7th ComHEP: Colombian Meeting on High Energy Physics

America/Bogota
Carlos E. Yaguna, Carlos Sandoval Usme (Universidad Nacional de Colombia), Gabriela Alejandra Navarro (Universidad Antonio Narino (CO)), Mario A Acero (Universidad del Atlantico), Nicolás Bernal (Universidad Antonio Nariño)
Description

This is the seventh Colombian Meeting on High Energy Physics (7th ComHEP).  We hope to bring together young and senior particle physicists from Colombia and abroad, to discuss recent progress in particle physics, cosmology and related areas. The program of the meeting will address a broad range of topics, divided in dedicated sessions on:

  • Standard Model and the Higgs boson
  • Beyond the Standard Model
  • Neutrino Physics
  • Neutrino Experiments 
  • Hadron and flavor physics
  • Dark matter
  • Cosmology and Cosmic rays
  • Theoretical physics

 

This year the conference will take place in the town of Villa de Leyva, in the auditorium of Hotel Santa Viviana.

 

Confirmed Speakers

  • Alexis Aguilar-Arevalo, ICN-UNAM, Mexico
  • Diego Aristizabal, UTFSM, Chile
  • Sergey Barsuk, CNRS/IN2P3, IJCLab, France
  • Reina Camacho, Université Paris Cité, CNRS/IN2P3, France
  • Camilo Carrillo, CIEMAT, Spain
  • Daniel de Florian, UNSAM, Argentina
  • Andrés Flórez, Universidad de los Andes, Colombia
  • Steven Goldfarb, University of Melbourne, Australia & IPPOG
  • Enrico Nardi, INFN-LNF, Italy
  • Orlando Peres, UNICAMP, Brazil
  • David Vanegas, Universidad de Medellín, Colombia
  • Tim Wolf, Max Planck Institute for Nuclear Physics, Germany

 

Follow us in twitter!

Scientific Organizing Committee 

  • Alex Tapia (Universidad de Medellín)
  • Carlos Avila (Universidad de los Andes)
  • Carlos Sandoval (Universidad Nacional de Colombia)
  • Carlos Yaguna (Universidad Pedagógica y Tecnológica de Colombia)
  • Diego Milanés (Universidad Nacional de Colombia)
  • Gabriela Alejandra Navarro (Universidad Antonio Nariño)
  • Herberth Cárdenas (Universidad Pedagógica y Tecnológica de Colombia)
  • Jairo Alexis Rodriguez (Universidad Nacional de Colombia) 
  • John Gómez (Instituto Tecnológico Metropolitano)
  • Jhovanny Mejía (Universidad de Antioquia)
  • José David Ruíz (Universidad de Antioquia)
  • Mario A. Acero Ortega (Universidad del Atlantico)
  • Oscar Alberto Zapata Noreña (Universidad de Antioquia)
  • Richard Benavides (Instituto Tecnológico Metropolitano)

Supporting Institutions

                          

      .                 


 

Participants
  • Avijit Hazra
  • Gabriela Alejandra Navarro
  • Jairo Jiménez
  • John David Gómez Aguirre
  • Juan Manuel Moreno Perez
  • Syeda Eman Zahra
  • Óscar Zapata
  • +96
    • 14:00 18:00
      Theory and Phenomenology
      Convener: Oscar Zapata (Universidad de Antioquia)
      • 14:00
        The Higgs Boson 45m
        Speaker: Daniel De Florian (International Center for Advanced Studies (AR))
      • 14:45
        The X17 anomaly: status and prospects 45m
        Speaker: Enrico Nardi
      • 15:30
        Break 30m
      • 16:00
        Multicomponent scalar dark matter: recent developments 20m

        In this talk I will discuss some recent developments concerning scenarios of multi-component scalar dark matter based on a single ZN symmetry.

        Speaker: Oscar Zapata
      • 16:20
        Decay constants and mass spectrum of pseudoscalars mesons 20m

        The Schwinger-Dyson equations (DSE) were obtained from a mass functional generation $M(p)$ for a fermion propagator. The DSE are obtained, which are analogous to the Euler-Lagrange equations in Quantum field theory (QFT), since they are the equations of motion of the Green's functions . The DSE's are an infinite set of integral equations coupled to each other and it is only possible to solve them by means of a truncation scheme. The Bethe-Salpeter equations (BSE) have as a solution the wave function of the states bound to a system of two particles. The BSEs are obtained from a covariant relativistic formalism. We solve abelian models for quantum chromodynamics (QCD) at low energies, which rules allow us to obtain the spectrum of mass from pseudoscalar mesons $J_p =0^-$ and the decay constants.

        Speaker: Ruben Hernando Criollo Estrella (Universidad de Nariño)
      • 16:40
        $\mathrm{SU}(4)$ weak singlet leptoquark in $R_{K^{(*)}}$ flavor anomalies 20m

        We present a detailed study of a proposed model to explain the experimental hints of new physics in B meson decays within the frameork of the Pati-Salam unification. The model is based on the local gauge group SU$(4)_L\otimes$SU$(4)_R \otimes$SU$(2)_L \otimes$U$(1)^\prime$ and part of its gauge bosons are (3,1)2/3 vector leptoquarks. The key feature of the model is that SU$(4)_R$ is broken at a high energy scale, which suppresses right-handed lepton flavor changing currents at the low energy scale. The constraints imposed on the model by independent measurements show that the mass of the leptoquark can be as low as 10 TeV, not requiring the introduction of quarks or leptons mixings with new vector-like fermions. We obtain constraints from various pseudo-observables for the leptoquark couplings and contrast them against a model-independent analysis.

        Speaker: Oscar David Rosero Cárdenas (Universidad de Nariño)
      • 17:00
        Scalar coupling evolution in a non-perturbative QCD resummation scheme 20m

        I will talk about the Standard Model scalar coupling ($\lambda$) evolution in a particular QCD resummation scheme, where the QCD coupling becomes infrared finite due to the
        presence of a dynamically generated gluon mass, leading to the existence of a non-perturbative infrared fixed point. We discuss how this scheme can be
        fixed taking recourse to phenomenological considerations in the infrared region. The QCD $\beta$ function associated to this non-perturbative
        coupling when introduced into the SM renormalization group equations increases the $\lambda$ values at high energies.

        Speaker: Dr John David Gómez Aguirre
      • 17:20
        Chern-Simons on the Null Plane 5m

        We present a canonical quantization for Chern-Simons
        on the Null Plane coordinates using the Dirac procedure and the
        Faddeev-Jackiw procedure. The constraint structure when using
        null-plane coordinates is considered and the gauge generators are
        derivated.

