A Multiphase Transport Research Articles

Jet-induced enhancement of deuteron production in pp and p-Pb collisions at the LHC

Jet-associated deuteron production in pp collisions at s=13 TeV and p-Pb collisions at sNN=5.02 TeV is studied in the coalescence model by using the phase-space information of proton and neutron pairs from a multiphase transport (AMPT) model at the kinetic freezeout. In the low transverse momentum (pT) region pT/A<1.5 GeV/c, where A is the mass number of a nucleus, the in-jet coalescence factor B2In-jet for deuteron production, given by the ratio of the in-jet deuteron number to the square of the in-jet proton number, is found to be larger than the coalescence factor B2 in the medium perpendicular to the jet by a factor of about 10 in pp collisions and of 25 in p−Pb collisions, which are consistent with the ALICE measurements at the LHC. Such large low-momentum enhancements mainly come from coalescence of nucleons inside the jet with the medium nucleons. Coalescence of nucleons inside the jet dominates deuteron production only at the higher pT region of pT/A≳4 GeV/c, where both the yield ratio d/p of deuteron to proton numbers and the B2 are also significantly larger in the jet direction than in the direction perpendicular to the jet due to the strong collinear correlation among particles produced from jet fragmentation. Studying jet-associated deuteron production in relativistic nuclear collisions thus opens up a new window to probe the phase-space structure of nucleons inside jets.

Study of baryon number transport dynamics and strangeness conservation effects using Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega$$\\end{document}-hadron correlations

In nuclear collisions at RHIC energies, an excess of Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega$$\\end{document} hyperons over Ω¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\bar{\\Omega }$$\\end{document} is observed, indicating that Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega$$\\end{document} has a net baryon number despite s and s¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\bar{s}$$\\end{document} quarks being produced in pairs. The baryon number in Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega$$\\end{document} may have been transported from the incident nuclei and/or produced in the baryon-pair production of Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega$$\\end{document} with other types of anti-hyperons such as Ξ¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\bar{\\Xi }$$\\end{document}. To investigate these two scenarios, we propose to measure the correlations between Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega$$\\end{document} and K and between Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega$$\\end{document} and anti-hyperons. We use two versions, the default and string-melting, of a multiphase transport (AMPT) model to illustrate the method for measuring the correlation and to demonstrate the general shape of the correlation. We present the Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Omega$$\\end{document}-hadron correlations from simulated Au+Au collisions at sNN=7.7\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sqrt{s_\ ext{NN}} = 7.7$$\\end{document} and 14.6GeV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$14.6 \\ \ extrm{GeV}$$\\end{document} and discuss the dependence on the collision energy and on the hadronization scheme in these two AMPT versions. These correlations can be used to explore the mechanism of baryon number transport and the effects of baryon number and strangeness conservation on nuclear collisions.

Transverse momentum spectra of f0(980) from coalescence model

We use a coalescence model to generate f0(980) particles for four configurations: ss¯ meson, uu¯ss¯ tetraquark, KK¯ molecule, and uu¯ p-wave state. The phase-space information of the coalescing constituents is taken from a multi-phase transport (AMPT) simulation of proton-proton (pp) and proton-lead (pPb) collisions at the LHC. It is shown that the transverse momentum spectra and production yields of f0(980) differ significantly among the configurations. It is suggested that the pT spectra of the f0(980) compared to those of other hadrons (such as pion) and the ratio of the f0(980)pT spectra in pPb over pp collisions can be exploited to tell the configuration of the f0(980).

Transverse momentum decorrelation of the flow vector in Pb–Pb collisions at sqrt{s_{_{textrm{NN}}}} = 5.02 TeV

Anisotropic flow, typically defined as the azimuthal correlations of the produced particles with respect to the common symmetry plane over a large kinematic, has been a popular approach in the last three decades to explore the properties of hot and dense QCD matter in high-energy heavy-ion collisions. These flow studies are usually based on the multi-particle correlations method, assuming that multi-particle correlations can be factorized into the product of flow coefficients. However, recent LHC measurements, based on new four-particle correlation observables, show evidence of flow angle decorrelation and flow magnitude decorrelation. These decorrelations break the assumption of the common symmetry plane and factorization. In this paper, we perform systematic studies to investigate the decorrelation with A Multi-Phase Transport (AMPT) model. We examine different tunings of the initial conditions, partonic cross sections, and hadronic interactions, revealing that the decorrelations are mainly driven by the initial geometry fluctuations while weakly influenced by the system’s dynamic evolution. Comparison to experimental data and the AMPT calculations presented in this paper promotes a new possibility to further constraints on the initial conditions of the heavy-ion collisions.

