相关论文: Semi-annihilation of Dark Matter
The semi-annihilation reaction takes the schematic form psi_i psi_j -> psi_k phi, where psi_i are stable dark matter particles and phi is an unstable state. Such reactions are allowed when dark matter is stabilized by a larger symmetry than…
Semi-annihilation is a generic feature of particle dark matter that is most easily probed by cosmic ray experiments. We explore models where the semi-annihilation cross section is enhanced at late times and low temperatures by the presence…
We study a novel dark matter production mechanism based on the freeze-in through semi-production, i.e. the inverse semi-annihilation processes. A peculiar feature of this scenario is that the production rate is suppressed by a small initial…
We study the impact of semi-annihilations x_i x_j <-> x_k X, where x_i is any dark matter and X is any standard model particle, on dark matter phenomenology. We formulate minimal scalar dark matter models with an extra doublet and a complex…
We study a nonstandard dark-matter thermal history in which strong self-interactions give rise to collective many-body effects at high number density, as in strongly interacting quantum media. At early times, dark matter occupies a…
The continued non-observation of events emanating from dark matter (DM) annihilations in various direct and indirect detection experiments calls into question the mechanism for determining the relic density of a weakly interacting massive…
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,…
We propose a new mechanism for dark matter freeze-out that results in the self-organized criticality in dark matter production, wherein the final relic abundance is independent of initial inputs, in analogy to scale invariance in other…
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…
This work presents an asymmetric dark matter model with relic density determined by the freeze-out of asymmetric semi-annihilations into long-lived particles slowly decaying into the Standard Model states. We carefully consider the $CPT$…
Approximate analytical solutions of the Boltzmann equation for particles that are either extremely relativistic or non-relativistic when they decouple from the thermal bath are well established. However, no analytical formula for the relic…
Dark matter semi-annihilation is a process through which two dark matter candidates annihilate to a single dark matter particle and a non-dark matter particle. Such processes are common when the symmetry stabilizing the dark matter differs…
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…
In some models of thermal relic dark matter, the relic abundance may be set by inelastic scattering processes (rather than annihilations) becoming inefficient as the universe cools down. This effect has been called coscattering. We present…
We show that the relic abundance of the minority component of asymmetric dark matter can be very sensitive to the expansion rate of the Universe and the temperature of transition between a non-standard pre-Big Bang Nucleosynthesis…
A solution to the Boltzmann equation governing the thermal relic abundance of cold dark matter is constructed by matched asymptotic approximations. The approximation of the relic density is an asymptotic series valid when the abundance does…
Dark matter may be a thermal relic whose abundance is set by mutual annihilations among multiple species. Traditionally, this coannihilation scenario has been applied to weak scale dark matter that is highly degenerate with other states. We…
The article describes Boltzmann equations for a potential case of multi-particle dark matter with symmetric and asymmetric dark matter components in a model-independent approach. We focus on the specific scenario where one of the DM…
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…
We propose a new mechanism for thermal dark matter freezeout, termed Co-Decaying Dark Matter. Multi-component dark sectors with degenerate particles and out-of-equilibrium decays can co-decay to obtain the observed relic density. The dark…