        Speaker: German Ramos
      • 17:25
        Representaciones de Álgebras de Lie graduadas. 5m

        Se construye el algebra de Líe del grupo de Poincare para extenderlo a álgebras de Lie graduada adicionando generadores fermionicos. Se estudiarán representaciones irreducibles minimales de estas álgebras y los respectivos súpercampos para construir densidades lagrangianas invariantes bajo las álgebras graduadas.

        Speakers: Juan Camilo Guzman Martinez (Universidad Nacional de Colombia, sede Bogotá), Mr Roberto Enrique Martinez Martinez
      • 17:30
        Alternative 3-3-1 models: a comprehensive analysis 5m

        We systematically review how anomaly-free 3-3-1 models, with and without exotic electric charges, can be constructed using as a basis closed sets of fermions that include each of the particles and antiparticles of all electrically charged fields. Our analysis reproduces not only the models known in the literature, but also shows the existence of several more independent models for one and three families not considered so far. A phenomenological analysis of the new models is performed, in which the lower bounds at 95% CL on the gauge boson masses are presented.

        Speaker: Yithsbey Giraldo Usuga (Universidad de Nariño)
    • 09:00 12:10
      Neutrino experiments
      Convener: Alex Tapia
      • 09:00
        Global status of neutrino oscillation parameters 45m
        Speaker: David Vanegas Forero (Universidad de Medellin)
      • 09:45
        Neutrino physics and Dark Matter searches with the Coherent CAPTAIN-Mills (CCM) experiment 45m

        The 10 ton liquid argon (LAr) scintillation detector Coherent CAPTAIN-
        Mills, at the LANSCE facility of the Los Alamos National Laboratory,
        sits at a distance of 23 m from the core of the Lujan Center spallation
        source, which is a copious source of neutrinos from stopped pions, as
        well as, possibly, new particles belonging to a hypothetical Dark Sector
        of particle physics. Besides studying neutrino interactions in LAr at
        energies below 52.8 MeV, relevant for future neutrino experiments,
        CCM has a rich physics program comprising searches for Dark
        Photons, Axion-like Particles (ALPs), and neutral heavy leptons with
        masses in the range of keV to MeV, exploring new regions of parameter
        space for these searches. A prototype detector instrumented with 120
        PMTs, CCM120 operated between 2018 and 2019, demonstrating the potential
        of such a detector for the search of Sub-GeV dark matter. The upgraded
        CCM200 detector, with 200 PMTs, improved shielding and LAr filtration
        and purification system is now taking beam. In this talk the status of
        the experiment, as well as results from CCM120 and expected sensitivity
        to new physics of CCM200 will be presented.

        Speaker: Alexis Aguilar-Arevalo (Instituto de Ciencias Nucleares, UNAM)
      • 10:30
        Break 30m
      • 11:00
        DUNE and the Liquid Argon Software (LArSoft) an overview 20m

        The deep underground neutrino experiment (DUNE) is a neutrino observatory and nucleon decay detector under construction, designed to give answers to modern physics problems like: the neutrino hierarchy and matter-antimatter asymmetry. To do that, in DUNE will be possible to perform precise measurements of neutrino oscillation parameters, in addition DUNE will be able to detect and measure electron neutrino fluxes from a core-collapse supernova within our galaxy and proton decay. In this talk a brief description of the experiment will be presented then a review of the Liquid Argon Software (LArSoft) is given, this framework is an important tool in the simulation and reconstruction of different phenomena across liquid argon time projection chambers. The basic steps for the reconstruction and simulation of events using LarSoft are shown and their main functionalities. Finally, the broad context of application of LarSoft in the DUNE experiment is addressed and some simulation examples will be discussed.

        Speaker: JOSE DAVID TAMARA JARAMILLO (Universidad Antonio Nariño)
      • 11:20
        Constraints on CP-violating Non-Standard neutrino interactions from NOvA 20m

        The NOvA experiment studies the disappearance of muon (anti)neutrinos and the appearance of electron (anti)neutrinos to measure the parameters governing the oscillation of neutrinos at the so-called atmospheric sector. Thanks to the long distance travelled by the neutrinos through the earth, NOvA can also explore the effects of possible Non-Standard Interactions with matter. Here I present the constraints on the NSI parameters based on the analysis of recent NOvA data.

        Speaker: Mario A Acero (Universidad del Atlantico)
      • 11:40
        Tensions between theory and experiment on final states interaction with neutrinos 5m

        Modeling neutrino final state interactions with target nuclei within neutrino detectors is an open research field. Experiments such as MINERvA, T2K and NOvA found discrepancies on their simulations with their data, which implies that the current theoretical models are not encoding the full physics of the interactions. In particular, long-baseline neutrino oscillation experiments are currently developing various analysis techniques to bridge the gap between theory and experiments through the tuning of the theoretical models, embedded in their simulations, to their data, emphasizing the regions of energies in which they operate. Further theoretical work is expected in the future to explain the findings of neutrino experiments on this regard. In this talk we summarize the latest analysis techniques coded in neutrino cross-section simulators used by some long-baseline neutrino oscillation experiments, focusing on the final state interactions tunings done over the GENIE 3.2 simulation.

        Speaker: Camilo Cortés Parra (Universidad Nacional de Colombia)
      • 11:45
        The importance of characterizing charged pions in neutrino interactions 5m

        Recent results from neutrino experiments studying neutrino interactions show that final state interactions are not fully explained by current theoretical models. In this regard, pion production in final state interactions is at the center of the discrepancies between theoretical models and experimental data. Hence, a characterization based on data of pion production and interactions in long-baseline neutrino experiments would contribute significantly to hadron identification, and therefore, to better tune the theoretical models embedded in the Monte Carlo simulations used by neutrino experiments to carry on their analyses. Currently, neutrino experiments such as MINERvA, T2K, and NOvA, published various improvements in the tuning of the nuclear theoretical models coded in their simulations based on their data. However, there are standing difficulties in hadron identification, which could be sorted if constraints from pion classification become available. This talk portraits the importance of developing better pion identification algorithms, and summarizes the ideas that could contribute to the improvement in pion identification.

        Speaker: Juan David Villamil Santiago
    • 14:00 18:00
      LHC experiments
      Convener: Gabriela Alejandra Navarro (Universidad Antonio Narino (CO))
      • 14:00
        ATLAS experiment status and perspectives 45m
        Speaker: Gabriela Alejandra Navarro (Universidad Antonio Narino (CO))
      • 14:45
        CMS experiment status and perspectives 45m
        Speaker: Camilo Carrillo (Imperial College (GB))
      • 15:30
        Break 30m
      • 16:00
        Optimization of a jet finding algorithm for the HL-LHC ATLAS L0 trigger 20m

        Upcoming hardware updates to the ATLAS detector will allow for jet finding algorithms similar to those used offline to be implemented at the lowest level of the trigger. This will allow to increase the coherence between the data selected in the analyses and those selected by the trigger. Motivated by the fact that the anti-kT is one of the most commonly used jet finding algorithms in the ATLAS analyses, we studied the performance of a modified anti-kT algorithm based on regions of interest (ROIs) which was developed with the intention to be run online in the L0 trigger of the HL-LHC ATLAS detector, and carried out a series of optimizations in order to improve the resulting trigger efficiency.

