Astrophobic Axions

TL;DR

This paper introduces a new class of axion models with flavor-dependent charges that suppress certain couplings, relax astrophysical constraints, and remain detectable via photon interactions, offering new dark matter and stellar energy loss explanations.

Contribution

It presents a novel axion model with generation-dependent charges that reduce couplings to nucleons and electrons, expanding viable mass ranges and experimental detection prospects.

Findings

Astrophobic axions can have masses up to 0.1 eV.

Suppressed couplings relax astrophysical constraints.

Flavor-violating couplings provide new experimental probes.

Abstract

We propose a class of axion models with generation dependent Peccei-Quinn charges for the known fermions that allow to suppress the axion couplings to nucleons and electrons. Astrophysical limits are thus relaxed, allowing for axion masses up to ${\cal O}(0.1)$ eV. The axion-photon coupling remains instead sizeable, so that next generation helioscopes will be able to probe this scenario. Astrophobia unavoidably implies flavor violating axion couplings, so that experimental limits on flavour-violating processes can provide complementary probes. The astrophobic axion can be a viable dark matter candidate in the heavy mass window, and can also account for anomalous energy loss in stars.