Mini-jet thermalization and diffusion of transverse momentum correlation in high-energy heavy-ion collisions

Transverse momentum correlation in azimuthal angle of produced hadrons due to mini-jets are studied first within the HIJING Monte Carlo model in high-energy heavy-ion collisions. Jet quenching in the early stage of thermalization is shown to lead to significant diffusion (broadening) of the correlation. Evolution of the transverse momentum density fluctuation that gives rise to such correlation in azimuthal angle in the later stage of heavy-ion collisions is further investigated within a linearized diffusion-like equation and is shown to be determined by the shear viscosity of the evolving dense matter. Such a diffusion equation for the transverse momentum fluctuation is solved with initial values given by HIJING and together with the hydrodynamic equation for the bulk medium. The final transverse momentum correlation in azimuthal angle is calculated along the freeze-out hyper-surface and is found further diffused for larger values of shear viscosity to entropy density ratio $\eta/s \sim 0.2-0.4$. Therefore the final transverse momentum correlation in azimuthal angle can be used to study the thermalization of mini-jets in the early stage of heavy-ion collisions and the viscous effect in the hydrodynamic evolution of the strongly coupled quark gluon plasma.Comment: RevTex 4, 4 pages and 2 figures, the method to determine the fluctuation in transverse fluid velocity in the initial time of the hydro evolution has been improved. The relevant parts have been rewritten with some discussions and references adde

Nuclear modification of high-p_T hadron spectra in p+A collisions at LHC

Multiple parton scatterings in high-energy p+A collisions involve multi-parton correlation inside the projectile and color coherence of multiple jets which will lead to nuclear modification of final hadron spectra relative to that in p+p collisions. Such modification of final hadron spectra in p+A collisions is studied within HIJING 2.1 model which includes initial parton shadowing, transverse momentum broadening, parton flavor and momentum correlation inside the projectile through flavor and momentum conservation and fragmentation of multiple jets. They are shown to modify the partonic flavor content of final jets and momentum spectra of final hadrons in p+A collisions at the Large Hadron Collider.Comment: 4 pages in RevTex with 4 figures, LHC pPb collision energy is changed to 5TeV and additional figures are adde

Hadron production in p+p, p+Pb, and Pb+Pb collisions with the HIJING 2.0 model at energies available at the CERN Large Hadron Collider

The HIJING (Heavy-ion Jet Interaction Generator) Monte Carlo model is updated with the latest parton distributions functions (PDF) and new set of the parameters in the two-component mini-jet model that controls total $p+p$ cross section and the central pseudorapity density. We study hadron spectra and multiplicity distributions using the HIJING 2.0 model and compare to recent experimental data from $p+p$ collisions at the LHC energies. We also give predictions of hadron production in $p+p$, $p+Pb$ and $Pb+Pb$ collisions at the full LHC energy.Comment: 9 pages in RevTex with 11 postscript figures, updated with new results and some new data are included in comparison. The title is changed in this versio

Chiral Quantum Network with Giant Atoms

In superconducting quantum circuits, chiral routing quantum information is often realized with the ferrite circulators, which are usually buck, lossy and require strong magnetic fields. To overcome these problems, we propose to realize chiral quantum networks by considering giant atoms interacting with photonic crystal waveguide (PCW). By assuming each coupling point modulated with time, the interaction become momentum-dependent, and giant atoms will chirally emit photons due to interference effects. Our analyze indicates that the chiral factor can approach 1, and both the emission direction and rate can be freely tuned by the modulating signals. By tailoring the chiral decay parameters, we demonstrate that high-fidelity state transfer between two remote giant atoms can be realized. Our proposal can be exploited as tunable toolbox with giant atoms for quantum information processing in future chiral quantum networks.Comment: 16 pages; 10 figure