An Updated Study of B Meson Oscillations using Dilepton Events

TL;DR

This study measures B meson oscillation parameters using dilepton events from Z^0 decays, updating previous results with new data and providing precise measurements of the mass difference in the B^0_d system and a lower limit for B^0_s.

Contribution

It presents an updated measurement of B meson oscillations, including new data and refined analysis techniques for decay time reconstruction.

Findings

Measured Delta(m_d) as 0.430 +/- 0.043 + 0.028 - 0.030 ps^-1

Established a lower limit of Delta(m_s) > 2.2 ps^-1 at 95% C.L.

Improved precision over previous measurements.

Abstract

This paper reports a study of B meson oscillations using hadronic Z^0 decays with two identified leptons, and updates a previous publication by including data collected in 1994. Decay times are reconstructed for each of the semileptonic B decays by forming vertices which include the lepton and by estimating the B meson momentum. The mass difference, Delta(m_d), between the two mass eigenstates in the B^0_d system is measured to be 0.430 +/- 0.043 + 0.028 - 0.030 ps^-1, where the first error is statistical and the second error is systematic. For the B^0_s system, a lower limit of Delta(m_s) > 2.2 ps^-1 is obtained at 95% C.L.