Constraining ALP-photon coupling using galaxy clusters
Martin Schlederer (II. Institut für theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany); Günter Sigl (II. Institut für theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany)
We study photon-ALP conversion by resonance effects in the magnetized plasma of galaxy clusters and compare the predicted distortion of the cosmic microwave background spectrum in the direction of such objects to measurements of the thermal Sunyaev-Zeldovich effect. Using galaxy cluster models based on current knowledge, we obtain upper limits on the photon-ALP coupling constant g of â²Â ðª(10â11 GeVâ1). The constraints apply to the mass range of 2 · 10â14 eV â²Â mALP â²Â 3 · 10â12 eV in which resonant photon-ALP conversions can occur. These limits are slightly stronger than current limits, and furthermore provide an independent constraint. We find that a next generation PRISM-like experiment would allow limits down to g â ðªÂ (10â14 GeVâ1), two orders of magnitude stronger than the currently strongest limits in this mass range.