Photon Mass Research Articles

Independent Tuning of Exciton and Photon Energies in an Exciton–Polariton Condensate by Proton Implantation‐Induced Interdiffusion

AbstractThe use of high energy proton implantation is demonstrated to precisely and independently shift the energies of both exciton and photon components of GaAs microcavity exciton–polaritons. The technique applies post‐growth proton implantation and annealing steps in order to create a small local interdiffusion across either the quantum well–barrier material interfaces, or between the layers of the cavity distributed Bragg reflector mirrors to induce energy shifts to the exciton or photon components, respectively. The polariton mode is tunable by an energy exceeding 10 meV with a corresponding increase (decrease) in effective mass for photon (exciton) energy shifts, while maintaining narrow‐linewidth polariton photoemission and condensation for both photonic and excitonic polaritons. This technique uniquely enables new opportunities to explore coherent polariton matter with narrow‐linewidth and heavy masses in tight‐binding, non‐Hermitian, and topological landscapes with sub‐µm feature‐sizes, while also being a simple post‐growth process.

Quantum excitations of static charges in the Ginzburg-Landau model of superconductivity

We point out that in superconductors there may exist localized quantum excitations of the electric and condensate fields surrounding a static charge, which cannot be interpreted as simply the ground state of the screened charge plus some number of massive photons. This is illustrated via a lattice Monte Carlo calculation of the energy spectrum of a pair of separated static charges in an effective Ginzburg-Landau model of superconductivity.

Special Relativity in Six Dimensions

In the four-dimensional spacetime theory of special relativity, the space coordinate is time contracted along the motion, while perpendicular coordinates are invariant and time varies with position. This leads to a velocity transformation valid at speed of light and used in showing invariance electric and magnetic fields which are invariant along x-axis but change occur along y, and z-axes, contrary to the classical electrodynamics. In this work we introduce a new six-dimensional spacetime theory which allows time (position) change of position (time) in three coordinate axes and still satisfy the Lorentz invariance conditions of metric and Maxwell’s wave equations between two frames. We derive a new velocity transformation rule which is valid at any relative speed of massive frames moving with respect to each other. We derived expressions for relativistic mass, energy, Doppler shift, time dilation, length contraction, photon rest mass, and used the conservation of relativistic power to prove that the electric and magnetic fields and consequently, Maxwell wave equations are Lorentz invariant between two massive frames with and without nonzero photon mass in vacuum and materials medium. Calculated photon mass is in excellent agreement with the measured and observed upper bounds of 1.24x10-54 kg and1.75x 10-53 kg, respectively.

Reheating with effective potentials

We consider reheating for a charged inflaton which is minimally coupled toelectromagnetism. The evolution of such an inflaton induces a time-dependentmass for the photon. We show how the massive photon propagator can beexpressed as a spatial Fourier mode sum involving three different sorts ofmode functions, just like the constant mass case. We develop accurateanalytic approximations for these mode functions, and use them to approximatethe effective force exerted on the inflaton 0-mode. This effective forceallows one to simply compute the evolution of the inflaton 0-mode and tofollow the progress of reheating.

Shielding Properties of Glass Samples Containing Li2O, K2O, Na2O, PbO and B2O3 by Geant4, XCOM and Experimental Data

Abstract: In the present work, glass samples containing 10Li2O, 10K2O, 20Na2O. xPbO, (60-x)B2O3 (where x = 0-60) were prepared by the melt quenching method. The shielding parameters of the prepared samples were measured experimentally and calculated theoretically. The measurements have been performed at energies of 356.5, 662, 1173 and 1333 keV to obtain the total mass attenuation coefficient (μm), using a gamma spectrometer containing a shielded NaI (TI) detector. The results of mass attenuation coefficient (μm), half-value layers (HVLs), mean free path (MFP), radiation protection efficiency (RPE), atomic and electronic electron cross-sections (σa and σe), effective atomic number (Zeff) and effective electron number (Neff) were calculated at energies from 1 keV to 100 GeV using the Monte Carlo simulation code Geant4 and XCOM. The calculated results were compared with each other and with the experimental values. Good agreement has been observed. Keywords: Shielding properties, Glass, Photon mass attenuation coefficient, Atomic and electronic cross-sections, Effective atomic and electron numbers, XCOM, Geant4.

