English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The axion-like particle (ALP)-photon mixing in the magnetic field around$\gamma$-ray sources or along the line-of-sight could induce oscillationbetween photons and ALPs, which then causes irregularities in the $\gamma$-rayspectra. In this work we try to search for such spectral irregularities in thespectrum of PKS $2155-304$ using 8.6 years of the Fermi Large Area Telescope(Fermi-LAT) data. No significant evidence for the presence of ALP-photonoscillation is obtained, and the parameter space of ALPs is constrained. Theexclusion region sensitively depends on the poorly known magnetic field of hostgalaxy cluster of PKS $2155-304$. If the magnetic field is as high as $\sim10~{\rm \mu G}$, the "hole"-like parameter region allowed in Ref.~\cite{Fermi}can be ruled out.

New Bounds on Axion-Like Particles From the Fermi Large Area Telescope observation of PKS $2155-304$