Transverse Momentum Distributions Of Charged Particles Research Articles

Comparative analysis of charged particle distributions in [formula omitted] collisions at [formula omitted] using Monte Carlo models and fitting functions

We conducted a detailed analysis of charged particle transverse momentum distributions using multiple Monte Carlo models – Pythia, HIJING, and QGSJET – compared against experimental data from the ATLAS detector in pp collisions at s=0.9TeV. Pythia emerged as the best among the models under study in representing most of the distributions due to its comprehensive modeling of parton showers, multiparton interactions, and underlying event dynamics, while QGSJET showed good results with the data in some of the distributions only. HIJING, however, was only able to replicate reduced phase-space distributions only.To further explore the collision medium and to extract important information about collective properties, we used the Tsallis-Pareto (TP) type function and the modified Hagedorn (MH) function. The Tsallis function enabled determination of the effective temperature (Teff) and the non-extensivity parameter (n1) while the MH function provided the kinetic freeze-out temperature (T0), transverse flow velocity (<βT>), and a secondary non-extensivity parameter (n2). Our investigation revealed changes in the effective freeze-out parameters based on event conditions. The Teff and <βT> derived from the TP and MH functions respectively exhibited higher values with a tighter pT cut of >500MeV compared to a more inclusive pT cut of >100MeV. Interestingly, the values of the non-extensivity parameters—n1 for the Tsallis function and n2 for the MH function were almost identical across both the experimental data and all three Monte Carlo models. These findings offer invaluable perspectives on the dynamics of charged particles in pp collisions at s=0.9TeV.

Analysis of Transverse-Momentum Distributions of Charged Particles in Proton–Proton Collisions at Energies in the Range of $$\boldsymbol{(s_{nn})^{1/2}=2.76}$$–7 TeV at the LHC

Analysis of Transverse-Momentum Distributions of Charged Particles in Proton–Proton Collisions at Energies in the Range of $$\boldsymbol{(s_{nn})^{1/2}=2.76}$$–7 TeV at the LHC

Study of Pseudorapidity and Transverse-Momentum Distributions of Charged Particles in pp Interactions at √s = 13 TeV Using Hadron Production Models

Pseudorapidity (η) and Transverse momentum (pT) distributions of charged particles produced in proton-proton (pp) collisions at √s = 13 TeV are studied. Transverse momentum distributions of charged particles are considered in the Pseudorapidity region of |η| < 0.8 and in the transverse momentum range of 0 < pT < 20 GeV/c. EPOS1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. In order to check the validity of simulations performed using these Monte-Carlo event generators, the results are compared to the measurements of ALICE experiment at the LHC CERN. For the pT distribution, the EPOS1.99 and QGSJET underpredict the experimental data while the EPOS-LHC model reproduced the distribution very well. EPOS-LHC model describes the experimental data very well as compared to the other two models for the ratio of pT spectra of charged particles at √s = 13 TeV to 7 TeV. EPOS-LHC also describes the pseudorapidity distribution very well while the EPOS 1.99 and QGSJETII-04 underpredict and overpredict the distribution respectively.

Pseudorapidity and transverse-momentum distributions of charged particles in proton–proton collisions at [formula omitted

The pseudorapidity (η) and transverse-momentum (pT) 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<pT<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.

Nucleon-gold collisions at200AGeV using taggedd + Auinteractions in the PHOBOS detector

Forward calorimetry in the PHOBOS detector has been used to study charged hadron production in d+Au, p+Au and n+Au collisions at sqrt(s_nn) = 200 GeV. The forward proton calorimeter detectors are described and a procedure for determining collision centrality with these detectors is detailed. The deposition of energy by deuteron spectator nucleons in the forward calorimeters is used to identify p+Au and n+Au collisions in the data. A weighted combination of the yield of p+Au and n+Au is constructed to build a reference for Au+Au collisions that better matches the isospin composition of the gold nucleus. The p_T and centrality dependence of the yield of this improved reference system is found to match that of d+Au. The shape of the charged particle transverse momentum distribution is observed to extrapolate smoothly from pbar+p to central d+Au as a function of the charged particle pseudorapidity density. The asymmetry of positively- and negatively-charged hadron production in p+Au is compared to that of n+Au. No significant asymmetry is observed at mid-rapidity. These studies augment recent results from experiments at the LHC and RHIC facilities to give a more complete description of particle production in p+A and d+A collisions, essential for the understanding the medium produced in high energy nucleus-nucleus collisions.

PACIAE 2.1: An updated issue of the parton and hadron cascade model PACIAE 2.0

We have updated the parton and hadron cascade model PACIAE 2.0 for relativistic nuclear collisions (cf. Comput. Phys. Comm. 183(2012)333) to the new issue of PACIAE 2.1. The PACIAE model is based on PYTHIA. In the PYTHIA model, once the generated particle/parton transverse momentum $p_T$ is randomly selected, its component of $[p_x,p_y]$ was originally put on the circle with radius $p_T$ randomly. It is now replaced by put on the circumference of ellipse with half major and minor axes of $p_T(1+\delta_p)$ and $p_T(1-\delta_p)$, respectively, in order to investigate better the transverse momentum anisotropy in final hadronic state.

Transverse momentum spectra of charged particles in proton–proton collisions at [formula omitted] with ALICE at the LHC

The inclusive charged particle transverse momentum distribution is measured in proton–proton collisions at s=900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (|η|<0.8) over the transverse momentum range 0.15<pT<10 GeV/c. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for |η|<0.8 is 〈pT〉INEL=0.483±0.001 (stat.)±0.007 (syst.) GeV/c and 〈pT〉NSD=0.489±0.001 (stat.)±0.007 (syst.) GeV/c, respectively. The data exhibit a slightly larger 〈pT〉 than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET.

PACIAE model predictions for Pb+Pb collisions at LHC compared to the Au+Au collisions at RHIC

The parton and hadron cascade model, PACIAE, is employed to simulate the 0–6, 0–10, 15–25, and 35–45% most central Au+Au collisions at , 62.4, 130, and 200 GeV and the 0–10% most central Pb+Pb collisions at GeV. The calculated charged multiplicity and the charged particle transverse momentum distribution, pseudorapidity distribution and extended longitudinal scaling for Au+Au collisions agree with the corresponding PHOBOS data. Thus the above observables calculated for Pb+Pb collisions would be a reasonable prediction.

Transverse-momentum distributions of charged particles produced in p-barp interactions at sqrt s-bar=630 and 1800 GeV.

Measurements of inclusive transverse-momentum spectra for charged particles produced in proton-antiproton collisions at ..sqrt..2 of 630 and 1800 GeV are presented and compared with data taken at lower energies.