Observation and study of the baryonicB-meson decaysB→D(*)pp¯

Abstract

We present results for B-meson decay modes involving a charm meson, protons, and pions using 455×10 6 BB pairs recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy e + e − collider. The branching fractions are measured for the following ten decays:, and B − →D * + ppπ − π − . The four B − and the two five-body B 0 modes are observed for the first time. The four-body modes are enhanced compared to the three-and the five-body modes. In the three-body modes, the M (pp) and M (D ( * )0 p) invariant mass distributions show enhancements near threshold values. In the four-body mode B 0 →D + ppπ − , the M (pπ − ) distribution shows a narrow structure of unknown origin near 1.5 GeV/c 2 . The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.

Search for the decay mode B0→ppp¯pLees1, Poireau2, Tisserand3 et al. 2018Phys. Rev. DSelf Cite122230View full textAdd to dashboardCite

“…It has been observed that, despite the phase space expectation, many three-body decays to one baryonantibaryon pair plus an accompanying meson have larger rates than their two-body counterpart, which is the decay to the same baryon-antibaryon pair but with no other particles in the final state, e.g., [11]. Also, some three-body decays are suppressed compared to the fourbody case [12,13]. The phenomenological approaches describe these observations in terms of gluonic and fragmentation mechanisms [14] and pole models [15].…”

First Observation of a BaryonicBc+Decay

“…Baryonic decays of B mesons provide good opportunities to study the mechanism of baryon production and to search for excited baryon resonances [13][14][15]. The observation of intriguing behavior in the baryonic decays of the B 0 and B þ mesons, e.g., the enhancements of the rate of multibody decays and the production of baryon pairs of low mass [16][17][18][19][20][21][22], has further motivated this study.…”

Search for the decayB¯0→ΛcLees1, Poireau2, Tisserand3 et al. 2014Phys. Rev. DSelf Cite212280View full textAdd to dashboardCite

“…This phenomenon is known as threshold enhancement and describes the dynamically enhanced decay rate at the baryon-antibaryon-mass threshold. It has been observed in baryonic B decays with open charm final states [5][6][7][8], charmless baryonic B decays [9] and in the decay J=ψ → γpp [10]. An example where the decay with the smaller PS is preferred is the ratio of…”