scholarly journals Comparing the Tsallis Distribution with and without Thermodynamical Description inp+pCollisions

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
H. Zheng ◽  
Lilin Zhu
Keyword(s):  
Experimental Data ◽  
Transverse Momentum ◽  
Transverse Energy ◽  
Transverse Mass ◽  
Heavy Particles ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Extra Factor ◽  
Particle Spectra ◽  
Tsallis Distribution

We compare two types of Tsallis distribution, that is, with and without thermodynamical description, using the experimental data from the STAR, PHENIX, ALICE, and CMS Collaborations on the rapidity and energy dependence of the transverse momentum spectra inp+pcollisions. Both of them can fit the particle spectra well. We show that the Tsallis distribution with thermodynamical description gives lower temperatures than the ones without it. The extra factormT(transverse mass) in the Tsallis distribution with thermodynamical description plays an important role in the discrepancies between the two types of Tsallis distribution. But for the heavy particles, the choice to usemTorET(transverse energy) in the Tsallis distribution becomes more crucial.

Centrality and rapidity dependences of negative pions in He–C collisions at 4.2 A GeV/c

2019 ◽  
Vol 34 (12) ◽  
pp. 1950092
Author(s):  
Akhtar Iqbal ◽  
Khusniddin Olimov ◽  
Mushtaq Ahmad ◽  
Ali Zaman ◽  
Obaidullah Jan ◽  
...  
Keyword(s):  
Experimental Data ◽  
Transverse Momentum ◽  
String Model ◽  
Research Paper ◽  
Weak Dependence ◽  
Mathematical Functions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Two Temperature ◽  
Alpha Carbon

In the current research paper, we investigated the dependence of [Formula: see text] spectra of [Formula: see text] mesons on centrality of collision and different rapidity [Formula: see text] range. These negative pions are produced in Alpha–Carbon collisions at a momentum of 4.2 A GeV/c. We used Boltzmann and Hagedorn functions for one and two temperature fitting, of transverse momentum spectra obtained from experimental data and Model (Quark Gluon String Model, QGSM) data. By fitting these mathematical functions, we analyzed the change in shape of slopes of [Formula: see text] spectra. The fitting results for spectral temperatures were consistently larger (both in the experiment and QGSM) for the [Formula: see text] spectra of negative pions produced in range of mid-rapidity in comparison with those produced in fragmentation regions of colliding nuclei. It was also observed that extracted spectral temperatures from experimental data have a weak dependence on the collision centrality. The pion spectra can be described nicely by fitting two temperature functions for the experimental [Formula: see text] spectra for whole range and for the interval [Formula: see text]. In the [Formula: see text] range of [Formula: see text], one temperature functions were found sufficient for fitting the experimental [Formula: see text] spectra. The extracted temperatures from experimental data were found more sensitive to the fitting range of [Formula: see text], in contrast with temperatures obtained from QGSM data.

Combined analysis of midrapidity transverse momentum spectra of the charged pions and kaons, protons and antiprotons in p+p and Pb+Pb collisions at (snn)1/2 = 2.76 and 5.02 TeV at the LHC

2020 ◽  
Vol 35 (29) ◽  
pp. 2050237
Author(s):  
Khusniddin K. Olimov ◽  
Shakhnoza Z. Kanokova ◽  
Alisher K. Olimov ◽  
Kobil I. Umarov ◽  
Boburbek J. Tukhtaev ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Center Of Mass ◽  
Heavy Ion ◽  
Transverse Flow ◽  
Alice Collaboration ◽  
Momentum Spectra ◽  
Charged Pions ◽  
Transverse Momentum Spectra ◽  
Tsallis Distribution ◽  
Freeze Out

