Electromagnetic radiation by quark-gluon plasma in a magnetic field

Abstract

The electromagnetic radiation by quark-gluon plasma in strong magnetic field is calculated. The contributing processes are synchrotron radiation and one-photon annihilation. It is shown that in relativistic heavy-ion collisions at RHIC and LHC synchrotron radiation dominates over the annihilation. Moreover, it constitutes a significant part of all photons produced by the plasma at low transverse momenta; its magnitude depends on the plasma temperature and the magnetic field strength. Electromagnetic radiation in magnetic field is probably the missing piece that resolves a discrepancy between the theoretical models and the experimental data. It is argued that electromagnetic radiation increases with the magnetic field strength and plasma temperature.

Magnetic contribution to dilepton production in heavy-ion collisions

“…If one tries to reconstruct the photon spectrum using (58), then the result will be incorrect as it misses an important B-dependent contribution. 2 To demonstrate how different these contributions are, we plotted their ratio in Fig. 5 for azimuthal angle β = 0, i.e., perpendicular to B.…”

“…To calculate the dilepton spectrum produced by quarks, (34) and (35) must be integrated with the equivalent photon flux n(ω)dω given by (2). It is helpful to note that the equivalent photon spectrum n(ω)dω (2) is boost invariant in our approximation.…”

“…However, it strongly interacts with a highly intense magnetic field that is frozen into the nuclear matter [1][2][3][4]. Therefore, it bears witness to the magnetic field existence and provides a rare opportunity to experimentally study its properties.…”

Electromagnetic fields and anomalous transports in heavy-ion collisions—a pedagogical review

“…possible ρ meson condensation in strong magnetic field [50][51][52][53][54], the neutral pion condensation in vaccum [55], the anisotropic viscosities in hydrodynamic equations [56][57][58][59][60], and the early-stage phenomena in heavy-ion collisions like the EM-field induced particle production [26,[61][62][63][64][65][66] and the dissociation of heavy-flavor mesons [67][68][69][70][71]. These topics will not be the main focus of this article.…”

One-loop QCD thermodynamics in a strong homogeneous and static magnetic field

“…Moreover the magnetic field may be assumed uniform because even though the spatial distribution of the magnetic field is globally inhomogeneous, but in the central region of the overlapping nuclei, the magnetic field in the transverse plane varies very smoothly, which is noticed in the hadron-string simulations [9] for Au-Au collisions at √ s N N = 200 GeV with an impact parameter, b = 10 fm. Therefore, a large number of QCD related phenomena are investigated in the strong and homogeneous magnetic field, such as the chiral magnetic effect related to the generation of electric current parallel to the magnetic field due to the difference in number of right and left-handed quarks [10][11][12], the axial magnetic effect due to the flow of energy by the axial magnetic field [13,14], the chiral vortical effect due to an effective magnetic field in the rotating QGP [15,16], the magnetic catalysis and the inverse magnetic catalysis at finite temperature arising due to the breaking and the restoration of the chiral symmetry [17][18][19][20][21], the thermodynamic properties [22][23][24], the refractive indices and decay constant [25,26] of mesons in a hot magnetized medium, the conformal anomaly and the production of soft photons [27,28] at RHIC and LHC, the dispersion relation in a magnetized thermal QED [29], the synchrotron radiation [30], the dilepton production from both the weakly [31][32][33][34] and the strongly [35] coupled plasma etc.…”