Related papers: Protophobic Light Vector Boson as a Mediator to th…
A vectorlike lepton could make up a tiny fraction of the dark matter. Its large Z-boson mediated direct detection cross section can compensate for the small relic abundance, giving rise to an interesting signal at future…
We propose to generalize the extensions of the Standard Model where the $Z$ boson serves as a mediator between the Standard Model sector and the dark sector $\chi$. We show that, like in the Higgs portal case, the combined constraints from…
Dark Matter could be a composite state of a confining sector with an approximate scale symmetry. We consider the case where the associated pseudo-Goldstone boson, the dilaton, mediates its interactions with the Standard Model. When the…
In this paper, we examine the evolution of light and feebly interacting non-abelian dark gauge bosons dark matter in the early universe. We specifically work on a multi-component dark matter scenario with a $SU(2)_{_R}$ gauge symmetry,…
In 2016, the ATOMKI collaboration announced [PRL {\bf 116}, 042501 (2016)] observing an unexpected enhancement of the $e^+-e^-$ pair production signal in one of the $^8$Be nuclear transitions induced by an incident proton beam on a $^7$Li…
We construct a model of hidden massive vector boson dark matter as a homogeneous coherent oscillation in the entire universe without any dangerous instability. We make use of a particular form of the vector boson coupling to a scalar field…
We study the possibility to directly detect the boosted dark matter generated from the scatterings with high energetic cosmic particles such as protons and electrons. As a concrete example, we consider the sub-GeV dark matter mediated by a…
In this paper, we present a model for sub-MeV dark matter with strong self interactions which can solve some of the small scale crisis of the $\Lambda$CDM. The dark matter is a Majorana fermion with only off-diagonal interactions with a…
Confining gauge dynamics in dark sector is promising to provide dark matter with a mass in the range of sub-GeV to GeV. These dark sectors consist of composite particles, such as dark baryons and dark mesons, that are neutral under the…
We propose a simple model in which dark matter particle exchanges mediate a new quantum force between muons and nucleons, resolving the proton charge radius puzzle. At the same time, the discrepancy between the measured anomalous magnetic…
Dark matter with mass below about a GeV is essentially unobservable in conventional direct detection experiments. However, newly proposed technology will allow the detection of single electron events in semiconductor materials with…
Minimal scenarios with light (sub-GeV) thermal dark matter are usually accompanied by a correspondingly light "dark sector". Taking as an example a simple fermionic dark matter model, we will show that the presence of the dark sector plays…
Motivated by recent cosmic ray experimental results there has been a proposition for a scenario where a secluded dark matter particle annihilates, primarily, into Standard Model leptons through a low mass mediator particle. We consider…
We consider models of dark matter where the couplings between the standard model and the dark sector fall at resonance due to kinematics and direct detection experiments become insensitive. To be specific, we consider a simple model of 100…
We study an experimental search of a GeV scale vector boson at BES-III/BEPCII. It is responsible for mediating a new U(1)$_d$ interaction, as recently exploited in the context of weakly interacting massive particle dark matter. At low…
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…
Axion-like particles (ALPs) are good candidates for mediators to the dark sector. We explore scenarios in which an ALP mediates interactions between dark matter and electroweak gauge bosons. These models yield testable electromagnetic…
We examine the phenomenology of a simplified model of fermionic dark matter coupled to a light scalar mediator carrying lepton number 2. We find that the mediator can be very light and still consistent with laboratory and cosmological…
Self-interacting dark matter (SIDM) is a simple and well-motivated scenario that could explain long-standing puzzles in structure formation on small scales. If the required self-interaction arises through a light mediator (with mass $\sim…
Recently a 6.8$\sigma$ anomaly has been reported in the opening angle and invariant mass distributions of $e^+ e^-$ pairs produced in $^8\text{Be}$ nuclear transitions. The data are explained by a 17 MeV vector gauge boson $X$ that is…