相关论文: Anapole dark matter annihilation into photons
We consider dark matter (DM) that interacts with ordinary matter exclusively through an electromagnetic anapole, which is the only allowed electromagnetic form factor for Majorana fermions. We show that unlike DM particles with an electric…
Thermal relics with masses in the GeV to TeV range remain possible candidates for the Universe's dark matter (DM). These neutral particles are often assumed to have vanishing electric and magnetic dipole moments so that they do not interact…
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…
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 cross section for a Majorana Dark Matter particle annihilating into light fermions is helicity suppressed. We show that, if the Dark Matter is the neutral Majorana component of a multiplet which is charged under the electroweak…
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…
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…
The electron-positron excess reported by the DAMPE collaboration recently may be explained by an electrophilic dark matter (DM). A standard model singlet fermion may play the role of such a DM when it is stablized by some symmetries, such…
The sole static electromagnetic property of a spin-$\frac{1}{2}$ Majorana fermion is its anapole moment. Though they cannot couple to single real photons, these particles can interact with electric currents through virtual photons. If a…
We consider direct detection prospects for a class of simplified models of fermionic dark matter (DM) coupled to left and right-handed Standard Model fermions via two charged scalar mediators with arbitrary mixing angle $\alpha$. DM…
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…
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 review simplified models in which a singlet Majorana dark matter candidate couples to Standard Model (SM) fermions through interactions mediated by scalar fermion partners. We summarize the two primary production mechanisms in these…
In this paper, we explore the possibility of a linearly polarized gamma-ray signal from dark matter annihilations in the Galactic center. Considering neutral weakly interacting massive particles, a polarized gamma-ray signal can be realized…
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 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 $\sim 1$…
The anapole moment is the only allowed electromagnetic moment for Majorana fermions. Fermionic dark matter acquiring an anapole can have a standard thermal history and be consistent with current direct detection experiments. In this paper,…
In this work we study the annihilation of fermionic dark matter, considering it as a neutral particle with non-vanishing magnetic ($M$) and electric ($D$) dipole moments. Effective cross section of the process $\chi \overline{\chi}…
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…