Photon Mass Research Articles

Theoretical bounds on dark Higgs mass in a self-interacting dark matter model with U(1)′

Motivated by the null results of current dark matter searches and the small-scale problems, we study a dark sector charged by a spontaneous broken gauge U(1)′. To explore the parameter space of this model, in addition to the consideration of the small-scale data, we also consider the theoretical bounds on the dark Higgs mass, with the upper bound coming from the tree-level perturbative unitarity and the lower bound from the one-loop Linde-Weinberg bound. We deeply examine the dependence of the Linde-Weinberg bound on gauge choice and energy scale, and present a Linde-Weinberg bound that is gauge and scale independent. Combining the theoretical and observational constraints, we obtain the following ranges for the parameter space: the dark matter mass is 10–500 GeV, the mediator (dark photon) mass is 0.5–5 MeV, the dark Higgs mass is 0.05–50 MeV, and the dark fine-structure constant is 0.001–0.4. We conclude that the dark Higgs in this model cannot be ignored in the phenomenological study of the dark sector. Published by the American Physical Society 2025

Dark photon dark matter radio signal from the Milky Way electron density

We consider Thomson-like processes between dark matter dark photons and free electrons in the Milky Way. The result is a radio signal background that can be detectable with current or future radio telescope arrays. In particular, we computed sensitivity prospects for the Atacama Large Millimeter Array radio telescope and for the future Square Kilometer Array, concluding that unconstrained parameter space in a wide range of dark photon masses can be probed. Published by the American Physical Society 2025

Radiation and Scattering of Massive Photons

With the aid of a modified Planck’s law for massive photons, it is shown that the ratio of the mean value of the photon mass equivalent to its rest (invariant) mass tends to be one with a decrease in temperature. A modified Stefan - Boltzmann law is obtained at different temperature regimes, as well as the Wien’s displacement law. At high temperatures the modified Planck’ s law approaches the standard Planck’ s law. It is also shown that the cross-section of the Thomson scattering slightly increases opacity of the scattering medium. The Compton shift in frequency for a massive photon appears to be frequency-dependent and slightly less than its value for a massless photon, except in the case of forward scattering when no change in frequency takes place. Astrophysical aspects of the massive photon hypothesis are discussed with regard to standard stellar models, early stages of the Universe, and the Breit-Weeler process, as well as active galactic nuclei. Estimates of the spreading time of the wave packet of the massive photon show that for frequencies ν ≥ 4.052 × 109Hz(λ ≤ 7.4) it exceeds the age of the Universe.

Electrically Tunable Spin‐Orbit Coupled Photonic Lattice in a Liquid Crystal Microcavity

AbstractA 1D photonic crystal is created with strong polarization dependence and tunable by an applied electric field. This is accomplished in a planar microcavity by embedding a cholesteric liquid crystal (LC), which spontaneously forms a uniform lying helix (ULH). The applied voltage controls the orientation of the LC molecules and, consequently, the strength of a polarization‐dependent periodic potential. It leads to opening or closing of photonic bandgaps in the dispersion of the massive photons in the microcavity. In addition, when the ULH structure possesses a molecular tilt, it induces a spin‐orbit coupling between the lattice bands of different parity. This interband spin‐orbit coupling (ISOC) is analogous to optical activity and can be treated as a synthetic non‐Abelian gauge potential. Finally, it is showed that doping the LC with dyes allows us to achieve lasing that inherits all the above‐mentioned tunable properties of LC microcavity, including dual and circularly‐polarized lasing.

Black hole mass estimate in OJ 287 based on the bulk-motion comptonization model

ABSTRACT The multiwavelength outburst activity in the BL Lacertae source OJ 287 has sparked a lot of controversy about whether the source contains one or two black holes (BHs) and what characteristics of this BH binary would be. In this article, we present the results of analysis of the X-ray flaring activity of OJ 287 using the data of Swift/XRT observations. We discovered that the energy spectra in all spectral states can be adequately fit with the XSPEC bulk-motion Comptonization (BMC) model. As a result, we found that the X-ray photon index of the BMC model, $\Gamma$ correlates with the mass accretion rate, $\dot{M}$. We found the photon index $\Gamma$ to increase monotonically with accretion rate $\dot{M}$ from $\Gamma \sim 2$ in the intermediate state (IS) to $\Gamma \sim 2.5$ the high/soft state (HSS) with subsequent saturation at $\Gamma \sim$ 2.6 level at higher luminosities. This type of behaviour of the spectral index is remarkably similar to the pattern observed in a number of established stellar-mass BH candidates. Assuming the universality of the observed pattern of the correlation between the photon index and mass accretion rate and using the well-studied stellar-mass binaries GX 339–4 and XTE J1859–226 to calibrate the model, we estimate a BH mass $\sim 2\times 10^8$ solar masses, which likely pertains to the secondary component of the BH binary in OJ 287.

