Measurement of the CKM angle $\gamma$ with $ B^\pm \to D[K^\mp \pi^\pm \pi^\pm \pi^\mp] h^\pm$ decays using a binned phase-space approach

TL;DR

This paper measures the CKM angle gamma using B meson decays into D mesons with a binned phase-space approach, utilizing LHCb data from multiple energies to achieve a precise determination.

Contribution

It introduces a binned phase-space method for measuring gamma in B decays involving D mesons, improving precision with extensive LHCb data.

Findings

Gamma measured as (54.8 +6.0/-5.8 +0.6/-0.6 +6.7/-4.3) degrees

First application of binned phase-space approach in this decay channel

Results consistent with Standard Model predictions

Abstract

The CKM angle $\gamma$ is determined from $C\!P$-violating observables measured in ${B^\pm \to D[ K^\mp \pi^\pm\pi^\pm\pi^\mp] h^\pm}$, $(h = K,\pi)$ decays, where the measurements are performed in bins of the decay phase-space of the $D$ meson. Using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of $7, 8$ and $13\,\text{TeV}$, corresponding to a total integrated luminosity of $9\,\text{fb}^{-1}$, $\gamma$ is determined to be \begin{equation*} \gamma = \left( 54.8 \: ^{+\:6.0 }_{-\:5.8} \: ^{+\:0.6}_{-\:0.6} \: ^{+\:6.7}_{-\:4.3} \right)^\circ, \end{equation*} where the first uncertainty is statistical, the second systematic and the third from the external inputs on the coherence factors and strong phases of the $D$-meson decays.