principle of relativity in physics.
        It is an alternative away from naturalness towards a new
        paradigm.
        It allows for an a priori derivation of the gauge structure of nature.
        In particular it can explain why there are precisely three generations
        of fermions.
        A specific form of dark matter is preferred.
        The standard model can only be extended in a minimalistic way.

        Speaker: Jochum Johan Van Der Bij
      • 54
        Tri-unification: a separate $SU(5)$ for each fermion family

        I discuss a grand unified theory that assigns a separate $SU(5)$ gauge group to each fermion family. The equality of the gauge couplings at the unification scale is enforced by means of a cyclic $\mathbb{Z}_3$ symmetry. Such tri-unification reconciles the idea of gauge non-universality with gauge coupling unification, opening the possibility to build consistent non-universal descriptions of Nature that are valid all the way up to the scale of grand unification. A minimal example which can account for all the quark and lepton masses and mixings will be presented, showing that it is possible to unify the gauge couplings into a single value associated with the cyclic $SU(5)^3$ gauge group while being consistent with the existing proton decay searches, in particular in the dominant $e^+ \pi^0$ channel.

        Speaker: Avelino Vicente (IFIC - CSIC / U. Valencia)
    • 13:00
      Lunch Break
    • 14:00
      Open Discussions
    • 15:00
      Excursion
    • 08:45
      Shuttle Bus from Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz
    • Morning: Session 1
      Convener: Milada Muhlleitner
      • 55
        A Holographic View of the QCD Axion
        Speaker: Tony Gherghetta (University of Minnesota (US))
      • 56
        BSM Physics with Charm

        Charm physics invites SM tests due to the abundance of data, complementarity with precision beauty and kaon searches
        and its part in the flavor puzzle. We present present puzzles, recent developments and future oppotunities for light and heavy new physics.

        Speaker: Gudrun Hiller (Technische Universitaet Dortmund (DE))
      • 57
        Phenomenology of parity solution to the strong CP problem
        Speaker: Keisuke Harigaya
    • 11:00
      Coffee Break
    • Morning: Session 2
      • 58
        Weakly-coupled light new physics (Teekolloquium)

        The existence of light, weakly-interacting new particles beyond the Standard Model is a well-motivated alternative to new particles existing at the TeV scale or beyond. With the example of axion-like particles (ALPs), which offer an explanation of the puzzling absence of the electric dipole moment of the neutron, we discuss the current status of both direct searches at the LHC and in flavor experiments, and indirect searches using precision measurements of electroweak and low-energy observables. We emphasize the importance of subtle quantum effects, which generate multiple ALP couplings to the Standard Model particles even if at a high scale only a single ALP coupling is non-vanishing.

        Speaker: Matthias Neubert
    • 12:30
      Lunch Break
    • 13:30
      Open Discussions
    • Afternoon Session: Session 1
      Convener: Matthias Neubert
      • 59
        Boosting the production of sterile neutrino dark matter with self-interactions

        Sterile neutrinos are well-motivated and simple dark matter (DM) candidates. However, sterile neutrino DM produced through oscillations by the Dodelson-Widrow mechanism is excluded by current X-ray observations and bounds from structure formation. One minimal extension, that preserves the attractive features of this scenario, is self-interactions among sterile neutrinos. In this work, we analyze how sterile neutrino self-interactions mediated by a scalar affect the production of keV sterile neutrinos for a wide range of mediator masses. We find four distinct regimes of production characterized by different phenomena, including partial thermalization for low and intermediate masses and resonant production for heavier mediators. We show that significant new regions of parameter space become available which provide a target for future observations.

        Speaker: Stefan Vogl (University of Freiburg)
      • 60
        Heavy Dark Matter EFT for any spin

        We construct an effective field theory for non-relativistic heavy dark matter of arbitrary spin based on the Little group formalism. We present the most general HDMEFT basis up to dimension seven and show that it reproduces the non-relativistic spin 1/2 case presented in the literature. We also discuss the matching onto the relativistic DM EFT.

        Speaker: Sandra Kvedaraite (University of Granada)
      • 61
        Origin of nontopological soliton dark matter

        Nontopological solitons with large global charges and masses, even above the Planck scale, can form in the early universe and dominate the dark matter abundance. In solitosynthesis, solitons prefer to grow as large as possible under equilibrium dynamics when an initial global charge asymmetry is present. Their abundance is set by when soliton formation via particle fusion freezes out, and their charges are set by the time it takes to accumulate free particles. I discuss improvements to the estimation of both quantities, and in particular show that much larger-charged solitons form than previously thought. The results are estimated analytically and validated numerically by solving the coupled Boltzmann equations. Without solitosynthesis, phase transitions can still form solitons from particles left inside false-vacuum pockets and determine their present-day abundance and properties. Even with zero charge asymmetry, solitons formed in this way can have very large charges on account of statistical fluctuations in the numbers of (anti)particles inside each pocket.

