Observation of a Λb0 − Λ¯b0 production asymmetry in proton-proton collisions at √s = 7 and 8 TeV
Authors
Aaij, R
Abdelmotteleb, ASW
Abellán Beteta, C
Ackernley, T
Adeva, B
Adinolfi, M
Afsharnia, H
Aidala, CA
Aiola, S
Ajaltouni, Z
Akar, S
Albrecht, J
Alessio, F
Alexander, M
Alfonso Albero, A
Aliouche, Z
Alkhazov, G
Alvarez Cartelle, P
Amato, S
Amey, JL
Amhis, Y
An, L
Anderlini, L
Andreianov, A
Andreotti, M
Archilli, F
Artamonov, A
Artuso, M
Arzymatov, K
Aslanides, E
Atzeni, M
Audurier, B
Bachmann, S
Bachmayer, M
Back, JJ
Baladron Rodriguez, P
Balagura, V
Baldini, W
Baptista Leite, J
Barlow, RJ
Barsuk, S
Barter, W
Bartolini, M
Baryshnikov, F
Basels, JM
Bashir, S
Bassi, G
Batsukh, B
Battig, A
Bay, A
Beck, A
Becker, M
Bedeschi, F
Bediaga, I
Beiter, A
Belavin, V
Belin, S
Bellee, V
Belous, K
Belov, I
Belyaev, I
Bencivenni, G
Ben-Haim, E
Berezhnoy, A
Bernet, R
Berninghoff, D
Bernstein, HC
Bertella, C
Bertolin, A
Betancourt, C
Betti, F
Bezshyiko, I
Bhasin, S
Bhom, J
Bian, L
Bieker, MS
Bifani, S
Billoir, P
Birch, M
Bishop, FCR
Bitadze, A
Bizzeti, A
Bjørn, M
Blago, MP
Blake, T
Blanc, F
Blusk, S
Bobulska, D
Boelhauve, JA
Boente Garcia, O
Boettcher, T
Boldyrev, A
Bondar, A
Bondar, N
Borghi, S
Borisyak, M
Borsato, M
Borsuk, JT
Bouchiba, SA
Bowcock, TJV
Publication Date
2021Journal Title
Journal of High Energy Physics
ISSN
1029-8479
Publisher
Springer Berlin Heidelberg
Volume
2021
Issue
10
Language
en
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Aaij, R., Abdelmotteleb, A., Abellán Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., 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) https://doi.org/10.1007/JHEP10(2021)060
Abstract
This article presents differential measurements of the asymmetry between
$\Lambda_b^0$ and $\overline{\Lambda}_b^0$ baryon production rates in
proton-proton collisions at centre-of-mass energies of $\sqrt{s}=7$ and
$8\,\textrm{TeV}$ collected with the LHCb experiment, corresponding to an
integrated luminosity of $3\,\textrm{fb}^{-1}$. The $\Lambda_b^0$ baryons are
reconstructed through the inclusive semileptonic decay
$\Lambda_b^0\rightarrow\Lambda_c^+\mu^-\overline{\nu}_{\mu}X$. The production
asymmetry is measured both in intervals of rapidity in the range $2.15<y<4.10$
and transverse momentum in $2<p_T<27\,\textrm{GeV}/c$. The results are found to
be incompatible with symmetric production with a significance of 5.8 standard
deviations for both $\sqrt{s}=7$ and $8\,\textrm{TeV}$ data, assuming no $C\!P$
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.
Keywords
Regular Article - Experimental Physics, Hadron-Hadron scattering (experiments), Heavy quark production, proton-proton scattering, Hard scattering, B physics
Identifiers
jhep10(2021)060, 16854
External DOI: https://doi.org/10.1007/JHEP10(2021)060
This record's URL: https://www.repository.cam.ac.uk/handle/1810/333297
Rights
Licence:
http://creativecommons.org/licenses/by/4.0/
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