        Speaker: Carlos Fernando Buitrago Cardenas (Universidad Nacional de Colombia (CO))
      • 16:20
        Test of Techniques for the Assembly of Silicon Pixel Detector Modules Needed for the High-Luminosity Upgrade of the CMS Experiment at CERN 20m

        The stages of the assembly process and preliminary testing of four-chip silicon modules (CROCs) designed to detect charged particles in the TFPX region of the Inner tracker at CMS experiment within the framework of CERN High Luminosity updates are detailed. These stages correspond to assembly using an Aerotech gantry, positioning data collection based on the angular opening and the average slide of the chips to select the modules prepared for the wire bonding process, and ends with the performance of two types of tests on these modules, the Shunt and Low Drop output Voltage (SLDO) and pixel alive test.
        In addition, it is recognized the importance of implementing this rigorous module assembly process in the future reconstruction of physical phenomena, product of proton-proton collisions, which could explain and deepen the understanding of the behavior of elementary particles within the standard model and even study the physics beyond it.
        In the assembly process, it was found that both the average angular opening and the average slide of the HDI with each of the chips did not exceed 25 µm, which makes the assembled modules suitable for performing the wire bonding process.
        In the testing process, it was possible to observe the behavior of the chips against the growth of the current induced by the power supply and also the number of functional pixels in the chips. A good correspondence was found between the results and the expected behavior for the chips.

        Speaker: Neidy Lorena Bucuru Rodriguez (Purdue University (US))
      • 16:40
        Experimental setup for high precision laser polarisation determination 20m

        In the context of high precision electron polarimetry for future e+e- colliders, a tool to precisely monitor laser polarisation in real time to the per-mille level is needed. We propose to investigate the capabilities of photo-elastic modulators to that purpose

        Speaker: Santiago Rodriguez Mendoza
    • 18:00 20:40
      Comunicación y diversidad

      https://cern.zoom.us/my/gabynavarro?pwd=dnB2MXdKaUtSN1h2NWpKNnIzR21MQT09

      Conveners: Gabriela Alejandra Navarro (Universidad Antonio Narino (CO)), Jose Ruiz (Universidad de Antioquia (CO)), Reina Coromoto Camacho Toro (LPNHE-Paris CNRS/IN2P3)
      • 18:00
        Comunicando la Materia Oscura 20m

        La búsqueda de materia oscura en aceleradores de partículas es un tema del cual se tiene muy poco material divulgativo, el objetivo de este proyecto es crear una estrategia de divulgación de este tema enfocada a personas sin formación en áreas afines a la astrofísica. Se realizó un estudio del tema y se buscaron referencias para determinar cuál debía ser el contenido, en qué orden se debía presentar y qué metodología se debía usar. El producto divulgativo que se realizó fue una serie de infografías en las cuales se abarcan las siguientes temáticas: el modelo estándar, materia oscura, aceleradores de partículas y cómo se realiza la búsqueda de materia oscura en aceleradores de partículas. Se eligieron estos temas y este orden para garantizar que los espectadores tengan los elementos suficientes para poder comprender la temática central del proyecto.

        Speaker: JESSICA VELASQUEZ MUNERA (Grupo de Fenomenología e Interacciones Fundamentales, Instituto de Física, Universidad de Antioquia)
      • 18:20
        Diversidad y género en HEP 20m
        Speaker: Dilia Maria Portillo Quintero (TRIUMF (CA))
      • 18:40
        Panel y mesas de trabajo: Diversidad, Equidad e inclusión (DEI) 2h
        • Identificación de problemáticas
        • Definición de indicadores, calidad de los datos existentes
        • Acciones afirmativas en DEI
        • Voces desde el sur global: ¿cómo se vive el trabajar en HECAP desde Colombia?
        • Género en ciencia
        • Hablemos de interseccionalidad
        • Vida estudiantil y postdoctoral: retos y perspectivas
        Speakers: Gabriela Alejandra Navarro (Universidad Antonio Narino (CO)), Jose Ruiz (Universidad de Antioquia (CO)), Reina Coromoto Camacho Toro (LPNHE-Paris CNRS/IN2P3)
    • 09:00 12:40
      Dark Matter / Cosmology / Astroparticles
      Convener: Carlos E. Yaguna
      • 09:00
        Dark Matter Direct Detection Searches 45m
        Speaker: Tim Michael Heinz Wolf (Max-Planck-Institut für Kernphysik)
      • 09:45
        Fermion and scalar two-component dark matter from a Z4 symmetry 20m

        We revisit a two-component dark matter model in which the dark matter particles are a singlet fermion (ψ) and a singlet scalar (S), both stabilized by a single Z4 symmetry. The model is remarkably simple, with its phenomenology determined by just five parameters: the two dark matter masses and three dimensionless couplings. In fact, S interacts with the Standard Model particles via the usual Higgs portal, whereas ψ only interacts directly with S, via the Yukawa terms ψc¯(ys+ypγ5)ψS. We consider the two possible mass hierarchies among the dark matter particles, MS<Mψ and Mψ<MS, and numerically investigate the consistency of the model with current bounds. The main novelties of our analysis are the inclusion of the yp coupling, the update of the direct-detection limits, and a more detailed characterization of the viable parameter space. For dark matter masses below 1.3 TeV or so, we find that not only is the model compatible with all known constraints, but it also gives rise to observable signals in future dark matter experiments. Our results show that both dark matter particles may be observed in direct-detection experiments and that the most relevant indirect-detection channel is due to the annihilation of ψ. We also argue that this setup can be extended to other ZN symmetries and additional dark matter particles.

        Speaker: Prof. Carlos E. Yaguna (UPTC)
      • 10:05
        Gauged Lepton number 20m

        A model of gauged lepton number with scotogenic Dirac neutrino masses and dark baryogenesis

        Speaker: DIEGO ALEJANDRO RESTREPO QUINTERO
      • 10:25
        Model for Dirac neutrino masses with two-component dark matter and extra gauge Abelian symmetry 20m

        We propose a model with a multicomponent and multiflavor dark matter which allows the realization of an effective operator for Dirac neutrino masses. Furthermore, it has an extra Abelian gauge symmetry that is spontaneously broken and generates masses for particles in the dark sector and it is responsible for the stablity of dark matter candidates. We explore the parameter space of the model and we analyze the impact of the constraint of the relic abundance of the candidates of dark matter.

