Charged particle multiplicities in pp interactions at root s=0:9, 2:36, and 7 TeV

Measurements of primary charged hadron multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of root s = 0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from vertical bar eta vertical bar < 0.5 to vertical bar eta vertical bar < 2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and the 7 TeV run in 2010. The multiplicity distribution at root s - 0.9 TeV is in agreement with previous measurements. At higher energies the increase of the mean multiplicity with root s is underestimated by most event generators. The average transverse momentum as a function of the multiplicity is also presented. The measurement of higher-order moments of the multiplicity distribution con firms the violation of Koba-Nielsen-Olesen scaling that has been observed at lower energies. RI Mignerey, Alice/D-6623-2011; Ruiz, Alberto/E-4473-2011; Stahl, Achim/E-8846-2011; Hektor, Andi/G-1804-2011; Wulz, Claudia-Elisabeth/H-5657-2011; Chen, Jie/H-6210-2011; Bolton, Tim/A-7951-2012; Yang, Fan/B-2755-2012; Krammer, Manfred/A-6508-2010; Tinoco Mendes, Andre David/D-4314-2011; Lokhtin, Igor/D-7004-2012; Petrushanko, Sergey/D-6880-2012; Kodolova, Olga/D-7158-2012; Dudko, Lev/D-7127-2012; Katkov, Igor/E-2627-2012; Snigirev, Alexander/D-8912-2012; Brona, Grzegorz/E-5544-2012; Servoli, Leonello/E-6766-2012; Tomei, Thiago/E-7091-2012; Novaes, Sergio/D-3532-2012; Padula, Sandra /G-3560-2012; Flix, Josep/G-5414-2012; Fruhwirth, Rudolf/H-2529-2012; Azzi, Patrizia/H-5404-2012; Torassa, Ezio/I-1788-2012