Exploring critical fluctuation phenomenon according to net-proton multiplicity information entropy in AMPT model

Information entropy can be used for investigating the critical fluctuation phenomenon by describing multiplicity fluctuations in heavy-ion collisions. In this study, a multiphase transport (AMPT) model in the default version (AMPT-DEF) and with the string melting (AMPT-SM) were used as event generators to simulate the Au+Au reaction at different incident energies. Owing to the influence of the distribution bin number in extracting its information entropy, two methods, i.e., data binning and weighting factors, were proposed to correct the information entropy analysis. The comparison between information entropy and kurtosis also reflects the necessity to correct the information entropy analysis. The corrected information entropy of net-proton multiplicity was analyzed in central Au+Au collisions at sNN= 4.7, 6.4, 7.7, 8.8, 11.5, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 140, 170, and 200 GeV with the impact parameter b=3 fm. The results indicated that the fluctuations of net-proton multiplicity were essentially identical at collision energies ranging from sNN= 4.7 GeV to sNN= 200 GeV in the same model. No critical fluctuation phenomenon was found in the central Au+Au collisions simulated using the AMPT models, similar to the case of the AMPT model, which does not have. Comparing the information entropy of AMPT-SM to AMPT-DEF, the effect of partonic phase leads to a bigger fluctuation, indicating that the corrected information entropy can be a useful probe to explore the phase transition. The mid-rapidity net-proton multiplicity information entropy was also calculated, and the results led to the same conclusion. The corrected information entropy may be useful for investigating critical fluctuations, which is important for exploring critical endpoint.

Impact of nuclear deformation on collective flow observables in relativistic U+U collisions

A Multi-Phase Transport (AMPT) model is used to investigate the efficacy of several flow observables to constrain the initial-state deformation of the Uranium nuclei in U$+$U collisions at nucleon-nucleon center-of-mass energy $\sqrt{s_{\mathrm{NN}}}$ = 193 GeV. The multiparticle azimuthal cumulant method is used to investigate the sensitivity of (I) a set of quantities that are sensitive to both initial- and final-state effects as well as (II) a set of dimensionless quantities that are more sensitive to initial-state effects to the Uranium nuclei quadrupole shape deformation. I find that the combined use of the flow harmonics, flow fluctuations and correlations, linear and nonlinear flow correlations to the quadrangular flow harmonic, and the correlations between elliptic flow and the mean-transverse momentum could serve to constrain the nuclear deformation of the Uranium nuclei. Therefore, a comprehensive set of measurements of such observables can provide a quantifying tool for the quadrupole shape deformation via data-model comparisons

Beam Energy Dependence of the Linear and Mode-Coupled Flow Harmonics Using the a Multi-Phase Transport Model

In the framework of the A Multi-Phase Transport (AMPT) model, the multi-particle azimuthal cumulant method is used to calculate the linear and mode-coupled contributions to the quadrangular flow harmonic (v4) and the mode-coupled response coefficient as functions of centrality in Au+Au collisions at sNN = 200, 39, 27 and 19.6 GeV. This study indicates that the linear and mode-coupled contributions to v4 are sensitive to beam energy change. Nevertheless, the correlations between different-order flow symmetry planes and the mode-coupled response coefficients show weak beam energy dependence. In addition, the presented results suggest that the experimental measurements that span a broad range of beam energies can be an additional constraint for the theoretical model calculations.

Measurements of second-harmonic Fourier coefficients from azimuthal anisotropies in p+p, p+Au, d+Au, and He3+Au collisions at sNN=200 GeV

Recently, the PHENIX Collaboration has published second- and third-harmonic Fourier coefficients $v_2$ and $v_3$ for midrapidity ($|\eta|<0.35$) charged hadrons in 0\%--5\% central $p$$+$Au, $d$$+$Au, and $^3$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV utilizing three sets of two-particle correlations for two detector combinations with different pseudorapidity acceptance [Phys. Rev. C {\bf 105}, 024901 (2022)]. This paper extends these measurements of $v_2$ to all centralities in $p$$+$Au, $d$$+$Au, and $^3$He$+$Au collisions, as well as $p$$+$$p$ collisions, as a function of transverse momentum ($p_T$) and event multiplicity. The kinematic dependence of $v_2$ is quantified as the ratio $R$ of $v_2$ between the two detector combinations as a function of event multiplicity for $0.5$$<$$p_T$$<$$1$ and $2$$<$$p_T$$<$$2.5$ GeV/$c$. A multiphase-transport (AMPT) model can reproduce the observed $v_2$ in most-central to midcentral $d$$+$Au and $^3$He$+$Au collisions. However, the AMPT model systematically overestimates the measurements in $p$$+$$p$, $p$$+$Au, and peripheral $d$$+$Au and $^3$He$+$Au collisions, indicating a higher nonflow contribution in AMPT than in the experimental data. The AMPT model fails to describe the observed $R$ for $0.5$$<$$p_T$$<$$1$ GeV/$c$, but there is qualitative agreement with the measurements for $2$$<$$p_T$$<$$2.5$ GeV/$c$.

