Data / Hora
Date(s) - 27/08/2024 - 27/12/2024
17:00 - 18:00
Categorias
SEMINÁRIOS DE PÓS-GRADUAÇÃO
Seminários dos alunos de pós-graduação desta semana, que serão apresentados na próxima quarta-feira, 28 de agosto, 17:00 e 17:30 horas, respectivamente, na sala L649.
1 – Por Victoria Ramos de Oliveira
Title: Search for CP violation in the D+ -> pi-pi+K+ phase space in the LHCb Experiment
Abstract: The Standard Model (SM) of particle physics serves as our best framework for understanding the interactions and properties of elementary particles. Within this model, CP violation, a phenomenon that distinguishes between particles and their antiparticles, plays a crucial role. It provides a necessary condition for baryogenesis and holds the potential to explain the matter-antimatter asymmetry observed in the universe. In this seminar, we focus on the search for CP violation in the doubly Cabibbo suppressed (DCS) decay channel D+ -> pi-pi+K+. using data collected by LHCb from 2016-2018 of pp collisions with a centre of mass energy of 13 TeV, corresponding to an integrated luminosity of 5.6 fb-1. The goal of this analysis is the implementation of a model-independent technique to perform a statistical comparison between the phase space, called Dalitz Plot (DP), of particle and antiparticle decay channel, searching for local differences in the distribution of events between the two DPs. To achieve this, we perform a rigorous selection process to remove background contributions from other charm decays. Additionally, machine learning algorithms are employed to reduce combinatorial background levels. The resulting sample of approximately 6 million signal candidates represents the largest dataset ever obtained for the DCS D+ decay channel, providing exceptional sensitivity for CP violation searches. Notably, this analysis is conducted in a blinded manner, ensuring unbiased results. Tests using the background region, the control channel \DptoKPP, and Monte Carlo simulations further validate our approach.
2 – Por Gustavo Loachamin
Title: Amplitude analysis of the Ds->KKK decay
Abstract: The study of particle decays involving heavy hadrons contributes to the development of new physics. This is partially because these decays may be sensitive to new interactions or new sources of charge-parity violation. The processes involving these types of interactions are described by quantum chromodynamics which is however limited by perturbative calculations. For this reason, phenomelogical models are used to provide a description of the phase-space of these decays.In this seminar, I will talk about the work done on the description of the phase-space of the decay channel Ds→KKK using the data collected in the run 2 of the LHCb experiment. I will describe the features of this decay, data collection, selection, fitting procedure and parametrization of the elements needed to obtain a description of this decay.