Midrapidity Antiproton-to-Proton Ratio in pp Collisons root s=0.9 and 7 TeV Measured by the ALICE Experiment

0357799 - ÚJF 2011 RIV US eng J - Journal Article
Aamodt, K. - Abel, N. - Abeysekara, U. - Quintana, A.A. - Abramyan, A. - Adamová, Dagmar - Bielčík, Jaroslav - Bielčíková, Jana - Kapitán, Jan - Kushpil, Svetlana - Kushpil, Vasilij - Pachr, M. - Petráček, Vojtěch - Rak, Jan - Šumbera, Michal - Tlustý, David - Wagner, Vladimír - Mareš, Jiří A. - Polák, Karel - Závada, Petr
Midrapidity Antiproton-to-Proton Ratio in pp Collisons root s=0.9 and 7 TeV Measured by the ALICE Experiment.
Physical Review Letters. Roč. 105, č. 7 (2010), 072002/1-072002/12. ISSN 0031-9007. E-ISSN 1079-7114
R&D Projects: GA MŠMT LA08015
Institutional research plan: CEZ:AV0Z10480505; CEZ:AV0Z10100502
Keywords : TOTAL CROSS-SECTIONS * ANTINUCLEON-NUCLEON * STRING MODEL
Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders
Impact factor: 7.621, year: 2010

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at root s = 0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45 < p(t) < 1.05 GeV/c and rapidity vertical bar y vertical bar < 0.5. The ratio is measured to be R-vertical bar y vertical bar<0.5 = 0.957 +/- 0.006(stat) +/- 0.0014(syst) at 0.9 Tev and R-vertical bar y vertical bar<0.5 = 0.991 +/- 0.005 +/- 0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.
Permanent Link: http://hdl.handle.net/11104/0195994