scholarly journals Entanglement and fast quantum thermalization in heavy ion collisions

2016 ◽  
Vol 31 (18) ◽  
pp. 1650110 ◽  
Author(s):  
Chiu Man Ho ◽  
Stephen D. H. Hsu
Keyword(s):  
Hilbert Space ◽  
Central Region ◽  
Heavy Ion Collisions ◽  
Degrees Of Freedom ◽  
Entanglement Entropy ◽  
Heavy Ion ◽  
Entropy Formula ◽  
Ion Collisions ◽  
Gauge Gravity ◽  
Gravity Duality

Let [Formula: see text] be subsystem of a larger system [Formula: see text] and [Formula: see text] be a typical state from the subspace of the Hilbert space [Formula: see text] satisfying an energy constraint. Then [Formula: see text] is nearly thermal. We discuss how this observation is related to fast thermalization of the central region ([Formula: see text]) in heavy ion collisions (HIC), where [Formula: see text] represents other degrees of freedom (soft modes, hard jets, collinear particles) outside of [Formula: see text]. Entanglement between the modes in [Formula: see text] and [Formula: see text] play a central role: the entanglement entropy [Formula: see text] increases rapidly in the collision. In gauge–gravity duality, [Formula: see text] is related to the area of extremal surfaces in the bulk, which can be studied using gravitational duals.

Gauge-gravity duality and heavy-ion collisions

2007 ◽  
Author(s):  
D. T. Son ◽  
Arttu Rajantie ◽  
Carlo Contaldi ◽  
Paul Dauncey ◽  
Horace Stoica
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Ion Collisions ◽  
Gauge Gravity ◽  
Gravity Duality

Sudden increase in the degrees of freedom in dense QCD matter

2021 ◽  
Author(s):  
Aditya Nath Mishra ◽  
Guy Paić ◽  
C. Pajares ◽  
R. P. Scharenberg ◽  
B. K. Srivastava
Keyword(s):  
Charged Particle ◽  
Energy Density ◽  
Heavy Ion Collisions ◽  
Degrees Of Freedom ◽  
Initial Temperature ◽  
Heavy Ion ◽  
Particle Multiplicity ◽  
Sudden Increase ◽  
Alice Experiment ◽  
Ion Collisions

In this paper, we analyzed charged particle transverse momentum spectra in high multiplicity events in proton–proton and nucleus–nucleus collisions at LHC energies from the ALICE experiment using the color string percolation model (CSPM). The color reduction factor and associated string density parameters are extracted for various multiplicity classes in [Formula: see text] collisions and centrality classes for heavy-ion collisions at various LHC energies to study the effect of collision geometry and collision energy. These parameters are used to extract the thermodynamical quantities temperature and the energy density of the hot nuclear matter. A universal scaling is observed in initial temperature when studied as a function of charged particle multiplicity scaled by transverse overlap area. From the measured initial energy density [Formula: see text] and the initial temperature T, a dimensionless quantity [Formula: see text] is constructed which is used to obtain the degrees of freedom (DOF) of the deconfined phase. A two-step behavior and a sudden increase in DOF of [Formula: see text]47 for the ideal gas, above the hadronization temperature (T [Formula: see text] 210[Formula: see text]MeV), are observed in case of heavy-ion collisions at LHC energies.

scholarly journals On the interplay between magnetic field and anisotropy in holographic QCD

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Umut Gürsoy ◽  
Matti Järvinen ◽  
Govert Nijs ◽  
Juan F. Pedraza
Keyword(s):  
Magnetic Field ◽  
Entanglement Entropy ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Chiral Condensate ◽  
Temperature Anisotropy ◽  
Ion Collisions ◽  
Holographic Qcd ◽  
Gauge Gravity ◽  
The Magnetic Field

Abstract We investigate the combined effects of anisotropy and a magnetic field in strongly interacting gauge theories by the gauge/gravity correspondence. Our main motivation is the quark-gluon plasma produced in off-central heavy-ion collisions which exhibits large anisotropy in pressure gradients as well as large external magnetic fields. We explore two different configurations, with the anisotropy either parallel or perpendicular to the magnetic field, focusing on the competition and interplay between the two. A detailed study of the RG flow in the ground state reveals a rich structure where depending on which of the two, anisotropy or magnetic field, is stronger, intermediate geometries with approximate AdS4 × ℝ and AdS3 × ℝ2 factors arise. This competition is also manifest in the phase structure at finite temperature, specifically in the dependence of the chiral transition temperature on anisotropy and magnetic field, from which we infer the presence of inverse magnetic and anisotropic catalyses of the chiral condensate. Finally, we consider other salient observables in the theory, including the quark-antiquark potential, shear viscosity, entanglement entropy and the butterfly velocity. We demonstrate that they serve as good probes of the theory, in particular, distinguishing between the effects of the magnetic field and anisotropy in the ground and plasma states. We also find that the butterfly velocity, which codifies how fast information propagates in the plasma, exhibits a rich structure as a function of temperature, anisotropy and magnetic field, exceeding the conformal value in certain regimes.

PARTONIC EQUATION OF STATE IN HIGH-ENERGY NUCLEAR COLLISIONS

2007 ◽  
Vol 16 (03) ◽  
pp. 715-727 ◽  
Author(s):  
NU XU
Keyword(s):  
Equation Of State ◽  
Heavy Ion Collisions ◽  
Degrees Of Freedom ◽  
Collective Motion ◽  
Radial Flow ◽  
Heavy Ion ◽  
High Energy ◽  
Experimental Results ◽  
Nuclear Collisions ◽  
Ion Collisions

After a brief introduction to the physics of high-energy nuclear collisions, we will present recent experimental results that are closely connected to the properties of the matter produced in Au + Au collisions at RHIC. Collective motion with parton degrees of freedom is called partonic collectivity. We will focus on collective observables such as transverse radial flow and elliptic flow. With experimental observations, we will demonstrate that collectivity is developed prior to the hadronic stage in heavy ion collisions at RHIC.

scholarly journals Early thermalization, hydrodynamics and energy loss in AdS/CFT

2015 ◽  
Vol 24 (10) ◽  
pp. 1530011 ◽  
Author(s):  
Paul M. Chesler ◽  
Wilke van der Schee
Keyword(s):  
Energy Loss ◽  
Strong Coupling ◽  
Gauge Theories ◽  
Heavy Ion ◽  
Strongly Coupled ◽  
Equilibrium Dynamics ◽  
Ion Collisions ◽  
Far From Equilibrium ◽  
Gauge Gravity ◽  
Gravity Duality

Gauge/gravity duality has provided unprecedented opportunities to study dynamics in certain strongly coupled gauge theories. This review aims to highlight several applications to heavy ion collisions including far-from-equilibrium dynamics, hydrodynamics and jet energy loss at strong coupling.

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