and production in Pb-Pb collisions at = 2.76 TeV
Collaboration
10 pages
Published in:
- Phys.Rev.Lett. 111 (2013) 222301
- Published: Nov 25, 2013
e-Print:
- 1307.5530 [nucl-ex]
Report number:
- CERN-PH-EP-2013-132
Experiments:
Citations per year
Abstract: (APS)
The ALICE measurement of KS0 and Λ production at midrapidity in Pb-Pb collisions at sNN=2.76 TeV is presented. The transverse momentum (pT) spectra are shown for several collision centrality intervals and in the pT range from 0.4 GeV/c (0.6 GeV/c for Λ) to 12 GeV/c. The pT dependence of the Λ/KS0 ratios exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher pT with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate pT is not observed in pp interactions at s=0.9 TeV and at s=7 TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured pT spectra above 2 GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of pT, models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the pT dependence of the Λ/KS0 ratio.Note:
- 16 pages, 3 captioned figures, 1 table, authors from page 11, published version contains only left panel of fig 2 and fig 3, figures at http://aliceinfo.cern.ch/ArtSubmission/node/603
- 25.75.-q
- 13.85.Ni
- 25.75.Dw
- 25.75.Nq
- heavy ion: scattering
- lead
- transverse momentum: momentum spectrum
- fragmentation
- hadronization
- baryon
References(0)
Figures(5)
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