Search for CP violation In B0-B0bar mixing using partial reconstruction of B0bar -> D*+Xl-nubar and kaon tagging

TL;DR

This paper reports a measurement of CP violation in B0-B0bar mixing using a novel partial reconstruction technique and kaon tagging, analyzing 425.7 fb-1 of data from the BABAR experiment, resulting in a CP asymmetry consistent with zero.

Contribution

It introduces a new partial reconstruction method combined with kaon tagging for measuring CP violation in B0-B0bar mixing.

Findings

Measured CP asymmetry ACP = (0.0006 +- 0.0017 + 0.0038 - 0.0032)

Result is consistent with no CP violation, competitive with other B factory measurements

Utilized a large dataset of 425.7 fb-1 from BABAR

Abstract

We describe in detail a previously published measurement of CP violation induced by B0-anti B0 oscillations, based on an integrated luminosity of 425.7 fb-1 collected by the BABAR experiment at the PEPII collider. We apply a novel technique to a sample of about 6 million B0bar -> D*+ l- nubar decays selected with partial reconstruction of the D*+ meson. The charged lepton identifies the flavor of one B meson at its decay time, the flavor of the other B is determined by kaon tagging. We determine a CP violating asymmetry ACP = (0.0006 +- 0.0017 + 0.0038 - 0.0032). This measurement is consistent and competitive with those obtained at the B factories with dilepton events.