Related papers: The Bactrian Effect: Multiple Resonances and Light…
The cosmological evolution can modify the dark matter (DM) properties in the early Universe to be vastly different from the properties today. Therefore, the relation between the relic abundance and the DM constraints today needs to be…
The gamma-ray line from dark matter (DM) annihilation is too weak to observe, but its observation will uncover much information, e.g., the DM mass and an nomalously large annihilation rate $\sim0.1$ pb into di-photon. In this work, we…
In this paper, we analyze the cosmological evolution, allowed parameter space, and observational prospects for a dark sector consisting of thermally produced pseudo-Dirac fermions with a small mass splitting, coupled to the Standard Model…
We consider a fermionic dark matter (DM) particle in renormalizable Standard Model (SM) gauge interactions in a simple $t$-channel model. The DM particle interactions with SM fermions is through the exchange of scalar and vector mediators…
AMS-02 provided the unprecedented statistics in the measurement of the positron fraction from cosmic rays. That may offer a unique opportunity to distinguish the positron spectrum coming from various dark matter (DM) annihilation channels,…
A stable Dirac fermion with four-fermion interactions to leptons suppressed by a scale Lambda ~ 1 TeV is shown to provide a viable candidate for dark matter. The thermal relic abundance matches cosmology, while nuclear recoil direct…
We present a model for dark matter with extra spatial dimensions in which Standard-Model (SM) fermions have localized wave functions. The underlying gauge group is $G_{\rm SM} \otimes {\rm U}(1)_z$, and the dark matter particle is a…
We reappraise the viability of asymmetric dark matter (ADM) realized as a Dirac fermion coupling dominantly to the Standard Model fermions. Treating the interactions of such a DM particle with quarks/leptons in an effective-interactions…
It has been pointed out recently that the presence of dilaton field in the early Universe can dilute the neutralino dark matter (DM) abundance, if Universe is not radiation dominated at DM decoupling, due to its dissipative-like coupling to…
We study a renormalizable model of Dirac fermion dark matter (DM) that communicates with the Standard Model (SM) through a pair of mediators -- one scalar, one fermion -- in the representation $(\boldsymbol{6},\boldsymbol{1}, \tfrac{4}{3})$…
We revisit an anomaly-free extension of the Standard Model (SM) $viz.$ gauged ${L_\mu-L_\tau}$ model in the Dirac framework, where the local $U(1)_{L_\mu-L_\tau}$ symmetry breaks and gives rise to a new gauge boson $Z'$ and corresponding…
In this article, we consider Dark Matter (DM) interactions and study the same in the light of the Cosmic Microwave Background Radiation (CMBR) data. In particular, we focus on the DM-electron interactions. Assuming that such interactions…
We study the phenomenology and detection prospects of a sub-GeV Dirac dark matter candidate with resonantly enhanced annihilations via a dark photon mediator. The model evades cosmological constraints on light thermal particles in the early…
We present constraints on decaying and annihilating dark matter (DM) in the 4 keV to 10 GeV mass range, using published results from the satellites HEAO-1, INTEGRAL, COMPTEL, EGRET, and the Fermi Gamma-ray Space Telescope. We derive…
We consider theories where dark matter is composed of a thermal relic of weak scale mass, whose couplings to the Standard Model (SM) are however too small to give rise to the observed abundance. Instead, the abundance is set by annihilation…
If the Dark Matter (DM) in the Universe has interactions with the standard-model particle, the pair annihilation may give the imprints in the cosmic ray. In this paper we study the pair annihilation processes of the DM, which is neutral,…
Dark matter (DM) annihilation could in principle contribute to the diffuse cosmic gamma-ray back- ground (CGB). While with standard assumptions for cosmological and particle physics parameters this contribution is expected to be rather…
In this paper, we construct a viable model for a GeV scale self-interacting dark matter (DM), where the DM was thermally produced in the early universe. Here, a new vector-like fermion with a dark charge under the $U(1)_{D}$ gauge symmetry…
We consider a model in which dark matter is a light (350 MeV) Dirac fermion which couples to quarks as an axial-vector current. At center-of-mass (CM) energies below the confinement scale, such a DM interaction structure may be described…
Recently, there have been hints for dark matter (DM) annihilation in the galactic center to one or more photon lines. In order to achieve the observed photon line flux, DM must have a relatively large effective coupling to photons,…