Pseudorapidity distributions of charged particles as a function of mid and forward rapidity mutiplicities in pp collisions at s\sqrt{s}s
c-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14 c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54 c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10 s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429 c69,-144,104.5,-217.7,106.5,-221 l0 -0 c5.3,-9.3,12,-14,20,-14 H400000v40H845.2724 s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7 c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47z M834 80h400000v40h-400000z'/> = 5.02, 7 and 13 TeV (original) (raw)
Related papers
The European Physical Journal C, 2019
The average total energy as well as its hadronic and electromagnetic components are measured with the CMS detector at pseudorapidities -6.6<\eta <-5.2$$-6.6<η<-5.2 in proton-proton collisions at a centre-of-mass energy \sqrt{s}=13\,\text {TeV} s=13TeV. The results are presented as a function of the charged particle multiplicity in the region |\eta |<2$$|η|<2. This measurement is sensitive to correlations induced by the underlying event structure over a very wide pseudorapidity region. The predictions of Monte Carlo event generators commonly used in collider experiments and ultra-high energy cosmic ray physics are compared to the data. All generators considered overestimate the fraction of energy going into hadrons.
The European Physical Journal C, 2010
The pseudorapidity density and multiplicity distribution of charged particles produced in protonproton collisions at the LHC, at a centre-of-mass energy √ s = 7 TeV, were measured in the central pseudorapidity region |η| < 1. Comparisons are made with previous measurements at √ s = 0.9 TeV and 2.36 TeV. At √ s = 7 TeV, for events with at least one charged particle in |η| < 1, we obtain dN ch /dη = 6.01±0.01(stat.) +0.20 −0.12 (syst.). This corresponds to an increase of 57.6 %±0.4 %(stat.) +3.6 −1.8 %(syst.) relative to collisions at 0.9 TeV, significantly higher than calculations from commonly used models. The multiplicity distribution at 7 TeV is described fairly well by the negative binomial distribution.
The pseudorapidity (η) and transverse-momentum (p T) distributions of charged particles produced in proton–proton collisions are measured at the centre-of-mass energy √ s = 13 TeV. The pseudorapidity distribution in |η| < 1.8 is reported for inelastic events and for events with at least one charged particle in |η| < 1. The pseudorapidity density of charged particles produced in the pseudorapidity region |η| < 0.5 is 5.31 ± 0.18 and 6.46 ± 0.19 for the two event classes, respectively. The transverse-momentum distribution of charged particles is measured in the range 0.15 < p T < 20 GeV/c and |η| < 0.8 for events with at least one charged particle in |η| < 1. The evolution of the transverse momentum spectra of charged particles is also investigated as a function of event multiplicity. The results are compared with calculations from PYTHIA and EPOS Monte Carlo generators.
Pseudorapidity distribution of charged hadrons in proton–proton collisions at s=13 TeV
Physics Letters B, 2015
The pseudorapidity distribution of charged hadrons in pp collisions at √ s = 13 TeV is measured using a data sample obtained with the CMS detector, operated at zero magnetic field, at the CERN LHC. The yield of primary charged long-lived hadrons produced in inelastic pp collisions is determined in the central region of the CMS pixel detector (|η| < 2) using both hit pairs and reconstructed tracks. For central pseudorapidities (|η| < 0.5), the charged-hadron multiplicity density is dN ch /dη| |η|<0.5 = 5.49 ± 0.01 (stat) ± 0.17 (syst), a value obtained by combining the two methods. The result is compared to predictions from Monte Carlo event generators and to similar measurements made at lower collision energies.
The European Physical Journal C, 2014
Pseudorapidity (η) distributions of charged particles produced in proton-proton collisions at a centre-of-mass energy of 8 TeV are measured in the ranges |η| < 2.2 and 5.3 < |η| < 6.4 covered by the CMS and TOTEM detectors, respectively. The data correspond to an integrated luminosity of L = 45 µb −1. Measurements are presented for three event categories. The most inclusive category is sensitive to 91-96 % of the total inelastic proton-proton cross section. The other two categories are disjoint subsets of the inclusive sample that are either enhanced or depleted in single diffractive dissociation events. The data are compared to models used to describe high-energy hadronic interactions. None of the models considered provide a consistent description of the measured distributions.
