Measurement of the B0bar Lifetime and the B0B0bar Oscillation Frequency Using Partially Reconstructed B0bar --> D*+ ell- nu-bar Decays

TL;DR

This paper reports a precise measurement of the B0 meson lifetime and oscillation frequency using a large sample of partially reconstructed decays at the BABAR experiment, providing key parameters for understanding B meson behavior.

Contribution

The study presents the first simultaneous measurement of B0 lifetime and oscillation frequency using partially reconstructed decays with high statistical precision.

Findings

B0 lifetime measured as 1.504 ps with small uncertainties

Oscillation frequency Delta_md measured as 0.511 ps^-1

Results are consistent with previous measurements and improve precision

Abstract

We present a simultaneous measurement of the B0bar lifetime tau_B0 and B0B0bar oscillation frequency Delta_md. We use a sample of about 50000 partially reconstructed B0bar --> D*+ ell- nu-bar decays identified with the BABAR detector at the PEP-II e+e- storage ring at SLAC. The flavor of the other B meson in the event is determined from the charge of another high-momentum lepton. The results are tau_B0 = (1.504 +/- 0.013 (stat) {+0.018}/{-0.013} (syst)) ps, Delta_md = (0.511 +/- 0.007 (stat) {+0.007}/{-0.006} (syst)) ps-1