This article presents differential measurements of the asymmetry between Λb0 and Λ¯b0 baryon production rates in proton-proton collisions at centre-of-mass energies of s = 7 and 8 TeV collected with the LHCb experiment, corresponding to an integrated luminosity of 3 fb−1. The Λb0 baryons are reconstructed through the inclusive semileptonic decay Λb0 → Λc+μ−ν¯ μX. The production asymmetry is measured both in intervals of rapidity in the range 2.15 < y < 4.10 and transverse momentum in 2 < pT< 27 GeV/c. The results are found to be incompatible with symmetric production with a significance of 5.8 standard deviations for both s = 7 and 8 TeV data, assuming no CP violation in the decay. There is evidence for a trend as a function of rapidity with a significance of 4 standard deviations. Comparisons to predictions from hadronisation models in Pythia and heavy-quark recombination are provided. This result constitutes the first observation of a particle-antiparticle asymmetry in b-hadron production at LHC energies. [Figure not available: see fulltext.]

Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., et al. (2021). Observation of a Λb0 − Λ¯b0 production asymmetry in proton-proton collisions at √s = 7 and 8 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2021(10) [10.1007/JHEP10(2021)060].

Observation of a Λb0 − Λ¯b0 production asymmetry in proton-proton collisions at √s = 7 and 8 TeV

Borsato M.;Calvi M.;Capelli S.;Carniti P.;Fazzini D.;Garcia Pardinas J.;Gotti C.;Martinazzoli L.;Martinelli M.;Meloni S.;Minotti A.;Petruzzo M.;Salomoni M.;Shields E. B.;
2021

Abstract

This article presents differential measurements of the asymmetry between Λb0 and Λ¯b0 baryon production rates in proton-proton collisions at centre-of-mass energies of s = 7 and 8 TeV collected with the LHCb experiment, corresponding to an integrated luminosity of 3 fb−1. The Λb0 baryons are reconstructed through the inclusive semileptonic decay Λb0 → Λc+μ−ν¯ μX. The production asymmetry is measured both in intervals of rapidity in the range 2.15 < y < 4.10 and transverse momentum in 2 < pT< 27 GeV/c. The results are found to be incompatible with symmetric production with a significance of 5.8 standard deviations for both s = 7 and 8 TeV data, assuming no CP violation in the decay. There is evidence for a trend as a function of rapidity with a significance of 4 standard deviations. Comparisons to predictions from hadronisation models in Pythia and heavy-quark recombination are provided. This result constitutes the first observation of a particle-antiparticle asymmetry in b-hadron production at LHC energies. [Figure not available: see fulltext.]
Articolo in rivista - Articolo scientifico
B physics; Hadron-Hadron scattering (experiments); Hard scattering; Heavy quark production; proton-proton scattering;
English
7-ott-2021
2021
2021
10
60
open
Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., et al. (2021). Observation of a Λb0 − Λ¯b0 production asymmetry in proton-proton collisions at √s = 7 and 8 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2021(10) [10.1007/JHEP10(2021)060].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/362686
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