Related papers: Testing PVLAS axions with resonant photon splittin…
Physics beyond the Standard Model predicts the possible existence of new particles that can be searched at the low energy frontier in the sub-eV range. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from…
Thermally emitting neutron stars represent a promising environment for probing the properties of axion-like particles. Due to the strong magnetic fields of these sources, surface photons may partially convert into such particles in the…
The helicity amplitudes of the high-energy photon splitting in the external Coulomb field are obtained exactly in the parameter $\al$. The cases of screened and unscreened potentials are investigated. The consideration is based on the…
Light axion-like particles (ALPs) that couple to two photons are allowed in a number of proposed extensions to the Standard Model of elementary particles. Of particular interest from a theoretical and observational standpoint is the energy…
A plasma under the influence of an external magnetic field changes the optical properties due to the Zeeman splitting of the energy levels. This splitting degenerates an initial single spectral line into a system of spectral lines with…
In this mini-review, possible manifestations of mixing between axion-like particles (ALPs) and energetic photons propagating over astronomical distances are considered. We discuss the evidence for the anomalous transparency of the Universe…
Axions and axion-like particles (ALPs) have gained immense attention in searches for beyond Standard Model (BSM) physics. Experiments searching for axions leverage their predicted couplings to Standard Model (SM) particles to look for…
Background radiation fields pervade the Universe, and above a certain energy any $\gamma$-ray flux emitted by an extragalactic source should be attenuated due to $e^+e^-$ pair production. The opacity could be alleviated if photons…
We consider the emission of a photon by a scalar charged particle in a constant and uniform magnetic field. In contrast to the conventional approach with both photon and outgoing charge being assumed to be detected, we study the case where…
Axionlike particles (ALPs) are hypothetical light (sub-eV) bosons predicted in some extensions of the Standard Model of particle physics. In astrophysical environments comprising high-energy gamma rays and turbulent magnetic fields, the…
Axion-like particles (ALPs) and photons inter-convert in the presence of a magnetic field. At keV energies in the environment of galaxy clusters, the conversion probability can become unsuppressed for light ALPs. Conversion of thermal X-ray…
There exists a growing evidence for the anomalous transparency of the Universe for energetic gamma rays. Popular explanations include conversion of photons into hypothetical axion-like particles (ALPs) and back in astrophysical magnetic…
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…
Over the last four decades, persistent and flaring emission of magnetars observed by various telescopes has provided us with a suite of light curves and spectra in soft and hard X-rays, with no emission yet detected above around 1 MeV.…
Recent experiments suggest that polarized photons may couple significantly to pseudoscalar particles such as axions. We study the possible observational signatures of axion-photon coupling for radiation from magnetic stars, with particular…
The mixing of the photon with a hypothetical sterile paraphotonic state would have consequences on the cosmological propagation of photons. Observations of gamma-rays from active galactic nuclei in GLAST and MAGIC will open a new domain in…
We study the effect of laser photon merging, or equivalently high harmonic generation, in the quantum vacuum subject to inhomogeneous electromagnetic fields. Such a process is facilitated by the effective nonlinear couplings arising from…
Starting from the Heisenberg-Euler effective Lagrangian, we determine the photon current and photon polarization tensor in inhomogeneous, slowly varying electromagnetic fields. To this end, we consider background field configurations…
The effect of an intense external linear polarized radiation field on the angular distributions and polarization states of the photons emitted during the radiative recombination is investigated. It is predicted, on symmetry grounds, and…
The PVLAS experiment has built an apparatus to measure rotations and ellipticities induced by a transverse magnetic field onto linearly polarized laser light.Available results can be interpreted as observation of an unexpectedly large…