# EPS-HEP2019

Jul 10 – 17, 2019
Ghent
Europe/Brussels timezone

## }Generic Loop Effects of New Scalars and Fermions in $b\to s\ell^+\ell^-$ and a Vector-like $4^{\rm th}$ Generation

Jul 13, 2019, 11:40 AM
20m
Campus Ledeganck - Aud. 5 (Ghent)

### Campus Ledeganck - Aud. 5

#### Ghent

Parallel talk Flavour Physics and CP Violation

### Speaker

Pere Arnan (ICCUB)

### Description

We investigate the possibility of accounting for the $b\to s\ell^+\ell^-$ anomalies via box contributions involving with new scalars and fermions.For this purpose we extend previous analysis by allowing that the new particles can also couple to right-handed Standard Model (SM) fermions as preferred by recent $b\to s\ell^+\ell^-$ data and the anomalous magnetic moment of the muon.

In the second part of the talk we illustrate this generic approach for a UV complete model in which we supplement the Standard Model by a $4^{\rm th}$ generation of vector-like fermions and a real scalar field. This model allows one to coherently address the observed anomalies in $b\to s\ell^+\ell^-$ transitions and in $a_\mu$ without violating the bounds from other observables (in particular $B_s -\bar B_s$ mixing) or LHC searches. In fact, we find that our global fit to this model, after the recent experimental updates, is very good and prefers couplings to right-handed SM fermions.

### Primary authors

Pere Arnan (ICCUB)