scholarly journals Completely dark photons from gravitational particle production during the inflationary era

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Edward W. Kolb ◽  
Andrew J. Long
Keyword(s):  
Dark Matter ◽  
Vector Field ◽  
Standard Model ◽  
Particle Production ◽  
Number Density ◽  
Massive Vector ◽  
Detailed Consideration ◽  
Electron Volt ◽  
Dark Photon ◽  
Wide Range

Abstract Starting with the de Broglie-Proca Lagrangian for a massive vector field, we calculate the number density of particles resulting from gravitational particle production (GPP) during inflation, with detailed consideration to the evolution of the number density through the reheating. We find plausible scenarios for the production of dark-photon dark matter of mass in a wide range, as low as a micro-electron volt to 1014 GeV. Gravitational particle production does not depend on any coupling of the dark photon to standard-model particles.

scholarly journals Dark Photon Search with PADME at LNF

2018 ◽  
Vol 46 ◽  
pp. 1860047
Author(s):  
Gabriele Piperno
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Effective Charge ◽  
Vector Boson ◽  
Charged Particles ◽  
Massive Vector ◽  
Dark Photon ◽  
The Standard Model

Dark Matter elusiveness could be explained by speculating that it lives in a separate sector with respect to the Standard Model and that interacts with it only by means of messengers. The simplest model foresees just one messenger: a, possibly massive, vector boson given by a new U(1) symmetry. This mediator can faintly mix with the photon and, hence, interact with SM charged particles, seeing an effective charge equal to [Formula: see text], with [Formula: see text] SM charge. The PADME experiment, hosted at Laboratori Nazionali di Frascati, is designed to search for such kind of particle, looking for its production in [Formula: see text] annihilations. Exploiting the DA[Formula: see text]NE linac, the collaboration aims to collect [Formula: see text] positrons on target by the end of 2018, reaching a sensitivity of [Formula: see text] for masses up to [Formula: see text][Formula: see text]Mev.

scholarly journals Resurrecting low-mass axion dark matter via a dynamical QCD scale

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Lucien Heurtier ◽  
Fei Huang ◽  
Tim M.P. Tait
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Temperature Dependent ◽  
Axion Field ◽  
Wide Range ◽  
The Standard Model ◽  
Low Mass ◽  
Higher Temperature ◽  
Relic Abundance ◽  
Dependent Mass

Abstract In the framework where the strong coupling is dynamical, the QCD sector may confine at a much higher temperature than it would in the Standard Model, and the temperature-dependent mass of the QCD axion evolves in a non-trivial way. We find that, depending on the evolution of ΛQCD, the axion field may undergo multiple distinct phases of damping and oscillation leading generically to a suppression of its relic abundance. Such a suppression could therefore open up a wide range of parameter space, resurrecting in particular axion dark-matter models with a large Peccei-Quinn scale fa ≫ 1012 GeV, i.e., with a lighter mass than the standard QCD axion.

scholarly journals Constraining dark photon properties with Asteroseismology

2019 ◽  
Vol 491 (1) ◽  
pp. 409-416
Author(s):  
Adrián Ayala ◽  
Ilidio Lopes ◽  
Antonio García Hernández ◽  
Juan Carlos Suárez ◽  
Íñigo Muñoz Elorza
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Matter Content ◽  
Solar Mass ◽  
Dark Photon ◽  
Mixing Parameter ◽  
The Standard Model ◽  
Red Giant ◽  
The Impact ◽  
The Universe

ABSTRACT Dark photons are particles invoked in some extensions of the Standard Model that could account for at least part of the dark matter content of the Universe. It has been proposed that the production of dark photons in stellar interiors could happen at a rate that depends on both, the dark photon mass and its coupling to Standard Model particles (the kinetic mixing parameter χ). In this work, we aim at exploring the impact of dark photon productions in the stellar core of solar mass red giant branch (RGB) stars during late evolutionary phases. We demonstrate that near the so-called RGB bump, dark photons production may be an energy sink for the star sufficiently significative to modify the extension of the star convective zones. We show that Asteroseismology is able to detect such variations in the structure, allowing us to predict an upper limit of $\rm 900\ eV$ and 5 × 10−15 for the mass and kinetic mixing of the dark photons, respectively. We also demonstrate that additional constraints can be derived from the fact that dark photons increase the luminosity of the RGB tip over the current observational uncertainties. This work thus paves the way for an empirical approach to deepen the study of such dark matter particles.

