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


Khachatryan V., Sirunyan A. M. , Tumasyan A., Adam W., Bergauer T., Dragicevic M., ...Daha Fazla

JOURNAL OF HIGH ENERGY PHYSICS, 2011 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: Konu: 1
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1007/jhep01(2011)079
  • Dergi Adı: JOURNAL OF HIGH ENERGY PHYSICS

Özet

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.