Multi-strange baryon production in pp collisions at root s=7 TeV with ALICE

0388916 - ÚJF 2013 RIV NL eng J - Journal Article
Abelev, B. - Adam, J. - Adamová, Dagmar - Bielčík, J. - Bielčíková, Jana - Čepila, J. - Křelina, M. - Krus, M. - Kushpil, Svetlana - Kushpil, Vasilij - Mareš, Jiří A. - Petráček, V. - Petráň, M. - Polák, Karel - Pospíšil, V. - Šmakal, R. - Šumbera, Michal - Tlustý, D. - Vajzer, Michal - Wagner, V. - Zach, Č. - Závada, Petr … Total 983 authors
Multi-strange baryon production in pp collisions at root s=7 TeV with ALICE.
Physics Letters. B. Roč. 712, 4-5 (2012), s. 309-318. ISSN 0370-2693. E-ISSN 1873-2445
R&D Projects: GA MŠMT LA08015
Institutional support: RVO:68378271 ; RVO:61389005
Keywords : multi-strange baryons * P-T spectra * mid-rapidity * proton-proton * LHC * ALICE
Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders
Impact factor: 4.569, year: 2012

A measurement of the multi-strange Xi(-) and Omega(-) baryons and their antiparticles by the ALICE experiment at the CERN Large Hadron Collider (LHC) is presented for inelastic proton-proton collisions at a centre-of-mass energy of 7 TeV. The transverse momentum (p(T)) distributions were studied at mid-rapidity (vertical bar y vertical bar < 0.5) in the range of 0.6 < p(T) < 8.5 GeV/c Xi(-) for and Xi(+) baryons, and in the range of 0.8 < P-T < 5 GeV/c for Omega(-) and<(Omega)over bar>(+). Baryons and antibaryons were measured as separate particles and we find that the baryon to antibaryon ratio of both particle species is consistent with unity over the entire range of the measurement. The statistical precision of the current data has allowed us to measure a difference between the mean p(T) of Xi(-) ((Xi) over bar)(+) and Omega(-) ((Omega) over bar (+)). Particle yields, mean pi, and the spectra in the intermediate pi range are not well described by the PYTHIA Perugia 2011 tune Monte Carlo event generator, which has been tuned to reproduce the early LHC data. The discrepancy is largest for Omega(-)((Omega) over bar (+)). This PYTHIA tune approaches the pi spectra of Xi(-) and Xi(+) baryons below p(T) <0.85 GeV/c and describes the Xi(-) and Xi(+) spectra above p(T) > 6.0 GeV/c. We also illustrate the difference between the experimental data and model by comparing the corresponding ratios of (Omega(-) +(Omega) over bar (+))/(Xi(-) + Xi(+)) as a function of transverse mass.
Permanent Link: http://hdl.handle.net/11104/0217818