Robin Leboucher ; Justine Serrano

2020
Centre de Physique des Particules de Marseille Marseille, France

Abstract: Being forbidden in the Standard Model, lepton flavour violating decays appears to be a good probe for searching physics beyond the standard model. In particular, the tau lepton, thanks to its high mass enables more lepton flavour violating decays: τ→lγ and τ→3l with l=e,μ. In addition the interest for τ decays is reinforced by several new physics models prediction on branching fractions just below current experimental limits.The data taking of Belle II, located at KEK, Japan, started in 2019 and should end by 2027,collecting 50 times more data than its predecessor, Belle. The large amount of e+e− collisions will provide a huge number of τ+τ− pairs, ideal for tau studies.Theτ-group of Belle II needs differ from other B and C mesons analysis, in particular because of the signal contamination by beam backgrounds. The use of latest simulated samples and back-grounds implies the requirement to update the "good track" definition by optimizing the track selection on impact parameters.

Note: Presented on 01 07 2020
Note: MSc