30-31 July 2018
Instituto de Física da Universidade de São Paulo
America/Sao_Paulo timezone
Evento comemorativo dos 10 anos da Rede Nacional de Física de Altas Energias

A multivariate selection of charmless B+ decays to three mesons in LHCb detector

31 Jul 2018, 11:30
15m
Auditório Novo 1 (Instituto de Física da Universidade de São Paulo)

Auditório Novo 1

Instituto de Física da Universidade de São Paulo

Análise de Dados Análise de Dados

Speaker

José Helder Lopes (UFRJ)

Description

The analysis of charmless decays $B^{\pm}\rightarrow h_1^{\pm}h_2^{+}h_3^{-}$, where $h_i$ are pions or kaons, collected by
LHCb in Run I, show strong evidence for CP asymmetries in the
three-body phase space. We are now analyzing data collected in Run II
(2015+2016) and will combine the results with the ones from Run I. After
a loose pre-selection, we use a multivariate method (MVA) to improve the
signal significance. We show here the comparison of results with
different inputs and different MVA methods, particularly boosted
decision trees (BDT) and artificial neural networks (MLP). Our final
choice, for the good performance and simplicity, is BDT with a reduced
set of input variables, as compared to Run I selection.

Primary author

Presentation Materials