PT Journal
AU Caputo, A
   Millar, AJ
   Vitagliano, E
TI Revisiting longitudinal plasmon-axion conversion in external magnetic fields
SO Physical Review D
JI Phys. Rev. D
PY 2020
BP 123004
EP 13pp
VL 101
IS 12
DI 10.1103/PhysRevD.101.123004
LA English
AB In the presence of an external magnetic field, the axion and the photon mix. In particular, the dispersion relation of a longitudinal plasmon always crosses the dispersion relation of the axion (for small axion masses), thus leading to a resonant conversion. Using thermal field theory, we concisely derive the axion emission rate, applying it to astrophysical and laboratory scenarios. For the Sun, depending on the magnetic field profile, plasmon-axion conversion can dominate over Primakoff production at low energies (less than or similar to 200 eV). This both provides a new axion source for future helioscopes and, in the event of discovery, would probe the magnetic field structure of the Sun. In the case of white dwarfs (WDs), plasmon-axion conversion provides a pure photon coupling probe of the axion, which may contribute significantly for low-mass WDs. Finally, we rederive and confirm the axion absorption rate of the recently proposed plasma haloscopes.
ER