We perform an effective field theory analysis using the charged lepton flavor violation diphoton operators, $\bar{\ell}_i\ell_j\gamma\gamma$. We explored the single and double radiative decays, $\ell_i\to\ell_j\gamma(\gamma)$, $e\to\mu$, $e\to\tau$, and $\mu\to\tau$ conversions in nuclei, and determined which processes can probe $\bar{\ell}_i\ell_j\gamma\gamma$ better. Using the current upper...
I will present a rather generic scotogenic model to provide a solution to neutrino masses, dark matter, and the baryon antibaryon asymmetry, while accommodating the current tension on the anomalous magnetic moment of the muon. The viable region of the parameter space is determined through a Markov Chain Monte Carlo numerical code, and satisfies both dark matter observables and lepton flavor...
This presentation offers a comprehensive overview of the ATLAS Forward Proton (AFP) detector within the ATLAS experiment at CERN. Positioned some millimeters from the proton-proton collision point at the LHC, the AFP detector comprises silicon-based trackers and a time-of-flight system strategically placed 210 meters away from the ATLAS interaction point. The silicon tracker facilitates...
We present a new feasibility study on the production of a Z´ boson at the LHC, through top anti-top fusion, with family non-universal couplings, considering proton-proton collisions at 13 TeV and 14 TeV. Such a hypothesis is well motivated theoretically and it can explain observed differences between SM predictions and experimental results, as well as being a useful tool to further probe...
Performance of the High level trigger reconstructing jets and how the results are compared to offline reconstructed jets. The main focus of the talk will be the vertex reconstruction, how it can be improved and what are the main reasons it usually fails.
The description of scalar mesons has been a persistent challenge in the field of light meson spectroscopy over the past several decades. Notably, the investigation of scalar states, such as the $a_{0}(980)$ and the $f_{0}(980)$, has been of significant interest due to the limited understanding of their properties. Amid these ongoing challenges, the study of three-body decays of charmed mesons,...
The strength of the coupling of the Higgs boson with other fermions and bosons has been extensively studied during the first two runs of the LHC. In this paper we study the production of the Higgs boson with 4-muon final state, i.e., Vector Boson Fusion (VBF). VBF is the process of two quarks, each emitting a Z vector boson, which then merge to create a Higgs boson. Three machine learning (ML)...
This work seeks to mitigate the increased pileup effects in Run 3 on the ATLAS detector by deriving efficiency scale factors and their corresponding uncertainties for pileup jet tagger: NN JVT. This is determined by looking at Z (ee/mumu)+jet events. This PU jet tagger has been tuned recently so further development of the software to allow for efficient determination of scale-factors is...
We propose and study a new and simple extension of the Standard Model in which the dark matter is a singlet Dirac fermion. The only other particle present in the model is a singlet scalar that mixes with the Higgs boson and couples to the dark matter. The model is based on a Z6 discrete symmetry that is spontaneously broken by the vev of the scalar, which generates the dark matter mass. We...
Weakly Interacting Massive Particles (WIMPs) and axions are arguably the most compelling dark matter (DM) candidates in the literature. Here, we consider a model where the PQ symmetry solves the strong CP problem, generates radiatively Dirac neutrino masses, and gives origin to multicomponent dark sector. Specifically, scotogenic Dirac neutrino masses arise at one-loop level. The lightest...
As a possible extension to the standard model, a leptophilic U(1) gauge boson that violates lepton universality and a fermionic self-interacting dark matter that couples to this new gauge boson can explain recent anomalies in flavour physics (like (g-2)mu) and small scale structure problems of cold dark matter (like the core-cusp problem). We discuss the parameter space in which the...
Los rayos cósmicos son partículas que llegan desde el espacio exterior y bombardean constantemente la Tierra en todas las direcciones. Están compuestos por protones, partículas alfa y el resto son núcleos pesados. Al interactuar con la atmósfera (oxígeno y nitrógeno), producen cascadas de partículas secundarias, entre las que se encuentran los neutrones, que podemos clasificar de la siguiente...
As electromagnetic showers may alter the abundance of Helium, Lithium, and Deuterium, we can place severe constraints on the lifetime and amount of energy injected by long-lived particles decaying into dark matter. Considering up-to-date measurements of the light element abundances that point to Yp = 0.245 ± 0.003,(D/H) = (2.527 ± 0.03) × 10−5,(7Li/H) = 1.58+0.35 −0.28 × 10−10, (6Li/7Li) =...
n this talk we present a variation of the Scotogenic Model that extends the gauge group by a global U(1) symmetry, and a scalar singlet that induces Spontaneous Symmetry Breaking to explain the origin of both Majorana masses and Lepton number violation. Then, we make a brief analysis of the viable parameter space that satisfies the conditions for fermionic dark matter, which can be considered...
