First Physics Results From Belle

TL;DR

This paper presents initial physics results from the Belle experiment, including B meson branching ratios and a preliminary measurement of the CP violation parameter sin(2phi_1), based on 6.2 fb^{-1} of data at the Upsilon(4S) resonance.

Contribution

It reports the first physics results from Belle, notably new B meson measurements and an early CP violation measurement at KEK-B.

Findings

Measurement of B meson branching ratios.

Preliminary value of sin(2phi_1) = 0.45.

Data sample of 6.2 fb^{-1} collected at Upsilon(4S).

Abstract

The Belle detector at the KEK-B asymmetric $e^{+}e^{-}$ collider has recorded 6.2 fb$^{-1}$ data at the $\Upsilon(4S)$ resonance by July 2000. Using this data sample, several new results on various B meson branching ratio measurements are presented. We also report on the measurement of the Standard Model CP violation parameter $\sin(2\phi_{1})$, where $\phi_{1}$ is one of angles of the CKM triangle. The preliminary result is $\sin(2\phi_{1})$ = $0.45^{+0.43 \pm 0.07}_{-0.44 \pm 0.08}$.