Photon polarization tensor in a magnetized plasma: Absorptive part

Abstract

We calculate the absorptive part of the photon polarization tensor in a hot magnetized relativistic plasma. In the derivation, we utilize a Landau-level representation for the fermion Green's function in a mixed coordinate-momentum space and obtain a closed-form expression for the one-loop polarization tensor. At the leading order in the coupling, its absorptive part is determined by particle and antiparticle splitting processes (e − ↔ e − + γ and e + ↔ e + + γ, respectively), as well as by particle-antiparticle annihilation processes (e − + e + ↔ γ). The interpretation in terms of quantum transitions between Landau levels is also given. By making use of the photon polarization tensor, we study the differential photon emission rate in the quantum limit of magnetized relativistic plasma. At low energies, the photon emission has a prolate profile with the symmetry axis along the line of the magnetic field. At high energies, on the other hand, the photon emission has an oblate profile. The underlying reasons for such emission profiles are given in both regimes. The general result for the photon polarization tensor is also used to calculate the longitudinal and transverse components of magneto-optical conductivity.

Photon polarization tensor in a magnetized plasma: Absorptive part

“…It appears that the corresponding problem poses only a technical complication that can be overcome with moderate effort. Such study is underway now [39]. A more difficult extension of the present work will be obtaining the real part of the photon polarization.…”

“…This is not surprising, of course, because the two processes are related by the charge conjugation symmetry. (Note, however, that the same is not true in a plasma at a nonzero chemical potential [39].) By taking this symmetry into account in Eq.…”

“…This is the consequence of the charge conjugation symmetry. It is expected, however, that both antisymmetric structures will be nonzero when µ = 0 [39]. The corresponding study will be presented elsewhere.…”

Dilepton Helical Production in a Vortical Quark-Gluon Plasma

“…The electromagnetic probe such as dilepton and photon barely interact with the fireball once produced, thus is a unique probe on the polarized distribution at early stage of the quark-gluon plasma (QGP). There have been extensive studies on polarized dilepton and photon rates arising from hydrodynamic gradient [49,50], momentum anisotropy [51,52,53], magnetic field [54,55,56,57,58,59,60,61], vorticity [62] and chiral imbalance [63,64]. The last three sources also couple to the spin of quarks, thus can further leads to spin polarized dilepton and photon rates.…”

In-medium polarization tensor in strong magnetic fields (I): Magneto-birefringence at finite temperature and density

“…The integral representation of the polarization tensor was derived within the lowest Landau level (LLL) approximation [20]. More recently, the polarization tensor was investigated in all the Landau levels focusing on the imaginary part [21][22][23]. We find that, in case of the fermion fluctuations, the sum of the vacuum and medium contributions is not simply constructive but is rather destructive in some kinetics basically due to the Pauliblocking effect on the thermally occupied positive-energy states.…”