Measurement of sin2phi_1 at Belle

TL;DR

This paper reports the first measurement of sin 2φ_1 using 6.2 fb^-1 of data from Belle, analyzing B meson decays to charmonia and kaon channels to explore CP violation.

Contribution

It presents the initial measurement of sin 2φ_1 at Belle, employing a novel analysis of B meson decay time distributions with flavor tagging.

Findings

Measured sin 2φ_1 = 0.45 with large statistical uncertainty

First measurement of this parameter at Belle

Method involves fitting proper time distributions of B decays

Abstract

With 6.2 fb^-1 of data collected on the Upsilon(4S), Belle reports its first measurement of sin 2\phi_1 = 0.45^{+0.43}_{-0.44}(stat)^{+0.07}_{-0.09}(sys). The result was obtained by fitting the proper time distribution of flavor tagged and fully reconstructed neutral B mesons decays to five different charmonia plus a Kshort or Klong channels. In this paper the analysis and results will be described briefly.