Limits on axionlike particles from Mrk 421 with 4.5-year period observations by ARGO-YBJ and Fermi-LAT

In this work, we investigate the axionlike particle (ALP)-photon oscillation effect in spectra of blazar Markarian 421 (Mrk 421) using 4.5 years Astrophysical Radiation with Ground-based Observatory at YangBaJing (ARGO-YBJ) and Fermi Large Area Telescope (Fermi-LAT) data. These data are collected during common operation time, which cover ten activity phases Mrk 421. No significant ALP-photon is confirmed. On other hand, not all observations can be individually used to set 95% confidence level (C.L.) constraint on ALP parameter space. However, significantly improved if analyses for combined. We find that upper limit C.L. coupling ${g}_{a\ensuremath{\gamma}}$ by ARGO-YBJ Fermi-LAT within $\ensuremath{\sim}[2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11},6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}]\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$ mass $\ensuremath{\sim}5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}\text{ }\mathrm{eV}\ensuremath{\lesssim}{m}_{a}\ensuremath{\lesssim}5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}\text{ }\mathrm{eV}$.