Related papers: Constraints on dark axion portal: missing energy a…
The link between ordinary Standard model (SM) photon and both dark photon and axion like particle (ALP) can be introduced through the dark axion portal coupling. Given the dark axion portal setup, in the present paper we refer the dark…
Axion-like particles (ALPs) can provide a portal to new states of a dark sector. We study the phenomenology of this portal when the ALP mainly decays invisibly, while its interaction with the standard model sector proceeds essentially via…
In rich dark sector models, dark photons heavier than tens of MeV can behave as semi-visible particles: their decays contain both visible and invisible final states. We present models containing multiple dark fermions which allow for such…
The optical dump at the LUXE experiment has the potential to create a large flux of $\mathcal{O}({\rm GeV})$ photons that can be used to look for new physics when directed at a solid material dump. The LUXE-NPOD extension of LUXE, which…
Axion-like particles (ALPs) are promising candidates for mediating interactions between a dark sector and the Standard Model (SM). In this work, considering the effective interactions of ALPs with the SM gauge bosons and a fermion dark…
We propose the possibility of discovering a light pseudoscalar particle $a$, axion-like particle (ALP), interacting mainly with quarks using the electron and photon scattering reaction chain $e + Z \rightarrow e + \gamma + Z$; $\gamma + Z…
We consider a model in which dark matter is a light (350 MeV) Dirac fermion which couples to quarks as an axial-vector current. At center-of-mass (CM) energies below the confinement scale, such a DM interaction structure may be described…
A search is performed for a new sub-GeV vector boson ($A'$) mediated production of Dark Matter ($\chi$) in the fixed-target experiment, NA64, at the CERN SPS. The $A'$, called dark photon, could be generated in the reaction $ e^- Z \to e^-…
We consider an experiment to search for dark sector particles in dark photon kinetic mixing model by analyze invisible and semi-invisible decays of neutral mesons $M^0 = \pi^0$, $\eta$, $\eta'$, $\omega$, $f_2(1270)$, produced in the NA64…
Axions and dark photons are common in many extensions of the Standard Model. The dark axion portal -- an axion coupling to the dark photon and photon -- can significantly modify their phenomenology. We study the cosmological constraints on…
We study portal interactions connecting visible and dark sectors, and involving local interactions of a photon, a dark photon and a axion-like particle (ALP) at future $e^+e^-$ colliders. These interactions, mediated by higher-dimensional…
If dark matter (DM) interacts with the Standard Model (SM) via the kinetic mixing (KM) portal, it necessitates the existence of portal matter (PM) particles which carry both dark and SM quantum numbers that will appear in vacuum…
Pairs of Standard Model fermions form dimension-3 singlet operators that can couple to new dark sector states. This "fermion portal" is to be contrasted with the lower-dimensional Higgs, vector and neutrino singlet portals. We characterise…
Inelastic dark matter scenarios have attracted considerable attention in contemporary particle physics. In this study, we investigate the phenomenology of sub-GeV inelastic dark matter interacting via a lepton-specific scalar portal. By…
Dark sectors provide beyond Standard Model scenarios which can address unresolved puzzles, such as the observed dark matter abundance or the baryon asymmetry of the Universe. A naturally small portal to the dark sector is obtained if…
In this thesis, we investigate various possibilities of Weakly Interacting Massive Particle (WIMP) dark matter (DM) and their implications. These possibilities are important because they challenge the viability of WIMP DM in light of tight…
The Dark Axion Portal provides a model for Dark Matter (DM) in which both Dark Photons $\gamma^\prime$ and Axions $a$ can contribute to the present day abundance of DM. We study the parameter space of the Dark Axion Portal to pinpoint…
Electron beam fixed target experiments such as NA64 and LDMX use missing energy-momentum to detect the production of dark matter and other long-lived states. The most studied production mechanism is dark Bremsstrahlung through a vector…
Hidden monopole is a plausible dark matter candidate due to its stability, but its direct experimental search is extremely difficult due to feeble interactions with the standard model particles in the minimal form. Then, we introduce an…
We consider the possible existence of a SM-neutral and light dark sector coupled to the visible sector through irrelevant portal interactions. Scenarios of this kind are motivated by dark matter and arise in various extensions of the…