# Measurement of $\phi_s$ and $\Delta\Gamma_s$ at LHCb

## TL;DR

This paper reviews the measurement of the $\phi_s$ and $\Delta\Gamma_s$ parameters at LHCb, which are crucial for testing the Standard Model and searching for new physics through $CP$ violation in $\bar{b}\to\bar{c}c\bar{s}$ decays.

## Contribution

It provides a comprehensive review of the LHCb measurements of $\phi_s$ and $\Delta\Gamma_s$ using 3.0 fb$^{-1}$ of data, including future prospects with additional decay modes.

## Key findings

- Measured $\phi_s$ and $\Delta\Gamma_s$ consistent with Standard Model predictions.
- Results from 3.0 fb$^{-1}$ dataset analyzed.
- Potential for improved precision with additional decay modes.

## Abstract

Determination of the mixing-induced $C\!P$-violating phase $\phi_{s}$ and decay width difference $\Delta\Gamma_{s}$ in $\bar{b}\to\bar{c}c\bar{s}$ decays is one of the main goals of the LHCb experiment. Thanks to the precise prediction of the $\phi_{s}$ value within the Standard Model, it represents an excellent probe to search for new physics. The measurements of $\phi_{s}$ and $\Delta\Gamma_{s}$ at LHCb are reviewed including results from the 3.0~fb$^{-1}$ dataset accumulated during 2011-2012. Further measurement improvement is expected from the inclusion of results obtained using decay modes with smaller branching fraction.