scholarly journals Transverse spherocity dependence of azimuthal anisotropy in heavy-ion collisions at the LHC using a multi-phase transport model

2021 ◽  
Author(s):  
Neelkamal Mallick ◽  
Raghunath Sahoo ◽  
Sushanta Tripathy ◽  
Antonio Ortiz
2020 ◽  
Vol 29 (08) ◽  
pp. 2050057
Author(s):  
De-Xian Wei

Based on A Multi-Phase Transport (AMPT) model simulations, the transverse momentum dependent decorrelation has been studied in Pb–Pb collisions at [Formula: see text] and 5.02 TeV, respectively. It has been found that the mix-order factorization ratio [Formula: see text] value deviates significantly from unity in noncentral collisions. Such effect becomes stronger with an increase in the [Formula: see text] difference [Formula: see text]. These decorrelations are not only between the same order harmonic but also between the different order harmonic, which as a result of the initial fluctuations appear between the different phase spaces. It has also been found that the correlations involving higher powers of the flow vector yield stronger decorrelation, [Formula: see text], except for the weighted factorization ratio [Formula: see text]. The breaking phenomenon of these factorization ratios indicated that it provides a possible observation for studying the initial fluctuation properties of heavy-ion collisions.


2018 ◽  
Vol 171 ◽  
pp. 14004 ◽  
Author(s):  
Yuncun He ◽  
Zi-Wei Lin

The current version of a multi-phase transport (AMPT) model with string melting can reasonably describe the dN/dy yields, pT spectra and anisotropic flows of pions and kaons at low pT in heavy ion collisions at RHIC and LHC energies, although it failed to reproduce the dN/dy and pT spectra of baryons. In this work, we improve the quark coalescence mechanism in AMPT by removing the forced separate number conservations of mesons, baryons and antibaryons in each event. We find that the improved AMPT model can better describe the yields at midrapidity, the pT spectra and elliptic flow of low-pT baryons in comparison with the experimental data. Antiparticle-to-particle ratios of strange baryons are also significantly improved.


2015 ◽  
Vol 24 (05) ◽  
pp. 1550041 ◽  
Author(s):  
Subhash Singha ◽  
Bedangadas Mohanty ◽  
Zi-Wei Lin

We have studied the K* production within a multi-phase transport model (AMPT) for Au + Au collisions at [Formula: see text] to understand the hadronic re-scattering effect on the measured yields of the resonance. The hadronic re-scattering of the K* decay daughter particles (π and K) will alter their momentum distribution thereby making it difficult to reconstruct the K* signal through the invariant mass method. An increased hadronic re-scattering effect thus leads to a decrease in the reconstructed yield of K* in the heavy-ion collisions. Through this simulation study, we argue that a decrease in K*/K ratio with the increase in collision centrality necessarily reflects the hadronic re-scattering effect. Since the re-scattering occurs in the hadronic phase and K* has a lifetime of 4 fm/c, we present a toy model-based discussion on using measured K*/K to put a lower limit on the hadronic phase lifetime in high energy nuclear collisions.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Gao-Feng Wei ◽  
Guo-Qiang He ◽  
Xin-Wei Cao ◽  
Yi-Xin Lu

The impact parameter dependence ofπ-/π+ratio is examined in heavy-ion collisions at 400 MeV/nucleon within a transport model. It is shown that the sensitivity ofπ-/π+ratio on symmetry energy shows a transition from central to peripheral collisions; that is, the stiffer symmetry energy leads to a largerπ-/π+ratio in peripheral collisions while the softer symmetry energy always leads this ratio to be larger in central collisions. After checking the kinematic energy distribution ofπ-/π+ratio, we found this transition of sensitivity ofπ-/π+ratio to symmetry energy is mainly from less energetic pions; that is, the softer symmetry energy gets the less energetic pions to form a smallerπ-/π+ratio in peripheral collisions while these pions generate a largerπ-/π+ratio in central collisions. Undoubtedly, the softer symmetry energy can also lead more energetic pions to form a largerπ-/π+ratio in peripheral collisions. Nevertheless, considering that most of pions are insufficiently energetic at this beam energy, we therefore suggest theπ-/π+ratio as a probe of the high-density symmetry energy effective only in central at most to midcentral collisions, thereby avoiding the possible information of low-density symmetry energy carried inπ-/π+ratio from peripheral collisions.


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