Hard thermal loops in a magnetic field and the chiral anomaly
Abstract
The fermionic dispersion relation in the presence of a background magnetic field and a high temperature QED plasma is calculated exactly in the external field, using the Hard Thermal Loop effective action. As the field strength increases there is a smooth transition from the weak-field ( qB ≪ q2T2) thermal dispersion relations to the vacuum Landau levels when the backgroun field is much stronger than any thermal effects ( qB ≫ q2T2). The self-energy at finite field strength acquires an imaginary part. The spectral width becomes important for critical field strengths ( qB ≈ q2T2), necessitating the use of the full spectral function. It is shown that the spectral function satisfies the usual condition of normalization and causality. Using the exact spectral function I also show that the production of chirality in an external electromagnetic field at high temperature is unaffected by the presence of the thermal masses of the fermions.
- Publication:
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Nuclear Physics B
- Pub Date:
- February 1997
- DOI:
- 10.1016/S0550-3213(96)00666-9
- arXiv:
- arXiv:hep-ph/9608271
- Bibcode:
- 1997NuPhB.487..207E
- Keywords:
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- High Energy Physics - Phenomenology
- E-Print:
- 30 pages, 5 figures, latex