Axionlike particles (alps), hypothetical light particles beyond the Standard Model, are expected to mix with photons in the presence of magnetic fields. This mixing can alter the propagation of high-energy gamma rays across cosmological distances. In this study, we investigate this effect by performing spectral fits to observations of multiple blazars, incorporating the photon-ALP oscillation mechanism. We use Monte Carlo simulations to fit the observed spectra under both the ALP and null hypotheses, evaluating model performance through chi-squared statistics. When the ALP mass lies in the range of $4.4\times {10}^{-10}\mathrm{eV}\le m_a\le 1.3\times {10}^{-8}\mathrm{eV}$, the ALP-photon coupling constant, $g_{a\gamma }$, is constrained to be below approximately $3.6\times {10}^{-11}{\mathrm{GeV}}^{-1}$. This parameter region is particularly favored in the scan of the ALP parameter space. We find that ALP effects are more pronounced during flaring states and in environments with stronger magnetic fields, resulting in improved spectral fits and tighter constraints on $m_a$ and $g_{a\gamma }$. Moreover, the normalized chi-squared difference between the ALP and null hypotheses increases with redshift, indicating that photon-ALP mixing becomes more significant over longer propagation distances. These results support the presence of photon-ALP conversion in high-energy astrophysical environments and suggest that alps may offer a more effective explanation for certain features in gamma-ray spectra, especially at high redshifts. Our findings provide new insights that may guide future observational and theoretical studies of ALP physics.

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• Dark matter
• Gamma ray astronomy
• Particle astrophysics