Limits on the Decay-Rate Difference of Neutral B Mesons and on CP, T, and CPT Violation in B0-B0bar Oscillations

TL;DR

This study measures decay-rate differences and symmetry violations in neutral B mesons using 88 million Y(4S) decays, finding results consistent with the Standard Model.

Contribution

It provides the first precise measurements of decay-rate difference and CP, T, CPT violation parameters in B0-B0bar oscillations from a large data set.

Findings

Decay-rate difference consistent with zero

No significant CP, T, CPT violation observed

Results align with Standard Model predictions

Abstract

Using events in which one of two neutral B mesons from the decay of an Y(4S) meson is fully reconstructed, we determine parameters governing decay (\Delta\Gamma_d/\Gamma_d), CP and T violation (|q/p|), and CP and CPT violation (Rez,Imz). The results, obtained from an analysis of 88 million Y(4S) decays recorded by BABAR, are -- sgn(Re(lambdaCP))\Delta\Gamma_d/Gamma_d = -0.008 +- 0.037 +- 0.018 [ -0.084, 0.068 ] |q/p| = 1.029 +- 0.013 +- 0.011 [ 1.001, 1.057 ] Re(lambdaCP)/|lambdaCP| Rez = 0.014 +- 0.035 +- 0.034 [ -0.072, 0.101 ] Imz = 0.038 +- 0.029 +- 0.025 [ -0.028, 0.104 ]. -- The values inside square brackets indicate the 90% confidence-level intervals. These results are consistent with Standard Model expectations.