Spectral temperature of π− mesons in proton–carbon interactions at 4.2 GeV/c in the framework of UrQMD model

2020 ◽  
Vol 35 (10) ◽  
pp. 2050066
Author(s):  
Imran Khan ◽  
Abdur Rehman ◽  
Ali Zaman
Keyword(s):  
Transverse Momentum ◽  
Molecular Dynamic ◽  
Thermodynamic Function ◽  
Relativistic Quantum ◽  
Boltzmann Distribution ◽  
Exponential Functions ◽  
Quantum Molecular Dynamic ◽  
Suitable Function ◽  
Hadron Spectra ◽  
Urqmd Model

Transverse momentum [Formula: see text] spectra of [Formula: see text] mesons calculated using ultra-relativistic quantum molecular dynamic (UrQMD) model (Latest version 3.3-p2) simulations have been compared with [Formula: see text] spectra of [Formula: see text] mesons, obtained experimentally in interactions of protons beam with carbon nuclei (propane as target) at momentum of 4.2 GeV/c. Spectral temperatures of negative pions obtained in experimental and UrQMD model simulated interactions of protons beam with carbon nuclei have been calculated by fitting both spectra with four different fitting functions, i.e. Hagedorn thermodynamic, Boltzmann distribution, Gaussian and exponential functions. These functions are used commonly for describing hadron spectra and their spectral temperatures. Hagedorn thermodynamic function has been recommended as the most suitable function to extract the temperature of negative pions at above momentum among these four functions.

Rapidity Distribution of Charged Pions From Pb+Pb and Au+Au Central Collisions

2016 ◽  
Vol 12 (1) ◽  
pp. 4153-4160
Author(s):  
Ahmed Mohamed Abdalla
Keyword(s):  
Molecular Dynamic ◽  
Dynamic Model ◽  
Good Description ◽  
Relativistic Quantum ◽  
Nucleon Nucleon ◽  
Molecular Dynamic Model ◽  
Quantum Molecular Dynamic ◽  
Central Collisions ◽  
Charged Pions ◽  
Rapidity Distributions

Rapidity distributions for charged pions produced from central collisions Pb+Pb and Au+Au at (b ≤ 3.4 fm.) in range of energy 2 GeV up to  = 200 GeV are investigated. The experimental results are studied  in terms of the Ultra-relativistic Quantum Molecular Dynamic Model Ur-QMD. In general, the model can give suitable predictions of rapidity distributions for production of charged pions from interactions with energies below 160 A GeV. This model is supported the assumption that the onset of de-confinement is located at low energies. It treats the initial nucleon-nucleon interactions within a string-hadronic framework. In addition, it includes effects such as string-string interactions and hadronic re-scattering that expected to be relevant in A+A collisions. There is a kind of similarity for mechanism responsible for production of the two charge states of pions and it can extended to other hadrons. Ultra-relativistic quantum molecular dynamic model give good description on energy dependence for charged pion productions and points of maximum rapidity. 

On transverse momentum spectra of negative pions in 12C+181Ta collisions at 4.2A GeV/c

2014 ◽  
Vol 23 (12) ◽  
pp. 1450084 ◽  
Author(s):  
Khusniddin K. Olimov ◽  
Akhtar Iqbal ◽  
S. L. Lutpullaev ◽  
Imran Khan ◽  
Viktor V. Glagolev ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Projectile Fragmentation ◽  
Minimum Bias ◽  
Fragmentation Region ◽  
Rapidity Range ◽  
Gaussian Functions ◽  
Collision Centrality ◽  
Hadron Spectra ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra

We studied the dependences of the experimental transverse momentum spectra of the negative pions, produced in minimum bias 12 C +181 Ta collisions at a momentum of 4.2 GeV/c per nucleon, on the collision centrality and the pion rapidity range. To examine quantitatively, the change in the shape of the pt spectra of π- mesons with the change of collision centrality and the pion rapidity range, all the extracted pt spectra were fitted by the four different functions commonly used for describing the hadron spectra. The extracted values of the spectral temperatures T1 and T2 were consistently larger for the pt spectra of π- mesons coming from midrapidity range as compared to those of the negative pions generated in the target and projectile fragmentation regions. The spectral temperatures of the negative pions coming from projectile fragmentation region proved to be larger than the respective temperatures of the negative pions coming from target fragmentation region. The extracted spectral temperatures T1 and T2 of the pt spectra of π- mesons were compatible within the uncertainties for the peripheral, semicentral and central 12 C +181 Ta collision events, selected using the number of participant protons. It was observed that Hagedorn and Boltzmann functions are more appropriate for describing the transverse momentum spectra of the negative pions as contrasted to Simple Exponential and Gaussian functions.

scholarly journals Significance of gluon density at soft and hard processes at LHC

2015 ◽  
Vol 39 ◽  
pp. 1560115
Author(s):  
A. A. Grinyuk ◽  
A. V. Lipatov ◽  
G. I. Lykasov
Keyword(s):  
Exact Solution ◽  
Transverse Momentum ◽  
Gluon Distribution ◽  
Gluon Density ◽  
Bfkl Equation ◽  
Transverse Momentum Dependent ◽  
Hadron Spectra ◽  
Saturation Region ◽  
Gluon Content

We study the role of the non-perturbative input to the transverse momentum dependent (TMD) gluon density in hard processes at the LHC. We derive the TMD gluon distribution from the fit of the inclusive hadron spectra measured at low transverse momenta in [Formula: see text] collisions at the LHC and demonstrate that the best description of these spectra for larger hadron transverse momenta can be achieved by matching the derived TMD gluon distribution with the exact solution of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation obtained at small transverse momenta outside the saturation region. A special attention is put to the phenomenological applications of presented TMD parton densities to some LHC processes, which are sensitive to the quark and gluon content of a proton.

scholarly journals High transverse momentum hadron spectra atsNN=17.3GeV inPb+Pbandp+pcollisions

2008 ◽  
Vol 77 (3) ◽  
Author(s):  
C. Alt ◽  
T. Anticic ◽  
B. Baatar ◽  
D. Barna ◽  
J. Bartke ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
High Transverse Momentum ◽  
Hadron Spectra
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