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Related papers: Extragalactic photon-ALP conversion at CTA energie…

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We revisit the adiabatic conversion between the QCD axion and axion-like particle (ALP) at level crossing, which can occur in the early universe as a result of the existence of a hypothetical mass mixing. This is similar to the…

High Energy Physics - Phenomenology · Physics 2018-10-26 Shu-Yu Ho , Ken'ichi Saikawa , Fuminobu Takahashi

We investigate the photon-axionlike particle (ALP) oscillation effects on TeV gamma-ray spectral irregularities from the uncertain redshift active galactic nuclei (AGN) VER J0521+211. The gamma-ray spectra are measured by Fermi-LAT and…

High Energy Physics - Phenomenology · Physics 2023-04-12 Hai-Jun Li , Wei Chao

Photons propagating in an external magnetic field may oscillate into axions or axion-like particles (ALPs). Such oscillations will lead to characteristic features in the energy spectrum of high-energy photons from astrophysical sources that…

High Energy Astrophysical Phenomena · Physics 2022-01-26 M. Kachelriess , J. Tjemsland

In the presence of a background magnetic field, axions or axion-like particles (ALPs) can be resonantly converted to photons when their mass is nearly equal to the effective photon mass. In this paper, we propose a novel method to constrain…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-21 Ashu Kushwaha , Rajeev Kumar Jain

We consider possible experimental tests of recent hypotheses suggesting that TeV photons survive the pair production interaction with extragalactic background light over cosmological distances by converting to axion-like particles (ALPs) in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. T. Avignone , R. J. Creswick , S. Nussinov

The conversion of CMB photons to axions (or axion-like particles (ALPs)) can lead to a unique spectral distortion in the temperature and polarization sky which can be explored in upcoming CMB experiments. In this work we have developed a…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-22 Harsh Mehta , Suvodip Mukherjee

Machine learning (ML) techniques have been applied with tremendous success in many areas of physics. In this work, we use ML to place bounds on the coupling between photons and axion-like particles (ALPs). This coupling causes ALPs and…

High Energy Astrophysical Phenomena · Physics 2020-03-24 Francesca Day , Sven Krippendorf

Well-motivated extensions of the standard model predict ultra-light and fundamental pseudo-scalar particles (e.g., axions or axion-like particles: ALPs). Similarly to the Primakoff-effect for axions, ALPs can mix with photons and…

High Energy Physics - Phenomenology · Physics 2018-05-02 Jhilik Majumdar , Francesca Calore , Dieter Horns

Axion-like particles (ALPs) are a common prediction of several extensions of the Standard Model of particle physics and could be detected through their coupling to photons, which enables ALP-photon conversions in external magnetic fields.…

High Energy Astrophysical Phenomena · Physics 2025-09-30 Francesco Schiavone , Leonardo Di Venere , Francesco Giordano

We introduce a mechanism by which a misaligned ALP can be dynamically converted into a dark photon in the presence of a background magnetic field. An abundance of non-relativistic ALPs will convert to dark photons with momentum of order the…

High Energy Physics - Phenomenology · Physics 2025-06-18 Edward Broadberry , Saurav Das , Anson Hook , Gustavo Marques-Tavares

High-energy photons may oscillate with axion-like particles (ALPs) when they propagate through the Milky Way's magnetic field, resulting in an alteration in the observed photon energy spectrum. The ultra-high energy gamma-ray spectra,…

High Energy Astrophysical Phenomena · Physics 2024-01-04 Jun Li , Xiao-Jun Bi , Lin-Qing Gao , Xiaoyuan Huang , Run-Min Yao , Peng-Fei Yin

Axion Like Particles (ALPs) are one promising kind of dark matter candidate particles that are predicted to couple with photons in the presence of magnetic fields. The oscillations between photons and ALPs travelling in the magnetic fields…

High Energy Astrophysical Phenomena · Physics 2019-11-06 Jia Bu , Ya-Ping Li

The Axion Like Particle (ALP) is a hypothetical pseudo-scalar particle beyond the Standard Model, with a compelling possible connection to dark matter and early universe physics. ALPs can be converted into photons via interactions with…

High Energy Astrophysical Phenomena · Physics 2020-03-04 Ryo Yamamoto , Noriko Y. Yamasaki , Kazuhisa Mitsuda , Masahiro Takada

Oscillations from high energy photons into light pseudoscalar particles in an external magnetic field are expected to occur in some extensions of the standard model. It is usually assumed that those axionlike particles (ALPs) could produce…

High Energy Astrophysical Phenomena · Physics 2012-09-13 Denis Wouters , Pierre Brun

Axion Like Particles (ALPs), postulated to solve the strong-CP problem, are predicted to couple with photons in the presence of magnetic fields, which may lead to a significant change in the observed spectra of gamma-ray sources such as…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-04 Miguel A. Sanchez-Conde

The detection of very high-energy neutrinos by IceCube experiment supports the existence of a comparable gamma-ray counterpart from the same cosmic accelerators. Under the likely assumption that the sources of these particles are of…

We present an analytical treatment of Axion-Like-Particle (ALP)--photon mixing with extragalactic background light (EBL) attenuation for constant, Gaussian-stochastic, and non-Gaussian magnetic field configurations--with direct implications…

High Energy Astrophysical Phenomena · Physics 2026-02-27 Andrea Addazi , Yi-Fu Cai , Salvatore Capozziello , Qingyu Gan , Gaetano Lambiase

High energy gamma-rays propagating in external magnetic fields may convert into axion-like particles (ALPs). In this case, the observed gamma-ray spectra are modified by the resulting energy-dependent conversion probability. In this study,…

High Energy Astrophysical Phenomena · Physics 2023-06-13 Qixin Yu , Dieter Horns

The idea that photons can convert into axion-like particles (ALPs) $\gamma \to a$ in or around an AGN and reconvert back into photons $a \to \gamma$ in the Milky Way magnetic field has been put forward in 2008 and has recently attracted…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Fabrizio Tavecchio , Marco Roncadelli , Giorgio Galanti

Several extensions of the Standard Model predict the existence of Axion-Like Particles (ALPs), very light spin-zero bosons with a two-photon coupling. ALPs can give rise to observable effects in very-high-energy astrophysics. Above roughly…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Marco Roncadelli , Alessandro De Angelis , Giorgio Galanti