scholarly journals On Distributions of Emission Sources and Speed-of-Sound in Proton-Proton (Proton-Antiproton) Collisions

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Li-Na Gao ◽  
Fu-Hu Liu
Keyword(s):  
Experimental Data ◽  
Speed Of Sound ◽  
Gaussian Function ◽  
Charged Particles ◽  
Emission Sources ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Model Calculations ◽  
High Energies ◽  
Rapidity Distributions

The revised (three-source) Landau hydrodynamic model is used in this paper to study the (pseudo)rapidity distributions of charged particles produced in proton-proton and proton-antiproton collisions at high energies. The central source is assumed to contribute with a Gaussian function which covers the rapidity distribution region as wide as possible. The target and projectile sources are assumed to emit isotropically particles in their respective rest frames. The model calculations obtained with a Monte Carlo method are fitted to the experimental data over an energy range from 0.2 to 13 TeV. The values of the squared speed-of-sound parameter in different collisions are then extracted from the width of the rapidity distributions.

scholarly journals Pseudorapidity Distribution of Charged Particles and Square Speed of Sound Parameter inp-porp-p-Collisions over an Energy Range from 0.053 to 7 TeV

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ya-Qin Gao ◽  
Tian Tian ◽  
Li-Na Gao ◽  
Fu-Hu Liu
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Speed Of Sound ◽  
Hydrodynamic Model ◽  
Charged Particles ◽  
Pseudorapidity Distribution ◽  
Proton Antiproton ◽  
Proton Proton ◽  
High Energies ◽  
Related Energy

Pseudorapidity distributions of charged particles produced in proton-proton (p-p) or proton-antiproton (p-p-) collisions over an energy range from 0.053 to 7 TeV are studied by using the four-component Landau hydrodynamic model. The results calculated by the model are in agreement with the experimental data of the UA5, PHOBOS, UA1, P238, CDF, ALICE, and CMS Collaborations which present orderly from low to high energies. According to the distribution widths of different components, the values and some features of square speed of sound parametercs2for “participant” and “spectator” quark components are obtained. It is shown that the speed of sound for “participant” quark components agrees approximately with that for “spectator” quark components in the error ranges. The present work is useful for studying nucleus-nucleus collisions in the related energy range.

scholarly journals A combined model for pseudo-rapidity distributions in Cu–Cu collisions at BNL-RHIC energies

2016 ◽  
Vol 25 (04) ◽  
pp. 1650025 ◽  
Author(s):  
Z. J. Jiang ◽  
J. Wang ◽  
Y. Huang
Keyword(s):  
Experimental Data ◽  
Proper Time ◽  
Charged Particles ◽  
Dense Matter ◽  
Rapidity Distribution ◽  
Experimental Measurements ◽  
Combined Model ◽  
Model Predictions ◽  
Phobos Collaboration ◽  
Rapidity Distributions

The charged particles produced in nucleus–nucleus collisions come from leading particles and those frozen out from the hot and dense matter created in collisions. The leading particles are conventionally supposed having Gaussian rapidity distributions normalized to the number of participants. The hot and dense matter is assumed to expand according to the unified hydrodynamics, a hydro model which unifies the features of Landau and Hwa–Bjorken model, and freeze out into charged particles from a time-like hypersurface with a proper time of [Formula: see text]. The rapidity distribution of this part of charged particles can be derived analytically. The combined contribution from both leading particles and unified hydrodynamics is then compared against the experimental data performed by BNL-RHIC-PHOBOS Collaboration in different centrality Cu–Cu collisions at [Formula: see text] and 62.4[Formula: see text]GeV, respectively. The model predictions are consistent with experimental measurements.

scholarly journals Energy Dependence of Slope Parameter in Elastic Nucleon-Nucleon Scattering

