Measurements of Direct CP Violating Asymmetries in Charmless Decays of Strange Bottom Mesons and Bottom Baryons

TL;DR

This paper reports the first measurements of direct CP violation in bottom strange mesons and bottom baryons, using data from the Fermilab Tevatron, and confirms CP violation in Bd-->Kpi decays with high significance.

Contribution

It provides the first measurements of direct CP violation in bottom strange mesons and bottom baryons, expanding the understanding of CP asymmetries in these particles.

Findings

First measurement of CP violation in bottom strange mesons (BsKpi).

First measurement of CP violation in bottom baryons (Lb decays).

Confirmed CP violation in Bd-->Kpi decays with 3.5 sigma significance.

Abstract

We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb-1 of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A_CP(BsKpi) = +0.39 +- 0.15 stat +- 0.08 syst, and bottom baryons, A_CP(Lb->ppi) = +0.03 +- 0.17 stat +- 0.05 syst and A_CP(Lb->pK) = +0.37 +- 0.17 +- 0.03 syst. In addition, we measure CP violation in Bd-->Kpi decays with 3.5sigma significance, A_CP(B->Kpi) = -0.086 +- 0.023 stat +- 0.009 syst, in agreement with the current world average. Measurements of branching fractions of Bs-->K+K- and B0-->pi+pi- decays are also updated.