scholarly journals Modified initial power spectrum and too big to fail problem

2020 ◽  
Vol 494 (4) ◽  
pp. 4907-4913 ◽  
Author(s):  
Hamed Kameli ◽  
Shant Baghram
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Power Spectrum ◽  
Initial Conditions ◽  
Dark Matter Halo ◽  
Current Status ◽  
Number Density ◽  
Too Big To Fail ◽  
Standard Case ◽  
Initial Power

ABSTRACT The galactic scale challenges of dark matter such as ‘missing satellite’ problem and ‘too big to fail’ problem are the main caveats of standard model of cosmology. These challenges could be solved either by implementing the complicated baryonic physics or it could be considered as an indication to a new physics beyond the standard model of cosmology. The modification of collisionless dark matter models or the standard initial conditions are two promising venues for study. In this work, we investigate the effects of the deviations from scale invariant initial curvature power spectrum on number density of dark matter haloes. We develop the non-Markov extension of the excursion set theory to calculate the number density of dark matter substructures and dark matter halo progenitor mass distribution. We show that the plausible solution to ‘too big to fail’ problem could be obtained by a Gaussian excess in initial power in the scales of k* ∼ 3 h Mpc−1 that is related to the mass scale of M* ∼ 1011 M⊙. We show that this deviation leads to the decrement of dark matter subhaloes in galactic scale, which is consistent with the current status of the non-linear power spectrum. Our proposal also has a prediction that the number density of Milky Way-type galaxies must be higher than the standard case.

scholarly journals New physics explanations of aμ in light of the FNAL muon g − 2 measurement

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Peter Athron ◽  
Csaba Balázs ◽  
Douglas H. J. Jacob ◽  
Wojciech Kotlarski ◽  
Dominik Stöckinger ◽  
...  
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Higgs Doublet ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Average Deviation ◽  
Dark Matter Relic Density ◽  
Wide Range ◽  
The Standard Model ◽  
Parameter Ranges

Abstract The Fermilab Muon g −2 experiment recently reported its first measurement of the anomalous magnetic moment $$ {a}_{\mu}^{\mathrm{FNAL}} $$ a μ FNAL , which is in full agreement with the previous BNL measurement and pushes the world average deviation $$ \Delta {a}_{\mu}^{2021} $$ ∆ a μ 2021 from the Standard Model to a significance of 4.2σ. Here we provide an extensive survey of its impact on beyond the Standard Model physics. We use state-of-the-art calculations and a sophisticated set of tools to make predictions for aμ, dark matter and LHC searches in a wide range of simple models with up to three new fields, that represent some of the few ways that large ∆aμ can be explained. In addition for the particularly well motivated Minimal Supersymmetric Standard Model, we exhaustively cover the scenarios where large ∆aμ can be explained while simultaneously satisfying all relevant data from other experiments. Generally, the aμ result can only be explained by rather small masses and/or large couplings and enhanced chirality flips, which can lead to conflicts with limits from LHC and dark matter experiments. Our results show that the new measurement excludes a large number of models and provides crucial constraints on others. Two-Higgs doublet and leptoquark models provide viable explanations of aμ only in specific versions and in specific parameter ranges. Among all models with up to three fields, only models with chirality enhancements can accommodate aμ and dark matter simultaneously. The MSSM can simultaneously explain aμ and dark matter for Bino-like LSP in several coannihilation regions. Allowing under abundance of the dark matter relic density, the Higgsino- and particularly Wino-like LSP scenarios become promising explanations of the aμ result.

scholarly journals Gravitational waves and dark photon dark matter from axion rotations

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Raymond T. Co ◽  
Keisuke Harigaya ◽  
Aaron Pierce
Keyword(s):  
Dark Matter ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Early Universe ◽  
Radial Direction ◽  
Particle Production ◽  
Baryon Asymmetry ◽  
Complex Field ◽  
Dark Photon ◽  
Pulsar Timing

Abstract An axion rotating in field space can produce dark photons in the early universe via tachyonic instability. This explosive particle production creates a background of stochastic gravitational waves that may be visible at pulsar timing arrays or other gravitational wave detectors. This scenario provides a novel history for dark photon dark matter. The dark photons may be warm at a level detectable in future 21-cm line surveys. For a consistent cosmology, the radial direction of the complex field containing the axion must be thermalized. We explore a concrete thermalization mechanism in detail and also demonstrate how this setup can be responsible for the generation of the observed baryon asymmetry.

