Measurement of the CP-violation Parameter sin2${\varphi }_1$ with a New Tagging Method at the ${\rm Y}(5S)$ Resonance

Belle Collaboration, Y. Sato, H. Yamamoto +160

We report a measurement of the CP-violation parameter sin2${\varphi }_1$ at the ${\rm Y}(5S)$ resonance using a new tagging method, called "$B$-$\pi$ tagging." In ${\rm Y}(5S)$ decays containing a neutra…