The mean transverse momentum of ultracentral heavy-ion collisions: A new probe of hydrodynamics

An equation for parton multiplicity in cascade with the recombination 1 → 2 ⊕ 2 → 1 is derived from a Kolmogorov-Chapman equation and solved. An evolution parameter τ of the cascade depends on the c.m. energy [Formula: see text]; an explicit form of the dependence is obtained from the condition that the mean multiplicity of charged particles in pp, [Formula: see text] collisions be reproduced. A considerable decrease in the mean multiplicity in heavy-ion collisions per pair of the colliding nucleons at high energies is predicted and compared to the parton cascade with no recombination.

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Polarization in relativistic heavy ion collisions: a theoretical perspective

EPJ Web of Conferences ◽

10.1051/epjconf/201817107001 ◽

2018 ◽

Vol 171 ◽

pp. 07001 ◽

Cited By ~ 3

Author(s):

Francesco Becattini

Keyword(s):

Heavy Ion Collisions ◽

Theoretical Perspective ◽

Heavy Ion ◽

Hydrodynamical Model ◽

Relativistic Heavy Ion Collisions ◽

Spin Vector ◽

Ion Collisions ◽

The Mean ◽

Theoretical Issues ◽

Covariant Decomposition

We review the theoretical framework for the calculation of particle polarization in relativistic heavy ion collisions within the hydrodynamical model. The covariant decomposition of the mean spin vector is presented and open theoretical issues addressed.

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Quarkonium measurements in heavy-ion collisions with the STAR experiment

EPJ Web of Conferences ◽

10.1051/epjconf/201817118015 ◽

2018 ◽

Vol 171 ◽

pp. 18015

Author(s):

Xinjie Huang

Keyword(s):

Transverse Momentum ◽

Nuclear Matter ◽

Heavy Ion Collisions ◽

Theoretical Calculations ◽

Heavy Ion ◽

Matter Effects ◽

Nuclear Modification ◽

Ion Collisions ◽

Star Experiment ◽

Nuclear Modification Factors

In these proceedings, we present the latest measurements of J/ψ and ϒ by the STAR experiment. The J/ψ and ϒ production measured in p+p collisions provide new baselines for similar measurements in Au+Au collisions, while the measurements in p+Au collisions can help quantify the cold nuclear matter effects. The J/ψ υ2 is measured in both U+U and Au+Au collisions to place constraints on the amount of J/ψ arising from recombination of deconfined charm and anti-charm pairs. Furthermore, the nuclear modification factors for ground and excited ϒ states as a function of transverse momentum and centrality are presented, and compared to those measured at the LHC as well as to theoretical calculations.

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Transverse momentum dependent decorrelation in Pb–Pb collisions at LHC

International Journal of Modern Physics E ◽

10.1142/s0218301320500573 ◽

2020 ◽

Vol 29 (08) ◽

pp. 2050057

Author(s):

De-Xian Wei

Keyword(s):

Transverse Momentum ◽

Heavy Ion Collisions ◽

Heavy Ion ◽

Transverse Momentum Dependent ◽

Model Simulations ◽

Ion Collisions ◽

Difference Formula ◽

Multi Phase ◽

Phase Transport ◽

Different Order

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.

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Correlation coefficient between harmonic flow and transverse momentum in heavy-ion collisions

Physical Review C ◽

10.1103/physrevc.101.064902 ◽

2020 ◽

Vol 101 (6) ◽

Cited By ~ 2

Author(s):

Piotr Bożek ◽

Hadi Mehrabpour

Keyword(s):

Transverse Momentum ◽

Correlation Coefficient ◽

Heavy Ion Collisions ◽

Heavy Ion ◽

Ion Collisions ◽

Harmonic Flow

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ϒ(1S) transverse momentum spectra through dissociation and regeneration in heavy-ion collisions

Physics Letters B ◽

10.1016/j.physletb.2019.135147 ◽

2020 ◽

Vol 801 ◽

pp. 135147 ◽

Cited By ~ 4

Author(s):

Juhee Hong ◽

Su Houng Lee

Keyword(s):

Transverse Momentum ◽

Heavy Ion Collisions ◽

Heavy Ion ◽

Ion Collisions ◽

Momentum Spectra ◽

Transverse Momentum Spectra

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JET CONVERSIONS IN QGP AND SUPPRESSION OF IDENTIFIED HADRONS

International Journal of Modern Physics E ◽

10.1142/s021830130700726x ◽

2007 ◽

Vol 16 (07n08) ◽

pp. 1930-1936 ◽

Cited By ~ 5

Author(s):

WEI LIU ◽

CHE MING KO ◽

BEN-WEI ZHANG

Keyword(s):

Transverse Momentum ◽

Quark Gluon Plasma ◽

Heavy Ion Collisions ◽

Heavy Ion ◽

Gluon Plasma ◽

Relativistic Heavy Ion Collisions ◽

High Transverse Momentum ◽

Ion Collisions ◽

Conversion Rates ◽

Gluon Jets

A gluon or quark jet traversing through a quark-gluon plasma can be converted into a quark or gluon jet through scatterings with thermal partons. Their conversion rates due to two-body elastic and inelastic scattering as well as scatterings involving gluon radiation are evaluated in the lowest order in Quantum Chromodynamics (QCD). Including both energy loss and conversions of quark and gluon jets in the expanding quark-gluon plasma produced in relativistic heavy ion collisions, we find a net conversion of quark jets to gluon jets. This reduces the difference between the nuclear modification factors for quark and gluon jets in central heavy ion collisions and thus enhances the p/π+ and [Formula: see text] ratios at high transverse momentum. Using the larger QCD coupling constant from lattice QCD calculations than that given by the perturbative QCD further enhances the net quark to gluon jet conversion rate, leading to a closer similarity between these ratios at high transverse momentum in central Au + Au collisions at [Formula: see text] and in p + p collisions at same energy as observed in experiments.

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