TY - JOUR
T1 - Λc+ production in Pb–Pb collisions at √sNN = 5.02 TeV
AU - ALICE Collaboration
AU - Acharya, S.
AU - Andrews, H.A.
AU - Evans, D.
AU - Graham, K.L.
AU - Jevons, O.
AU - Jones, P.G.
AU - Jusko, A.
AU - Krivda, M.
AU - Kvapil, J.
AU - Lietava, R.
AU - Villalobos Baillie, O.
AU - Willsher, E.
AU - Zardoshti, N.
PY - 2019/6/10
Y1 - 2019/6/10
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85064946256&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2019.04.046
DO - 10.1016/j.physletb.2019.04.046
M3 - Article
SN - 0370-2693
VL - 793
SP - 212
EP - 223
JO - Physics Letters B
JF - Physics Letters B
ER -