        Speaker: Dr Nicholas Orlofsky (University of Warsaw)
      • 62
        First-order phase transitions and darkogenesis in Twin Higgs models

        I will discuss phase transitions in Twin Higgs (TH) models. Previous studies found that phase transitions cannot be first-order. We show that strong first-order phase transitions (FOPTs) can occur provided that appropriate source of $Z_2$ symmetry breaking between the twin and Standard Model (SM) sectors is present. The strongest FOPTs are found in scenarios with large twin fermion Yukawa couplings and light twin sfermions in the framework of supersymmetric TH models. I will present predictions for gravitational waves. I will also discuss the EW symmetry non-restoration scenario in which the EW symmetry breaking occurs at temperatures much above the EW scale and implications for darkogenesis (baryogenesis from dark sector).

        Speaker: Marcin Badziak
      • 63
        Probing Inflationary Reheating via Axion Experiments

        In this talk, we will explore the phenomenological implications for axion dark matter production via misalignment during inflationary reheating. We investigate scenarios involving inflaton oscillating in a generic potential $\sim \phi^n$, considering inflaton decay and annihilation for reheating. For low reheating temperatures, the parameter space leading to the correct relic abundance can be enlarged beyond the standard case. Depending on the type of inflaton-matter couplings and the value of $n$, we find that certain parts of the extended parameter space are already constrained by ADMX, CAPP, and MUSE experiments. Future Haloscope experiments are expected to impose more stringent constraints. We highlight the potential to utilize axion experiments in constraining the dynamics of reheating.

        Speaker: Dr Yong Xu (JGU Mainz)
      • 64
        Bubble wall velocity in cosmological phase transitions

        The early Universe represents a unique laboratory for frontier physics, providing extreme conditions and amazing chances to test theoretical models. A large class of cosmological phenomena may allow us to probe particle physics at energy scales much beyond the reach of current and future colliders. Within this class, first order phase transitions cover a privileged role since they may leave behind several imprints. Among the others, a stochastic background of gravitational waves could be an invaluable experimental handle to the physics beyond the Standard Model, possibly related to the electroweak sector, and complementing collider searches. The crucial properties of cosmological relics depend on the dynamics of the bubbles nucleated during the phase transition: how they interact with the surrounding plasma and the friction they experience. In this talk we discuss about a substantial step forward in the quantitative theoretical description of the bubble dynamics, allowing for unprecedented precision in the extraction of physical observables such as the bubble speed and efficiency factors.

        Speaker: Luigi Delle Rose (Università della Calabria)
    • 16:00
      Coffee Break
    • Afternoon Session: Panel Discussion on New Physics Directions in the LHC era and beyond (Panelists: Tao Han, Gudrun Hiller, Mariano Quiros, James Wells)
      Convener: Dr Florian Goertz (Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany)
    • 17:30
      BBQ Dinner
    • 19:30
      Discussions and lab tours
    • 21:00
      Shuttle Bus to Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz
    • 08:45
      Shuttle Bus from Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz
    • Morning: Session 1
      Convener: Alexei Smirnov
      • 65
        Pushing the limits of dark matter -- from the Cosmos to the Lab
        Speaker: Julia Harz
      • 66
        Probing dark sectors with gravitational waves

        Gravitational waves provide a new window into the early Universe, and thus a new way of probing the dynamics of dark sectors. I will provide an overview of primordial gravitational wave sources, highlight what we have learned recently and speculate about possible future insights.

        Speaker: Pedro Schwaller
      • 67
        Adagio for Thermal Relics

        Weaker gravity during an early epoch would yield a smaller Hubble rate, which is the measure of efficiency for primordial processes. A slower cosmic tempo can accommodate alternative cosmological histories. We consider this possibility for thermal relic dark matter, in the context of extra dimensional models. These models could potentially alleviate the hierarchy problem and may be testable at the LHC or a future high energy collider.

        Speaker: Hooman Davoudiasl
    • 11:00
      Coffee Break
    • Morning: Session 2
      Convener: Tony Gherghetta (University of Minnesota (US))
      • 68
        Dark branes for PTA data and dark matter

        In the setup of a warped extra dimension we have proposed a far IR brane, at the GeV scale, with a conformal sector confining at a first order phase transition, and generating a stochastic gravitational waves background which can accommodate the recent NANOGrav signal. If dark matter is localized in the dark brane, it has only gravitational interactions with the Standard Model: it can easily reproduce the thermal relic density by annihilations into radions, and avoid direct detection experiments. A region in the parameter space of dark matter and radion masses is selected.

        Speaker: Mariano Quiros Carcelen (The Barcelona Institute of Science and Technology (BIST) (ES))
      • 69
        SM and beyond: The lessons, the puzzles, and the way forward
        Speaker: Tao Han
      • 70
        Closing Remarks
        Speaker: Dr Florian Goertz (Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany)
    • 13:00
      Lunch Break
    • 14:00
      Closing/Discussions
    • 15:15
      Shuttle Bus to Premier Inn Hotel via Heidelberg Hauptbahnhof and Alois-Link-Platz