Related papers: Dark matter annihilation with s-channel internal H…
We consider scenarios in which the annihilation of self-conjugate spin-1 dark matter to a Standard Model fermion-antifermion final state is chirality suppressed, but where this suppression can be lifted by the emission of an additional…
We consider a dark sector consisting of dark matter that is a Dirac fermion and a scalar mediator. This model has been extensively studied in the past. If the scalar couples to the dark matter in a parity conserving manner then dark matter…
Many dark matter interaction types lead to annihilation processes which suffer from p-wave suppression or helicity suppression, rendering them subdominant to unsuppressed s-wave processes. We demonstrate that the natural inclusion of dark…
There has been interest recently on particle physics models that may give rise to sharp gamma ray spectral features from dark matter annihilation. Because dark matter is supposed to be electrically neutral, it is challenging to build weakly…
A massive real scalar dark matter particle $S$ can couple to Standard Model leptons or quarks through a vector-like fermionic mediator $\psi$, a scenario known as the Vector-like portal. Due to helicity suppression of the annihilation cross…
For Majorana dark matter, gauge boson bremsstrahlung plays an important role in enhancing an otherwise helicity-suppressed s-wave annihilation cross-section. This is well known for processes involving a radiated photon or gluon together…
If the Dark Matter is the neutral Majorana component of a multiplet which is charged under the electroweak interactions of the Standard Model, its main annihilation channel is into W+W-, while the annihilation into light fermions is…
The era of indirect detection searches for dark matter has begun, with the sensitivities of gamma-ray detectors now approaching the parameter space relevant for weakly interacting massive particles. In particular, gamma ray lines would be…
We consider the indirect detection of dark matter within an extension of the standard model (SM) including a singlet fermion as cold dark matter (CDM) and a singlet pseudo-scalar as a mediator between dark matter and the SM particles. The…
We consider the possibility that the Higgs can be produced in dark matter annihilations, appearing as a line in the spectrum of gamma rays at an energy determined by the masses of the WIMP and the Higgs itself. We argue that this phenomenon…
Gamma ray spectral features are of interest for indirect searches of dark matter (DM). Following Barger et al, we consider 3 simple scenarios of DM that annihilates into Standard Model (SM) fermion pairs. Scenario 1 is a Majorana DM…
We consider a simplified model in which Majorana fermion dark matter annihilates to charged fermions through exchange of charged mediators. We consider the gamma-ray signals arising from the processes $XX \rightarrow \bar f f \gamma$,…
Simplified models provide a useful way to study the impacts of a small number of new particles on experimental observables and the interplay of those observables, without the need to construct an underlying theory. In this study, we perform…
We present a comprehensive study of a model where the dark matter is composed of a singlet real scalar that couples to the Standard Model predominantly via a Yukawa interaction with a light quark and a colored vector-like fermion. A…
We consider the indirect detection of dark matter that is captured in the Sun and subsequently annihilates to long-lived dark mediators. If these mediators escape the Sun before decaying, they can produce striking gamma ray signals, either…
We propose a fermionic dark matter model by extending Standard Model with a Dirac fermion and a real pseudoscalar. The fermion dark matter particle interacts with the Standard Model sector via the Higgs portal through a dimension five…
We consider a singlet Dirac fermion with Peccei-Quinn(PQ) symmetry as dark matter. A singlet complex scalar is introduced to mediate between dark matter and the SM through Higgs portal interaction and electroweak PQ anomalies. We show that…
We present simplified models for the galactic center gamma-ray excess where Dirac dark matter annihilates into pairs or triplets of on-shell bosonic mediators to the Standard Model. These annihilation modes allow the dark matter mass to be…
We consider scenarios in which dark matter is a Majorana fermion which couples to Standard Model fermions through the exchange of charged mediating particles. The matrix elements for various dark matter annihilation processes are then…
The gamma-ray excess observed from the Galactic Center can be interpreted as dark matter particles annihilating into Standard Model fermions with a cross section near that expected for a thermal relic. Although many particle physics models…