Measurement of gamma in B-+ -> D(*) K-+ and B-+ -> D K*-+ decays with a Dalitz analysis of D -> Ks pi- pi+

TL;DR

This paper measures the CP-violating phase gamma in B meson decays using a Dalitz plot analysis of D meson decays, providing a value with associated uncertainties from a large data sample.

Contribution

It presents a novel measurement of gamma using Dalitz analysis of D decays from B mesons, including detailed uncertainty evaluation and model considerations.

Findings

Measured gamma = 67 +/- 28 +/- 13 +/- 11 degrees

Dalitz model uncertainty due to pipi S-wave is 3 degrees

Result has a two-fold ambiguity in gamma

Abstract

We present a measurement of the Cabibbo-Kobayashi-Maskawa CP-violating phase gamma with a Dalitz plot analysis of neutral D-meson decays to the Ks pi- pi+ final state from B-+ -> D(*) K-+ and B-+ -> D K*-+ decays, using a sample of 227 million BBbar pairs collected by the BaBar detector. We measure gamma = 67 +/- 28 +/- 13 +/- 11, where the first error is statistical, the second is the experimental systematic uncertainty and the third reflects the Dalitz model uncertainty. This result suffers from a two-fold ambiguity. The contribution to the Dalitz model uncertainty due to the description of the pipi S-wave in D0 -> Ks pi- pi+, evaluated using a K-matrix formalism, is found to be 3 degrees.