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  • Open Access

Searching for missing direct photons in heavy-ion collisions with P and CP violation

Jonathan D. Kroth* and Kirill Tuchin†

  • *Contact author: jdkroth@iastate.edu
  • †Contact author: tuchink@gmail.com
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Phys. Rev. D 114, 056010 – Published 8 September, 2026

DOI: https://doi.org/10.1103/22sz-l456

Abstract

We compute synchrotron radiation from a plasma in which P- and CP-violating parameters, a chiral chemical potential and a chiral gradient, couple to fermions. To do this, we compute exact wave functions for the fermions in the presence of these parameters and an external constant magnetic field. We find that these parameters increase the synchrotron radiation emitted by the fermions while also decreasing the traditionally large synchrotron radiation elliptic flow coefficient v2. We apply these results to the quark-gluon plasma, where just such a contribution could provide a solution to the missing direct photons puzzle. We also use our wave functions to give a derivation of the chiral magnetic effect.

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Phys. Rev. D 114, 056010– Published 8 September, 2026
  • Received 11 February 2026
  • Accepted 21 August 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.

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