First Order Harmonic Flow of Heavy Quarks using a Hybrid Transport Model

We report the investigation of the first order flow of charmed quarks in gold-to-gold collision at the energy near to the speed of the light using A Multi-Phase Transport (AMPT) model. We have used the AMPT string melting version known as partonic interactions option. In this study, we investigated the directed flow v1 of the charmed quark D0 as a function of rapidity. The model predicts the correct sign for D0v1, but the size of the predicted directed flow signal is too small by about an order of magnitude comparing to the real data from the STAR collaboration analysis. The AMPT model shows that the charm quark v1 magnitude is larger than that of the light quarks at large rapidity. This indicates that the charm quarks can retain more information from initial condition than the light quarks.

Pion, kaon, and (anti)proton production in U+U collisions at sNN=193 GeV measured with the STAR detector

We present the first measurements of transverse momentum spectra of $\pi^{\pm}$, $K^{\pm}$, $p(\bar{p})$ at midrapidity ($|y| < 0.1$) in U+U collisions at $\sqrt{s_{NN}}$ = 193 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The centrality dependence of particle yields, average transverse momenta, particle ratios and kinetic freeze-out parameters are discussed. The results are compared with the published results from Au+Au collisions at $\sqrt{s_{NN}} =$ 200 GeV in STAR. The results are also compared to those from A Multi Phase Transport (AMPT) model.

Simulations of momentum correlation functions of light (anti)nuclei in relativistic heavy-ion collisions at sNN=39 GeV

Momentum correlation functions of light (anti)nuclei formed by the coalescence mechanism of (anti)nucleons are calculated for several central heavy-ion collision systems, namely ${}_{5}^{10}\text{B}+{}_{5}^{10}\text{B}$, ${}_{8}^{16}\text{O}+{}_{8}^{16}\text{O}$, ${}_{20}^{40}\text{Ca}+{}_{20}^{40}\text{Ca}$, as well as ${}_{79}^{197}\text{Au}+{}_{79}^{197}\text{Au}$ in different centralities at center-of-mass energy $\sqrt{{s}_{NN}}$ = 39 GeV within the framework of a multiphase transport (AMPT) model complemented by the Lednick\'y and Lyuboshitz analytical method. Momentum correlation functions for identical or nonidentical light (anti)nuclei are constructed and analyzed for the above collision systems. The Au+Au results demonstrate that emission of light (anti)nuclei occurs from a source with smaller space extent in more peripheral collisions. The effect of system size on the momentum correlation functions of identical or nonidentical light (anti)nuclei is also explored by several collision system in central collisions. The results indicate that the emission source size of light (anti)nuclei pairs deduced from their momentum correlation functions and system size is self-consistent. Momentum correlation functions of nonidentical light nuclei pairs gated on velocity are applied to infer the average emission sequence of them. The results illustrate that protons are emitted on average on a timescale similar to neutrons but earlier than deuterons or tritons in the small relative momentum region. In addition, a larger interval of the average emission order among them is exhibited for smaller collision systems or at more peripheral collisions.

Investigation of dynamical pseudorapidity fluctuations using strongly intensive quantities on event-by-event basis in nucleus–nucleus interactions at CERN SPS energies

The event-by-event pseudorapidity and multiplicity fluctuations have been investigated for relativistic charged particles produced in [Formula: see text]O–AgBr at 60[Formula: see text]A[Formula: see text]GeV/c and 200[Formula: see text]A[Formula: see text]GeV/c, and [Formula: see text]S–AgBr at 200[Formula: see text]A[Formula: see text]GeV/c. The strongly intensive measures ([Formula: see text], [Formula: see text] and [Formula: see text]) have been studied to unravel the underlying dynamics of multiparticle production. The multiplicity and pseudorapidity dependence of these fluctuation measures has been investigated and significant deviations from the expected reference values of independent particle production model have been observed, implying the presence of genuine dynamical fluctuations and correlations in these interactions. These deviations are due to the correlated particle production and not the modifications in single-particle spectrum. The hadronic rescatterings present within the framework of a multi-phase transport (AMPT) model are found to have no significant impact on the behavior of these observables. Both default and string melting AMPT generally show the same qualitative behavior as that of the experimental data. However, the string melting AMPT exhibits slightly better quantitative agreement with the experimental results.