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
V. A. Okorokov
Keyword(s):  
Experimental Data ◽  
Energy Dependence ◽  
Nucleon Nucleon ◽  
High Energy ◽  
Slope Parameter ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Elastic Proton ◽  
Energy Domain ◽  
Very High Energy

The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on all the available experimental data at low and intermediate momentum transfer values. Energy dependence of the elastic diffraction slope is approximated by various analytic functions. The expanded “standard” logarithmic approximations with minimum number of free parameters allow description of the experimental slopes in all the available energy range reasonably. The estimations of asymptotic shrinkage parameterαP′are obtained for various|t|domains based on all the available experimental data. Various approximations differ from each other both in the low energy and very high energy domains. Predictions for diffraction slope parameter are obtained for elastic proton-proton scattering from NICA up to future collider (FCC/VLHC) energies, for proton-antiproton elastic reaction in FAIR energy domain for various approximation functions.

Models prediction of hadrons production ratios in pp collisions at s = 7 TeV

2019 ◽  
Vol 34 (13) ◽  
pp. 1950090 ◽  
Author(s):  
M. Ajaz ◽  
M. Bilal ◽  
Y. Ali ◽  
M. K. Suleymanov ◽  
K. H. Khan
Keyword(s):  
Experimental Data ◽  
Transverse Momentum ◽  
Charged Particles ◽  
Hadron Production ◽  
Proton Proton ◽  
Proton Collisions ◽  
Particle Ratios ◽  
Production Models ◽  
Lhcb Detector ◽  
Proton Proton Collisions

The pseudorapidity [Formula: see text] dependence of charged-particles ratios in three transverse momentum [Formula: see text] regions, obtained by hadron production models, in proton–proton collisions at 7 TeV are compared with the measurements of LHCb detector. Compared to the experimental data, the [Formula: see text] ratios are independent of [Formula: see text] and [Formula: see text] and are very well predicted by all models (DPMJETIII, EPOS1.99, EPOS-LHC, HIJING1.383, QGSJETII-04 and Sibyll2.3c). All models predict the [Formula: see text] ratio at low [Formula: see text] for [Formula: see text], but underestimate afterward while reproducing the experimental data at medium and high [Formula: see text] very well. The [Formula: see text] ratio is described by the models very well at high [Formula: see text] in the low and medium [Formula: see text] region. At high [Formula: see text], models predict the experimental data well, except Sibyll2.3c that slightly overestimates. The [Formula: see text] ratio is predicted by EPOS1.99, HIJING and Sibyll at low [Formula: see text] and EPOS-LHC, EPOS1.99 and Sibyll predicted at high [Formula: see text] for low [Formula: see text]. For medium [Formula: see text], EPOS1.99 and Sibyll predict very well for [Formula: see text] while EPOS-LHC and HIJING models reproduce the data for [Formula: see text]. All models underpredict the [Formula: see text] ratio for [Formula: see text]. For the [Formula: see text] and [Formula: see text] ratios, only Sibyll and EPOS1.99 models could reproduce some regions of [Formula: see text] and [Formula: see text]. None of the models satisfactorily predict all the ratios. the same particle ratios are well described by most of the models while the discrepancies occur mostly in predicting the different particles ratios.

scholarly journals Tensor pomeron, vector odderon and diffractive production of meson and baryon pairs in proton-proton collisions

2019 ◽  
Vol 206 ◽  
pp. 06005 ◽  
Author(s):  
Piotr Lebiedowicz ◽  
Otto Nachtmann ◽  
Antoni Szczurek
Keyword(s):  
Experimental Data ◽  
High Energy ◽  
Proton Proton ◽  
Proton Collisions ◽  
High Energies ◽  
Energy Proton ◽  
Diffractive Production ◽  
Proton Proton Collisions ◽  
Theoretical Results ◽  
The Continuum