The experimental transverse momentum spectra of the charged pions and kaons, protons and antiprotons, produced at midrapidity in [Formula: see text] collisions at [Formula: see text] and 5.02 TeV, central (0–5%) and peripheral (60–80%) Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] TeV, central (0–5%), semicentral (40–50%) and peripheral (80–90%) Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] TeV, measured by ALICE collaboration, were analyzed using the Tsallis distribution function as well as Hagedorn formula with the embedded transverse flow. To exclude the influence (on the results) of different available fitting [Formula: see text] ranges in the analyzed collisions, we compare the results obtained from combined (simultaneous) fits of midrapidity spectra of the charged pions and kaons, protons and antiprotons with the above theoretical model functions using the identical fitting [Formula: see text] ranges in [Formula: see text] as well as Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] and 5.02 TeV. Using the combined fits with the thermodynamically consistent Tsallis distribution as well as the simple Tsallis distribution without thermodynamical description, it is obtained that the global temperature [Formula: see text] and non-extensivity parameter [Formula: see text] slightly increase (consistently for all the particle types) with an increase in center-of-mass (c.m.) energy [Formula: see text] of [Formula: see text] collisions from 2.76 TeV to 5.02 TeV, indicating that the more violent and faster [Formula: see text] collisions at [Formula: see text] TeV result in a smaller degree of thermalization (higher degree of non-equilibrium) compared to that in [Formula: see text] collisions at [Formula: see text] TeV. The [Formula: see text] values for pions and kaons proved to be very close to each other, whereas [Formula: see text] for protons and antiprotons proved to be significantly lower than that for pions and kaons, that is [Formula: see text]. The results of the combined fits using Hagedorn formula with the embedded transverse flow are consistent with practically no (zero) transverse (radial) flow in [Formula: see text] collisions at [Formula: see text] and 5.02 TeV. Using Hagedorn formula with the embedded transverse flow, it is obtained that the value of the (average) transverse flow velocity increases and the temperature [Formula: see text] decreases with an increase in collision centrality in Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] and 5.02 TeV, which is in good agreement with the results of the combined Boltzmann–Gibbs blast-wave fits to the particle spectra in Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] and 5.02 TeV in recent works of ALICE collaboration. The temperature [Formula: see text] parameter, which approximates the kinetic freeze-out temperature, was shown to coincide in central (0–5%) Pb[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] and 5.02 TeV, which implies, taking into account the results of our previous analysis, that kinetic freeze-out temperature stays practically constant in central heavy-ion collisions in [Formula: see text] GeV energy range.

scholarly journals Tsallis Statistical Interpretation of Transverse Momentum Spectra in High-EnergypA Collisions

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Bao-Chun Li ◽  
Zhao Zhang ◽  
Jun-Hui Kang ◽  
Guo-Xing Zhang ◽  
Fu-Hu Liu
Keyword(s):  
Transverse Momentum ◽  
Charged Pion ◽  
Statistical Interpretation ◽  
Incident Momentum ◽  
Proton Production ◽  
Momentum Spectra ◽  
Angular Interval ◽  
Transverse Momentum Spectra ◽  
Tsallis Distribution ◽  
The Difference

In Tsallis statistics, we investigate charged pion and proton production forpCu andpPb interactions at 3, 8, and 15 GeV/c. Two versions of Tsallis distribution are implemented in a multisource thermal model. A comparison with experimental data of the HARP-CDP group shows that they both can reproduce the transverse momentum spectra, but the improved form gives a better description. It is also found that the difference betweenqandq′is small when the temperatureT = T′for the same incident momentum and angular interval, and the value ofqis greater thanq′in most cases.

scholarly journals Kinetic Freeze-Out Properties from Transverse Momentum Spectra of Pions in High Energy Proton-Proton Collisions

Physics ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 277-308
Author(s):  
Li-Li Li ◽  
Fu-Hu Liu
Keyword(s):  
Transverse Momentum ◽  
Blast Wave ◽  
Complex Structure ◽  
Excitation Functions ◽  
Proton Proton ◽  
Proton Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Tsallis Distribution ◽  
Proton Proton Collisions

Transverse momentum spectra of negative and positive pions produced at mid-(pseudo)rapidity in inelastic or non-single-diffractive proton-proton collisions over a center-of-mass energy, s , range from a few GeV to above 10 TeV are analyzed by the blast-wave fit with Boltzmann (Tsallis) distribution. The blast-wave fit results are well fitting to the experimental data measured by several collaborations. In a particular superposition with Hagedorn function, both the excitation functions of kinetic freeze-out temperature ( T 0 ) of emission source and transverse flow velocity ( β T ) of produced particles obtained from a given selection in the blast-wave fit with Boltzmann distribution have a hill at s ≈ 10 GeV, a drop at dozens of GeV, and then an increase from dozens of GeV to above 10 TeV. However, both the excitation functions of T 0 and β T obtained in the blast-wave fit with Tsallis distribution do not show such a complex structure, but a very low hill. In another selection for the parameters or in the superposition with the usual step function, T 0 and β T increase generally quickly from a few GeV to about 10 GeV and then slightly at above 10 GeV, there is no such the complex structure, when also studying nucleus-nucleus collisions.

