Year: 2020
Type: article
Abstract: QCD axions or axionlike particles are among the most popular candidates for cold dark matter (DM) in the Universe. We proposed to detect axionlike DM, using linearly polarized pulsar light as a probe. Because of birefringence effect potentially caused by an oscillating galactic axion DM background, when pulsar light travels across the Galaxy, its linear polarization angle may vary with time. With a $\mathrm{soliton}+\mathrm{NFW}$ galactic DM halo profile, we show that this strategy can potentially probe an axion-photon coupling as small as $\ensuremath{\sim}{10}^{\ensuremath{-}13}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$ for axion mass ${m}_{a}\ensuremath{\sim}{10}^{\ensuremath{-}22}--{10}^{\ensuremath{-}20}\text{ }\text{ }\mathrm{eV}$, given the current measurement accuracy. An exclusion limit stronger than CAST ($\ensuremath{\sim}{10}^{\ensuremath{-}10}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$) and SN1987A ($\ensuremath{\sim}{10}^{\ensuremath{-}11}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$) could be extended up to ${m}_{a}\ensuremath{\sim}{10}^{\ensuremath{-}18}\text{ }\text{ }\mathrm{eV}$ and $\ensuremath{\sim}{10}^{\ensuremath{-}19}\text{ }\text{ }\mathrm{eV}$, respectively.
Authors: Tao Liu, George Smoot, Yue Zhao
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2916190484