        Speaker: DAVID ALEJANDRO SUAREZ ROLDAN
      • 10:45
        Break 30m
      • 11:15
        Enhancing the early universe with rotating axion field. 20m

        Rotations of an axion field in field space provide a natural origin for an era of kination domination in the early universe. We investigate how this cosmological scenario affects the spectrum of possible primordial gravitational waves, its implication for structure formation and relieving the Hubble tension.

        Speaker: Nicolas Fernandez (Rutgers)
      • 11:35
        Scalar potential analysis of the Z5 multi-component dark matter model 20m

        In recent years the multi-component scalar dark matter models with discrete symmetries $\mathbb{Z}_N$ have been widely studied in the literature. Among them, the $\mathbb{Z}_5$ model proposes two complex fields that transform as singlets under the Standard Model gauge group. The scalar potential brings along with eleven free parameters that must be restricted. In that sense, the primary purpose of this research is to develop a detailed analysis of the scalar potential with the objective of establishing the perturbative unitarity, vacuum stability, and positivity conditions, and finally to determine the viable parameter space of the model.

        Speaker: DIEGO ALEJANDRO RIOS PEREZ
      • 11:55
        Dark Matter production in Non-Standard Cosmologies 5m

        Synopsis In the standard cosmological scenario, it is proposed a Universe dominated by radiation just after the inflationary phase and prior to Big Bang Nucleosynthesis (BBN) but actually, there is not much observational information supporting this hypothesis. This research project is intended to take advantage of this gap in our knowledge of cosmic history to modify the post-inflationary period and alter Dark Matter (DM) production through the introduction of a time-dependent inflaton decay rate.

        The existence of DM in the Universe has been one of the open and more relevant questions in physics and astronomy in the last decades. There are a large number of gravitational evidence about its existence, but there is no conclusive evidence about its nature as a particle. Through the previous decades, a worldwide program focused on discovering this particle has been carried out following three major strategies: direct detection, indirect detection, and production at colliders.

        Despite the great effort, the DM particle nature remains one of the central mysteries in physics. The important thing is that there is no particle belonging to the Standard Model (SM) of particle physics with the required properties to explain the observed astrophysical phenomena related to DM.

        Until relatively recently the DM models proposed hinged on a standard cosmology basis, however, due to the enormous difficulty present in detecting this particle, it was evident the necessity to introduce models in different scenarios.

        According to standard cosmology, the Universe has undergone a series of stages characterized by definite processes and the domination of one component over the rest during its evolution. Summarizing, in its first seconds, the Universe went through three main periods, inflation, reheating, and BBN. In the standard scenario, during inflation, a Universe dominated by a scalar field is hypothesized followed by a period of radiation domination from the end of reheating until BBN. However, there are no reasons to assume that the Universe was radiation-dominated prior to BBN simply because at the moment we do not have much observational information about this period and, in this sense, it is, therefore, possible that the cosmological history featured, for example, an additional early matter-dominated epoch due to e.g. slow post-inflationary reheating or massive metastable particles that dominated the total energy density. Even more exotic scenarios that change the expansion history of the Universe compared to the standard radiation-dominated case can also be realized, all of them are called non-standard cosmologies and they can have significant consequences for the physics of the early Universe.

        One of the most interesting consequences concerning non-standard cosmologies is that early periods in these scenarios can alter the cosmological abundances of particle species. In particular, they can have a significant impact on our expectations for the DM relic abundance, since non-standard eras can change the expansion rate of the Universe, leading to entropy injections that may dilute the DM relic abundance, or provide a non-thermal production mechanism for DM.

        In the frame of the present work, it is pretended to develop the phenomenology of a simplified WIMP DM model in a non-standard cosmology with a matter-dominated Universe in the period ranging from the end of inflation and the end of reheating and with a generic time-dependent rate for dissipation of matter into radiation [1]. The main goal of this research project is to find the parameter space for a WIMP particle in the proposed frame able to account for 85% of DM in the Universe and evade the constraints imposed by experiments.

        References

        [1] Raymond T. Co, Eric Gonzalez, and Keisuke Harigaya. Increasing temperature toward the completion of reheating. Journal of Cosmology and Astroparticle Physics, 2020(11):038–038, nov 2020.

        Speaker: Ms Valentina Franco Velásquez (Universidad de Antioquia)
      • 12:00
        Analysis of the mechanisms of dark matter production in the early universe. 5m

        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 relics in the thermal bath in the early universe. This analysis is done by finding an approximate solution of the equation analytically, and then numerically, using Python programming. Once we have the results, we adapt the calculations to characterize the Feebly Interacting Massive Particles or FIMP and Strongly Interacting Massive Particles or SIMP.

        Speaker: Mateo Escorcia (Universidad del Atlántico)
      • 12:05
        Bases de la Teoría Cuántica de Campos en Espacios Curvos: Creación de Partículas 5m

        En el presente trabajo se muestran rudimentos básicos de la teoría cuántica de campos en el espacio-tiempo plano a espacio-tiempos curvos, donde se plantea la no unicidad del vacío y se muestra un ejemplo particular simple en el cual se evidencia esto.

        Basado en: P. C. W. Davies N.D. Birrel. Quantum fields in curved space. Cambridge Monographs on Mathematical Physics, 1984.

        Speaker: Daniela Ávila Durán
      • 12:10
        Delimitación de las dimensiones del operador escalar en 4D CFT 5m

        En el presente trabajo se estudian las generalidades de la teoría conforme (CFT) como, por ejemplo, el algebra conforme, las funciones de correlación, los límites de unitaridad y la expansión del producto operador (OPE). Elementos con los que se abordaran argumentos teóricos, incluyendo el cómo establecer limites en las dimensiones del operador escalar en cuatro dimensiones de las CFT´s.

        Basado en Riccardo Rattazzi y col. “Bounding scalar operator dimensions in 4D CFT”. En: Journal of High Energy Physics 2008.12 (2008).

        Speaker: Ayda Milena Bernal (Universidad Pedagógica y Tecnológica de Colombia)
      • 12:15
        Restricciones físicas para la existencia de agujeros de gusano desde la teoría de la relatividad general 5m

        En este trabajo se estudian las restricciones físicas impuestas por la teoría de la relatividad general de Einstein para la existencia de soluciones tipo agujero de gusano. Se hace un análisis partiendo de las condiciones energéticas usadas comúnmente en relatividad general, junto con las restricciones impuestas por la ecuación de Raychaudhuri [1], relacionada también con las condiciones energéticas mencionadas. Se espera llegar al hecho de que es necesario considerar materia ``exótica'' para la existencia de agujeros de gusano, reproduciendo así el análisis realizado en [2] y siguiendo el trabajo recopilatorio de la tesis de maestría de Catalina Miritescu, Traversable wormholes [3]. Para este análisis tomamos la solución propuesta por Visser [4], la cual consiste en unir dos espacios de Schwarzschild cuyos horizontes han sido removidos. Se encuentra que esta solución requiere una densidad de energía superficial negativa para su existencia.