Bounds on the photon mass via the Shapiro effect in the solar system

Bounds on the photon mass via the Shapiro effect in the solar system

Transition Edge Sensors: Physics and Applications

Transition Edge Sensors (TESs) are amongst the most sensitive cryogenic detectors and can be easily optimized for the detection of massive particles or photons ranging from X-rays all the way down to millimetre radiation. Furthermore, TESs exhibit unmatched energy resolution while being easily frequency domain multiplexed in arrays of several hundred pixels. Such great performance, along with rather simple and sturdy readout and amplification chains make TESs extremely compelling for applications in many fields of scientific endeavour. While the first part of this article is an in-depth discussion on the working principles of Transition Edge Sensors, the remainder of this review article focuses on the applications of Transition Edge Sensors in advanced scientific instrumentation serving as an accessible and thorough list of possible starting points for more comprehensive literature research.

Revisiting dark photon constraints from CMB spectral distortions

ABSTRACT Spectral distortions of the cosmic microwave background (CMB) provide stringent constraints on energy and entropy production in the post-BBN (big bang nucleosynthesis) era. This has been used to constrain dark photon models with COBE/FIRAS and forecast the potential gains with future CMB spectrometers. Here, we revisit these constraints by carefully considering the photon to dark photon conversion process and evolution of the distortion signal. Previous works only included the effect of CMB energy density changes but neglected the change to the photon number density. We clearly define the dark photon distortion signal and show that in contrast to previous analytic estimates the distortion has an opposite sign and a $\simeq 1.5$ times larger amplitude. We furthermore extend the treatment into the large distortion regime to also cover the redshift range $\simeq 2 \times 10^{6}-4 \times 10^{7}$ between the μ-era and the end of BBN using cosmotherm . This shows that the CMB distortion constraints for dark photon masses in the range $10^{-4}\, {\rm eV}\lesssim m_{\rm d}\lesssim 10^{-3}\, {\rm eV}$ were significantly underestimated. We demonstrate that in the small distortion regime the distortion caused by photon to dark photon conversion is extremely close to a μ-type distortion independent of the conversion redshift. This opens the possibility to study dark photon models using CMB distortion anisotropies and the correlations with CMB temperature anisotropies as we highlight here.

Electromagnetic field in an expanding universe

An expanding universe filled with a massive electromagnetic field is studied. The electromagnetic field (photon) is found to acquire mass during an inflationary period. The photon mass varies with the Hubble parameter as m γ = 3ℏ H/c 2, where H, ℏ and c are the Hubble parameter, Planck constant, and speed of light. A leftover magnetic field since the inflationary era permeates the space between galaxies and interstellar media. The strength of the electromagnetic field changes with the scale factor, E ∝ a −3. The photon gains mass when interacting with the gravitational field while remaining massless in flat space. The massive electromagnetic field adds energy density to the Universe proportional to m 2.

Synthesis and characterization of metakaolin-based geopolymers doped with CRT waste glass for radiation shielding applications

This study presents the influence of CRT glass on the gamma-ray interaction processes in metakaolin-based geopolymers. Four batches of G-CRT composites (namely, G, G-10CRT, G-20CRT, and G-30CRT, which represent geopolymer (G) samples doped with 0, 10, 20, and 30 wt% of CRT glass) were prepared using the cold hydrostatic press method. The mass attenuation coefficients of the prepared C-xCRT samples were computed using XCOM and FLUKA simulations for photons within the energy range of 15 keV–15 MeV. The density of the pristine geopolymer increased from about 1.86 g/cm3 to 2.09, 2.26, and 2.34 g/cm3 for G-10CRT, G-20CRT, and G-30CRT, respectively. The photon mass and linear attenuation coefficients of the geopolymers increased with CRT glass concentration. The half-value layer and mean free path were within the ranges 0.070–18.079 cm and 0.101–26.083 cm for G; 0.036–15.110 cm and 0.052–21.799 cm for G-10CRT; 0.024–13.197 cm and 0.014–19.039 cm for G-20CRT; and 0.018–12.074 and 0.026–17.419 cm for G-30CRT. The G-30CRT had the best gamma attenuating prowess in contrast to other G-xCRT. CRT-rich G-xCRT had a higher effective atomic number. For 10 mm thick geopolymer, the absorbed dose rates were 0.211 μR/h, 0.66 μR/h, 1.11 μR/h, and 1.55 μR/h for G, G-10CRT, G-20CRT, and G-30CRT, respectively, for 100 keV photons. The introduction of CRT glass into the geopolymer matrix improved their photon interaction cross-section. The geopolymers showed outstanding photon interaction ability compared to ordinary concrete and some shielding glasses at low photon energies. The CRT glass-doped geopolymer samples are useful for preparing radiation shielding concrete.

