Limits on the Decay-Rate Difference of Neutral-B Mesons and on CP, T, and CPT Violation in B0-antiB0 Oscillations

TL;DR

This paper sets limits on decay-rate differences and CP, T, and CPT violation in B0-antiB0 oscillations using a large dataset from the BABAR experiment, confirming Standard Model predictions.

Contribution

It provides the first comprehensive limits on decay-rate differences and violation parameters in B0-antiB0 mixing with high statistical precision.

Findings

No significant decay-rate difference observed.

Results consistent with Standard Model expectations.

Tight bounds on CP, T, and CPT violation parameters.

Abstract

Using events in which one of two neutral-B mesons from the decay of an Y(4S) resonance is fully reconstructed, we set limits on the difference between the decay rates of the two neutral-B mass eigenstates and on CP, T, and CPT violation in B0-antiB0 mixing. The reconstructed decays, comprising both CP and flavor eigenstates, are obtained from 88 million Y(4S) --> Banti-B decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We determine six independent parameters governing oscillations (Deltam, DeltaGamma/Gamma), CPT and CP violation (Re Z, Im Z), and CP and T violation (Im lambdaCP, |q/p|), where lambdaCP characterizes B0 and anti-B0 decays to states of charmonium plus K0S or K0L. The results are sgn(Re lambdaCP)xDeltaGamma/Gamma = -0.008 +/- 0.037(stat) +/- 0.018(syst) [-0.084,0.068], |q/p| = 1.029 +/- 0.013(stat) +/- 0.011(syst) [ 1.001,1.057], (Re lambdaCP)/|lambdaCP|xRe z = 0.014 +/- 0.035(stat) +/- 0.034(syst) [-0.072,0.101], Im z = 0.038 +/- 0.029(stat) +/- 0.025(syst) [-0.028,0.104], The values inside square brackets indicate the 90% confidence-level intervals. The values of Im lambdaCP and Deltam are consistent with previous analyses and are used as cross-checks. These measurements are in agreement with Standard Model expectations.