        Referencias:
        [1] Amalkumar Raychaudhuri. “Relativistic cosmology. I”. En: Physical Review 98.4 (1955), pag. 1123
        [2] Michael S Morris y Kip S Thorne. “Wormholes in spacetime and their use for interstellar travel: A
        tool for teaching general relativity”. En: American Journal of Physics 56.5 (1988), pags. 395-412.
        [3] Catalina-Ana Miritescu. “Traversable Wormhole Constructions”. Tesis de maestría. Imperial CollegeLondon, 2020.
        [4] Matt Visser. “Traversable wormholes from surgically modified Schwarzschild spacetimes”. En: Nuclear Physics B 328.1 (1989), pags. 203-212.

        Speaker: Julian Cortez (Universidad Pedagogica y Tecnologica de Colombia)
      • 12:20
        Expansión acelerada tardía del universo en un modelo de gravitación modificada tipo f(R, G) con acoplamiento a campos escalares. 5m

        En este trabajo, se estudia la expansión acelerada tardía del universo en un modelo de gravitación modificada tipo f (R, G) con acoplamiento de un campo escalar al invariante de Gauss-Bonnet. En este sentido se consideran tres propuestas para f(R) del tipo exponencial en el escalar de curvatura R. En primera instancia se obtienen las ecuaciones generales de movimiento asociadas al modelo propuesto, las cuales se expresan mejor de manera conveniente en términos de la cantidad statefinder yH(z) que se usa con frecuencia en la literatura, posteriormente se resuelven numéricamente considerando condiciones iniciales motivadas físicamente, valores apropiados de los parámetros del modelo para las tres propuestas que se tienen de la función f(R) y distintas formas para el potencial del campo escalar y la función de acoplamiento al invariante de Gauss-Bonnet. Por último, se verifica si para las distintas propuestas de f(R) la fenomenología resultante es compatible con los últimos datos de la colaboración Planck 2018, además los resultados obtenidos se comparan con los correspondientes al modelo Lambda-Cold-Dark- Matter.

        Speaker: CARLOS ALBERTO MEZA MORALES (Universidad del Atlantico)
      • 12:25
        Simulaciones de Neutrones Cósmicos de Baja Energía para Agricultura de Precisión 5m

        Una aplicación de los neutrones cósmicos se basa en optimizar el consumo de agua mediante la automatización de los sistemas de riego en la industria agrícola. Los neutrones interactúan fácilmente con el hidrógeno, el cual se encuentra en las moléculas de agua presentes en la humedad del suelo. Actualmente se cuenta con sensores diseñados para detectar los neutrones de bajas energías que emergen del suelo luego de la interacción con el suelo húmedo. Mediante simulaciones se pueden hacer predicciones de diferentes configuraciones de estos escenarios que, por ejemplo, son de ayuda en la calibración de los sensores. URANOS (Ultra Rapid Neutron-Only Simulation) es un software, que se presenta como una opción intuitiva para el usuario, donde se puede simular la interacción de neutrones de bajas energías con el suelo. Sin embargo, al usar modelos parametrizados para el flujo de rayos cósmicos y la respuesta de la interacción entre los neutrones y el suelo húmedo se corre el riesgo de propagar errores y obtener resultados de baja confiabilidad. Por otra parte FLUKA es un entorno de simulación Montecarlo de propagación de partículas y su interacción con el medio, el cual usa de base principios físicos. En este trabajo se comparó los resultados de las simulaciones hechas en URANOS con los resultados de FLUKA con el fin de incluir una mejora en las parametrizaciones del flujo de neutrones de bajas energías a las que se encuentran sujetos los modelos utilizados en URANOS.

        Speaker: Yessica Dominguez
      • 12:30
        Optimización de la eficiencia de detección de neutrones de un detector Cherenkov de agua 5m

        Los neutrones son partículas subatómicas que conforman parte de la componente hadrónica de los rayos cósmicos que ingresan a la Tierra. Su detección y caracterización es de particular interés para el estudio de decrecimientos de Forbush producidos por la emisión de masa coronal que altera el flujo de rayos cósmicos. El decrecimiento de Forbush se evidencia mayoritariamente en energías inferiores a los cientos de GeV. Los detectores de neutrones son especialmente sensibles a estos cambios y, por lo tanto, muy eficientes para estudiar este fenómeno. En este trabajo se realiza la calibración, caracterización y puesta en marcha de un detector de agua Cherenkov en el campus de la Universidad Industrial de Santander. Se busca optimizar la eficiencia de este detector Cherenkov agregando compuestos de cloro al volumen activo del tanque para la detección de neutrones cósmicos de baja energía.

        Speaker: Victor Clarizio-Canelon (Universidad Central de Venezuela - Universidad Industrial de Santander)
      • 12:35
        Muografía en la Industria Petroquímica 5m

        En la actualidad existe la necesidad de estudiar las estructuras internas de los sistemas de producción en la industria. Estas estructuras pueden ser de grandes dimensiones lo dificulta la observación de los componentes internos por medio de técnicas convencionales como el empleo de rayos gamma. Particularmente en las Torres de Craqueo Catalítico de la industria Petroquímica, deben monitorearse las densidades entre sus capas con el objetivo de determinar la cantidad de residuos para su eventual mantenimiento. Para esta tarea se propone la implementación de la muografía como técnica de detección de variaciones de densidad en las torres. En este trabajo se determinó la resolución, espacial y temporal, de esta técnica con el fin de explorar la viabilidad de su implementación. Se realizaron simulaciones del flujo de muones para diferentes configuraciones de densidad. Además se realizaron mediciones del flujo detectado por una torre de paneles centelladores, entre los cuales se dispuso un recipiente donde se colocaron objetos de diferentes densidades, donde se logró obtener una disminución de hasta un 20% del flujo de muones para diferentes rangos de densidad de la muestra.

