Study of CP violation in $B^\pm$ decays to $\overline{D^0}(D^0) K^\pm$ at FCCee

TL;DR

This paper explores measuring the CP-violating angle gamma_s in B meson decays at FCCee, aiming to improve understanding of CP violation through precise triangle angle measurements in flavor physics.

Contribution

It proposes a method to directly measure the angle gamma_s using specific B decay modes, with an estimated resolution of about 1 degree, enhancing CP violation studies.

Findings

Potential to measure gamma_s with ~1° precision

Feasibility of using B± decays to D0(K) for gamma_s

Supports further tests of the CKM matrix unitarity

Abstract

The great progress made recently in the sector of Flavor Physics has enabled to establish CP violation in the B-meson decays. The unitarity triangle derived from the unitarity relation $V_{ub}^* V_{ud} + V_{cb}^* V_{cd} + V_{tb}^* V_{td} = 0$ has been measured very precisely. To further asses our understanding of CP violation, it would be useful to carry out similar measurement of other triangles. In this note, we investigate the triangle derived from the relation $V_{ub}^* V_{us} + V_{cb}^* V_{cs} + V_{tb}^* V_{ts} = 0$. Two angles of this triangle ($\alpha_s$ and $\beta_s$) could be measured very accurately at FCCee using the decays $B_s(\overline{B_s})\rightarrow D^\pm_sK^\mp$ and $B_s(\overline{B_s})\rightarrow J/\psi \phi$ respectively, as discussed elsewhere by us. This note concentrates on the measurement of the third angle $\gamma_s$ using the modes $B^\pm \to \overline{D^0}(D^0)K^\pm$. We show that a direct measurement of the angle $\gamma_s$ is possible with some specific $B^\pm$ decays with an estimated resolution of the order of 1$^\circ$.