May 29, 2018 to June 3, 2018
Hyatt Regency Indian Wells Conference Center
US/Pacific timezone

Combined Measurement of the CP Violating Angle $\beta$ by the BaBar and Belle Experiments

May 30, 2018, 2:30 PM
South Foyer | Ocotillo Room (Hyatt Regency Indian Wells Conference Center)

South Foyer | Ocotillo Room

Hyatt Regency Indian Wells Conference Center

44600 Indian Wells Lane, Indian Wells, CA 92210, USA


Dr Tomonari Miyashita (Caltech)


We present a recent joint measurement of the CP violating angle $\beta$ using 1.1 inverse attobarns of data collected by the BaBar and Belle experiments. This analysis is based on a time-dependent Dalitz plot analysis of $B\to D^\star h^0$ with $D\to K^0_S\pi^+\pi^−$ decays. These decays provide experimental access to cos(2$\beta$) as well as sin(2$\beta$), and can therefore resolve an ambiguity in the determination of the apex of the CKM Unitarity Triangle. As part of the analysis, a full Dalitz plot amplitude analysis of $D\to K^0_S\pi^+\pi^−$ is performed on a high-statistics charm data set. We report the first evidence for cos(2$\beta$)>0, an observation of CP violation, and the exclusion of the second solution of the CKM Unitarity Triangle of $\beta=68.1\pm0.7$ degrees at a significance of 7.3 standard deviations.
E-mail [email protected]
Collaboration name BaBar and Belle

Primary author

Presentation materials