Study of ππ S-wave in B± → π+π−π± decays

Abstract

The LHCb amplitude analysis has shown an intriguing distribution of the local CP asymmetries observed in the B± → π+π−π± decays. The π+π− S-wave in the previous amplitude analysis was modelled by different approaches among which the S-wave amplitude is described by a sum of the ππ ↔ K K ̄ rescattering amplitude and a σ pole in the standard isobar model. This disserta- tion aims to better describe the π+π− S-wave in a new formalism instead of the conventional isobar model. This new approach, called the Multi-Meson model, is expected to incorporate the low energy dynamics such as the final state interactions and coupled channels.
The Multi-Meson model is implemented in Laura++ and its behaviour in the low energy region is studied based on the toy simulation generated. Fits to the toys are performed and results of both the isobar parameters and new parameters of the model are obtained and studied.

Date of Award	25 Jan 2022
Original language	English
Awarding Institution	University of Bristol
Supervisor	Konstantinos A. Petridis (Supervisor) & Patricia Magalhaes (Supervisor)