Sensitivities on dark photon from the forward physics experiments

Neutrino-electron scattering experiments can explore the potential presence of a light gauge boson A′ which arises from an additional U(1)B−L group, or a dark photon A′ which arises from a dark sector and has kinetic mixing with the SM hypercharge gauge field. We generically call it a dark photon. In this study, we investigate the effect of the dark photon on neutrino-electron scattering νe−→ νe− at the newly proposed forward physics experiments such as FASERν, FASERν2, SND@LHC and FLArE(10 tons). We estimate the anticipated sensitivities to the U(1)B−L gauge coupling in a wide range of the dark photon mass MA′. We compare the sensitivities of the proposed forward physics experiments with the current limits from TEXONO, GEMMA, BOREXINO, LSND, and CHARM II as well as NA64e experiments. We also extend the calculation to obtain the sensitivities on the kinetic mixing parameter ϵ in a wide range of dark photon mass MA′. We demonstrate that the sensitivities do not improve for MA′< 1 GeV at the Forward Physics Facilities.

Geometry of massive particle surfaces

We propose a generalization of the photon surfaces of Claudel, Virbhadra and Ellis to the case of massive charged particles, considering a timelike hypersurface such that any worldline of a particle with mass $m$, electric charge $q$ and a fixed total energy $\mathcal{E}$, initially touching it, will forever remain in this hypersurface. Such surfaces can be defined not only with particle motion equations, but instead using the partially umbilic nature of the surface geometry. Such an approach should be especially useful in the case of nonintegrable equations of motion. It can be applied to the theory of nonthin accretion disks, and can also serve as a new tool for some general problems such as uniqueness theorems, Penrose inequalities, and hidden symmetries. A condition for the stability of worldlines is derived, which reduces to differentiation along the flow of surfaces of a certain energy. A number of examples of electrovacuum and dilaton solutions are considered; conditions are found for marginally stable surfaces of massive particles, regions of stable or unstable surfaces of massive particles and photons, as well as solutions that satisfy the no-force condition.

Self-interacting dark baryons

Using results from lattice QCD, it is possible to quantitatively design models of dark baryons leading to velocity-dependent self-interaction cross sections that match the values needed for solving small-scale structure problems of standard cold dark matter. However it is not obvious that the main dark matter component in such models will be nucleons rather than large nuclei, or dark pions or atoms, whose scattering properties would be different. We first identify the parameters of a dark SU(3) sector analogous to QCD---the confinement scale $\mathrm{\ensuremath{\Lambda}}$ and pion mass ${m}_{\ensuremath{\pi}}$---needed to reproduce desired self-interaction cross sections. Then we show that these values can generically be compatible with the absence of a sufficiently stable deuteron bound state, and hence leading to no heavier nuclei, thus establishing the consistency of the scenario for self-interacting dark nucleons. The range of dark photon masses needed to avoid dominant pion or atomic dark matter is determined, as well as allowed values for the kinetic mixing parameter. The dark proton might be detected directly in future searches, by dark photon exchange.

New thermal relic targets for inelastic vector-portal dark matter

We examine the vector-portal inelastic dark matter (DM) model with DM mass $m_\chi$ and dark photon mass $m_{A'}$, in the `forbidden dark matter' regime where $1 \lesssim m_{A'}/m_\chi \lesssim 2$, carefully tracking the dark sector temperature throughout freezeout. The inelastic nature of the dark sector relaxes the stringent cosmic microwave background (CMB) and self-interaction constraints compared to symmetric DM models. We determine the CMB limits on both annihilations involving excited states and annihilation into $e^+e^-$ through initial-state-radiation of an $A'$, as well as limits on the DM self-scattering, which proceeds at the one-loop level. The unconstrained parameter space serves as an ideal target for accelerator $A'$ searches, and provides a DM self-interaction cross section that is large enough to observably impact small-scale structure.

Tailoring the humidity response of cellulose nanocrystal-based films by specific ion effects

HypothesisThe optical properties and humidity response of iridescent films made of cellulose nanocrystal (CNC) and polyethylene glycol (PEG) can be tailored by the incorporation of electrolytes chosen based on specific ion effects (SIE). ExperimentsA series of inorganic salts comprising five different cations and five anions based on the Hofmeister series were mixed with CNC/PEG suspensions, followed by an air-dried process into iridescent solid films. These films were tested in changing relative humidity (RH) environments from 30% to 90% and their photonic properties and mass change monitored. The underlying structures and the mechanism of their formation were quantified in terms of interparticle distance derived from small angle X-ray scattering experiment and pitch size quantified by scanning electron microscope (SEM). FindingsThe specific color and color range of CNC/PEG based films are controlled by a specific anion effect achieved by selection of the salt while the specific cation effect is negligible. The salting-in type anions with the same valency result in a red-shift color when films are in the dried state. The salting-in type leads to a greater color changing range during RH changes than the salting-out type. The resultant mass gain/loss trend is consistent with the color change. In contrast, cations do not show any relationships between salting-in effect and the measured properties as observed for anions. The observed SIE can be used to engineer CNC/polymer-based humidity and bio-diagnostic colorimetric indicator devices.

