Measurement of CP violating phase $\phi_s$ and control of penguin pollution at LHCb

TL;DR

This paper reports on LHCb measurements of the CP-violating phase _s in _s oscillations, discusses potential New Physics signals, and introduces a method to estimate penguin diagram contributions affecting these measurements.

Contribution

It presents the latest LHCb results on _s phase using specific decay channels and proposes a new approach to estimate penguin pollution in _s measurements.

Findings

Measured _s phase using _s _KK and _s _pipi channels.

Provided branching fractions and upper limits for _d Kshh modes.

Outlined a method to estimate penguin diagram contributions.

Abstract

The study of CP violation in \Bs\, oscillations is a key measurement at the LHCb experiment. In this document, we discuss the latest LHCb results on the CP-violating phase, called $\phi_s$, using \BsJKK\, and \BsJpipi\, channels. To conclude on the presence of New Physics in $\phi_s$, the estimation of the sub-dominant contributions from the Standard Model becomes crucial now. We outline a method to estimate the contribution of penguin diagrams in $\phi_s$. Branching fractions and upper limits of \BdKshh\,($ h^{(')}=K,\pi)$\, modes are presented.