A search for the charmless baryonic decay B+ → anti-Λ p anti-p p is performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 5.4 fb^−1. The branching fraction for this decay is measured for the first time relative to that of the topologically similar decay B+ → J/ψ K+, with J/ψ → anti-Λ p K−. The branching fraction is measured to be BF(B+ → anti-Λ p anti-p p) = (2.15 ± 0.35 ± 0.12 ± 0.28) × 10^−7, where the first uncertainty is statistical, the second is systematic, and the third arises from the uncertainty in the normalization channel branching fraction. The CP asymmetry is measured to be A_CP = (5.4 ± 15.6 ± 2.4)%, where the uncertainties are statistical and systematic. The background-subtracted invariant-mass distributions of anti-Λ p and anti-p p pairs exhibit pronounced enhancements at both kinematic thresholds, in contrast to a uniform phase-space distribution.

Aaij, R., Abdelmotteleb, A. s. w., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adefisoye, A. a., et al. (2025). First Observation of the Charmless Baryonic Decay B+ → anti-Λ p anti-p p. PHYSICAL REVIEW LETTERS, 135(26), 1-14 [10.1103/3pcs-dxtn].

First Observation of the Charmless Baryonic Decay B+ → anti-Λ p anti-p p

Bellavista, A.;Caporale, M.;Carbone, A.;Ferrari, F.;Galli, D.;Patrignani, C.;Spedicato, E.;Zenesini, F.;
2025

Abstract

A search for the charmless baryonic decay B+ → anti-Λ p anti-p p is performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 5.4 fb^−1. The branching fraction for this decay is measured for the first time relative to that of the topologically similar decay B+ → J/ψ K+, with J/ψ → anti-Λ p K−. The branching fraction is measured to be BF(B+ → anti-Λ p anti-p p) = (2.15 ± 0.35 ± 0.12 ± 0.28) × 10^−7, where the first uncertainty is statistical, the second is systematic, and the third arises from the uncertainty in the normalization channel branching fraction. The CP asymmetry is measured to be A_CP = (5.4 ± 15.6 ± 2.4)%, where the uncertainties are statistical and systematic. The background-subtracted invariant-mass distributions of anti-Λ p and anti-p p pairs exhibit pronounced enhancements at both kinematic thresholds, in contrast to a uniform phase-space distribution.
2025
Aaij, R., Abdelmotteleb, A. s. w., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adefisoye, A. a., et al. (2025). First Observation of the Charmless Baryonic Decay B+ → anti-Λ p anti-p p. PHYSICAL REVIEW LETTERS, 135(26), 1-14 [10.1103/3pcs-dxtn].
Aaij, R.; Abdelmotteleb, A.  s.  w.; Abellan Beteta, C.; Abudinén, F.; Ackernley, T.; Adefisoye, A.  a.; Adeva, B.; Adinolfi, M.; Adlarson, P.; Agapop...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1036900
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