Transverse momentum spectra of heavy baryons and mesons in forward rapidity range in small collision system at the LHC

2019 ◽  
Vol 94 (9) ◽  
pp. 1431-1450
Author(s):  
Li-Na Gao ◽  
Fu-Hu Liu
2014 ◽  
Vol 23 (12) ◽  
pp. 1450084 ◽  
Author(s):  
Khusniddin K. Olimov ◽  
Akhtar Iqbal ◽  
S. L. Lutpullaev ◽  
Imran Khan ◽  
Viktor V. Glagolev ◽  
...  

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Xing-Wei He ◽  
Feng-Min Wu ◽  
Hua-Rong Wei ◽  
Bi-Hai Hong

We describe the transverse momentum spectra or transverse mass spectra of π ± , K ± , p , and p ¯ produced in central gold-gold (Au-Au), central lead-lead (Pb-Pb), and inelastic proton-proton (pp) collisions at different collision energies range from the AGS to LHC by using a two-component (in most cases) Erlang distribution in the framework of multisource thermal model. The fitting results are consistent with the experimental data, and the final-state yield ratios of negative to positive particles are obtained based on the normalization constants from the above describing the transverse momentum (or mass) spectra. The energy-dependent chemical potentials of light hadrons ( π , K , and p ) and quarks ( u , d , and s ) in central Au-Au, central Pb-Pb, and inelastic (pp) collisions are then extracted from the modified yield ratios in which the contributions of strong decay from high-mass resonance and weak decay from heavy flavor hadrons are removed. The study shows that most types of energy-dependent chemical potentials decrease with increase of collision energy over a range from the AGS to LHC. The curves of all types of energy-dependent chemical potentials, obtained from the fits of yield ratios vs. energy, have the maximum at about 3.510 GeV, which possibly is the critical energy of phase transition from a liquid-like hadron state to a gas-like quark state in the collision system. At the top RHIC and LHC, all types of chemical potentials become small and tend to zero at very high energy, which confirms that the high energy collision system possibly changes completely from the liquid-like hadron-dominant state to the gas-like quark-dominant state and the partonic interactions possibly play a dominant role at the LHC.


2014 ◽  
Vol 23 (09) ◽  
pp. 1450047 ◽  
Author(s):  
Akhtar Iqbal ◽  
Khusniddin K. Olimov ◽  
Imran Khan ◽  
B. S. Yuldashev ◽  
Mahnaz Q. Haseeb

The dependences of the experimental transverse momentum spectra of the negative pions, produced in minimum bias 12 C + 12 C collisions at a momentum of 4.2A GeV/c, on the collision centrality and the pion rapidity range were studied. To analyze quantitatively the change in the pt spectra of π- mesons with the changes of collision centrality and pion rapidity range, the extracted pt spectra were fitted by Hagedorn, Boltzmann, Simple Exponential and Gaussian functions. The values of the extracted 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 T1 and T2 extracted from fitting the pt spectra of π- mesons in range pt = 0.1–1.2 GeV/c practically coincided with each other in peripheral, semicentral and central 12 C + 12 C collision events, and thus did not show any collision centrality dependence. However, the values of T1 and T2 extracted from fitting in range pt = 0.1–0.7 GeV/c were consistently and noticeably larger in case of central collisions as compared to peripheral and semicentral 12 C + 12 C collisions. Hagedorn and Boltzmann functions provided significantly better fits of the transverse momentum spectra of the negative pions with the physically acceptable values of the extracted temperatures as compared to Gaussian and Simple Exponential functions.


2018 ◽  
Vol 171 ◽  
pp. 13006
Author(s):  
Alessandro De Falco

The ALICE Collaboration has measured ϕ meson production in the dimuon channel at the forward rapidity (2.5 < y < 4) in pp and Pb–Pb collisions at several center of mass energies. Results in pp collisions at center of mass energies √s = 5.02 and 8 TeV are reported. They complement the previously published results at √s = 2.76 and √s = 7 TeV, providing a solid baseline for Pb–Pb collisions. In Pb–Pb, the preliminary ϕ meson transverse momentum spectra for different centrality classes and the yields as a function of the collision centrality in the transverse momentum range 2 < pT < 7 GeV/c are presented.


Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 488
Author(s):  
Muhammad Waqas ◽  
Guang-Xiong Peng

Transverse momentum spectra of π+, p, Λ, Ξ or Ξ¯+, Ω or Ω¯+ and deuteron (d) in different centrality intervals in nucleus–nucleus collisions at the center of mass energy are analyzed by the blast wave model with Boltzmann Gibbs statistics. We extracted the kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume from the transverse momentum spectra of the particles. It is observed that the non-strange and strange (multi-strange) particles freezeout separately due to different reaction cross-sections. While the freezeout volume and transverse flow velocity are mass dependent, they decrease with the resting mass of the particles. The present work reveals the scenario of a double kinetic freezeout in nucleus–nucleus collisions. Furthermore, the kinetic freezeout temperature and freezeout volume are larger in central collisions than peripheral collisions. However, the transverse flow velocity remains almost unchanged from central to peripheral collisions.


Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 803
Author(s):  
Hai-Ling Lao ◽  
Fu-Hu Liu ◽  
Bo-Qiang Ma

The transverse momentum spectra of different types of particles, π±, K±, p and p¯, produced at mid-(pseudo)rapidity in different centrality lead–lead (Pb–Pb) collisions at 2.76 TeV; proton–lead (p–Pb) collisions at 5.02 TeV; xenon–xenon (Xe–Xe) collisions at 5.44 TeV; and proton–proton (p–p) collisions at 0.9, 2.76, 5.02, 7 and 13 TeV, were analyzed by the blast-wave model with fluctuations. With the experimental data measured by the ALICE and CMS Collaborations at the Large Hadron Collider (LHC), the kinetic freeze-out temperature, transverse flow velocity and proper time were extracted from fitting the transverse momentum spectra. In nucleus–nucleus (A–A) and proton–nucleus (p–A) collisions, the three parameters decrease with the decrease of event centrality from central to peripheral, indicating higher degrees of excitation, quicker expansion velocities and longer evolution times for central collisions. In p–p collisions, the kinetic freeze-out temperature is nearly invariant with the increase of energy, though the transverse flow velocity and proper time increase slightly, in the considered energy range.


2012 ◽  
Vol 86 (9) ◽  
Author(s):  
O. Adriani ◽  
L. Bonechi ◽  
M. Bongi ◽  
G. Castellini ◽  
R. D’Alessandro ◽  
...  

2017 ◽  
Vol 32 (05) ◽  
pp. 1750029 ◽  
Author(s):  
M. V. Tokarev ◽  
I. Zborovský

Experimental data on transverse momentum spectra of strange particles [Formula: see text] produced in [Formula: see text] collisions at [Formula: see text] obtained by the STAR and PHENIX collaborations at RHIC are analyzed in the framework of [Formula: see text]-scaling approach. The concept of the [Formula: see text]-scaling is based on fundamental principles of self-similarity, locality, and fractality of hadron interactions at high energies. General properties of the data [Formula: see text]-presentation are studied. Self-similarity of fractal structure of protons and fragmentation processes with strange particles is discussed. A microscopic scenario of constituent interactions developed within the [Formula: see text]-scaling scheme is used to study the dependence of momentum fractions and recoil mass on the collision energy, transverse momentum and mass of produced inclusive particle, and to estimate the constituent energy loss. We consider that obtained results can be useful in study of strangeness origin, in searching for new physics with strange probes, and can serve for better understanding of fractality of hadron interactions at small scales.


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