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Astrophobic Axions
Luca Di Luzio1, Federico Mescia2, Enrico Nardi3
1Institute for Particle Physics Phenomenology, Department of Physics, Durham University, DH1 3LE, Durham, United Kingdom.
Physical Review Letters
|July 14, 2018
Summary
We introduce astrophobic axion models with suppressed couplings to nucleons and electrons, relaxing astrophysical limits. These models allow for heavy axion dark matter candidates detectable by future helioscopes.
Area of Science:
- Particle Physics
- Cosmology
- Astrophysics
Background:
- Axions are hypothetical particles proposed to solve the strong CP problem.
- Astrophysical observations place stringent limits on axion properties, particularly their mass and couplings.
- Existing axion models often face constraints from stellar energy loss and nucleon/electron couplings.
Purpose of the Study:
- To propose a new class of axion models with generation-dependent Peccei-Quinn charges.
- To explore scenarios where axion couplings to Standard Model fermions are suppressed.
- To investigate the phenomenological consequences for axion detection and dark matter viability.
Main Methods:
- Theoretical model building with generation-dependent Peccei-Quinn charges.
- Analysis of axion couplings to nucleons, electrons, and photons.
- Evaluation of astrophysical and experimental constraints.
- Assessment of dark matter candidate status and stellar anomaly explanations.
Main Results:
- A class of "astrophobic" axion models is proposed, suppressing couplings to nucleons and electrons.
- Axion masses up to O(0.1) eV are allowed, relaxing astrophysical limits.
- Sizable axion-photon coupling enables probing by next-generation helioscopes.
- Flavor-violating axion couplings provide complementary experimental probes.
- Astrophobic axions are viable heavy dark matter candidates and can explain stellar energy loss anomalies.
Conclusions:
- Astrophobic axion models offer a compelling alternative to standard axion scenarios.
- These models reconcile axion properties with astrophysical and experimental data.
- Future experiments, particularly helioscopes and flavor physics searches, are crucial for testing these models.
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