TY  - JOUR
AU  - LHCb Collaboration (Aaij, R. et al
AU  - Jashal, B. K.
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
AU  - Remon Alepuz, C.
AU  - Ruiz Vidal, J.
PY  - 2021
DA  - 2021//
TI  - Observation of a Lambda(0)(b) – (Lambda)over-bar(b)(0) production asymmetry in proton-proton collisions at root s=7 and 8 TeV
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 060
EP  - 38pp
VL  - 10
IS  - 10
PB  - Springer
KW  - Hadron-Hadron scattering (experiments)
KW  - Heavy quark production
KW  - proton-proton scattering
KW  - Hard scattering
KW  - B physics
AB  - This article presents differential measurements of the asymmetry between Lambda(0)(b) and (Lambda) over bar (0)(b) baryon production rates in proton-proton collisions at centre-of-mass energies of root s = 7 and 8 TeV collected with the LHCb experiment, corresponding to an integrated luminosity of 3 fb(-1). The Lambda(0)(b) baryons are reconstructed through the inclusive semileptonic decay Lambda(0)(b) -> Lambda(+)(c) mu(-)(nu) over bar X-mu. The production asymmetry is measured both in intervals of rapidity in the range 2:15 < y < 4:10 and transverse momentum in 2 < p T < 27 GeV/c. The results are found to be incompatible with symmetric production with a significance of 5.8 standard deviations for both root 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.
SN  - 1029-8479
UR  - https://arxiv.org/abs/2107.09593
UR  - https://doi.org/10.1007/JHEP10(2021)060
DO  - 10.1007/JHEP10(2021)060
LA  - English
N1  - WOS:000705235400002
ID  - LHCbCollaborationAaij_etal2021
ER  -