We report several anomaly-free Z' models and their corresponding LHC and low-energy constraints. We also discuss the possibility of explaining some experimental anomalies using a Z' model.
A study of the two zero textures for the Dirac neutrino mass matrix
$M_\nu$ in a basis where the charged leptons are diagonal is carried through. Current neutrino oscillation data are used in our analysis.
Phenomenological implications of $M_\nu$ on the leptonic CP violation and neutrino mass spectrum are explored.
Accurate modeling of neutrino final state interactions with target nuclei using neutrino detectors is an open field of research. Experiments such as MINERvA, T2K, and NOvA had shown discrepancies between their simulations and their data, which implies that the leading theoretical models embedded in the simulations are not encoding the full physics of the interactions. In particular,...
The latest results of neutrino experiments have shown a difficulty in the modeling and reconstruction of the final states, especially those produced by charged pions, where there are strong differences between what is predicted by the models and what is obtained. A better understanding and more accurate characterization of these interactions and decays can contribute significantly to improve...
Recently the neutrino experiments ANTARES and IceCube have released new constraints to the non-standard neutrino interaction (NSI) parameter $\epsilon^d_{\mu\tau}$ (flavor off-diagonal). To the light of this new data, in this work, we study the new physics implications on the parameter space of a simplified $Z^\prime$ model with lepton flavor violating ($\mu\tau$) couplings. For a $Z^\prime$...
Measurements of low-energy electrons produced by electron neutrino interactions and cosmic rays are crucial for neutrino oscillation measurements, the detection of supernova bursts and searches for beyond the standard model physics at neutrino experiments. In particular, electrons from cosmic muons that decay at rest, called Michel electrons, have well-known energy spectra below 50 MeV. They...
In the different neutrino experiments, especially those of long-line baseline, the identification and subsequent reconstruction of the events has been a problem due to the lack of high-resolution detectors, which implies that it is difficult to differentiate between processes with similar topologies. The LiquidO project proposes an opaque scintillating liquid that confines light and allows for...
Las interacciones de corrientes neutras en leptones de distintas familias son discutidas en el presente trabajo. Estos procesos están suprimidos dentro del Modelo Estándar (ME) debido a que la interacción débil es quiral. Sin embargo, se han establecido las cotas experimentales (más recientes) para los procesos de decaimiento del bosón $Z^0$ en $e\mu,e\tau,\mu\tau$ en la colaboración ATLAS,...
Knowledge of the Earth’s interior composition is highly relevant to many geophysical and geochemical problems. Neutrino oscillations are modified in a non-trivial way by the effects of matter. They can provide valuable and unique information not only on the density but also on the chemical and isotopic composition of the deep regions of the planet. In this paper, we re-examine the possibility...
Charmonium production has been modeled using NRQCD factorization. It is necessary to test the theoretical precision of the factorization formula along with the estimation of the short-distance dynamics through the fitting with the experimental data. The present talk presents a brief review of the literature's theoretical predictions of charmonium production applied to the decay mode...
The present work aims to carry out a comparative study of jet reconstruction algorithms when employed to analyze events originating from a dark QCD model. Specifically, it focuses on two definitions used in the ATLAS experiment: LCTopo Trimmed, which has been established as the standard for jet reconstruction, and UFOCSSK SoftDrop, a more sophisticated method expected to become the new...
In the present work, Monte Carlo simulation methods were employed using the MADGRAPH software. A range of masses was tested for a fourth type of neutral lepton, HNL, symmetrically coupled with the three generations of neutrinos in the standard model. Additionally, different orders of magnitude for the coupling of the HNL with the neutrinos were tested. The reconstruction of the HNL signal is...
JUNO will be an underground detector, filled with 40 ktn of liquid scintillation and boasting excellent resolution. It will enable simultaneous studies of great importance in the fields of neutrino and supernova physics. An intriguing area of research is the potential observability of Earth matter effects on the energy spectrum of neutrinos originating from core-collapse supernovae (CCSN)...
We present an analysis of the mechanisms of dark matter production in the early universe. There are many different models that try to explain such production. In this short talk we focus on three of these mechanisms. The first and the most recognized is the Weakly Interacting Massive Particles or WIMP model, which we work on by applying the Boltzmann equation to study the behavior of the WIMP...
