Improved constraints on $\gamma$: CKM2014 update

TL;DR

This paper presents an updated, highly precise measurement of the CKM angle gamma from LHCb data, achieving the most accurate value to date with uncertainty below 10 degrees, advancing our understanding of quark mixing.

Contribution

It provides the first single-experiment measurement of gamma with uncertainty below 10 degrees, improving the precision of CKM parameter constraints.

Findings

Most precise gamma value: (73^{+9}_{-10}) degrees.

Uncertainty in gamma has dropped below 10 degrees.

Inclusion of B→Dπ decays complicates interpretation.

Abstract

I report on an updated combination of all currently available tree-level measurements of the CKM angle $\gamma$ from LHCb. This combination currently gives LHCb's most precise value of $\gamma = (73^{+9}_{-10})^\circ$ obtained from $B\to DK$-like decays. For the first time in a single experiment, the uncertainty has dropped below $10^\circ$. When using $B\to D\pi$ decays in addition, the situation becomes more difficult to interpret.