Jet quenching parameter of the quark-gluon plasma in a strong magnetic field: Perturbative QCD and AdS/CFT correspondence

Abstract

We compute the jet quenching parameterq of QCD plasma in the presence of strong magnetic field in both weakly and strongly coupled regimes. In weakly coupled regime, we computeq in perturbative QCD at complete leading order (that is, leading log as well as the constant under the log) in QCD coupling constant α s , assuming the hierarchy of scales α s eB T 2 eB. We consider two cases of jet orientations with respect to the magnetic field: 1) the case of jet moving parallel to the magnetic field, 2) the case jet moving perpendicular to the magnetic field. In the former case, we findq ∼ α 2 s (eB)T log(1/α s ), while in the latter we havê q ∼ α 2 s (eB)T log(T 2 /α s eB). In both cases, this leading order result arises from the scatterings with thermally populated lowest Landau level quarks. In strongly coupled regime described by AdS/CFT correspondence, we findq ∼ √ λ(eB)T or q ∼ √ λ √ eBT 2 in the same hierarchy of T 2 eB depending on whether the jet is moving parallel or perpendicular to the magnetic field, respectively, which indicates a universal dependence ofq on (eB)T in both regimes for the parallel case, the origin of which should be the transverse density of lowest Landau level states proportional to eB. Finally, the asymmetric transverse momentum diffusion in the case of jet moving perpendicular to the magnetic field may give an interesting azimuthal asymmetry of the gluon Bremsstrahlung spectrum in the BDMPS-Z formalism. *

Novel quantum phenomena induced by strong magnetic fields in heavy-ion collisions

“…For example, the electrical conductivity will be an important input for the magnetohydrodynamics, which in turn will be relevant for the estimate of the magnetic-field profile. The techniques and ingredients developed in the computation of the heavy-quark diffusion coefficients have been applied in a few works for the jet quenching parameter [237] and the electrical conductivity [238,239] It would be instructive to see the computation of the coupling strength at the three-point vertex among two quarkonia and an external magnetic field by using the Bethe-Salpeter amplitudes obtained in the ladder approximation and the heavy-quark limit [240,241]. This computation involves a typical technique for the perturbation theory in the presence of a magnetic field.…”

Heavy-Quark Diffusion Dynamics in Quark–Gluon Plasma under Strong Magnetic Fields

“…After Ref. [3], a few works have been done for the jet quenching parameter [9] and the electrical conductivity [10,11] in the strong magnetic fields.…”

“…[3]. It is instructive to compare the mass correction (8) with the gluon contribution (9). The ratio is written as…”

Magnetic field in expanding quark-gluon plasma

“…calculating the transport coefficients [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], their values at the temperatures of phenomenological interest are not yet certain.…”