First Physics Results at BABAR

TL;DR

This paper reports the initial physics results from the BABAR experiment, including measurements of CP violation parameter sin2beta, B meson lifetimes, and oscillation frequency, based on early data collected at the Y(4S) resonance.

Contribution

It provides the first measurements of sin2beta, B meson lifetimes, and oscillation frequency using data from the BABAR detector at SLAC.

Findings

Preliminary sin2beta = 0.12 ± 0.37 (stat) ± 0.09 (syst)

Measured B meson lifetimes and oscillation frequency

Demonstrated the capability of BABAR for CP violation studies

Abstract

The BABAR detector, which operates at the SLAC PEP-II asymmetric e^+e^- collider at energies near the Y(4S) resonance, started operation on the 26th of May 1999. We present the first study of sin2beta, with samples of B0 --> J/psi K0S and B0 --> psi(2S) K0S decays, using 9.0 fb-1 of data recorded between January and July 2000 at the Y(4S) resonance and 0.8 fb-1 recorded 40 MeV below the Y(4S) resonance. A preliminary result of sin2beta = 0.12+/-0.37 (stat) +/- 0.09 (syst) was obtained. Details of the analysis are given. Moreover, we present measurements of charged and neutral B meson lifetimes and B^0 B^0bar oscillation frequency.