Related papers: Annihilation Cross Sections for Relic Densities in…
We study precise calculation of neutralino relic density in the minimal supergravity model. We compare the exact formula for the thermal average of the neutralino annihilation cross section times relative velocity with the expansion formula…
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…
Thermal production of light dark matter with sub-GeV scale mass can be attributed to $3\rightarrow 2$ self-annihilation processes. We consider the thermal average for annihilation cross sections of dark matter at $3\rightarrow 2$ and…
We investigate the dark matter annihilation in the brane-world and quintessence scenarios, in which the modified cosmological expansion rate can enhance the thermal relic density of dark matter. According to the observed dark matter…
We find an exact formula for the thermally averaged cross section times the relative velocity $\langle \sigma v_{\text{rel}} \rangle$ with relativistic Maxwell-Boltzmann statistics. The formula is valid in the effective field theory…
We compute the neutralino relic density in the minimal supersymmetric standard model by using exact expressions for the neutralino annihilation cross section into all tree-level final states, including all contributions and interference…
We derive a full set of exact, analytic expressions for the annihilation of the lightest neutralino pairs into all two-body tree-level final states in the framework of minimal supersymmetry. We make no simplifying assumptions about the…
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…
We enlarge our set of supersymmetric models and update accelerator constraints in our precise calculation of the relic density of the lightest neutralino, which includes relativistic Boltzmann averaging, subthreshold and resonant…
We present the first exact and most general neutralino-neutralino annihilation cross sections in the presence of flavor violation. The existing set of calculations in literature do not include flavour violation. These calculations are…
Evaluating the relic density of dark matter is an interesting possibility to constrain the parameter space of new physics models. However, this calculation is affected by several sources of uncertainty. On the particle physics side,…
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 give a review on the thermal average of the annihilation cross-sections for $3\rightarrow 2$ and general higher-order processes. Thermal average of higher order annihilations highly depend on the velocity of dark matter, especially, for…
If dark matter (DM) is a weakly interacting massive particle (WIMP) that is a thermal relic of the early Universe, then its total self-annihilation cross section is revealed by its present-day mass density. The canonical thermally averaged…
We investigate the possibility that ultra-high energy cosmic rays (UHECRs) originate from the annihilation of relic superheavy (SH) dark matter in the Galactic halo. In order to fit the data on UHECRs, a cross section of $<\sigma_Av>\sim…
In this paper, we calculate the relic abundance of the dark matter particles when they can annihilate into sterile neutrinos with the mass $\lesssim 100 \text{ GeV}$ in a simple model. Unlike the usual standard calculations, the sterile…
We evaluate the relic density of neutralinos in the minimal supergravity (mSUGRA) model. All 2-->2 neutralino annihilation diagrams, as well as all processes involving sleptons, charginos, neutralinos and third generation squarks are…
Using the CLEO III detector, we measure absolute cross sections for e+e- --> hadrons at seven center-of-mass energies between 6.964 and 10.538 GeV. The values of R, the ratio of hadronic and muon pair production cross sections, are…
We consider dark matter annihilation into Standard Model particles and show that the least detectable final states, namely neutrinos, define an upper bound on the total cross section. Calculating the cosmic diffuse neutrino signal, and…
The total cross section for top quark pair production close to threshold in e+e- annihilation is investigated. Details are given about the calculation at next-to-next-to-leading logarithmic order. The summation of logarithms leads to a…