We review some selected results of the tensor-pomeron and vectorodderon model of soft high-energy proton-proton scattering and central exclusive production of meson and baryon pairs in proton-proton collisions. We discuss the theoretical aspects of this approach and consider the phenomenological implications in a variety of processes at high energies, comparing to existing experimental data. We consider the diffractive dipion and dikaon production including the continuum and the dominant scalar and tensor resonance contributions as well as the photoproduction processes. The theoretical results are compared with existing CDF experimental data and predictions for planned or current LHC experiments, ALICE, ATLAS, CMS, LHCb are presented.

scholarly journals QUESTIONS AND PROSPECTS IN QUARKONIUM POLARIZATION MEASUREMENTS FROM PROTON–PROTON TO NUCLEUS–NUCLEUS COLLISIONS

2012 ◽  
Vol 27 (23) ◽  
pp. 1230022 ◽  
Author(s):  
PIETRO FACCIOLI
Keyword(s):  
Experimental Data ◽  
Quark Gluon Plasma ◽  
Gluon Plasma ◽  
The Other ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Experimental Knowledge ◽  
Polarization Measurements ◽  
Systematic Effects

Polarization measurements are the best instrument to understand how quark and antiquark combine into the different quarkonium states, but no model has so far succeeded in explaining the measured J/ψ and ϒ polarizations. On the other hand, the experimental data in proton–antiproton and proton–nucleus collisions are inconsistent, incomplete and ambiguous. New analyses will have to properly address often underestimated issues: the existence of azimuthal anisotropies, the dependence on the reference frame, the influence of the experimental acceptance on the comparison with other measurements and with theory. Additionally, a recently developed frame-invariant formalism will provide an alternative and often more immediate physical viewpoint and, at the same time, will help probing systematic effects due to experimental biases. The role of feed-down decays from heavier states, a crucial missing piece in the current experimental knowledge, will have to be investigated. Ultimately, quarkonium polarization measurements will also offer new possibilities in the study of the properties of the quark–gluon plasma.

GENETIC PROGRAMMING FOR HADRONIC INTERACTIONS AT HIGH ENERGIES

2007 ◽  
Vol 18 (03) ◽  
pp. 329-334 ◽  
Author(s):  
M. Y. EL-BAKRY ◽  
A. RADI
Keyword(s):  
Experimental Data ◽  
Genetic Programming ◽  
Rapidity Distribution ◽  
Proton Proton ◽  
Hadronic Interactions ◽  
High Energies ◽  
Gp Model

Genetic programming (GP) has been used to discover a function that describes pseudo-rapidity distribution of created pions from proton–proton (p-p) interactions at high and ultra-high energies. The predicted distributions from the GP-based model are compared with the experimental data. The discovered function of GP model has proven matching better for experimental data.

scholarly journals Photoproduction of vector mesons in proton–proton ultraperipheral collisions at the CERN Large Hadron Collider

2018 ◽  
Vol 33 (14n15) ◽  
pp. 1850086 ◽  
Author(s):  
Ya-Ping Xie ◽  
Xurong Chen
Keyword(s):  
Experimental Data ◽  
Large Hadron Collider ◽  
Good Description ◽  
Hadron Collider ◽  
Dipole Model ◽  
Vector Mesons ◽  
Model Framework ◽  
Proton Proton ◽  
Cern Large Hadron Collider ◽  
Rapidity Distributions

Photoproduction of vector mesons is computed with dipole model in proton–proton ultraperipheral collisions (UPCs) at the CERN Large Hadron Collider (LHC). The dipole model framework is employed in the calculations of vector mesons production in diffractive processes. Parameters of the bCGC model are refitted with the latest inclusive deep inelastic scattering experimental data. Employing the bCGC model and boosted Gaussian light-cone wave function for vector mesons, we obtain the prediction of rapidity distributions of [Formula: see text] and [Formula: see text] mesons in proton–proton ultraperipheral collisions at the LHC. The predictions give a good description of the experimental data of LHCb. Predictions of [Formula: see text] and [Formula: see text] mesons are also evaluated in this paper.

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