TestingCPTinvariance inBd0–B¯d0andBs0–B¯s0oscillations

Abstract

Recent CDF and D0 measurements of ${B}_{s}^{0}--{\overline{B}}_{s}^{0}$ mixing make it possible to search for $CP$ violation and test $CPT$ symmetry in a variety of ${B}_{s}$ decays. Considering both coherent ${B}_{d}^{0}{\overline{B}}_{d}^{0}$ decays at the $\ensuremath{\Upsilon}(4S)$ resonance and coherent ${B}_{s}^{0}{\overline{B}}_{s}^{0}$ decays at the $\ensuremath{\Upsilon}(5S)$ resonance, we formulate their time-dependent and time-integrated rates by postulating small $CPT$ violation in ${B}_{d}^{0}--{\overline{B}}_{d}^{0}$ and ${B}_{s}^{0}--{\overline{B}}_{s}^{0}$ oscillations. We show that the opposite-sign dilepton events from either $C$-odd or $C$-even ${B}_{q}^{0}{\overline{B}}_{q}^{0}$ states (for $q=d$ or $s$) can be used to determine or constrain the $CPT$-violating parameter at a super-$B$ factory. The possibility of distinguishing between the effect of $CPT$ violation and that of $\ensuremath{\Delta}B=\ensuremath{-}\ensuremath{\Delta}Q$ transitions is also discussed.