        Speaker: Rafael Martinez Rivero
    • 09:00 12:40
      Neutrinos theory
      Convener: Dr Mario A Acero (Universidad del Atlantico)
      • 09:00
        Beyond the standard model neutrinos 45m
        Speaker: Orlando L. G. Peres
      • 09:45
        Different aspects of neutrino phenomenology 45m
        Speaker: Diego Aristizabal (Universidad Tecnica Federico Santa Maria (USM))
      • 10:30
        Break 30m
      • 11:00
        Neutrino Masses and Majoron production in the type 1 Seesaw Mechanism 20m

        In this talk we introduce the neutrino mass problem of the Standard Model of particle physics. Then, we analyze how to generate these masses by introducing right-handed Majorana singlets in the type 1 Seesaw mechanism framework. Afterwards, we explain the origin of these masses through the spontaneous symmetry breaking of a global U(1) symmetry, which introduces a new scalar singlet with a massive Goldstone mode, referred to as the Majoron. We conclude the talk by showing some preliminary results regarding the production of both Majorons and Heavy neutrinos at different experiments.

        Speaker: Gustavo Ardila
      • 11:20
        Five texture zeros in the lepton sector 20m

        We have assumed special structures for the charged and neutral mass matrices in
        the lepton sector, inspired by structures for the up and down quark mass matrices that result by
        assuming a certain number of symmetrical zeros in their entries named texture zeros. A prediction
        of the lepton mixing matrix results from the rotation matrices that diagonalize the mass matrices
        in the neutral and charged lepton sectors. The use of texture zeros reduces the number of spurious
        parameters to explain observations in this sector.

        Speaker: Richard Benavides
      • 11:40
        El fenómeno de cambio de sabor de neutrinos desde la teoría cuántica de campos 5m

        Aunque el fenómeno de oscilación de neutrinos es bien conocido y estudiado, el acercamiento estándar desde la mecánica cuántica incluye algunos problemas, por ejemplo, en el cálculo de la probabilidad de oscilación. Estudiando la oscilación desde la Teoría Cuántica de Campos se busca ofrecer un mejor panorama en cuanto a estos problemas y plantear la posibilidad de organizar y dar solución a las paradojas presentadas por dicho fenómeno.

        Speaker: Jairo Luis Jiménez Mejía (Universidad del Atlántico)
      • 11:45
        Prueba de la mecánica cuántica por medio de la oscilación de neutrinos utilizando la desigualdad de Leggett-Garg 5m

        El objetivo principal es exponer los límites de la mecánica cuántica con ayuda de la desigualdad de Leggett-Garg, utilizando el fenómeno de oscilación de neutrinos como mediador entre los dos, el cual se fundamenta en el cambio de estado de sabor, fenómeno que corresponde a una superposición coherente de los estados de masa. Se propone estudiar la violación de la desigualdad de Leggett-Garg con neutrinos, debido al hecho de que la longitud de coherencia cuántica en la que se produce la interferencia de los estados de masa y se observa el fenómeno de oscilación, se extiende a distancias considerablemente grandes, lo cual será beneficioso para ampliar el entendimiento que se tiene sobre los límites de la naturaleza entre lo clásico y lo cuántico.

        Speaker: RICARDO JOSE ZAMORA BARRIOS (Universidad del atlantico)
    • 14:00 18:30
      LHC results
      Conveners: Carlos Sandoval Usme (Universidad Nacional de Colombia), Gabriela Alejandra Navarro (Universidad Antonio Narino (CO))
      • 14:00
        Jet physics at the LHC 45m
        Speaker: Reina Coromoto Camacho Toro (LPNHE-Paris CNRS/IN2P3)
      • 14:45
        BSM Physics at the LHC, status and perspectives 45m
        Speaker: Carlos Andres Florez Bustos (Universidad de los Andes (CO))
      • 15:30
        Break 30m
      • 16:00
        Quarkophobic W' for LHC searches 20m

        We consider a simplified model where a W' boson is added to the standard model with negligible couplings to quarks, but generic couplings to leptons and electroweak bosons. We study the implications of such a model for LHC searches. Consequently, we propose an LHC search through the vector boson fusion topology which would have sensitivity for such a new particle with the current proton-proton collisions's energy and available luminosity.

        Speaker: Jose Ruiz (Universidad de Antioquia (CO))
      • 16:20
        Searches of new physics in the final state $B \tau \nu$ in $pp$ collisions 20m

        The $R_{D^{(\ast)}}$ anomaly is one of the most intriguing experimental results in particle physics. Experiments as BaBar, Belle and LHCb have measured a consistent tension with the standard model. In this work we study a consequence of different solutions to this tension as a sequential $\mathrm{W}'$ boson, EFT and leptoquark. Such models, are not only able to explain the $R_{D^{(\ast)}}$ anomaly but also to produce distinctive signatures at the LHC. We proposed a search for the signature $\mathrm{b},\tau,p_{T}^{miss}$ maximizing the statistical significance with regard to standard model backgrounds as $W^{\pm} + \text{jets}$, $Z^{0} + \text{jets}$ and $t\bar{t}$. We finally show how the different models require a differentiated selection criteria and the exclusion that can be achieved.

        Speaker: Tomas Atehortua Garces (Universidad de Antioquia (CO))
      • 16:40
        Use of the Lund plane technique for the identification of W bosons in ATLAS experiment 20m

        Particle tagger methods are a powerful tool to filter unwanted data and improve the final results of the experiment. In this case, the performance of different tagger methods of W bosons in collision events of the ATLAS experiment will be studied, taking special attention to the methods based on the so-called Lund Jet Plane, which according to preliminary results presents a better performance than the methods currently used.

        Speaker: Rafael Andrei Vinasco Soler (Universidad Nacional de Colombia (CO))
      • 17:00
        Feasibility studies for searches enhanced by machine learning methods of leptoquarks with preferencial couplings to third generation fermions at the LHC. 20m

        In recent years, the observations reported by LHCb, Babar, and Belle experiments of the apparent anomalies in B-meson decays, together with the possible anomaly on the magnetic angular momentum of muons reported by the Muon $g-2$ experiment at Fermilab, indicate that, perhaps, lepton flavour universality is violated in the SM, in turn being a window to search new physics.

        Of the new models that intent to extend the SM to explain violation of lepton flavour universality, several of them introduce new particles with preferential couplings to third generation fermions. Some of the most popular models include the hypothetical production of heavy mass particles in particular we concéntrate on Leptoquarks (LQ). In this project, we seek to conduct feasibility studies for the LHC associated with the production of these new hypothetical particles through different production mechanism and with preferential couplings to third generation fermions. These studies are conducted using different simulation packages to emulate the LHC conditions and the statistical analysis will use Machine Learning (ML) methods.

