非表示:
キーワード:
High Energy Physics - Experiment, hep-ex
MPINP:
LHCb - Abteilung Hinton
要旨:
Decays of $B^0$ and $B_{s}^0$ mesons to the charmless baryonic final states
$p \overline{p} h^+ h^{\prime-}$, where $h$ and $h^\prime$ each denote a kaon
or a pion, are searched for using the LHCb detector. The analysis is based on a
sample of proton-proton collision data collected at center-of-mass energies of
$7$ and $8\,$TeV, corresponding to an integrated luminosity of $3\,$fb$^{-1}$.
Four-body charmless baryonic $B_{s}^0$ decays are observed for the first time.
The decays $B^0_{s}\to p \overline{p} K^+ K^-$, $B^0_{s}\to p \overline{p}
K^\pm \pi^\mp$, $B^0\to p \overline{p} K^\pm \pi^\mp$ and
$B^0\to p \overline{p} \pi^+\pi^-$ are observed with a significance greater
than $5$ standard deviations; evidence at $4.1$ standard deviations is found
for the $B^0\to p \overline{p} K^+ K^-$ decay and an upper limit is set on the
branching fraction for $B^0_{s}\to p \overline{p} \pi^+ \pi^-$. Branching
fractions in the kinematic region $m(p \overline{p})<2850\,$MeV$/c^2$ are
measured relative to the $B^0 \to J/\psi (\to p \overline{p}) K^*(892)^0$
channel.