scholarly journals Dark photon dark matter from charged inflaton

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Hassan Firouzjahi ◽  
Mohammad Ali Gorji ◽  
Shinji Mukohyama ◽  
Borna Salehian
Keyword(s):  
Dark Matter ◽  
Energy Density ◽  
Global Minimum ◽  
Longitudinal Mode ◽  
Inflaton Field ◽  
Dark Photon ◽  
Transverse Modes ◽  
Matter Production ◽  
Wide Range ◽  
Relic Density

Abstract We present a scenario of vector dark matter production during inflation containing a complex inflaton field which is charged under a dark gauge field and which has a symmetry breaking potential. As the inflaton field rolls towards the global minimum of the potential the dark photons become massive with a mass which can be larger than the Hubble scale during inflation. The accumulated energy of the quantum fluctuations of the produced dark photons gives the observed relic density of the dark matter for a wide range of parameters. Depending on the parameters, either the transverse modes or the longitudinal mode or their combination can generate the observed dark matter relic energy density.

scholarly journals STUECKELBERG: A FORERUNNER OF MODERN PHYSICS II

2008 ◽  
Vol 23 (08) ◽  
pp. 1105-1112 ◽  
Author(s):  
FRANCESCO CIANFRANI ◽  
ORCHIDEA MARIA LECIAN
Keyword(s):  
Vector Field ◽  
Scattering Amplitudes ◽  
Standard Model ◽  
The Other ◽  
Massive Vector ◽  
Other Hand ◽  
The Standard Model ◽  
Modern Physics ◽  
The One ◽  
Definition Of

We will investigate some aspects of Stueckelberg's work, which have contributed to the development of modern physics. On the one hand, the definition of diffuse boundaries in the calculation of scattering amplitudes will be reviewed, and compared with the other proposals by physicists of that time. On the other hand, the applications of Stueckelberg's description of a massive vector field in the Standard Model will be discussed.

scholarly journals Sensitivity of the SHiP experiment to light dark matter

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
C. Ahdida ◽  
◽  
A. Akmete ◽  
R. Albanese ◽  
A. Alexandrov ◽  
...  
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Mass Range ◽  
Weakly Interacting Massive Particles ◽  
Neutrino Detector ◽  
Mass Window ◽  
Dark Photon ◽  
Experimental Campaign ◽  
The Standard Model ◽  
The Universe

Abstract Dark matter is a well-established theoretical addition to the Standard Model supported by many observations in modern astrophysics and cosmology. In this context, the existence of weakly interacting massive particles represents an appealing solution to the observed thermal relic in the Universe. Indeed, a large experimental campaign is ongoing for the detection of such particles in the sub-GeV mass range. Adopting the benchmark scenario for light dark matter particles produced in the decay of a dark photon, with αD = 0.1 and mA′ = 3mχ, we study the potential of the SHiP experiment to detect such elusive particles through its Scattering and Neutrino detector (SND). In its 5-years run, corresponding to 2 · 1020 protons on target from the CERN SPS, we find that SHiP will improve the current limits in the mass range for the dark matter from about 1 MeV to 300 MeV. In particular, we show that SHiP will probe the thermal target for Majorana candidates in most of this mass window and even reach the Pseudo-Dirac thermal relic.

Combining First-Principles and Data Modeling for the Accurate Prediction of the Refractive Index of Organic Polymers

2017 ◽  
Author(s):  
Mohammad Atif Faiz Afzal ◽  
Chong Cheng ◽  
Johannes Hachmann
Keyword(s):  
First Principles ◽  
Data Modeling ◽  
Accurate Prediction ◽  
Index Of Refraction ◽  
Structure Theory ◽  
Organic Polymers ◽  
Number Density ◽  
Lorenz Equation ◽  
In Silico Studies ◽  
Wide Range

Organic materials with a high index of refraction (RI) are attracting considerable interest due to their potential application in optic and optoelectronic devices. However, most of these applications require an RI value of 1.7 or larger, while typical carbon-based polymers only exhibit values in the range of 1.3–1.5. This paper introduces an efficient computational protocol for the accurate prediction of RI values in polymers to facilitate in silico studies that an guide the discovery and design of next-generation high-RI materials. Our protocol is based on the Lorentz-Lorenz equation and is parametrized by the polarizability and number density values of a given candidate compound. In the proposed scheme, we compute the former using first-principles electronic structure theory and the latter using an approximation based on van der Waals volumes. The critical parameter in the number density approximation is the packing fraction of the bulk polymer, for which we have devised a machine learning model. We demonstrate the performance of the proposed RI protocol by testing its predictions against the experimentally known RI values of 112 optical polymers. Our approach to combine first-principles and data modeling emerges as both a successful and highly economical path to determining the RI values for a wide range of organic polymers.

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