scholarly journals Squeezed spectra of bosons and antibosons with different in-medium masses

2021 ◽  
pp. 2150043
Author(s):  
Yong Zhang ◽  
Hui-Qiang Ding ◽  
Shi-Yao Wang
Keyword(s):  
Transverse Momentum ◽  
Mass Difference ◽  
Mass Region ◽  
Transverse Mass ◽  
Medium Mass ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
The Difference ◽  
Increasing Temperature ◽  
Freeze Out

In this paper, we study the influence of the in-medium mass difference between boson and antiboson on their spectra. The in-medium mass difference may lead to a difference between the transverse momentum spectra of boson and antiboson. This effect increases with the increasing in-medium mass difference between boson and antiboson. The difference between the transverse momentum spectra of boson and antiboson increases with the increasing expanding velocity of the source and decreases with the increasing transverse momentum in large transverse mass region ([Formula: see text][Formula: see text]GeV). The interactions between the hadron and the medium may increase with the increasing temperature of the medium and the higher freeze-out temperature may lead to a larger mass difference between boson and antiboson, and may give rise to a larger difference between the transverse momentum spectra of boson and antiboson for higher freeze-out temperature.

Systematic analysis of midrapidity transverse momentum spectra of identified charged particles in p + p collisions at (snn)1/2 = 2.76, 5.02, and 7 TeV at the LHC

2020 ◽  
Vol 35 (27) ◽  
pp. 2050167
Author(s):  
Khusniddin K. Olimov ◽  
Akhtar Iqbal ◽  
Samina Masood
Keyword(s):  
Transverse Momentum ◽  
Collision Energy ◽  
Radial Flow ◽  
Transverse Flow ◽  
Systematic Analysis ◽  
Limiting Behavior ◽  
Momentum Spectra ◽  
Charged Pions ◽  
Transverse Momentum Spectra ◽  
Tsallis Distribution

The experimental transverse momentum spectra of the charged pions and kaons, protons and antiprotons, produced at midrapidity in inelastic [Formula: see text] collisions at [Formula: see text], 5.02, and 7 TeV, measured by ALICE collaboration, are analyzed systematically using the thermodynamically consistent Tsallis distribution function as well as Hagedorn function with the embedded transverse flow. To compare directly the results obtained from combined (simultaneous) fits with the above theoretical model functions of midrapidity spectra of the charged pions and kaons, protons and antiprotons in [Formula: see text] collisions at [Formula: see text], 5.02, and 7 TeV, we use the optimal identical fitting [Formula: see text] ranges [Formula: see text] in [Formula: see text] collisions at [Formula: see text], 5.02, and 7 TeV. The parameter [Formula: see text] increases consistently for all the particle species with increasing [Formula: see text] of [Formula: see text] collisions from 2.76 to 5.02 TeV, remaining practically constant within fit errors in the collision energy range [Formula: see text] TeV, suggesting probably a saturation and limiting behavior of the [Formula: see text] value in [Formula: see text] collisions at [Formula: see text] TeV. Approximate equality of the extracted nonextensivity parameter [Formula: see text] for the pions and kaons ([Formula: see text]) and relation [Formula: see text] are obtained in [Formula: see text] collisions at [Formula: see text], 5.02, and 7 TeV. Very negligible transverse (radial) flow velocity (consistent with zero value within the fit errors) is obtained in [Formula: see text] collisions at [Formula: see text], 5.02, and 7 TeV from fitting the [Formula: see text] distributions of the charged pions and kaons, protons and antiprotons with the Hagedorn formula with the embedded transverse flow in the selected optimal identical [Formula: see text] ranges as well as in the full measured [Formula: see text] ranges.

