Studies of the decays $B^+ \to p \bar p h^+$ and observation of $B^+ \to \kern 0.1em\bar{\kern -0.1em\Lambda}(1520)p$

TL;DR

This paper investigates the decay dynamics and $C ext{P}$ violation in three-body charmless $B^+$ decays, reports no significant asymmetry, and presents the first observation of the decay $B^+ o ar{ ext{Λ}}(1520)p$ with a measured branching fraction.

Contribution

It provides the first observation of the decay $B^+ o ar{ ext{Λ}}(1520)p$ and measures its branching fraction, expanding understanding of $B$ meson decay modes.

Findings

No significant $C ext{P}$ asymmetry observed in $B^+ o p ar p K^+$ decays.

First observation of $B^+ o ar{ ext{Λ}}(1520)p$ decay.

Measured branching fraction of $B^+ o ar{ ext{Λ}}(1520)p$ as $(3.9^{+1.0}_{-0.9} ext{(stat)} \pm0.1 ext{(syst)} \pm0.3 ext{(BF)}) imes 10^{-7}$.

Abstract

Dynamics and direct $C\P$ violation in three-body charmless decays of charged $B$ mesons to a proton, an antiproton and a light meson (pion or kaon) are studied using data, corresponding to an integrated luminosity of 1.0$ {\,fb}^{-1}$, collected by the ${LHCb}$ experiment in $pp$ collisions at a center-of-mass energy of 7 TeV. Production spectra are determined as a function of Dalitz-plot and helicity variables. The forward-backward asymmetry of the light meson in the $p\bar p$ rest frame is measured. No significant $C\P$ asymmetry in $B^+ \to p \bar p K^+$ decay is found in any region of the Dalitz plane. We present the first observation of the decay $B^+ \to \kern 0.1em\bar{\kern -0.1em\Lambda}(1520)(\to K^+\bar p)p$ near the $K^+\bar p$ threshold and measure $\mathcal{B}(B^+ \to \kern 0.1em\bar{\kern -0.1em\Lambda}(1520)p)=(3.9^{+1.0}_{-0.9} (\mathrm{stat})\pm0.1 (\mathrm{syst})\pm0.3 (\mathrm{BF}))\times 10^{-7}$, where BF denotes the uncertainty on secondary branching fractions.