Simultaneous determination of CKM angle $\gamma$ and charm mixing parameters

TL;DR

This paper combines measurements from charm and beauty sectors to simultaneously determine the CKM angle gamma and charm mixing parameters, achieving the most precise gamma measurement from a single experiment and significantly improving charm mixing precision.

Contribution

It introduces a novel combined analysis method that simultaneously extracts gamma and charm mixing parameters using LHCb data, enhancing precision over previous separate measurements.

Findings

Charm mixing parameters: x = (0.400^{+0.052}_{-0.053})% and y = (0.630^{+0.033}_{-0.030})%

CKM angle gamma: (65.4^{+3.8}_{-4.2})^ extdegree, most precise from a single experiment

Improved charm mixing parameter y precision by a factor of two

Abstract

A combination of measurements sensitive to the $CP$ violation angle $\gamma$ of the Cabibbo-Kobayashi-Maskawa unitarity triangle and to the charm mixing parameters that describe oscillations between $D^0$ and $\bar{D}^0$ mesons is performed. Results from the charm and beauty sectors, based on data collected with the LHCb detector at CERN's Large Hadron Collider, are combined for the first time. This method provides an improvement on the precision of the charm mixing parameter $y$ by a factor of two with respect to the current world average. The charm mixing parameters are determined to be $x = (0.400^{\,+0.052}_{\,-0.053})\%$ and $y = (0.630^{\,+0.033}_{\,-0.030})\%$. The angle $\gamma$ is found to be $\gamma = (65.4^{\,+3.8}_{\,-4.2})^\circ$ and is the most precise determination from a single experiment.