Related papers: Long-lived vectors from electromagnetic cascades a…
Neutral gauge bosons beyond the Standard Model are becoming interesting as possible mediators to explain several experimental anomalies. They have small masses, below one GeV, and are referred to as dark photons, $U$, $A'$ or $Z'$ bosons.…
Very high energy (VHE $>$100 GeV) gamma rays coming from blazars can produce pairs when interacting with the Extragalactic Background Light (EBL) and the Cosmic Microwave Background, generating an electromagnetic cascade. Depending on the…
A model of dark sector where $O({\rm few~GeV})$ mass dark matter particles $\chi$ couple to a lighter dark force mediator $V$, $m_V \ll m_\chi$, is motivated by the recently discovered mismatch between simulated and observed shapes of…
Inelastic Dark Matter (iDM) is an interesting thermal DM scenario that can pose challenges for conventional detection methods. However, recent studies demonstrated that iDM coupled to a photon by electric or magnetic dipole moments can be…
It has been shown that the longitudinal mode of a massive vector boson can be produced by inflationary fluctuations and account for the dark matter content of the Universe. In this work we examine the possibility of instead producing the…
The discovery of the Higgs boson has fully confirmed the Standard Model of particles and fields. Nevertheless, there are still fundamental phenomena, like the existence of dark matter and the baryon asymmetry of the Universe, which deserve…
Direction measurement of weakly interacting massive particles in time-projection chambers can provide definite evidence of their existence and help to determine their properties. This article demonstrates several concepts for charge…
We generalize the Schwinger mechanism and calculate the probability of the decay of intense electromagnetic fields to pseudoscalar particles. We also point out that our estimate for axion emission in a previous paper was incorrect.
The Heavy Photon Search experiment (HPS) at the Thomas Jefferson National Accelerator Facility searches for electro-produced dark photons. We report results from the 2016 Engineering Run consisting of 10608/nb of data for both the prompt…
Experiments using proton beams at high luminosity colliders and fixed target facilities provide impressive sensitivity to new light weakly coupled degrees of freedom. With these experiments in mind, we revisit the production of dark vectors…
We present a type of dark energy models where the particles of dark energy phi are dynamically produced via a quantum transition at very low energies. The scale where the transition takes places depends on the strength g of the interaction…
We calculate the early universe evolution of perturbations in the dark matter energy density in the context of simple dark sector models containing a GeV scale light mediator. We consider the case that the mediator is long lived, with…
A new theory of WIMP Dark Matter has been proposed, motivated directly by striking Data from the PAMELA and ATIC collaborations. The WIMP is taken to be charged under a hidden gauge symmetry G_Dark, broken near the GeV scale; this also…
The reactions $\gamma p \rightarrow K^{+}\Sigma^{\pm}\pi^{\mp}$ were studied with the SAPHIR detector using a tagged photon beam at the electron stretcher facility ELSA in Bonn. The decays $\Sigma^{-} \rightarrow n\pi^{-}$ and $\Sigma^{+}…
We analyze the sensitivity of fixed-target experiments to sub-GeV thermal relic dark matter models, accounting for variations in both mediator and dark matter mass, and including dark matter production through both on- and off-shell…
Direct detection strategies are proposed for dark matter particles with MeV to GeV mass. In this largely unexplored mass range, dark matter scattering with electrons can cause single-electron ionization signals, which are detectable with…
Dark matter is five times more abundant than ordinary visible matter in our Universe. While laboratory searches hunting for dark matter have traditionally focused on the electroweak scale, theories of low mass hidden sectors motivate new…
Axion-like particles (ALPs), relatively light (pseudo-)scalars coupled to two gauge bosons, are a common feature of many extensions of the Standard Model. Up to now there has been a gap in the sensitivity to such particles in the MeV to 10…
The physics program of the Higgs factory will focus on measurements of the 125 GeV Higgs boson, with the Higgs-strahlung process being the dominant production channel at 250 GeV. However, production of extra light scalars is still not…
We explore the sensitivity of the Short-Baseline Near Detector (SBND) experiment to light dark matter using MeV-scale electromagnetic activity. Inelastic scattering of dark matter with argon nuclei can excite nuclear states that…