Spontaneous symmetry breaking and massive photons from a Fresnel-type potential

Spontaneous symmetry breaking and massive photons from a Fresnel-type potential

QCD QED Potentials, Quark Confinement

One of the enduring puzzles in high energy particle physics is why quarks do not exist independently ‎despite their existence inside the hadron as quarks have never been found in isolation. This problem may ‎be solved by formulating a QCD potential for the entire range of interaction distances of the quarks. The ‎mystery could be related to the fundamental origin of the mass of elementary particles despite the success ‎of the quantum field theories to the highest level of accuracy. The renormalization program is an essential ‎part of the calculation of the scattering amplitudes, where the infinities of the calculated masses of the ‎elementary particles are subtracted for the progressive calculation of the higher-order perturbative terms. ‎The mathematical structure of the mass term from quantum field theories expressed in the form of infinities ‎suggests that there may exist a finite dynamical mass in the limit when the input mass parameter ‎approaches zero. The Lagrangian recovers symmetry at the same time as the input mass becomes zero, ‎whereas the self-energy diagrams acquire a finite dynamical mass in the 4-dimensional space when the ‎dimensional regularization method of renormalization is utilized. We report a new finding that using the ‎mathematical expression of the self-energy(mass) for photons and gluons calculated from this method, the ‎complex form of the QCD and QED interaction potentials can be obtained by replacing the fixed ‎interaction mediating particle’s mass and coupling constants in Yukawa potential with the scale-‎dependent running coupling constant and the corresponding dynamical mass. The derived QCD QED ‎potentials predict the behavior of the related elementary particles exactly as verified by experimental ‎observation.‎

Dark photon kinetic mixing effects for the CDF W -mass measurement

A new $U(1)_X$ gauge boson $X$ primarily interacting with a dark sector can have renormalizable kinetic mixing with the standard model (SM) $U(1)_Y$ gauge boson $Y$. This mixing besides introduces interactions of dark photon and dark sector with SM particles, it also modifies interactions among SM particles. The modified interactions can be casted into the oblique $S$, $T$ and $U$ parameters. We find that with the dark photon mass larger than the $Z$ boson mass, the kinetic mixing effects can reduce the tension of the W mass excess problem reported recently by CDF from $7\sigma$ deviation to within $3 \sigma$ compared with theory prediction. If there is non-abelian kinetic mixing between $U(1)_X$ and $SU(2)_L$ gauge bosons, in simple renormalizable models of this type a triplet Higgs is required to generate the mixing. We find that this triplet with a vacuum expectation value of order 5 GeV can naturally explain the W mass excess.

Directive properties of radiating source systems in massive electromagnetism

We investigate the problem of electromagnetic radiation in massive electromagnetism with focus on the directive radiation characteristics of Proca antennas (sources embedded into Proca metamaterial domains.) It is theoretically demonstrated that the recently proposed nonlocal Proca metamaterial implies the existence of point nonlocal sources possessing a perfectly isotropic radiation pattern. Based on rigorous analysis, we derive exact expressions for the directive radiation patterns of arbitrary discrete distributions of Proca source systems, i.e., radiating arrays emitting massive photons. Examples of linear discrete Proca arrays are given and comparison with massless photon radiation sources is provided.

3D bionic reactor optimizes photon and mass transfer by expanding reaction space to enhance photocatalytic CO2 reduction

Use of 3D photocatalytic reactor has been widely explored for development of efficient photocatalytic systems. In the present study, a bionic palisade cells BiOBr/Sr2Nb2O7/Al6Si2O13 photocatalytic reactor with high strength was prepared through combination of 3D printing technology and solvothermal method. The carefully designed and optimized bionic palisade cell structure exhibited a periodic porous structure with high surface area. The controllable periodic structure effectively regulated the internal photon transfer and mass transfer. Photon transfer ensured that light is fully scattered within the structure, which improved light utilization. High mass transfer ensured smooth flow of reactant inside the structure, which increased reactant adsorption on the surface of photocatalysts. The interface electric field of the BiOBr/Sr2Nb2O7 p-n heterojunction effectively separated the photogenerated electrons and holes. The BOB/SNO/ASO structure had high photocatalytic CO2 reduction performance under the simulated sunlight. The CO yield for the reaction was 13.68 μmol/g/h, whereas that of CH4 yield was 6.37 μmol/g/h. Therefore, the findings of the present study provide a basis for design and preparation of high-performance 3D photocatalytic reactors.

