Measurement of the B0 Lifetime with Partially Reconstructed B0 --> D*- l+ nu Decays

TL;DR

This paper reports a precise measurement of the B0 meson lifetime using a large dataset and a partial reconstruction technique focusing on semileptonic decays, achieving a result with statistical and systematic uncertainties.

Contribution

It introduces a partial reconstruction method for B0 lifetime measurement using semileptonic decays, improving accuracy with a large data sample.

Findings

Measured B0 lifetime as 1.529 ps with uncertainties

Used partial reconstruction with lepton and slow pion

Analyzed 23 million BBbar pairs

Abstract

The B0 lifetime has been measured with a sample of 23 million BBbar pairs collected by the BaBar detector at the PEP-II e+e- storage ring during 1999 and 2000. Events from the semileptonic decay B0 --> D*- l+ nu have been selected with a partial reconstruction method in which only the charged lepton and the slow pion from the D*- --> D0bar pi- decay are reconstructed. The result is tau_B0 = 1.529+/-0.012 (stat) +/- 0.029 (syst) ps.