Measurement of the Polarization in the Decays Bd→J/ψK*0 and Bs→J/ψφ

Le résumé fourni par la source

This Letter reports on measurements of the longitudinal polarization fractions in the decays ${B}_{d}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{*0}$ and ${B}_{s}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\varphi}$ using data collected with the Collider Detector at Fermilab. ${B}_{d}$ mesons are reconstructed through the decay chain ${B}_{d}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{*0}$, $J/\ensuremath{\psi}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, ${K}^{*0}\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$. A sample of $65\ifmmode\pm\else\textpm\fi{}10{B}_{d}$ events is used to obtain a longitudinal polarization fraction of ${\ensuremath{\gamma}}_{L}/\ensuremath{\gamma}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.65\ifmmode\pm\else\textpm\fi{}0.10(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.04(\mathrm{syst})$. ${B}_{s}$ mesons are reconstructed through the decay chain ${B}_{s}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\varphi}$, $J/\ensuremath{\psi}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, $\ensuremath{\varphi}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}$. A sample of $19\ifmmode\pm\else\textpm\fi{}5{B}_{s}$ events is used to obtain the result ${\ensuremath{\gamma}}_{L}/\ensuremath{\gamma}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.56\ifmmode\pm\else\textpm\fi{}0.21(\mathrm{stat}{)}_{\ensuremath{-}0.04}^{+0.02}(\mathrm{syst})$.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.