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Λ c + production in Pb–Pb collisions at s NN =5.02 TeV

, ; Acharya, S; Adolfsson, Jonatan LU ; Christiansen, Peter LU ; Ljunggren, Martin LU ; Nassirpour, Adrian LU ; Oskarsson, Anders LU ; Richert, Tuva LU ; Silvermyr, David LU and Stenlund, Evert LU , et al. (2019) In Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 793. p.212-223
Abstract
A measurement of the production of prompt Λ c + baryons in Pb–Pb collisions at s NN =5.02 TeV with the ALICE detector at the LHC is reported. The Λ c + and Λ‾ c − were reconstructed at midrapidity (|y|<0.5) via the hadronic decay channel Λ c + →pK S 0 (and charge conjugate) in the transverse momentum and centrality intervals 6<p T <12 GeV/c and 0–80%. The Λ c + /D 0 ratio, which is sensitive to the charm quark hadronisation mechanisms in the medium, is measured and found to be larger than the ratio measured in minimum-bias pp collisions at s=7 TeV and in p–Pb collisions at s NN =5.02 TeV. In particular, the values in p–Pb and Pb–Pb collisions differ by about two standard deviations of the combined statistical and systematic... (More)
A measurement of the production of prompt Λ c + baryons in Pb–Pb collisions at s NN =5.02 TeV with the ALICE detector at the LHC is reported. The Λ c + and Λ‾ c − were reconstructed at midrapidity (|y|<0.5) via the hadronic decay channel Λ c + →pK S 0 (and charge conjugate) in the transverse momentum and centrality intervals 6<p T <12 GeV/c and 0–80%. The Λ c + /D 0 ratio, which is sensitive to the charm quark hadronisation mechanisms in the medium, is measured and found to be larger than the ratio measured in minimum-bias pp collisions at s=7 TeV and in p–Pb collisions at s NN =5.02 TeV. In particular, the values in p–Pb and Pb–Pb collisions differ by about two standard deviations of the combined statistical and systematic uncertainties in the common p T interval covered by the measurements in the two collision systems. The Λ c + /D 0 ratio is also compared with model calculations including different implementations of charm quark hadronisation. The measured ratio is reproduced by models implementing a pure coalescence scenario, while adding a fragmentation contribution leads to an underestimation. The Λ c + nuclear modification factor, R AA , is also presented. The measured values of the R AA of Λ c + , D s + and non-strange D mesons are compatible within the combined statistical and systematic uncertainties. They show, however, a hint of a hierarchy (R AA D 0 <R AA D s + <R AA Λ c + ), conceivable with a contribution from coalescence mechanisms to charm hadron formation in the medium. © 2019 European Organization for Nuclear Research (Less)
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Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
volume
793
pages
12 pages
publisher
Elsevier
external identifiers
  • scopus:85064946256
ISSN
0370-2693
DOI
10.1016/j.physletb.2019.04.046
language
English
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yes
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93420296-1cd7-4632-9c6f-332235319466
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2019-05-13 12:48:44
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2019-06-04 03:57:55
@article{93420296-1cd7-4632-9c6f-332235319466,
  abstract     = {A measurement of the production of prompt Λ c + baryons in Pb–Pb collisions at s NN =5.02 TeV with the ALICE detector at the LHC is reported. The Λ c + and Λ‾ c − were reconstructed at midrapidity (|y|&lt;0.5) via the hadronic decay channel Λ c + →pK S 0 (and charge conjugate) in the transverse momentum and centrality intervals 6&lt;p T &lt;12 GeV/c and 0–80%. The Λ c + /D 0 ratio, which is sensitive to the charm quark hadronisation mechanisms in the medium, is measured and found to be larger than the ratio measured in minimum-bias pp collisions at s=7 TeV and in p–Pb collisions at s NN =5.02 TeV. In particular, the values in p–Pb and Pb–Pb collisions differ by about two standard deviations of the combined statistical and systematic uncertainties in the common p T interval covered by the measurements in the two collision systems. The Λ c + /D 0 ratio is also compared with model calculations including different implementations of charm quark hadronisation. The measured ratio is reproduced by models implementing a pure coalescence scenario, while adding a fragmentation contribution leads to an underestimation. The Λ c + nuclear modification factor, R AA , is also presented. The measured values of the R AA of Λ c + , D s + and non-strange D mesons are compatible within the combined statistical and systematic uncertainties. They show, however, a hint of a hierarchy (R AA D 0 &lt;R AA D s + &lt;R AA Λ c + ), conceivable with a contribution from coalescence mechanisms to charm hadron formation in the medium. © 2019 European Organization for Nuclear Research},
  author       = {,  and Acharya, S and Adolfsson, Jonatan and Christiansen, Peter and Ljunggren, Martin and Nassirpour, Adrian and Oskarsson, Anders and Richert, Tuva and Silvermyr, David and Stenlund, Evert and Vislavicius, Vytautas},
  issn         = {0370-2693},
  language     = {eng},
  pages        = {212--223},
  publisher    = {Elsevier},
  series       = {Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics},
  title        = {Λ c + production in Pb–Pb collisions at s NN =5.02 TeV},
  url          = {http://dx.doi.org/10.1016/j.physletb.2019.04.046},
  volume       = {793},
  year         = {2019},
}