Single-particle space-momentum angle distribution effect on two-pion HBT correlation with Coulomb interaction

We calculate the HBT radius for with Coulomb interaction using the string melting version of a multiphase transport (AMPT) model. We study the relationship between the single-particle space-momentum angle and the particle sources and discuss HBT radii without single-particle space-momentum correlation. Additionally, we study the Coulomb interaction effect on the numerical connection between the single-particle space-momentum angle distribution and the transverse momentum dependence of .

Specific heat and its high-order moments in relativistic heavy-ion collisions from a multiphase transport model

Energy dependence of specific heat extracted from temperature fluctuation of Au + Au collisions at $\sqrt{{s}_{NN}}$ = 7.7 to 200 GeV was investigated by using a multiphase transport (AMPT) model. The results were compared with those from other models and some differences at low $\sqrt{{s}_{NN}}$ were found. To explain the above differences and describe the properties of the hot dense matter at low $\sqrt{{s}_{NN}}$, a new quantity ${C}_{v}^{*}$ was derived for describing specific heat in heavy-ion collisions. It was found that, by using ${C}_{v}^{*}$ together with its high-order moments (skewness and kurtosis), thermal properties of the hot dense matter can be described and different thermal properties with or without parton process can be clearly distinguished. The proposed observable provides a way to learn the property of QCD matter in heavy-ion collisions.

Impact of event activity variable on the ratio observables in isobar collisions

The STAR isobar data of 96Ru+96Ru and 96Zr+96Zr collisions at sNN=200 GeV show that ratios of observables (RO) such as the multiplicity distribution, p(Nch), and the harmonic flow, vn, deviate from unity, when presented as a function of centrality, c[1]. These deviations have been attributed to the differences in the shape and radial profiles between 96Ru and 96Zr nuclei. In addition, the ratios RO(x) depend on the choice of the event activity variable x, which could be either Nch or centrality. We estimate the difference ΔR between these two choices, based on the published p(Nch), as well as those from a multiphase transport (AMPT) model with varied nuclear structure parameters: nuclear radius (R0), surface diffuseness (a0), quadrupole deformation (β2), and octupole deformation (β3). In contrary to Rvn(c), Rvn(Nch) is nearly independent of the analysis approaches, suggesting that nonflow effects are better controlled by Nch than c. The ratios of observables sensitive to the chiral magnetic effect (CME) are also much closer to unity for x=Nch than x=c, indicating that the ratios calculated at the same Nch provide a better baseline for the non-CME background. According to the AMPT results, the dominant parameter for ΔR is a0, while R0 and βn are only important in central collisions. The published p(Nch) is also used to estimate ΔR〈pT〉 for mean transverse momentum, which is non-negligible compared with R〈pT〉−1.

Impact of nuclear structure on the background in the chiral magnetic effect in Ru4496+Ru4496 and Zr4096+Zr4096 collisions at sNN=7.7–200 GeV from a multiphase transport model

Impacts of nuclear structure on multiplicity $({N}_{\mathrm{ch}})$ and anisotropic flows $({v}_{2}$ and ${v}_{3})$ in the isobaric collisions of $_{44}^{96}\mathrm{Ru}+_{44}^{96}\mathrm{Ru}$ and $_{40}^{96}\mathrm{Zr}+_{40}^{96}\mathrm{Zr}$ at $\sqrt{{s}_{NN}}$ = 7.7, 27, 62.4, and 200 GeV are investigated by using the string melting version of a multiphase transport (AMPT) model. In comparison with the experimental data released recently by the STAR Collaboration, it is found that the impact of quadrupole deformation ${\ensuremath{\beta}}_{2}$ on the ${v}_{2}$ difference is mainly manifested in the most central collisions, while the octupole deformation ${\ensuremath{\beta}}_{3}$ is in the near-central collisions, and the neutron skin effect dominates in the mid-central collisions. Viewing from the energy dependence, these effects are magnified at lower energies.