Probing the dark photon via polarized DIS scattering at the HERA and EIC

The dark photon is widely predicted in many new physics beyond the Standard Model. In this work, we propose to utilize the polarized lepton cross section and single-spin asymmetry in neutral current DIS process at the HERA and upcoming Electron-Ion Collider (EIC) to probe the properties of the dark photon. It shows that we can constrain the mixing parameter ϵ<0.02 when the dark photon mass mAD<10GeV at the HERA with polarized lepton beam and this bound is comparable to the limit from the unpolarized data of HERA I and II. With the help of high integrated luminosity and high electron beam polarization of the EIC, the upper limit of the ϵ could be further improved. Depending on the assumption of the systematic error of the cross section measurements, we obtain ϵ<0.01∼0.02 for the mass region mAD<10GeV under the integrated luminosity of 300fb−1. A similar and robust upper limit for the ϵ could be obtained from the single-spin asymmetry measurement, which is not depending on the assumption of the systematic errors.

Hitting two BSM particles with one lepton-jet: search for a top partner decaying to a dark photon, resulting in a lepton-jet

A maverick top partner model, decaying to a dark photon was suggested in Ref. [1]. The dark photon decays to two overlapping electrons for dark photon masses of \approx 100≈100 MeV, and results in a so-called lepton-jet. The event includes a top quark as well, which results in events with two boosted objects, one heavy and the other light. We propose a search strategy exploiting the unique signal topology. We show that for a set of kinematic selections, both in hadronic and leptonic decay channel of the SM top quark, almost all background can be eliminated, leaving enough signal events up to top partner mass of about 3.5 TeV for the search to be viable at the LHC Run 2. Further, integrated luminosity needed for the proposed search to be sensitive is presented as a function of top partner mass.

Einstein–Cartan–Holst–Proca dynamos massive photons as dark matter and GWs

In this paper, we extend Shaposhnikov et al.'s parity violating the Einstein–Cartan–Holst action by adding to Holst term H, a Proca photon–torsion coupling χpt = 10−24 as computed by De Sabbata, Garcia de Andrade, and Sivaram. The strength of Holst term is obtained, in the case of early universe torsion as, T ∼ 1 MeV. The gravity part is the Planck mass product with the Holst term. The photon mass in this case yields m2 γ H ∼ 10−69 GeV4. Therefore, in this case, the photon interacts very weakly with spin-torsion matter in Einstein–Cartan (EC) gravity and the strength of the Maxwell–Proca–Holst interaction is much weaker than in the pure gravity sector. For dark photons, this situation changes drastically since a dark photon mass reaches 1.5 GeV, and from this mass and T = 10−3 GeV, one obtains a Maxwell–Proca–Holst strength of 10−6 GeV4, which is now comparable with the gravity sector. Dynamo mechanism competes with the chirality and dissipation by the handness of the magnetic field with respect to the torsion trace vector to regenerate the magnetic field decay. Bombacigno and Mantovani recently found a sign of the Immirzi parameter in the Holst–Nieh–Yan extension of EC gravity. Here, we also find torsion waves for the Immirzi inverse parameter in the sense that this divergence of torsion trace is porportional to the Immirzi field.

The dark side of the proton

We study the sensitivity of the High-Luminosity LHC to a light baryonic dark photon B, primarily coupled to quarks, as a constituent of the proton. This is achieved by allowing for a dark photon parton distribution function (PDF) in the PDF evolution equations. Depending on the mass and coupling of the dark photon, the evolution of standard quark and gluon PDFs is distorted to varying degrees. By analysing the effect of the dark photon on the tails of Drell-Yan invariant mass distributions, we demonstrate the potential of the LHC in determining competitive bounds on dark photon parameter space.

Gravitational production of dark photon dark matter with mass generated by the Higgs mechanism

We study the gravitational production of dark photon dark matter during inflation, when dark photons acquire mass by the Higgs mechanism. In the previous study, it was assumed that the dark photon has a Stückelberg mass, or a mass generated by the Higgs mechanism with a sufficiently heavy Higgs boson. In this paper we consider a case in which the Higgs boson is not fully decoupled; the Higgs field changes its vacuum expectation value after inflation. Then, the dark photon mass also changes with time after inflation, and the time evolution of the longitudinal mode is different from the case with a Stückelberg mass. Consequently, the spectrum of the dark photon energy density can have two peaks at an intermediate scale and a small scale. We show that the dark photon can explain the dark matter if its current mass is larger than 6 μeV × (HI /1014 GeV)-4 and smaller than 0.8 GeV × (HI /1014 GeV)-3/2, with HI being the Hubble parameter during inflation. A higher mass is required if one considers a larger gauge coupling constant. The result for the Stückelberg mass can be reproduced in the limit of a small gauge coupling constant. We also comment on the constraints set by various conjectures in quantum gravity theory.