Electromagnetic spectral function and dilepton rate in a hot magnetized QCD medium

Abstract

The dilepton production rate in hot QCD medium is studied within a effective description of the medium in the presence of magnetic field. This could be done by obtaining the one-loop self energy of photon due to the effective (quasi-) quark loop at finite temperature under an arbitrary external magnetic field while employing the real time formalism of Thermal Field Theory. The effective quarks and gluons encode hot QCD medium effective in terms of their respective effective fugacities. The magnetic field enters in the form of landau level quantization, in the matter sector (quarks, antiquarks). The full Schwinger proper time propagator including all the Landau levels is considered for the quasi quarks while calculating the photon self energy. The electromagnetic Debye screening (in terms of the self-energy) has seen to be influenced both by the hot QCD medium effects and magnetic field. Analogous results are also obtained from the semi classical transport theory. The imaginary part of the photon self energy function is obtained from the discontinuities of the self energy across the Unitary cuts which are also present at zero magnetic field and the Landau cuts which are purely due to the magnetic field. The dilepton production rate is then obtained in terms of the product of electromagnetic spectral functions due to quark loop and lepton loop. The modifications of both the quarks/antiquarks as well as leptons in presence of an arbitrary external magnetic field have been considered in the formalism. Significant enhancement of the low invariant mass dileptons due the appearance of the Landau cuts in the electromagnetic spectral function at finite external magnetic field has been observed. A substantial enhancement of dilepton rate is also found when the EOS effects are considered through the effective quarks/antiquraks.

General structure of the neutral ρ meson self-energy and its spectral properties in a hot and dense magnetized medium

“…(132) where the Källén function goes to zero at each threshold of the Unitary and Landau cuts defined in terms of the unit step functions therein, which is a consequence of the dimensional reduction. In order to extract physical and finite results out of these spikes, we have used Ehrenfest's coarse-graining (CG) [38,40,41]. In this method, the whole invariant mass region has been discretized in small bins followed by bin averages.…”

Anisotropic pressure of deconfined QCD matter in presence of strong magnetic field within one-loop approximation

“…In recent years numerous activities have been in progress such as magnetic catalysis [1][2][3], inverse magnetic catalysis [4][5][6][7][8][9][10][11][12] and chiral magnetic effect [13][14][15] at finite temperature, and the chiral-and color-symmetry broken/restoration phase [16][17][18][19][20]. Also in progress is the study related to the equation of state (EoS) in thermal perturbative QCD (pQCD) models [21,22], holographic models [23,24] and various thermodynamic properties [19,20,25,26], refractive indices and decay constant of hadrons [27][28][29][30][31][32][33][34]; soft photon production from conformal anomaly [35,36] in HIC; modification of dispersion properties in a magnetized hot QED [37,38] and QCD [38][39][40][41] medium; and various transport coefficients [42]…”

Generalization of Bantilan-Ishi-Romatschke flow to magnetohydrodynamics

“…Generally, the inhomogeneous Maxwell equations, i.e. 9) are employed to obtain the field tensor. However, in the iMHD limit, the current is ambiguous and one cannot solve the aforementioned equations to determine the field tensor.…”