Local and global polarization of Λ hyperons across RHIC-BES energies: The roles of spin hall effect, initial condition, and baryon diffusion

We perform a systematic study on the local and global spin polarization of $\mathrm{\ensuremath{\Lambda}}$ and $\overline{\mathrm{\ensuremath{\Lambda}}}$ hyperons in relativistic heavy-ion collisions at beam energy scan energies via the ($3+1$)-dimensional CLVisc hydrodynamics model with a multiphase transport (AMPT) and simulating many accelerated strongly interacting hadron (SMASH) initial conditions. Following the quantum kinetic theory, we decompose the polarization vector as the parts induced by thermal vorticity, shear tensor and the spin Hall effect (SHE). We find that the polarization induced by the SHE and the total polarization strongly depends on the initial conditions. At $7.7\phantom{\rule{0.28em}{0ex}}\mathrm{GeV}$, the SHE gives a sizable contribution and even flips the sign of the local polarization along the beam direction for the AMPT initial condition, which is not observed for the SMASH initial condition. Meanwhile, the local polarization along the out-of-plane direction induced by the SHE with the AMPT initial condition does not always increase with decreasing collision energies. Next, we find that the polarization along the beam direction is sensitive to the baryon diffusion coefficient, but the local polarization along the out-of-plane direction is not. Our results for the global polarization of $\mathrm{\ensuremath{\Lambda}}$ and $\overline{\mathrm{\ensuremath{\Lambda}}}$ agree well with the data of the STAR Collaboration. Interestingly, the global polarization of $\overline{\mathrm{\ensuremath{\Lambda}}}$ is not always larger than that of $\mathrm{\ensuremath{\Lambda}}$ due to various competing effects. Our findings are helpful for understanding the polarization phenomenon and the detailed structure of quark-gluon plasma in relativistic heavy-ion collisions.

Event topology and constituent-quark scaling of elliptic flow in heavy-ion collisions at the Large Hadron Collider using a multiphase transport model

Transverse spherocity is an event shape observable, which separates the events based on their geometrical shapes. In this work, we use transverse spherocity to study the identified light flavor production in heavy-ion collisions using A Multi-Phase Transport (AMPT) model. We obtain the elliptic flow coefficients for pions, kaons and protons in Pb+Pb collisions at sqrt{s_mathrm{{NN}}} = 5.02 TeV as a function of transverse spherocity and collision centrality. Also, we study the number of constituent-quark (NCQ) scaling of elliptic flow which interprets the dominance of the quark degrees of freedom at the early stages of the collision. We observe a clear dependence of the elliptic flow for identified particles on transverse spherocity. It is found that the NCQ-scaling is strongly violated in events with low transverse spherocity compared to transverse spherocity-integrated events, confirming the fragmentation-based hadronization mechanism for high-momentum partons involved in the dynamics of jetty-like events.

Exploring the effect of hadron cascade time on particle production in Xe+Xe collisions at sNN=5.44 TeV using a multiphase transport model

Heavy-ion collisions at ultrarelativistic energies provide extreme conditions of energy density and temperature to produce a deconfined state of quarks and gluons. Xenon (Xe), being a deformed nucleus, further gives access to the effect of initial geometry on final state particle production. This study focuses on the effect of nuclear deformation and hadron cascade-time on the particle production and elliptic flow using a multiphase transport (AMPT) model in $\mathrm{Xe}+\mathrm{Xe}$ collisions at $\sqrt{{s}_{NN}}=5.44\phantom{\rule{0.16em}{0ex}}\mathrm{TeV}$. We explore the effect of hadronic cascade time on identified particle production through the study of ${p}_{\mathrm{T}}$-differential particle ratios. The effect of hadronic cascade time on the generation of elliptic flow is studied by varying the cascade time between 5 and $25\phantom{\rule{0.16em}{0ex}}\mathrm{fm}/c$. This study shows the final state interactions among particles generate additional anisotropic flow with increasing hadron cascade time, especially at very low and high ${p}_{\mathrm{T}}$.

Event-shaped-dependent cumulants in p-Pb collisions at 5.02TeV

In this paper, we present a novel event-shaped cumulants (ESC) response approach, based on a multi-phase transport (AMPT) model simulations, to analyze p-Pb collisions at [Formula: see text] TeV. We find that the Pearson coefficients between the subset cumulants of the final harmonics [Formula: see text] and the subset cumulants of initial eccentricity [Formula: see text] in the ESC basis are significantly enhanced. These Pearson coefficients are strongly-dependent on the charged multiplicity, the set number of events (SNE), and only weakly-dependent on the order of the multi-particle cumulants (two-particles, four-particles, and so on). Our results show that the ESC method can suppress the event-by-event fluctuations.