Photon-axion mixing effects and mirror cavity experiments

Physics Letters B, 2019

We analyze axion--photon mixing in the framework of quantum field theory. The condensate structure of the vacuum for mixed fields induces corrections to the oscillation formulae and leads to non-zero energy of the vacuum for the component of the photon mixed with the axion. This energy generates a new effect of the vacuum polarization and it has the state equation of the cosmological constant, $w = -1$. This result holds for any homogeneous and isotropic curved space-time, as well as for diagonal metrics. Numerical estimates of the corrections to the oscillation formulae are presented by considering the intensity of the magnetic field available in the laboratory. Moreover, we estimate the vacuum energy density induced by axion--photon mixing in the Minkowski space-time. A value compatible with that of the energy density of the universe can be obtained for axions with a mass of $(10^{-3}-10^{-2}) eV$ in the presence of the strong magnetic fields that characterize astrophysical objects such as pulsars or neutron stars. In addition, a value of the energy density less than that of the Casimir effect is obtained for magnetic fields used in experiments such as PVLAS. The vacuum polarization induced by this energy could be detected in next experiments and it might provide an indirect proof of the existence of the axion--photon mixing. The quantum field theory effects presented in this work may lead to new methods for studying axion-like particles.

Physical review letters, 2016

We show that the magnetic component of the photon field produced by dark matter axions via the two-photon coupling mechanism in a Sikivie haloscope is an important parameter passed over in previous analysis and experiments. The interaction of the produced photons will be resonantly enhanced as long as they couple to the electric or magnetic mode structure of the haloscope cavity. For typical haloscope experiments the electric and magnetic couplings are equal, and this has implicitly been assumed in past sensitivity calculations. However, for future planned searches such as those at high frequency, which synchronize multiple cavities, the sensitivity will be altered due to different magnetic and electric couplings. We define the complete electromagnetic form factor and discuss its implications for current and future dark matter axion searches over a wide range of masses.

Physical Review Letters, 2007

We point out that photon regeneration-experiments that search for the axion, or axion-like particles, may be resonantly enhanced by employing matched Fabry-Perot optical cavities encompassing both the axion production and conversion magnetic field regions. Compared to a simple photon regeneration experiment, which uses the laser in a single-pass geometry, this technique can result in a gain in rate of order F 2 , where F is the finesse of the cavities. This gain could feasibly be 10 (10−12) , corresponding to an improvement in sensitivity in the axion-photon coupling, gaγγ , of order F 1/2 ∼ 10 (2.5−3) , permitting a practical purely laboratory search to probe axion-photon couplings not previously excluded by stellar evolution limits, or solar axion searches.

We explore how the Peccei-Quinn (PQ) axion parameter space can be constrained by the frequencydependence dimming of radiation from astrophysical objects. To do so we perform accurate calculations of photon-axion conversion in the presence of a variable magnetic field. We propose several tests where the PQ axion parameter space can be explored with current and future astronomical surveys: the observed spectra of isolated neutron stars, occultations of background objects by white dwarfs and neutron stars, the light curves of eclipsing binaries containing a white dwarf. We find that the lack of dimming of the light curve of a detached eclipsing white dwarf binary recently observed, leads to relevant constraints on the photon-axion conversion. Current surveys designed for Earth-like planet searches are well matched to strengthen and improve the constraints on the PQ axion using astrophysical objects radiation dimming.

An experiment is described to detect dark matter axions trapped in the halo of our galaxy. Galactic axions are converted into microwave photons via the Primakoff effect in a static background field provided by a superconducting magnet. The photons are collected in a high Q microwave cavity and detected by a low noise receiver. The axion mass range accessible by this experiment is 1.3 -13 µeV. The expected sensitivity will be rougly 50 times greater than achieved by previous experiments in this mass range. The assembly of the detector is well under way at LLNL and data taking will start in mid-1995.

Physics Letters B, 2011

We explore how the Peccei-Quinn (PQ) axion parameter space can be constrained by the frequencydependence dimming of radiation from astrophysical objects. To do so we perform accurate calculations of photon-axion conversion in the presence of a variable magnetic field. We propose several tests where the PQ axion parameter space can be explored with current and future astronomical surveys: the observed spectra of isolated neutron stars, occultations of background objects by white dwarfs and neutron stars, the light curves of eclipsing binaries containing a white dwarf. We find that the lack of dimming of the light curve of a detached eclipsing white dwarf binary recently observed, leads to relevant constraints on the photon-axion conversion. Current surveys designed for Earth-like planet searches are well matched to strengthen and improve the constraints on the PQ axion using astrophysical objects radiation dimming.

Cornell University - arXiv, 2021

According to the model (ΛCDM), based on deep cosmological observations, the current universe is constituted of 5% baryonic matter and 25 % non-baryonic cold dark matter (of speculative origin). These include quanta of scalar filed like dilaton(φ) of scale symmetry origin and quanta of pseudoscalar field of extra standard model symmetry (Peccei-Quinn) origin, like axion (φ ′). These fields couple to di-photons through dim-5 operators. In magnetized medium, they in principle can interact with the three degrees of freedom (two transverse (A ,⊥) and one longitudinal (A L)) of photon(γ) as long as the total spin is conserved. Because of intrinsic spin being zero, both φ and φ ′ could in principle have interacted with A L , (having s z = 0). However, out of φ and φ ′ only one interacts with A L. Furthermore, the ambient external magnetic field and media, breaks the intrinsic Lorentz symmetry of the system invoking Charge conjugation, Parity and Time reversal symmetries, we analyse the mixing dynamics of φγ and φ ′ γ systems and the structural difference of their mixing pattern. The strength of electromagnetic (EM) signals due to φγ and φ ′ γ mixing as a result would be different. We conclude by commenting on the possibility of detecting this difference-in polarimetric observables the EMS-using the existing space-borne detectors.

Classical and Quantum Gravity, 2014

We study the problem of axion-photon coupling in the magnetic field influenced by gravitational radiation. We focus on exact solutions to the equations for axion electrodynamics in the pp-wave gravitational background for two models with initially constant magnetic field. The first model describes the response of an initially constant magnetic field in a gravitational-wave vacuum with unit refraction index; the second model is characterized by a non-unit refraction index prescribed to the presence of ordinary and/or dark matter. We show that both models demonstrate anomalous behavior of the electromagnetic field generated by the axion-photon coupling in the presence of magnetic field, evolving in the gravitational wave background. The role of axionic dark matter in the formation of the anomalous response of this electrodynamic system is discussed.

Physical Review D, 2009

A resonantly-enhanced photon-regeneration experiment to search for the axion or axion-like particles is described. This experiment is a shining light through walls study, where photons travelling through a strong magnetic field are (in part) converted to axions; the axions can pass through an opaque wall and convert (in part) back to photons in a second region of strong magnetic field. The photon regeneration is enhanced by employing matched Fabry-Perot optical cavities, with one cavity within the axion generation magnet and the second within the photon regeneration magnet. Compared to simple single-pass photon regeneration, this technique would result in a gain of (F/π) 2 , where F is the finesse of each cavity. This gain could feasibly be as high as 10 10 , corresponding to an improvement in the sensitivity to the axion-photon coupling, gaγγ , of order (F/π) 1/2 ∼ 300. This improvement would enable, for the first time, a purely laboratory experiment to probe axionphoton couplings at a level competitive with, or superior to, limits from stellar evolution or solar axion searches. This report gives a detailed discussion of the scheme for actively controlling the two Fabry-Perot cavities and the laser frequencies, and describes the heterodyne signal detection system, with limits ultimately imposed by shot noise.

Nature Physics