        Speaker: Cristian Rodriguez (Universidad de los Andes)
      • 17:20
        Machine learning approach for vector boson fusion identification 20m

        The strength of the Higgs boson's coupling with other fermions and bosons is extensively studied during the first two LHC runs. In this work, the production of the Higgs boson, namely, Vector Boson Fusion (VBF) is studied. VBF is the process of two quarks, each of which emits a vector boson, W or Z boson, which then merge to create a Higgs boson. Machine learning (ML) models are built to discriminate Higgs boson events from non-Higgs boson events. The results of these models are compared with those obtained by making linear cuts.

        Speaker: Mr Anderson Alexis Ruales Barbosa (Universidad de Antioquia (CO))
      • 17:40
        Boosted Higgs boson in association with a vector boson 5m

        This work studies the improvement that could be obtained by applying machine learning techniques to an ongoing event selection.

        Speaker: Juan Manuel Moreno Perez (Universidad Nacional de Colombia (CO))
      • 17:45
        Calibration of the Jet Vertex Tagger algorithm in the ATLAS detector 5m

        This work uses jet-vertex tagger (JVT) and forward jet-vertex-tagger (fJVT) which discriminate pile-up events from high scattering processes coming from the first vertex and thus calibrate these algorithms by determining the scaling factors of their efficiency with their corresponding uncertainties using data from the ATLAS experiment.

        Speaker: Ms Laura Juliana Caviedes Betancourt (Universidad Nacional de Colombia (CO))
      • 17:50
        COFFEA: Columnar Object Framework For Effective Analysis 20m

        Columnar analysis is a paradigm that describes the way the user writes the analysis application that is best described in contrast to the the traditional paradigm in high-energy particle physics (HEP) of using an event loop. Coffea is a prototype package for pulling together all the typical needs of a high-energy collider physics (HEP) analysis. In this talk I will provide an introduction to Coffea and it's functionalities. We will have a hands on tutorial on how to implement a basic analysis.

        Speaker: Daniel Ocampo Henao (Universidad de Antioquia (CO))
    • 18:30 19:50
      CONHEP network meeting
      Convener: Carlos Sandoval Usme (Universidad Nacional de Colombia)
      • 18:30
        IPPOG 20m
        Speaker: Steven Goldfarb (University of Melbourne (AU))
      • 18:50
        LA-CoNGA Physics 20m
        Speaker: Reina Coromoto Camacho Toro (LPNHE-Paris CNRS/IN2P3)
      • 19:10
        Erasmus+ - Paris Saclay 20m
      • 19:30
        COMHEP VIII 20m
        Speaker: Carlos Sandoval Usme (Universidad Nacional de Colombia)
    • 09:00 13:35
      QCD and Heavy Flavours
      Convener: Diego Milanes Carreno (Universidad Nacional de Colombia (CO))
      • 09:00
        Quarkonium production 45m
        Speaker: Sergey Barsuk (Université Paris-Saclay (FR))
      • 09:45
        Addressing the $B$ meson anomalies within the minimal $U_1$ leptoquark model 20m

        Very recently the LHCb experiment released the first measurement of the ratio $R(\Lambda_c)$. Moreover, the BABAR experiment reported a new result of the leptonic decay ratio of Upsilon meson $\Upsilon(3S)$, namely, $R_{\Upsilon(3S)}$. Both measurements are below their corresponding Standard Model predictions (deficit), deviating by \sim 1.1\sigma∼1.1σ and \sim 1.8\sigma∼1.8σ, respectively. In addition, the LHCb recently presented the first search of the LFV decay $B^0 \to K^{\ast 0}\mu^\pm\tau^\mp$. Motivated by these new data, in this work we study their impact on the phenomenology of the singlet vector leptoquark ($U_1$) model addressing the hints of lepton flavor universality violation in the semileptonic decays of BB mesons (BB meson anomalies), by carrying out a global fit analysis. In general, we found that a minimal version of the $U_1$ model with a mass of 1.8 TeV can successfully explain the BB meson anomalies, while being compatible with all other flavor observables and LHC bounds. Interestingly, our study shows that the new observables generate strong tension, leading to non-trivial effects on the global fit. Future improvements at the LHCb and Belle II experiments would help to understand their complementarity. Moreover, we also analyze the impact of the expected sensitivity on flavor observables at Belle II to provide a further test of the $U_1$ model. Finally, we study the minimal assumptions under which the $U_1$model could, in addition, provide a combined explanation of the anomalous magnetic moment of the muon.

        Speaker: Nestor Quintero Poveda (Universidad Santiago de Cali)
      • 10:05
        The Triplet vector boson model: flavor and collider constraints. 20m

        The triplet vector boson (TVB) is a simplified new physics model involving massive vector bosons transforming as a weak triplet vector, which it has been proposed as a combined explanation for the anomalous b→sμ+μ− and b→cτν¯τ data (the so-called B-meson anomalies). In this work, we carry out an updated view of the TVB model, including the Belle II perspectives. We perform a global fit to explore the allowed parameter space by the most current b→sμ+μ− and b→cτν¯τ data by considering all relevant low-energy flavor observables. Our results are confronted with the most recent LHC constraints. We also incorporate in our study the first measurement of the ratio R(Λc)=BR(Λb→Λcτν¯τ)/BR(Λb→Λcμν¯μ) very recently obtained by LHCb. In particular, we show that the TVB model can provide an explanation for the B meson anomalies; however, this framework is in strong tension with LHC bounds. With respect to future flavor measurements at Belle II, our results suggest that a small new physics window would be allowed to explain the b→cτν¯τ data in agreement with LHC constraints solely. Furthermore, the implications of our phenomenological analysis of the TVB model to some known flavor parametrizations are also discussed.

        Speaker: Eduardo Rojas
      • 10:25
        Break 30m
      • 10:55
        Search for B_c to Phi K+ decay using LHCb experiment Run 2 data 20m

        There is no Bc annihilation decay experimentally observed to date. The B_c -> Phi K+ decay can proceed via annihilation of anti-b and c quarks into a W intermediate boson or, alternatively, involving final-state rescattering effects. Observation of the B_c -> Phi K+ decay will provide a new insight on the B_c meson properties and will allow a new independent determination of the V_cb CKM matrix element. The analysis is performed using LHCb experiment data from Run 2 at 13 TeV center of mass energy. Phi meson is reconstructed via decays to two charged kaons. The B+ decay to Phi K+ is used for normalization.

        Speaker: Jonnatan Pereira (Universidad Nacional de Colombia (CO))
      • 11:15
        D+s ------> K+K-K+ radiation topologies analysis 20m

        There is no unique way of considering which one is the topology supposed to be the dominant one in decays such as $D^+_s \rightarrow K^+K^-K^+$ or $D^+ \rightarrow K^+K^-K^+$. There could be relevant contributions coming from either the radiation topology or the annihilation one. Meanwhile, there are extensive analyses of the annihilation topologies considering the weak vertex as a constant, exists at the moment no clear way of radiation topologies management. The present work consists of presenting a parametrization for the radiation topologies, firstly in terms of form factors and secondly taking the limit where the weak vertex is a constant. Additionally, it is presented a differential decay rate analysis in terms of the invariant masses of the channel, and it is shonw how the radiation topologies should be coupled to the unitarized amplitudes with two bodies final states interactions.