Determination of Photon Mass with its Main Physical Parameters Energy, Wavelength and Velocity

The excitation, transition, vibration and rotation of nuclei, atoms and molecules leading to the emission of all photons from gamma rays to radio waves as a result of the physical mechanisms responsible for excited states. The photon energy with its corresponding frequency, wavelength and distance can be determined by the main physical parameters (mass, distance, time) of the mentioned particles (Sanad, 2024). The photon mass as a particle can be determined by its main physical parameters (energy, wavelength, velocity). The determined photon mass is 2.2X10-34 kg and it is the same value of all electromagnetic radiation from gamma rays to radio waves.

Light-light scattering in Very Special Relativity Quantum Electrodynamics and cosmic anisotropies

We consider scattering of light by light in Very Special Relativity (VSR) Quantum Electrodynamics (QED) with a non-zero photon mass. In order to preserve gauge invariance and Sim(2) symmetry we made use of a recently introduced infrared regularization of VSR theories. Additionally, we show that all one loop diagrams with any number of photon external legs and zero fermion legs reduce to the standard QED result with the effective electron mass, as required by unitarity. It follows that the Euler-Heisenberg Lagrangian is the same as in QED. The total cross section of scattering of light by light exhibits tiny anisotropies that could be detected at cosmological scales. In particular, they should be looked at the Cosmic Microwave Background (CMB) Radiation for low photon frequencies.

Search for Leptonic Decays of Dark Photons at NA62.

The NA62 experiment at CERN, configured in beam-dump mode, has searched for dark photon decays in flight to electron-positron pairs using a sample of 1.4×10^{17} protons on dump collected in 2021. No evidence for a dark photon signal is observed. The combined result for dark photon searches in lepton-antilepton final states is presented and a region of the parameter space is excluded at 90% confidence level, improving on previous experimental limits for dark photon mass values between 50 and 600 MeV/c^{2} and coupling values in the range 10^{-6} to 4×10^{-5}. An interpretation of the e^{+}e^{-} search result in terms of the emission and decay of an axionlike particle is also presented.

Aharonov-Bohm effect mediated by massive photons

Virtual photons play an essential role in the locally realistic description of the Aharonov-Bohm interference. We show that the effect of virtual photons in the interferometer is manifested by a change in their spectrum. In particular, when a vacuum is confined between two ideal conducting plates, the photons obey the two-dimensional Proca equation, the wave equation with finite effective mass. This results in a short-range interaction between a test charge and a magnetic flux, and hence the Aharonov-Bohm effect is reduced exponentially at a large distance between the two bodies. On the other hand, a semiclassical description is also possible, and this raises the interesting question of how to prove the physical reality of virtual photons.

Deepest sensitivity to wavelike dark photon dark matter with superconducting radio frequency cavities

Wavelike, bosonic dark matter candidates like axions and dark photons can be detected using microwave cavities known as haloscopes. Traditionally, haloscopes consist of tunable copper cavities operating in the TM010 mode, but ohmic losses have limited their performance. In contrast, superconducting radio frequency (SRF) cavities can achieve quality factors of ∼1010, perhaps 5 orders of magnitude better than copper cavities, leading to more sensitive dark matter detectors. In this paper, we first derive that the scan rate of a haloscope experiment is proportional to the loaded quality factor QL, even if the cavity bandwidth is much narrower than the dark matter halo line shape. We then present a proof-of-concept search for dark photon dark matter using a nontunable ultrahigh-quality SRF cavity. We exclude dark photon dark matter with kinetic mixing strengths of χ>1.5×10−16 for a dark photon mass of mA′=5.35 μeV, achieving the deepest exclusion to wavelike dark photons by almost an order of magnitude. Published by the American Physical Society 2024

