Related papers: Semi-Annihilation of Fermionic Dark Matter
We investigate a Z3 symmetric model with two-loop radiative neutrino masses. Dark matter in the model is either a Dirac fermion or a complex scalar as a result of an unbroken Z3 symmetry. In addition to standard annihilation processes,…
Dark matter annihilations have been fiercely restricted by the non-observation of excess events in indirect detection probes. Typically the interactions that dictate annihilation are also present in the dark matter-nucleon scattering cross…
In this work we give a comprehensive analysis on the phenomenology of a specific $\mathbb{Z}_3$ dark matter (DM) model in which neutrino mass is induced at two loops by interactions with a DM particle that can be a complex scalar or a Dirac…
Semi-annihilation is a generic feature of dark matter theories with symmetries larger than Z_2. We explore a model based on a Z_4-symmetric dark sector comprised of a scalar singlet and a "wino"-like fermion SU(2)_L triplet. This is the…
Dark matter (DM) annihilation can be significantly enhanced through narrow resonances or the Sommerfeld enhancement effect, with both mechanisms potentially combining in a super-resonant annihilation process. In such scenarios, the…
We consider an incarnation of left-right symmetric model with a local gauge symmetry of $SU(3)_C \otimes SU(2)_L \otimes U(1)_L \otimes SU(2)_R \otimes U(1)_R$. Heavy scalars and fermions present in the {\bf 27} of $E_6$ are included in the…
Semi-annihilation is a generic feature of dark matter theories with symmetries larger than Z2. We investigate two examples with multi-component dark sectors comprised of an SU(2)L singlet or triplet fermion besides a scalar singlet. These…
By extending the Standard Model with three right-handed neutrinos (N_i) and a second Higgs doublet (H_2), odd under a Z_2 symmetry, it is possible to explain non-zero neutrino masses and to account for the dark matter. We consider the case…
If dark matter (DM) annihilation accounts for the tantalizing excess of cosmic ray electron/positrons, as reported by the PAMELA, ATIC, HESS and FERMI observatories, then the implied annihilation cross section must be relatively large. This…
We propose a Two-Loop induced radiative neutrino model with hidden gauged $U(1)$ symmetry, in which a dark matter of Dirac fermion arises. The relic density gets contribution from annihilation and semi-annihilation due to a residual…
We investigate the direct detection phenomenology of a class of dark matter (DM) models in which DM does not directly interact with nuclei, {but rather} the products of its annihilation do. When these annihilation products are very light…
We study indirect detection signals from solar annihilation of dark matter (DM) particles into light right-handed (RH) neutrinos with a mass in a $1-5$ GeV range. These RH neutrinos can have a sufficiently long lifetime to allow them to…
We analyse the phenomenology of a simplified model for a real scalar dark matter candidate interacting with quarks via a coloured fermionic mediator. In the coannihilation regime, the dark matter abundance is controlled by the dynamics of…
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…
Semi-annihilation is a generic feature of dark matter theories stabilised by symmetries larger than a $Z_2$. It contributes to thermal freeze out, but is irrelevant for direct and collider searches. This allows semi-annihilating dark matter…
There are several ways to explain the dark matter relic density other than by the ordinary freeze-out scenario. For example, the freeze-in mechanism may constitute an alternative for generating the correct relic density for dark matter…
Dark Matter (DM) may have a relic density that is in part determined by a particle/antiparticle asymmetry, much like baryons. If this is the case, it can accumulate in stars like the Sun to sizable number densities and annihilate to…
We show that the thermal relic abundance of dark matter can be affected by a new type of reaction: semi-annihilation. Semi-annihilation takes the schematic form X_i X_j -> X_k phi, where X_i are stable dark matter particles and phi is an…
The identity of Dark Matter (DM) is one of the most captivating topics in particle physics today. The R-parity conserving Minimal Supersymmetric Standard Model (MSSM), which naturally provides a DM candidate in the form of the lightest…
The dark matter relic density being a powerful observable to constrain models of new physics, the recent experimental progress calls for more precise theoretical predictions. On the particle physics side, improvements are to be made in the…