Related papers: Initial State Radiation in Majorana Dark Matter An…
The energy spectra of Standard Model particles originated from Dark Matter annihilations can be significantly altered by the inclusion of electroweak gauge boson radiation from the final state. A situation where this effect is particularly…
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…
Recent analyses have shown that the inclusion of electroweak corrections can alter significantly the energy spectra of Standard Model particles originated from dark matter annihilations. We investigate the important situation where the…
We study in this paper the scenario where the dark matter is constituted by Majorana particles which couple to a light Standard Model fermion and an extra scalar via a Yukawa coupling. In this scenario, the annihilation rate into the light…
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…
Arguably, the most popular candidate for Dark Matter (DM) is a massive, stable, Majorana fermion. However, annihilation of Majorana DM to two fermions features a helicity-suppressed s-wave rate. The process radiating a gauge boson via…
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…
It is well known that the annihilation of Majorana dark matter into fermions is helicity suppressed. Here, we point out that the underlying mechanism is a subtle combination of two distinct effects, and we present a comprehensive analysis…
Arguably, the most popular candidate for Dark Matter (DM) is a massive, stable, Majorana fermion. However, annihilation of Majorana DM to two fermions often features a helicity-suppressed s-wave rate. Radiating a gauge boson via electroweak…
We discuss simple models which predict the existence of significant gamma-ray fluxes from dark matter annihilation. In this context the dark matter candidate is a Majorana fermion with velocity-suppressed tree-level annihilation into…
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…
In models of anapole dark matter (DM), the DM candidate is a Majorana fermion whose primary interaction with standard model (SM) particles is through an anapole coupling to off-shell photons. As such, at tree-level, anapole DM undergoes…
We consider a complete list of simplified models in which Majorana dark matter particles annihilate at tree level to $hh$ or $hZ$ final states, and calculate the loop-induced elastic scattering cross section with nuclei in each case.…
We calculate the radiative corrections to the annihilation of the Dark Matter particles into leptons. Lepton masses are taken into account. As the Dark Matter particles are considered both Dirac and Majorana fermions. We sum up all the…
Inspired by the excess of gamma rays from the Galactic Center, we confront a number of simplified dark matter models with experimental data. Assuming a single dark matter particle coupled to standard matter via a spin-0 mediator, we compare…
We discuss a simple theory for neutrino masses where the total lepton number is a local gauge symmetry spontaneously broken below the multi-TeV scale. In this context, the neutrino masses are generated through the canonical seesaw mechanism…
We consider effective operators describing Dark Matter (DM) interactions with Standard Model fermions. In the non-relativistic limit of the DM field, the operators can be organized according to their mass dimension and their velocity…
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 $XX \rightarrow \bar f f \gamma$,…
Beyond the Standard Model physics is required to explain both dark matter and the baryon asymmetry of the universe, the latter possibly generated during a strong first-order electroweak phase transition. While many proposed models tackle…
The computation of the energy spectra of Standard Model particles originated from the annihilation/decay of dark matter particles is of primary importance in indirect searches of dark matter. We compute how the inclusion of electroweak…