Physical Review Letters, 2010
Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at ffiffi ffi s p ¼ 7 TeV are measured with the inner tracking system of the CMS detector at the LHC. The chargedhadron 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 dN ch =dj jj<0:5 ¼ 5:78 AE 0:01ðstatÞ AE 0:23ðsystÞ for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from ffiffi ffi s p ¼ 0:9 to 7 TeV is ½66:1 AE 1:0ðstatÞ AE 4:2ðsystÞ%. The mean transverse momentum is measured to be 0:545 AE 0:005ðstatÞ AE 0:015ðsystÞ GeV=c. The results are compared with similar measurements at lower energies.
Physical Review C, 2008
We present results for final state charged particle (pseudo-)rapidity distributions in rmp\rm{p}rmp + barrmp\bar{\rm{p}}barrmp / rmp\rm{p}rmp + rmp\rm{p}rmp and Pb+Pb/Au+Au at ultra high energies (17.3 GeV leq\leqleq sqrtsrmNN\sqrt{s_{\rm{NN}}}sqrtsrmNN leq\leqleq 14 TeV) from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD-v2.3) model. In addition, excitation functions of produced charged particle multiplicities ($N_{\rm{ch}}$) and pseudorapidity spectra are investigated up to LHC energies. Good agreement is observed between UrQMD and measured pseudorapidity distributions of charged particles up to the highest Tevatron and Sp$\bar{\rm{p}}$S energies.
Eur.Phys.J., 2014
Pseudorapidity (η) distributions of charged particles produced in proton-proton collisions at a centre-of-mass energy of 8 TeV are measured in the ranges |η| < 2.2 and 5.3 < |η| < 6.4 covered by the CMS and TOTEM detectors, respectively. The data correspond to an integrated luminosity of L = 45 µb −1. Measurements are presented for three event categories. The most inclusive category is sensitive to 91-96 % of the total inelastic proton-proton cross section. The other two categories are disjoint subsets of the inclusive sample that are either enhanced or depleted in single diffractive dissociation events. The data are compared to models used to describe high-energy hadronic interactions. None of the models considered provide a consistent description of the measured distributions.
Charged-particle multiplicities in proton–proton collisions
A detailed study of pseudorapidity densities and multiplicity distributions of primary charged particles produced in proton–proton collisions, at √ s = 0.9, 2.36, 2.76, 7 and 8 TeV, in the pseudorapidity range |η| < 2, was carried out using the ALICE detector. Measurements were obtained for three event classes: inelastic, non-single diffractive and events with at least one charged particle in the pseudorapidity interval |η| < 1. The use of an improved track-counting algorithm combined with ALICE's measurements of diffractive processes allows a higher precision compared to our previous publications. A KNO scaling study was performed in the pseudorapidity intervals |η| < 0.5, 1.0 and 1.5. The data are compared to other experimental results and to models as implemented in Monte Carlo event generators PHOJET and recent tunes of PYTHIA6, PYTHIA8 and EPOS.
Charged-particle multiplicity measurement in proton–proton collisions at TeV with ALICE at LHC
The European Physical …, 2010
The pseudorapidity density and multiplicity distribution of charged particles produced in protonproton collisions at the LHC, at a centre-of-mass energy √ s = 7 TeV, were measured in the central pseudorapidity region |η| < 1. Comparisons are made with previous measurements at √ s = 0.9 TeV and 2.36 TeV. At √ s = 7 TeV, for events with at least one charged particle in |η| < 1, we obtain dN ch /dη = 6.01±0.01(stat.) +0.20 −0.12 (syst.). This corresponds to an increase of 57.6 %±0.4 %(stat.) +3.6 −1.8 %(syst.) relative to collisions at 0.9 TeV, significantly higher than calculations from commonly used models. The multiplicity distribution at 7 TeV is described fairly well by the negative binomial distribution.