We present the contributions from all types of one-loop corrections to the scattering amplitude for the pair production of polarized charginos or neutralinos from polarized electron-positron annihilation. The contributions are classified in terms of “prototypes” distinguished by the number of particles inside the loops and their spins. The results are quoted in terms of the Veltman-Passarino fu...

We introduce a novel dark matter scenario where the visible sector and the dark sector share a common asymmetry. The two sectors are connected through an unstable mediator with baryon number one, allowing the standard model baryon asymmetry to be shared with dark matter via semi-annihilation. The present-day abundance of dark matter is then set by thermal freeze-out of this semi-annihilation pr...

We present a complete calculation of the cross section for neutralino annihilation into the two-gluon final state. This channel can be quite important for the phenomenology of neutralino annihilation due to the well-known helicity suppression of neutralino annihilation into light quarks and leptons. In addition, we calculate the cross section for annihilation of neutralinos into a gluon and qua...

A relativistic quantum mechanics is formulated in which all of the interactions are in the four-momentum operator and Lorentz transformations are kinematic. Interactions are introduced through vertices, which are bilinear in fermion and antifermion creation and annihilation operators, and linear in boson creation and annihilation operators. The fermionantifermion operators generate a unitary Li...

Recent claims of a line in the Fermi-LAT photon spectrum at 130 GeV are suggestive of dark matter annihilation in the galactic center and other dark matter-dominated regions. If the Fermi feature is indeed due to dark matter annihilation, the best-fit line cross-section, together with the lack of any corresponding excess in continuum photons, poses an interesting puzzle for models of thermal da...

We calculate the production cross sections for D∗+D∗−, D+D∗− and D+D− in e+e− annihilation through one virtual photon in the framework of perturbative QCD with constituent quarks. The calculated cross sections for D∗+D∗− and D+D∗− production are roughly in agreement with the recent Belle data. The helicity decomposition for D ∗ meson production is also calculated. The fraction of the D L D ∗∓ T...

A leading interpretation of the electron/positron excesses seen by PAMELA and ATIC is dark matter annihilation in the galactic halo. Depending on the annihilation channel, the electron/positron signal could be accompanied by a galactic gamma ray or neutrino flux, and the non-detection of such fluxes constrains the couplings and halo properties of dark matter. In this paper, we study the interpl...

Positron annihilation was applied to measuring critical pore sizes in various materials. In recent years, positron annihilation with a variable-energy positron beam has emerged as a powerful tool for the investigation of porous thin films synthesized as low-k dielectrics, high performance gas sensor materials, and so on. This paper is a brief overview of recent progress in nanopore characteriza...