A search for the charmless baryonic decay B+→Λ¯pp¯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/ψK+, with J/ψ→Λ¯pK-. The branching fraction is measured to be B(B+→Λ¯pp¯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 ACP=(5.4±15.6±2.4)%, where the uncertainties are statistical and systematic. The background-subtracted invariant-mass distributions of Λ¯p and p¯p pairs exhibit pronounced enhancements at both kinematic thresholds, in contrast to a uniform phase-space distribution.

First Observation of the Charmless Baryonic Decay B+ → (Λ)over-barp(p)over-barp / R. Aaij, A. . .A.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 135:26(2025 Dec 22), pp. 261901.1-261901.14. [10.1103/3pcs-dxtn]

First Observation of the Charmless Baryonic Decay B+ → (Λ)over-barp(p)over-barp

S. Cesare;C. Mancuso;D. Marangotto;A. Merli;N. Neri;G. Tonani;T. Tork;Z. Wang;
2025

Abstract

A search for the charmless baryonic decay B+→Λ¯pp¯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/ψK+, with J/ψ→Λ¯pK-. The branching fraction is measured to be B(B+→Λ¯pp¯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 ACP=(5.4±15.6±2.4)%, where the uncertainties are statistical and systematic. The background-subtracted invariant-mass distributions of Λ¯p and p¯p pairs exhibit pronounced enhancements at both kinematic thresholds, in contrast to a uniform phase-space distribution.
Settore PHYS-01/A - Fisica sperimentale delle interazioni fondamentali e applicazioni
   European Particle physics Latin American NETwork
   EPLANET
   European Commission
   SEVENTH FRAMEWORK PROGRAMME - SP3-People - Marie-Curie Actions
   246806
22-dic-2025
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/1251302
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