        Speaker: David Alejandro Baron Ospina
      • 11:35
        Measurement of the $B^{+}$ differential cross section as a function of transverse momentum and multiplicity density in pPb collisions at $\sqrt{s_{NN}}=8.16$ TeV 20m

        We present the first observation of the $B^{+}$ meson production suppression in high-multiplicity respect to low multiplicity pPb collisions at $\sqrt{s_{NN}} = 8.16$ TeV with data collected by the CMS detector during 2016 and corresponding to an integrated luminosity of 175 nb$^{-1}$. The measurement uses exclusive decay channel $B^{+}\rightarrow J/\psi \ K^{+}$. The inclusive results show a good agreement with theoretical calculations from the FONLL within uncertainties. The cross section ratio measurements scaled by the charged-particle multiplicity density, from low to high multiplicity, shows a significant decrease on the $p_{T}$ dependence with increasing charged-particle multiplicity density. Results may indicate interplays of beauty quark energy loss, diffusion effects models in high multiplicity events, and gluon saturation models in lower multiplicity events.

        Speaker: Camilo Jose Torres Castano (Universidad de Antioquia (CO))
      • 11:55
        Study of Bs0 -> φφφ via charmonium resonances 5m

        Multiple fits were done with the run 2 of the LHCb data, to extract signal of
        $B_s^0 \rightarrow \phi \phi \phi$ events via charmonia resonances. First, 3D
        fits in the bins of the $B_s^0$ invariant mass were computed to get the
        estimated number of true $\phi \phi \phi$ events. With a new histogram with the
        resulting signal for each bin, a fit was applied, to extract the $B_s^0$
        signal. After this fit, from the triggered data of 1972 events, it returned $321.26 \pm 49.3$ events in the signal yields. This procedure also was applied in the bins of the Dalitz plot of the three body decay $B_s^0 \rightarrow \phi \phi \phi$ to then apply a fit of a $\eta_c$ resonance. However due to the low number of events, the yields and uncertainties didn't converged correctly.

        Speaker: Cindy Catalina Moreno Sarria (Universidad Nacional de Colombia (CO))
      • 12:00
        A holographic bottom-up description of light nuclide spectroscopy and stability 20m

        This work explores a holographic proposal to describe light nuclide spectroscopy by considering extensions to the well-known bottom-up AdS/QCD proposals, the hardwall and softwall models. We also propose an alternative description inspired by the Woods-Saxon potential. We find the static dilaton associated with this potential in this Wood-Saxon-like model. We compute the nuclide spectra finding that, despite their pure AdS/QCD origin, hardwall and softwall, as monoparametric models, have good accuracy and precision since the RMS error is near 11$\%$ and 4 $\%$ respectively. In the case of the Wood-Saxon model, the RMS was around 1$\%$. We also discuss configurational entropy as a tool to categorize which model is suitable to describe nuclides in terms of stability. We found that configurational entropy resembles a stability line, independent from nuclear spin, for symmetric light nuclides when considering softwall and Wood-Saxon-like models. For the hardwall case, configurational entropy, despite increasing with the constituent number, depends on the nuclear spin. Thus, the Woods-Saxon-like model emerges as the best choice to describe light nuclide spectroscopy in the bottom-up scenario.

        Speaker: Miguel Angel Martín Contreras (Universidad de Valparaíso)
      • 12:20
        Flavored axions and the flavor problem 5m

        A Peccei-Quinn~(PQ) symmetry is proposed, in order to generate in the standard Model~(SM) quark sector a realistic mass matrix ansatz with five texture-zeros. Limiting our analysis to Hermitian mass matrices we show that this requires a minimum of 4 Higgs doublets. This model allows assigning values close to 1 for several Yukawa couplings, giving insight into the origin of the mass scales in the SM. Since the PQ charges are non-universal the model features Flavor-Changing Neutral Currents~(FCNC) at the tree level. From the analytical expressions for the FCNC we report the allowed region in the parameter space obtained from the measurements of branching ratios of semileptonic meson decays.

        Speaker: Dr juan salazar (Universidad de Nariño)
      • 12:25
        Implementation of trigger lines for luminosity measurements in run 3 20m

        The biggest particle accelerators quantify the number of interactions with luminosity, the proportionality factor between the number of events per second and the cross section. For Run 3, LHCb experiment uses Allen software for High Level Trigger 1 (HLT1) developed on Graphics Processing Units (GPUs). The implementation of new trigger lines for luminosity measurements requires the development and testing over Monte Carlo samples before its integration to LHCb software. Here, we show some code and results of new trigger lines in the Allen project.

        Speaker: Mr Andres Gomez (Universidad Nacional de Colombia)
      • 12:45
        Preliminary results for the Dalitz plot analysis of the $D^{+}\rightarrow K{-}K{+}K{+}$ decay using the Multi-meson model 20m

        This work presents the selection of the $D^{+}\rightarrow K{-}K{+}K{+}$ candidates and progress in the amplitude analysis of this decay using the Multi-meson model (Triple-M), a model based on an effective chiral Lagrangian. The study is based on a sample of $pp$-collision data, collected at a centre-of-mass energy of 13 TeV with the LHCb detector between 2016 and 2018. The results of the amplitude analysis using the latest version of the Multi-meson model are expected to give hints towards a more solid theoretical understanding of heavy-meson decays into three mesons. In particular, the $K{+}K{-}$ scattering amplitudes for the combinations of spin (0,1) and isospin (0,1) of the two-body system may be obtained from a Dalitz plot fit using the decay amplitude derived with the Triple-M.

        Speaker: Juan Sebastian Ordonez Soto (Universidad Nacional de Colombia (CO))
      • 13:05
        Approaching the lepton flavour universality violation in B meson decays using a leptoquark model 5m

        Recent measurements on semi-leptonic decays of the B meson suggest a violation of lepton universality. This goes against the Standard Model prediction where none of its interactions distinguish lepton flavours. A posible explanation for this anomaly lies in the context of Beyond Standard Models. In this talk a model with new physics will be presented, which makes use of leptoquarks - hypothetical particles mediating interactions between quarks and leptons - and it will be shown how it can account for lepton violation in semi-leptonic decays.

        Speaker: Nicolas Gomez Cruz
    • 13:35 13:55
      Closing 20m
      Speaker: Carlos Sandoval Usme (Universidad Nacional de Colombia)