6–10 Jan 2025
Santa Maria University
Chile/Continental timezone

Fermion self-energy and effective mass in a noisy magnetic background

9 Jan 2025, 09:05
35m
Building A (Santa Maria University)

Building A

Santa Maria University

Avda. España 1680, Valparaíso, Chile

Speaker

Prof. Enrique Munoz (Pontificia Universidad Catolica de Chile)

Description

In this work[1], we consider the propagation of QED fermions in the presence of a classical background magnetic field with white-noise stochastic fluctuations. The effects of the magnetic field fluctuations are incorporated into the fermion and photon propagators[3] in a quasiparticle picture, which we developed in previous works [2] using the replica trick. In the very strong-field limit, we explicitly calculate the fermion self-energy involving radiative contributions at first order in α, in order to obtain the noise-averaged mass of the fermion propagating in the fluctuating magnetized medium. Our analytical results reveal a leading double-logarithmic contribution ∼ ln (eB/m2) to the mass, with an imaginary part representing a spectral broadening proportional to the magnetic noise autocorrelation Δ. While a uniform magnetic field already breaks Lorentz invariance, inducing the usual separation into two orthogonal subspaces (perpendicular and parallel with respect to the field), the presence of magnetic noise further breaks the remaining symmetry, thus leading to distinct spectral widths associated with fermion and antifermion, and their spin projection in the quasiparticle picture.

References:
[1] J.D. Castano-Yepes and E. Munoz, Phys. Rev. D 110, 056003 (2024)
[2] J.D. Castano-Yepes, M. Loewe, E. Munoz, J.C. Rojas and R. Zamora, Phys. Rev. D 107, 096014 (2023)
[3] J.D. Castano-Yepes and E. Munoz, Phys. Rev. D 109, 056007 (2024)

Author

Prof. Enrique Munoz (Pontificia Universidad Catolica de Chile)

Co-author

Dr Jorge Castano-Yepes (Pontificia Universidad Catolica de Chile)

Presentation materials