Effective photon mass in the presence of a gravity gradient emulated by an electromagnetic medium

Geometry- and gravity-induced effective photon mass is known to arise in many cases, such as various optical waveguides, Kaluza–Klein theories, and many other optical and general relativity situations. Here we study the appearance of effective photon mass in the Newtonian limit due to the presence of a gravity gradient emulated by an electromagnetic medium. The effective photon mass squared appears to be proportional to the local gravity gradient, and it becomes negative in an optical anti-waveguide around the unstable equilibrium location. A similar effect is observed in the emulated Kottler–Møller spacetime where the absolute value of the gravity-induced effective photon mass appears to coincide with the Unruh temperature. We demonstrate that similar to the Unruh effect, a bath of thermal radiation should be observed in an optical anti-waveguide near the unstable equilibrium, whose temperature is defined by the emulated local gravity gradient, and which remains unchanged in the c→∞ limit.

Analysis of high-frequency limit in absorption cross-section for Kerr–Newman–de Sitter black hole

In this paper, we study the critical impact parameter and Lyapunov exponent for a massive charged particle and a photon in the Kerr–Newman–de Sitter (KNdS) spacetime. From the geodesic equations obtained for the particle traveling parallel to the rotation axis (on-axis) of the KNdS spacetime and using the complex angular momentum (CAM) technique, it is found that the total absorption cross-section at a high-frequency limit oscillates with decreasing amplitude. We show that the black hole charge and spin affect the total absorption cross-section in the case of both the massive charged particle and photon.

Search for light long-lived neutral particles from Higgs boson decays via vector-boson-fusion production from pp collisions at s=13\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sqrt{s}=13$$\\end{document} TeV with the ATLAS detector

A search is reported for long-lived dark photons with masses between 0.1 GeV and 15 GeV, from exotic decays of Higgs bosons produced via vector-boson-fusion. Events that contain displaced collimated Standard Model fermions reconstructed in the calorimeter or muon spectrometer are probed. This search uses the full LHC Run 2 (2015–2018) data sample collected in proton–proton collisions at s=13\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sqrt{s}=13$$\\end{document} TeV, corresponding to an integrated luminosity of 139 fb-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$fb^{-1}$$\\end{document}. Dominant backgrounds from Standard Model processes and non-collision sources are estimated using data-driven techniques. The observed event yields in the signal regions are consistent with the expected background. Upper limits on the Higgs boson to dark photon branching fraction are reported as a function of the dark photon mean proper decay length or of the dark photon mass and the coupling between the Standard Model and the potential dark sector. This search is combined with previous ATLAS searches obtained in the gluon–gluon fusion and WH production modes. A branching fraction above 10% is excluded at 95% CL for a 125 GeV Higgs boson decaying into two dark photons for dark photon mean proper decay lengths between 173 and 1296 mm and mass of 10 GeV.

Dispersive interaction between two atoms in Proca quantum electrodynamics

We analyze the influence of a massive photon in the dispersive interaction between two atoms in their fundamental states. We work in the context of Proca quantum electrodynamics. The photon mass not only introduces a new length scale but also gives rise to a longitudinal polarization for the electromagnetic field. We obtain explicitly the interaction energy between the atoms for any distance regime and consider several particular cases. We show that, for a given interatomic distance, the greater the photon mass the better it is the nonretarded approximation. Published by the American Physical Society 2024

First Scan Search for Dark Photon Dark Matter with a Tunable Superconducting Radio-Frequency Cavity.

Dark photons have emerged as promising candidates for dark matter, and their search is a top priority in particle physics, astrophysics, and cosmology. We report the first use of a tunable niobium superconducting radio-frequency cavity for a scan search of dark photon dark matter with innovative data analysis techniques. We mechanically adjusted the resonant frequency of a cavity submerged in liquid helium at a temperature of 2K, and scanned the dark photon mass over a frequency range of 1.37MHz centered at 1.3GHz. Our study leveraged the superconducting radio-frequency cavity's remarkably high quality factors of approximately 10^{10}, resulting in the most stringent constraints to date on a substantial portion of the exclusion parameter space on the kinetic mixing coefficient ε between dark photons and electromagnetic photons, yielding a value of ε<2.2×10^{-16}.