A measurement of the B^0-anti-B^0 oscillation frequency and determination of flavor-tagging efficiency using semileptonic and hadronic B^0 decays

TL;DR

This paper measures the B^0-anti-B^0 oscillation frequency and evaluates flavor-tagging efficiency using data from the BABAR detector, providing key parameters for understanding B meson behavior.

Contribution

It presents the first measurement of the B^0-anti-B^0 oscillation frequency and characterizes flavor-tagging performance in a comprehensive way.

Findings

Oscillation frequency Delta_md = 0.512+/-0.017+/-0.022 ps^{-1}

Flavor-tagging efficiency and mis-identification probabilities quantified

Methodology for flavor tagging in B meson decays established

Abstract

B^0-anti-B^0 flavor oscillations are studied in e^+e^- annihilation data collected with the BABAR detector at center-of-mass energies near the Y(4S) resonance. One B is reconstructed in a hadronic or semileptonic decay mode, and the flavor of the other B in the event is determined with a tagging algorithm that exploits the relation between the flavor of the heavy quark and the charges of its decay products. Tagging performance is characterized by an efficiency e_i and a probability for mis-identification, w_i, for each tagging category. We report a determination of the wrong-tag probabilities, w_i, and a preliminary result for the time-dependent B^0-anti-B^0 oscillation frequency, Delta_md = 0.512+/-0.017+/-0.022 hbar-ps^{-1}.