Related papers: Enhanced Long-Lived Dark Photon Signals at the LHC
We study the signatures of the triplet-quadruplet dark matter model at the LHC and future colliders, including the 100 TeV Super Proton-Proton Collider and the 240 GeV Circular Electron Positron Collider. The dark sector in this model…
Many extensions of the SM contain hidden sectors which are uncharged under the SM gauge group. The simplest model with an additional $U(1)$ group predicts the existence of the new gauge boson, dark photon $Z_D$. In this work we consider…
We propose a novel approach for discovering a light dark photon in the forward experiments at the LHC, including the SND@LHC and the FASER experiments. Assuming the dark photon is lighter than twice the electron mass and feebly interacts…
We study a simple Dirac fermion dark matter model in U(1)$_{L_\mu-L_\tau}$ theory. The new light gauge boson $X$ plays important roles in both dark matter physics and the explanation for the muon $g-2$ anomaly. The observed dark matter…
A toy model giving rise to long lived super heavy particles and an small vacuum density energy, of the order of the one measured in the present universe, is constructed. This model consists in hidden sector invariant under an $SU(2)_L$…
Visible signals from the decays of light long-lived hidden sector particles have been extensively searched for at beam dump, fixed-target, and collider experiments. If such hidden sectors couple to the Standard Model through mediators…
In this paper, we present a model in which an up-type vector-like quark (VLQ) is charged under a new $U(1)_d$ gauge force which kinetically mixes with the SM hypercharge. The gauge boson of the $U(1)_d$ is the dark photon, $\gamma_d$.…
We analyse supersymmetric models augmented by an extra $U(1)$ gauge group. To avoid anomalies in these models without introducing exotics, we allow for family-dependent $U(1)^\prime$ charges, and choose a simple form for these, dependent on…
In view of ongoing measurements of the Higgs-like boson at the LHC and direct searches for dark matter, we explore the possibility of accommodating the potential results in a simple new-physics model with discrete gauge symmetry as well as…
We consider the phenomenological consequences of a hidden Higgs sector extending the Standard Model (SM), in which the ``shadow Higgs'' are uncharged under the SM gauge groups. We consider a simple U(1) model with one Higgs singlet. One…
We study dark matter (DM) models in which there are two dark sector particles, $\chi_1$ and $\chi_2$, of near mass. In such models, co-annihilation of $\chi_1$ and $\chi_2$ may be the dominant process controlling the DM relic density during…
We propose a simplified model of dark matter with a scalar mediator to accommodate the di-photon excess recently observed by the ATLAS and CMS collaborations. Decays of the resonance into dark matter can easily account for a relatively…
We consider a class of models with extra complex scalars that are charged under both the Standard Model and a hidden strongly coupled $SU(N)_H$ gauge sector, and discuss the scenarios where the new scalars are identified as the messenger…
We consider extending the Standard Model by including an additional Abelian gauge group broken at low energies under which the right-handed top quark is the only effectively charged Standard Model fermion. The associated gauge boson $(Z')$…
The possibility of light dark matter (DM) annihilating through a dark photon (DP) which kinetically mixes (KM) with the Standard Model (SM) hypercharge field is a very attractive scenario. For DM in the interesting mass range below $\sim 1$…
An analysis is given of the Stueckelberg extension of the Standard Model with a hidden sector gauge group $U(1)_X$ where the mass growth for the extra gauge boson occurs via the Stueckelberg mechanism, and where the kinetic mixing in the…
The discovery of a standard model (SM)-like Higgs boson with a relatively heavy mass $m_h$ and hints of di-photon excess has deep implication to supersymmetric standard models (SSMs). We consider the SSM extended with hypercharge $\pm1$…
We perform a detailed study of an effective field theory which includes the Standard Model particle content extended by a pair of Weyl fermionic SU(2)-doublets with opposite hypercharges. A discrete symmetry guarantees that a linear…
We use a Hybrid Deep Neural Network (HDNN) to identify a boosted dark photon jet as a signature of a heavy vector-like fermionic portal matter (PM) connecting the visible and the dark sectors. In this work, the fermionic PM, which mixes…
An extension of the Standard Model is studied, in which two new vector bosons are introduced, a first boson $Z'$ coupled to the SM by the usual minimal coupling, producing an enlarged gauge sector in the SM. The second boson $A'$ field, in…