Transverse-Momentum and Pseudorapidity Distributions of Charged Hadrons in pp Collisions at [sqrt] s=7 TeV

• Main Authors: Paus, Christoph M. E. (Contributor), Zanetti, Marco (Contributor), Alver, Burak Han (Contributor), Bauer, Gerry P. (Contributor), Bendavid, Joshua L. (Contributor), Busza, Wit (Contributor), Butz, Erik M. (Contributor), Cali, Ivan Amos (Contributor), Chan, M. (Contributor), D'Enterria, David (Contributor), Everaerts, Pieter Bruno Bart (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Goncharov, Maxim (Contributor), Hahn, Kristian Allan (Contributor), Harris, P. (Contributor), Kim, Y. (Contributor), Klute, Markus (Contributor), Lee, Y. J. (Contributor), Li, Wei (Contributor), Loizides, Constantin (Contributor), Luckey, P. David, Jr (Contributor), Ma, Teng (Contributor), Nahn, Steven (Contributor), Roland, Christof E. (Contributor), Roland, Gunther M. (Contributor), Rudolph, Matthew Scott (Contributor), Stephans, George S. F. (Contributor), Sumorok, Konstanty C. (Contributor), Sung, K. (Contributor), Wenger, Edward Allen (Contributor), Wyslouch, Boleslaw (Contributor), Xie, S (Author), Yilmaz, Yetkin (Contributor), Yoon, A. S. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor), Xie, S. (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2011-02-04T23:02:08Z.
• Subjects: Article
• Online Access: Get fulltext

 Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at [sqrt]s=7  TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dNch/dη||η|<0.5=5.78±0.01(stat)±0.23(syst) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from [sqrt]s=0.9 to 7 TeV is [66.1±1.0(stat)±4.2(syst)]%. The mean transverse momentum is measured to be 0.545±0.005(stat)±0.015(syst)  GeV/c. The results are compared with similar measurements at lower energies.