Abstract
The theories of the Standard Model and General Relativity do not provide all the answers to the current open problems of theoretical high-energy physics. On the other hand, string theory constitutes a very fertile theoretical framework where it is possible to find several answers and build physics beyond the standard model. Furthermore, it is the most compelling candidate to become...
Axionlike particles (ALPs) appear in several dark sector studies. They have gained increasing attention from the theoretical and experimental community. In this work, we propose the first search for ALPs to be conducted at the Brazilian Synchrotron Light Laboratory (LNLS). In this work, we derive the projected sensitivity of a proposed experiment for the production of ALPs via the channel eþe−...
Bootstrapping is an emerging numerical method that is used to calculate the eigenvalue of the Hamiltonian for some non-relativistic Quantum systems. The approach consist on using the hermitian property of the hamiltonian and the other operators to select the correct values of the energy of the system. We will show a basic introduction to this method, and applied it in the hydrogen atom and the...
One of the most intriguing problems of the SM is the masslessness of neutrinos, which is contradicted by the experimental evidence. It has been established that neutrinos have a small mass, but different from zero, therefore the first experimental proof of new physics beyond the SM has been achieved. Also, it is very important mencionate that cosmology requires a heavy neutral stable particle...
We report the most general classification of 3-3-1 models with $\beta =\sqrt{3}$. We found several solutions where anomaly cancellation occurs among fermions of different families. These solutions are particularly interesting as they generate non-universal heavy neutral vector bosons. Non-universality in the SM fermion charges under an additional gauge group generates Charged Lepton Flavor...
Models beyond the Standard Model with extra scalars have been highly motivated by the recent
discovery of a Higgs boson. The Two Higgs Doublet Model Type III considers the most general
case for the scalar potential, allowing mixing between neutral CP-even and CP-odd scalar fields.
This work presents the results of the study on the t → cγ decay at one loop level if neutral flavor
changing...
El presente trabajo sobre el formalismo de los espinores
de helicidad y las propiedades del Little Group de Wigner, con el objetivo de construir amplitudes de dispersi ́on tanto en el caso de part ́ıculas sin masa, revisando ejemplos de la teor ́ıa de Yukawa y la QED, como en el de part ́ıculas masivas. Esto se realiz ́o a partir del estudio de las amplitudes de tres puntas como pieza...
The muon anomalous magnetic moment g-2 deviates by more than three sigmas from the corresponding standard model (SM) prediction. It is possible that this experimental anomaly is a consequence of physics beyond the SM.
We calculate the radiative corrections to g-2 due to a neutral exotic scalar field and compare it with the current literature. We use this result to calculate the allowed...
The effect of Higgs Mixing is calculated for any Abelian gauge extension of the standard model and the effects in possible Dirac dark fermion dark matter candidates are discussed
Se estudió el fenómeno de oscilación de neutrinos y su cuanticidad por medio de la desigualdad de Leggett-Garg, fundamentada bajo el concepto de macrorealismo, el cual establece que un sistema macroscópico con dos estados posibles se encontrará en uno de esos estados en un momento dado, sin encontrarse nunca en una superposición de los mismos, eje central de la mecánica cuántica. El fenómeno...
We study the annihilation of a pair of ‘t Hooft-Polyakov monopoles due to confinement by a string. We analyze the regime in which the scales of monopoles and strings are comparable. We compute the spectrum of the emitted gravitational waves and find it to agree with the previously calculated pointlike case for wavelengths longer than the system width and before the collision. However, we...
In the context of scattering amplitudes in gauge theories, we construct using the Amplituhedron formalism the on-shell diagrams for the N=4 Super yang mills theory in the planar limit using the recursion relation BCFW starting with the 3-point amplitudes.
We discuss the production of primordial gravitational waves (GW) from radiative inflaton decay during the period of reheating, assuming perturbative decay of the inflaton either into a pair of bosons or fermions, leading to successful reheating satisfying constraint from Big Bang nucleosynthesis. Assuming that the inflaton ϕ oscillates in a general monomial potential V(ϕ)∝ϕ^n, which results in...
An analysis of the late-time evolution of the Universe for an f(R)-gravity model built from an exponential function of the scalar curvature is presented. The corresponding field equations, written in terms of a suited statefinder function are solved numerically, allowing to study the evolution of interesting cosmological parameters, which present values (at z = 0), are shown to be compatible...
