Instituição de defesa: CBPF - Centro Brasileiro de Pesquisas Físicas

Resumo: The search for explanations to the asymmetry between matter and antimatter in the Universe has been a longstanding effort in Physics. The fact that antimatter is relatively scarce compared to matter leads to the question of why the universe appears to favor matter over antimatter. The source of this unbalance is the violation of the CP symmetry, which arises from the presence of a complex phase in the Cabibbo-Kobayashi-Maskawa (CKM) matrix of the Standard Model of particle physics. The presence of CP violation in the charm sector is very small, so it can be useful to provide evidence for new physics beyond the Standard Model. In this work a fundamental step is performed in order to search for CP violation in charmed mesons. Using LHCb experiment data, this study examines charge asymmetry in the Cabibbo favoured D ±8 → π∓π±π± decay. The goal is to validate this channel as a reliable control for detecting CP violation in the singly Cabibbo suppressed decay D± → π∓π±π±. The analysis is performed using the data collected in pp collisions at √s = 13 TeV by LHCb in the years 2016-2018 (Run 2), corresponding to 5.6 fb−1 of integrated luminosity. While the majority of the phase space displayed non-significant charge asymmetries, some areas require fine-tuning for a more accurate understanding. Despite minor adjustments needed, our findings provide a promising insight into the sources of charge asymmetry, emphasising the importance of understanding non-CP asymmetries in the D± → π∓π±π± channel for observing CP asymmetries in this decay.

Área:

Data da defesa: 15/09/2023

Banca: Maria Clemencia Rosario Mora Herrera; Irina Nasteva