Charged-particle multiplicity measurement in proton?proton collisions at $\sqrt{s}=0.9$ and 2.36�TeV with ALICE at LHC [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 539.7 Atomic and nuclear physics
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2010
• Mô tả vật lý: Size: p. 89-108 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 267829
• Chủ đề: 1. 72 physics of elementary particles and fields; 2. Linear colliders; 3. Multiplicity; 4. Particle production; 5. Proton-proton interactions

Tóm tắt

 Charged-particle production was studied in proton-proton collisions collected at the LHC with the ALICE detector at centre-of-mass energies 0.9 TeV and 2.36 TeV in the pseudorapidity range |?|<
 1.4. In the central region (|?|<
 0.5), at 0.9 TeV, we measure charged-particle pseudorapidity density dNch/d?= 3.02 � 0.01 (stat.)$ +0.08\atop{-0.05} $(syst.) for inelastic interactions, and d<
 em>
 N<
 /em>
 <
 sub>
 ch<
 /sub>
 /d? = 3.58 � 0.01 (stat.)$ +0.12\atop{-0.12} $(syst.) for non-single-diffractive interactions. At 2.36 TeV, we find d<
 em>
 N<
 /em>
 <
 sub>
 ch<
 /sub>
 /d? = 3.77 � 0.01 (stat.)$ +0.25\atop{-0.12} $(syst.) for inelastic, and d<
 em>
 N<
 /em>
 <
 sub>
 ch<
 /sub>
 /d? = 4.43 � 0.01(stat.)$ +0.17\atop{-0.12} $(syst.) for non-single-diffractive collisions. The relative increase in charged-particle multiplicity from the lower to higher energy is 24.7% � 0.5%(stat.)$ +5.7\atop{-2.8} $%(syst.) for inelastic and 23.7% � 0.5%(stat.)$ +4.6\atop{-1.1} $% 1.1%(syst.) for non-single-diffractive interactions. This increase is consistent with that reported by the CMS collaboration for non-single-diffractive events and larger than that found by a number of commonly used models. The multiplicity distribution was measured in different pseudorapidity intervals and studied in terms of KNO variables at both energies. The results are compared to proton-antiproton data and to model predictions.