Related papers: Lepton Jets from Radiating Dark Matter
In this thesis a simple extension of the Standard Model has been investigated. The Standard Model gauge group has been extended by an additional $U(1)_X$ group. The model introduces a new Higgs particle as well as three particles (a gauge…
We analyze the potential dark matter implications of LHC events with missing transverse momentum and a resonance, such as a Z', decaying to a pair of jets or leptons. This final state contains significant discovery potential, but has not…
Any form of dark matter which was in thermal equilibrium with the Standard Model in the early Universe must have some annihilation mechanism in order to avoid overclosure. In general, such models are now constrained by the negative…
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…
We investigate the consequences of models where dark sector quarks could be produced at the LHC, which subsequently undergo a dark parton shower, generating jets of dark hadrons that ultimately decay back to Standard Model hadrons. This…
The proposed DarkQuest beam dump experiment, a modest upgrade to the existing SeaQuest/SpinQuest experiment, has great potential for uncovering new physics within a dark sector. We explore both the near-term and long-term prospects for…
A search is presented for particle dark matter produced in association with a pair of top quarks in pp collisions at a centre-of-mass energy of sqrt(s) = 8 TeV. The data were collected with the CMS detector at the LHC and correspond to an…
Light dark matter with mass smaller than about 10 GeV is difficult to probe from direct detection experiments. In order to have the correct thermal relic abundance, the mediator of the interaction between dark matter and the Standard Model…
We explore direct collider probes of the resonant leptogenesis mechanism for the origin of matter. We work in the context of theories where the Standard Model is extended to include an additional gauged U(1) symmetry broken at the TeV…
A renormalizable UV model for Axion-Like Particles (ALPs) or hidden photons, that may explain the dark matter usually involves a dark Higgs field which is a singlet under the standard model (SM) gauge group. The dark sector can couple to…
We consider a model for a Z'-boson coupled only to baryon minus lepton number and hypercharge. Besides the usual right-handed neutrinos, we add a pair of fermions with a fractional lepton charge, which we therefore call leptinos. One of the…
We study the possibility that light dark matter can be produced with right relic density by the decay of other dark sector particles. We study this possibility in a model with right-handed neutrinos, a dark sector singlet scalar and a dark…
This paper explores a simplified extension of the standard model featuring a neutral fermion quintuplet and a scalar quadruplet, which together generate neutrino masses through tree and loop level mechanisms. The quintuplet fermions decay…
We reemphasise the usefulness of angular correlations in LHC searches for missing transverse energy ($E_T^{\mathrm{miss}}$) signatures that involve jet $(j)$ pairs with large invariant mass. For the case of mono-jet production via…
Massive photon-like particles are predicted in many extensions of the Standard Model with a hidden sector where dark matter is secluded. They are vector bosons mediating the interaction between dark matter particles and can be produced in…
In this work, we consider the case of a strongly coupled dark/hidden sector, which extends the Standard Model (SM) by adding an additional non-Abelian gauge group. These extensions generally contain matter fields, much like the SM quarks,…
We propose a search strategy using the LHC as a photon collider to open sensitivity to scalar lepton (slepton $\tilde{\ell}$) production with masses around 15 to 60 GeV above that of neutralino dark matter $\tilde{\chi}^0_1$. This region is…
The evidence for dark matter signals a new class of particles at the TeV scale, which may manifest themselves indirectly through loop effects. In a simple model we show that these loop effects may be responsible for the enhanced muon…
In the first part of this thesis, we consider an extension to the Standard Model composed by a Massive Vector Doublet under SU(2)L and a Left-handed Heavy Neutral Lepton. We study the production of these exotic leptons with a Same Flavor…
We discuss singlet fermion dark matter within a left-right symmetric model promoting baryon and lepton numbers as separate gauge symmetries. We add a simple Dirac fermionic dark matter singlet under $SU(2)_{L,R}$ with nonzero and equal…