Radiative and Collisional Jet Energy Loss in the Quark-Gluon Plasma at the BNL Relativistic Heavy Ion Collider

The discovery of the jet quenching in central Au + Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory has provided clear evidence for the formation of strongly interacting dense matter. It has been predicted to occur due to the energy loss of high energy partons that propagate through the quark–gluon plasma. In this paper we investigate the dependence of the parton energy loss due to elastic scatterings in a parton plasma on the value of the strong coupling and its running with the evolution of the system. We analyze different prescriptions for the QCD coupling and calculate the energy and length dependence of the fractional energy loss. Moreover, the partonic quenching factor for light and heavy quarks is estimated. We found that the predicted enhancement of the heavy to light hadrons (D/π) ratio is strongly dependent on the running of the QCD coupling constant.

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On Pseudorapidity Distribution and Speed of Sound in High Energy Heavy Ion Collisions Based on a New Revised Landau Hydrodynamic Model

Advances in High Energy Physics ◽

10.1155/2015/184713 ◽

2015 ◽

Vol 2015 ◽

pp. 1-23 ◽

Cited By ~ 5

Author(s):

Li-Na Gao ◽

Fu-Hu Liu

Keyword(s):

Speed Of Sound ◽

Hydrodynamic Model ◽

Quark Gluon Plasma ◽

Heavy Ion Collisions ◽

Heavy Ion ◽

Gluon Plasma ◽

High Energy ◽

Relativistic Heavy Ion Collider ◽

Central Source ◽

Ion Collisions

We propose a new revised Landau hydrodynamic model to study systematically the pseudorapidity distributions of charged particles produced in heavy ion collisions over an energy range from a few GeV to a few TeV per nucleon pair. The interacting system is divided into three sources, namely, the central, target, and projectile sources, respectively. The large central source is described by the Landau hydrodynamic model and further revised by the contributions of the small target/projectile sources. The modeling results are in agreement with the available experimental data at relativistic heavy ion collider, large hadron collider, and other energies for different centralities. The value of square speed of sound parameter in different collisions has been extracted by us from the widths of rapidity distributions. Our results show that, in heavy ion collisions at energies of the two colliders, the central source undergoes a phase transition from hadronic gas to quark-gluon plasma liquid phase; meanwhile, the target/projectile sources remain in the state of hadronic gas. The present work confirms that the quark-gluon plasma is of liquid type rather than being of a gas type.

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STUDY OF VECTOR MESON FRAGMENTATION USING A BROKEN SU(3) MODEL

International Journal of Modern Physics A ◽

10.1142/s0217751x12501035 ◽

2012 ◽

Vol 27 (19) ◽

pp. 1250103 ◽

Cited By ~ 7

Author(s):

D. INDUMATHI ◽

H. SAVEETHA

Keyword(s):

Quark Gluon Plasma ◽

Light Quark ◽

Heavy Ion ◽

Gluon Plasma ◽

Dglap Evolution ◽

Relativistic Heavy Ion Collider ◽

Breaking Parameter ◽

Fragmentation Functions ◽

Scaled Energy ◽

Gluon Fragmentation

Inclusive hadro-production in e+e- annihilation processes is examined to study the fragmentation process. A broken SU(3) model is used to determine the quark and gluon fragmentation functions of octet vector mesons, ρ and K*, in a simple way with an SU(3) breaking parameter λ. These are expressed in terms of just two light quark fragmentation functions, V(x, Q2) and γ(x, Q2) and the gluon fragmentation function Dg(x, Q2). These functions are parametrized at the low input scale of [Formula: see text], evolved through LO DGLAP evolution including charm and bottom flavor at appropriate thresholds, and fitted by comparison with data at the Z-pole. The model is extended with the introduction of a few additional parameters to include a study of singlet–octet mixing and hence ω and ϕ fragmentation. The model gives good fits to the available data for x ≳0.01, where x is the scaled energy of the hadron. The model is then applied successfully to ω, ϕ production in pp collisions at the relativistic heavy ion collider, RHIC, these data form an important baseline for the study of Quark Gluon Plasma in heavy nucleus collisions at RHIC, and also in future at the LHC.

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THERMAL RADIATION FROM AN EVOLVING VISCOUS QUARK GLUON PLASMA

International Journal of Modern Physics E ◽

10.1142/s0218301313500043 ◽

2013 ◽

Vol 22 (01) ◽

pp. 1350004 ◽

Cited By ~ 1

Author(s):

SUKANYA MITRA ◽

PAYAL MOHANTY ◽

SOURAV SARKAR ◽

JAN-E ALAM

Keyword(s):

Quark Gluon Plasma ◽

Heavy Ion ◽

Gluon Plasma ◽

Viscous Effects ◽

Relativistic Heavy Ion Collider ◽

Nuclear Collisions ◽

Evolution Dynamics ◽

Small Change ◽

Photon Spectra ◽

Space Time Evolution

The effects of viscosity on the space-time evolution of quark gluon plasma produced in nuclear collisions at relativistic heavy ion collider energies have been studied. The entropy generated due to the viscous motion of the fluid has been taken into account in constraining the initial temperature by the final multiplicity (measured at the freeze-out point). The viscous effects on the photon spectra has been introduced consistently through the evolution dynamics and phase space factors of all the participating partons/hadrons in the production process. In contrast to some of the recent calculations the present work includes the contribution from the hadronic phase. A small change in the transverse momentum (pT) distribution of photons is observed due to viscous effects.

