title: Constraining the axion-photon coupling with massive stars.
abstract: We point out that stars in the mass window ~8-12M([circumpunct]) can serve as sensitive probes of the axion-photon interaction, g(Aγγ). Specifically, for these stars axion energy losses from the helium-burning core would shorten and eventually eliminate the blue loop phase of the evolution. This would contradict observational data, since the blue loops are required, e.g., to account for the existence of Cepheid stars. Using the MESA stellar evolution code, modified to include the extra cooling, we conservatively find g(Aγγ)</~0.8×10(-10) GeV(-1), which compares favorably with the existing bounds.
authors: Theoretical Division, T-2, MS B285, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. friedland@lanl.gov
authors: Alexander
authors: A
authors: Friedland
authors: Maurizio
authors: M
authors: Giannotti
authors: Michael
authors: M
authors: Wise