A Measurement of CP Asymmetry in b->sgamma using a Sum of Exclusive Final States

TL;DR

This paper measures the CP asymmetry in b->sgamma decays using exclusive final states, providing a precise estimate consistent with the Standard Model, based on data from the BABAR detector.

Contribution

It presents the first measurement of CP asymmetry in b->sgamma decays using a sum of exclusive final states with improved accuracy.

Findings

CP asymmetry measured as -0.011±0.030(stat)±0.014(syst)

Results are consistent with Standard Model predictions

Analysis uses 383 BB events from BABAR detector

Abstract

We perform a measurement of the CP asymmetry in b->sgamma decays using a sample of 383 BB events collected by the BABAR detector at the PEP-II asymmetric B factory. We reconstruct sixteen flavor-specific B decay modes containing a high-energy photon and a hadronic system (Xs) containing an s quark. We measure the \CP asymmetry to be -0.011+/- 0.030(stat)+/-0.014(syst) for a photon energy threshold at 1.6 GeV and the hadronic system mass between 0.6 and 2.8 GeV/c2.