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Jet energy loss and high photon production in hot quark-gluon plasma

Nuclear Physics A ◽

10.1016/j.nuclphysa.2009.10.040 ◽

2009 ◽

Vol 830 (1-4) ◽

pp. 459c-462c ◽

Cited By ~ 2

Author(s):

G.-Y. Qin ◽

C. Gale ◽

S. Jeon ◽

G.D. Moore ◽

J. Ruppert

Keyword(s):

Energy Loss ◽

Quark Gluon Plasma ◽

Gluon Plasma ◽

Photon Production ◽

Jet Energy

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Parton showers as sources of energy-momentum deposition in the quark-gluon plasma and their implication for shockwave formation at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

Physical Review C ◽

10.1103/physrevc.86.024905 ◽

2012 ◽

Vol 86 (2) ◽

Cited By ~ 31

Author(s):

R. B. Neufeld ◽

I. Vitev

Keyword(s):

Large Hadron Collider ◽

Quark Gluon Plasma ◽

Hadron Collider ◽

Heavy Ion ◽

Gluon Plasma ◽

Relativistic Heavy Ion Collider ◽

Cern Large Hadron Collider

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Measuring the isotropization time of quark-gluon plasma from direct photons at energies available at the BNL Relativistic Heavy Ion Collider (RHIC)

Physical Review C ◽

10.1103/physrevc.79.054910 ◽

2009 ◽

Vol 79 (5) ◽

Cited By ~ 17

Author(s):

Lusaka Bhattacharya ◽

Pradip Roy

Keyword(s):

Quark Gluon Plasma ◽

Heavy Ion ◽

Gluon Plasma ◽

Relativistic Heavy Ion Collider ◽

Direct Photons

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Measurements of jets in heavy ion collisions

EPJ Web of Conferences ◽

10.1051/epjconf/201817205010 ◽

2018 ◽

Vol 172 ◽

pp. 05010 ◽

Cited By ~ 2

Author(s):

Christine Nattrass

Keyword(s):

Energy Loss ◽

Heavy Ion Collisions ◽

Particle Production ◽

Hadron Collider ◽

Heavy Ion ◽

Gluon Plasma ◽

High Energy ◽

Jet Quenching ◽

Relativistic Heavy Ion Collider ◽

Ion Collisions

The Quark Gluon Plasma (QGP) is created in high energy heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). This medium is transparent to electromagnetic probes but nearly opaque to colored probes. Hard partons produced early in the collision fragment and hadronize into a collimated spray of particles called a jet. The partons lose energy as they traverse the medium, a process called jet quenching. Most of the lost energy is still correlated with the parent parton, contributing to particle production at larger angles and lower momenta relative to the parent parton than in proton-proton collisions. This partonic energy loss can be measured through several observables, each of which give different insights into the degree and mechanism of energy loss. The measurements to date are summarized and the path forward is discussed.

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Radiative and collisional jet energy loss in a quark-gluon plasma

Indian Journal of Physics ◽

10.1007/s12648-011-0092-9 ◽

2011 ◽

Vol 85 (6) ◽

pp. 873-877 ◽

Cited By ~ 1

Author(s):

G. Y. Qin ◽

J. Ruppert ◽

C. Gale ◽

S. Jeon ◽

G. D. Moore ◽

...

Keyword(s):

Energy Loss ◽

Quark Gluon Plasma ◽

Gluon Plasma ◽

Jet Energy

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Energy Loss in Perturbative QCD

Annual Review of Nuclear and Particle Science ◽

10.1146/annurev.nucl.50.1.37 ◽

2000 ◽

Vol 50 (1) ◽

pp. 37-69 ◽

Cited By ~ 455

Author(s):

R. Baier ◽

D. Schiff ◽

B. G. Zakharov

Keyword(s):

Energy Loss ◽

Quark Gluon Plasma ◽

Heavy Ion ◽

Gluon Plasma ◽

Radiative Energy ◽

Opening Angle ◽

Radiative Energy Loss ◽

Ion Collisions ◽

Theoretical Approaches ◽

The Difference

▪ Abstract We review the propagation of energetic partons in hot or cold QCD matter, as known from recent work. We summarize advances in the understanding of both collisional and radiative energy loss. Our emphasis is on radiative energy loss, which has very interesting properties that may help to detect the quark-gluon plasma produced in heavy-ion collisions. We describe two different theoretical approaches, which lead to the same radiated gluon energy spectrum. The case of a longitudinally expanding QCD plasma is investigated. The energy lost by a jet with given opening angle is calculated with the aim of making predictions for the suppression (quenching) of hard jet production. Phenomenological implications for the difference between hot and cold matter are discussed. Numerical estimates of the loss suggest that it may be significantly greater in hot matter than in cold. This makes the magnitude of the radiative energy loss a remarkable signal for quark-gluon plasma formation.

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