scholarly journals Transverse momentum spectra of mesons in p+p collisions at CERN SPS energies from the UrQMD transport model

2019 ◽  
Vol 199 ◽  
pp. 05003
Author(s):  
Vitalii Ozvenchuk ◽  
Andrzej Rybicki
Keyword(s):  
Experimental Data ◽  
Transverse Momentum ◽  
Transport Model ◽  
Inverse Slope ◽  
Pion Multiplicity ◽  
Momentum Spectra ◽  
Rapidity Distributions ◽  
Inverse Slope Parameter ◽  
Transverse Momentum Spectra ◽  
Complicated Pattern

The UrQMD transport model, version 3.4, is used to study the new experimental data on total yields, rapidity distributions and transverse momentum spectra of π±, K±, p and $\bar p$ produced in inelastic p + p interactions at SPS energies, recently published by the NA61/SHINE Collaboration. The comparison of model predictions to these new measurements is presented as a function of collision energy. In addition, we compare with the experimental data the results on kaon-over-pion multiplicity ratio and the inverse slope parameter of negative kaons produced at midrapidity. A complicated pattern of discrepancies between the experimental data and the UrQMD transport model is apparent. We conclude that new experimental data analyzed in this contribution still constitute a challenge for the present version of the model.

scholarly journals Inferring freeze-out parameters from pion measurements at RHIC and LHC

2015 ◽  
Vol 24 (06) ◽  
pp. 1550046 ◽  
Author(s):  
Priyanka Sett ◽  
Prashant Shukla
Keyword(s):  
Transverse Momentum ◽  
System Size ◽  
Transverse Flow ◽  
Particle Multiplicity ◽  
Charged Particle Multiplicity ◽  
Momentum Range ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Tsallis Distribution ◽  
Freeze Out

We analyze the transverse momentum spectra of charged pions measured in Au + Au collisions at [Formula: see text] and in Pb + Pb collisions at [Formula: see text] using the Tsallis distribution modified to include transverse flow. All the spectra are well described by the modified Tsallis distribution in an extended transverse momentum range upto 6 GeV/c. The kinetic freeze-out temperature (T), average transverse flow (β) and degree of nonthermalization (q) are obtained as a function of system size for both the energies. With increasing system size β shows increasing trend whereas T remains constant. While the systems at RHIC and LHC energies show similar β and q, the parameter T is higher at LHC as compared to RHIC. The kinetic freeze-out temperature is also extracted using the measured charged particle multiplicity and HBT volume of the system as a function of system size and collision energies.

scholarly journals PRODUCTIONS OF HEAVY FLAVORED MESONS IN RELATIVISTIC HEAVY ION COLLISIONS IN THE RECOMBINATION MODEL

2011 ◽  
Vol 20 (05) ◽  
pp. 1213-1226 ◽  
Author(s):  
R. PENG ◽  
C. B. YANG
Keyword(s):  
Experimental Data ◽  
Transverse Momentum ◽  
Heavy Quark ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Recombination Model ◽  
Ion Collisions ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
Fragmentation Functions

We find the distributions of shower partons initiated by heavy quarks c and b by studying the fragmentation functions in the framework of the recombination model. The transverse momentum spectra of heavy flavored mesons are predicted with these distributions. We find that the contribution from the recombination of thermal-shower partons is an important part in the total spectrum for the mesons. We predict the heavy flavored meson productions for different centralities with the heavy quark fugacities fitted by the experimental data of J/ψ transverse momentum spectra in Au+Au collisions.

Spectres des particules négatives et des photons dans les collisions p–W, 16O–W et 32S–W à 200 GeV/nucléon

1989 ◽  
Vol 67 (12) ◽  
pp. 1219-1221
Author(s):  
Jean-Marc Beaulieu
Keyword(s):  
Transverse Momentum ◽  
Significant Variation ◽  
Transverse Energy ◽  
Momentum Spectra ◽  
200 Gev ◽  
Transverse Momentum Spectra ◽  
Several Intervals

Transverse momentum spectra of negative particles and photons have been measured in p + W, 16O + W, and 32S + W collisions, at a laboratory energy of 200 GeV/nucleon. Spectra obtained with the various beams and for several intervals of transverse energy were compared. No significant variation was detected.

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