Related papers: Breaking up the Proton: An Affair with Dark Forces
Dark sector may couple to the Standard Model via one or more mediator particles. We discuss two types of mediators: the dark photon $A^{\prime}$ and the dark scalar mediator $\phi$. The total cross-sections and various differential…
A dark photon is a hypothetical particle that is similar to a photon with a small mass and interacts very weakly with ordinary matter through a kinetic mixing with the ordinary photon. In this paper, we propose a new way to probe the…
The Large Hadron-Electron Collider (LHeC) will operate at $\sqrt{s}$ = 1.2 TeV and accumulate about 1/ab of integrated electron-proton luminosity. Novel studies of high energy photon-photon interactions at the LHeC, at the $\gamma\gamma$…
We present a search for the e+e- decay of a hypothetical dark photon, also names U vector boson, in inclusive dielectron spectra measured by HADES in the p (3.5 GeV) + p, Nb reactions, as well as the Ar (1.756 GeV/u) + KCl reaction. An…
We consider current observational constraints on the electromagnetic charge of dark matter. The velocity dependence of the scattering cross-section through the photon gives rise to qualitatively different constraints than standard dark…
Proton-proton collisions at the LHC generate high-intensity collimated beams of forward neutrinos up to TeV energies. Their recent observations and the initiation of a novel LHC neutrino program motivate investigations of this previously…
We estimate the sensitivity of various experiments detecting ultra-high-energy cosmic rays to primary photons with energies above 10^19 eV. We demonstrate that the energy of a primary photon may be significantly (up to a factor of ~ 10)…
A search for evidence of particle dark matter (DM) and unparticle production at the LHC has been performed using events containing two charged leptons, consistent with the decay of a Z boson, and large missing transverse momentum. This…
Extensions of the Standard Model (SM) gauge group with a new $U(1)_X$ predict an additional gauge boson. Through kinetic mixing with the SM photons featured by a coupling $\epsilon$, the ensuing so-called dark photons $\gamma'$, which…
Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum with the ATLAS experiment at the LHC are reported. Data were collected in proton--proton collisions at a center-of-mass energy of…
Several models of particle physics different from the Standard Model predict the existence of a dark sector that is weakly coupled to the visible one: the two sectors may couple via the vector portal, where a dark photon with mass in the…
The production of isolated photons in deep-inelastic scattering $ep\to e \gamma X$ is measured with the H1 detector at HERA. The measurement is performed in the kinematic range of negative four-momentum transfer squared $4<Q^2<150 $~GeV$^2$…
The simple interpretation of PAO's UHECRs' penetration depth measurements suggests a transition at the energy range $1.1 - 35 \cdot 10^{18} $ eV from protons to heavier nuclei. A detailed comparison of this data with air shower simulations…
The proposed electron-proton collider LHeC is a unique facility where electroweak interactions can be studied with a very high precision in a largely unexplored kinematic regime of spacelike momentum transfer. We have simulated inclusive…
We explore the phenomenology of a class of models where the dark matter particle can inelastically up-scatter to a heavier excited state via off-diagonal dipolar interactions with the interstellar plasma (gas or free electrons). The heavier…
Experiments involving proton-proton collisions at energies $\sqrt{s_{NN}}$ = 0.9, 2.76 and 7 TeV in Large Hadron Collider (LHC) have produced a vast amount of high-precision data. Here, in this work, we have chosen to analyse the two…
The standard model (SM) of particle physics is spectacularly successful, yet the measured value of the muon anomalous magnetic moment $(g-2)_\mu$ deviates from SM calculations by 3.6$\sigma$. Several theoretical models attribute this to the…
A search for diphoton events with large missing transverse energy is presented. The data were collected with the ATLAS detector in proton-proton collisions at sqrt(s) = 7 TeV at the CERN Large Hadron Collider and correspond to an integrated…
Light new particles can be emitted in decays of excited nuclear states. Experiments analyzing such transitions and incorporating high-resolution detectors can be sensitive to new MeV-scale physics at a level competitive with upcoming…
The Large Hadron electron Collider (LHeC) has been designed to push the field of deep inelastic scattering to the high energy and intensity frontier using an intense electron beam with a proton beam from the High Luminosity-Large Hadron…