Observation of a Λ0b − ̄ Λ0b production asymmetry in proton-proton collisions at √s=7 and 8 TeV

Abstract: This article presents differential measurements of the asymmetry between Λ0b and Λ0b 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 Λ0b baryons ar...

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Main Authors: Aaij, Roel (Author) , Archilli, Flavio (Author) , Bachmann, Sebastian (Author) , Berninghoff, Daniel (Author) , Borsato, Martino (Author) , Frau, Giulia (Author) , Gerick, David (Author) , Grabowski, Jascha (Author) , Günther, Paul André (Author) , Han, Xiaoxue (Author) , Hansmann-Menzemer, Stephanie (Author) , Hu, Jiangqiao (Author) , Kopecná, Renata (Author) , Leverington, Blake (Author) , Li, Peilian (Author) , Malygina, Hanna (Author) , Marks, Jörg (Author) , Meinert, Nis (Author) , Neubert, Sebastian (Author) , Sarpis, Mindaugas (Author) , Schmelling, Michael (Author) , Unverzagt, Daniel Joachim (Author) , Uwer, Ulrich (Author) , Viemann, Harald (Author) , Waldi, Roland (Author) , Wang, Chishuai (Author) , Witola, Lukas (Author) , Zhelezov, Alexey (Author)
Corporate Author: LHCb Collaboration (Author)
Format: Article (Journal)
Language:English
Published: October 7, 2021
In: Journal of high energy physics
Year: 2021, Issue: 10, Pages: 1-36
ISSN:1029-8479
DOI:10.1007/JHEP10(2021)060
Online Access:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1007/JHEP10(2021)060
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Author Notes:The LHCb collaboration
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Summary:Abstract: This article presents differential measurements of the asymmetry between Λ0b and Λ0b 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 Λ0b baryons are reconstructed through the inclusive semileptonic decay Λ0b → Λ+c μ−νμX. 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.
Item Description:Im Titel ist "0" hoch- und "b" in Λ0b − ̄ Λ0b tiefgestellt, dabei steht jeweils "0" über "b"
Im Titel steht der Buchstabe s unter dem Wurzelsymbol
Im Titel steht das zweite lambda mit einem Oberstrich
The LHCb collaboration: R. Aaij, F. Archilli, S. Bachmann, D. Berninghoff, M. Borsato, G. Frau, D. Gerick, J.P. Grabowski, P.A. Günther, X. Han, S. Hansmann-Menzemer, J. Hu, R. Kopecna, B. Leverington, P. Li, H. Malygina, J. Marks, N. Meinert, A.B. Morris, S. Neubert, M. Sarpis, M. Schmelling, D.J. Unverzagt, U. Uwer, H. Viemann, R. Waldi, C. Wang, L. Witola, M. Zavertyaev, A. Zhelezov, und weitere 955
Gesehen am 12.11.2021
Physical Description:Online Resource
ISSN:1029-8479
DOI:10.1007/JHEP10(2021)060