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arXiv · 2307.12385

Heavy QCD axion model in light of pulsar timing arrays

Moslem Ahmadvand·Ligong Bian·Soroush Shakeri
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Abstract

Recently, pulsar timing array experiments reported the observation of a stochastic gravitational wave background in the nanohertz range frequency band. We show that such a signal can be originated from a cosmological first-order phase transition (PT) within a well-motivated heavy (visible) QCD axion model. Considering the Peccei-Quinn symmetry breaking at the TeV scale in the scenario, we find a supercooled PT, in the parameter space of the model, prolonging the PT with the reheating temperature at the GeV scale.

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Moslem Ahmadvand, Ligong Bian, Soroush Shakeri. 2023-07-23. Heavy QCD axion model in light of pulsar timing arrays. https://doi.org/10.1103/physrevd.108.115020

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