Anisotropic photon emission from gluon fusion and splitting in a strong magnetic background I: The two-gluon one-photon vertex

Abstract

Having in mind the pre-equilibrium stage in peripheral heavy-ion collisions as a possible scenario for the production of electromagnetic radiation, we compute the two-gluon one-photon vertex in the presence of an intense magnetic field at one-loop order. The quarks in the loop are taken such that two of them occupy the lowest Landau level, with the third one occupying the first exited Landau level. When the field strength is the largest of the energy (squared) scales, the tensor basis describing this vertex corresponds to two of the three vector particles polarized in the longitudinal direction whereas the third one is polarized in the transverse direction. However, when the photon energy is of order or larger than the field strength, the explicit one-loop computation contains extra tensor structures that spoil the properties of the basis, compared to the case when the field strength is the largest of the energy scales, which signals that the calculation is incomplete. Nevertheless, by projecting the result onto the would-be basis, we show that the squared amplitude for processes involving two gluons and one photon exhibits the expected properties such as a preferred in-plane photon emission and a slightly decreasing strength for an increasing magnetic field strength. We comment on possible venues to improve the one-loop calculation that include accounting for progressive occupation of the three quarks of the lowest and first excited Landau levels such that, still working in the large field limit, a more complete description can be achieved when the photon energy increases.

12 pages, 4 figures. Part I

References in corpus (19)

• Status and initial physics performance studies of the MPD experiment at NICA
• Pseudo-Critical Enhancement of Thermal Photons in Relativistic Heavy-Ion Collisions
• Multi-messenger heavy-ion collision physics
• The Glasma, Photons and the Implications of Anisotropy
• Effect of the anomalous magnetic moment of quarks on magnetized QCD matter and meson spectra
• Mapping the Electromagnetic Fields of Heavy-Ion Collisions with the Breit-Wheeler Process
• Magnetic-field Induced Screening Effect and Collective Excitations
• Ellipticity of photon emission from strongly magnetized hot QCD plasma
• The Magneto-Sono-Luminescence and its signatures in photon and dilepton production in heavy ion collisions
• On the role of magnetic field in photon excess in heavy ion collisions
• Effect of magnetic field on the photon radiation from quark-gluon plasma in heavy ion collisions
• The emission of electromagnetic radiation from the early stages of relativistic heavy-ion collisions
• Rate and ellipticity of dilepton production in a magnetized quark-gluon plasma
• Magnetic corrections to the boson self-coupling and boson-fermion coupling in the linear sigma model with quarks
• Polarization tensor of magnetized quark-gluon plasma at nonzero baryon density
• Gluon polarization tensor in a magnetized medium: Analytic approach starting from the sum over Landau levels
• Electromagnetic response in an expanding quark-gluon plasma
• Magnetic correction to the Anomalous Magnetic Moment of Electron
• Direct Photons in Hydrodynamic Modeling of Relativistic Nuclear Collisions

Cited by in corpus (6)

• QED Fermions in a noisy magnetic field background
• Strongly interacting matter in extreme magnetic fields
• Influence of magnetic field-induced anisotropic gluon pressure during pre-equilibrium in heavy-ion collisions: A faster road towards isotropization
• Two-gluon one-photon vertex in a magnetic field and its explicit one-loop approximation in the intermediate field strength regime
• Interaction field strength between a scalar particle and two massless vector bosons in presence of an external magnetic field
• Hydrodynamic model of heavy-ion collisions with low momentum components