Measurement of theB0−B0mixing rate withB0(B0)→D*∓π±partial reconstruction
Citations Over TimeTop 14% of 2003 papers
Abstract
We report a measurement of the ${B}^{0}\ensuremath{-}{B}^{0}$ mixing parameter $\ensuremath{\Delta}{m}_{d}$ based on a $29.1{\mathrm{fb}}^{\ensuremath{-}1}$ sample of $\ensuremath{\Upsilon}(4S)$ resonance decays collected by the Belle detector at the KEKB asymmetric ${e}^{+}{e}^{\ensuremath{-}}$ collider. We use events with a partially reconstructed ${B}^{0}({B}^{0})\ensuremath{\rightarrow}{D}^{*\ensuremath{\mp}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ candidate and where the flavor of the accompanying B meson is identified by the charge of the lepton from a ${B}^{0}({B}^{0})\ensuremath{\rightarrow}{X}^{\ensuremath{\mp}}{\mathcal{l}}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\nu}$ decay. The proper-time difference between the two B mesons is determined from the distance between the two decay vertices. From a simultaneous fit to the proper-time distributions for the same-flavor $({B}^{0}({B}^{0}),{\mathcal{l}}^{\ifmmode\pm\else\textpm\fi{}})$ and opposite-flavor $({B}^{0}({B}^{0}),{\mathcal{l}}^{\ensuremath{\mp}})$ event samples, we measure the mass difference between the two mass eigenstates of the neutral B meson to be $\ensuremath{\Delta}{m}_{d}=(0.509\ifmmode\pm\else\textpm\fi{}0.017(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.020(\mathrm{syst})){\mathrm{ps}}^{\ensuremath{-}1}.$