We have obtained spectra of the Galactic center at energies 400–600 keV from high-resolution data acquired by the TGRS Ge spectrometer on board the WIND mission during 1995–1997. The data were obtained using an on-board occulter, and are relatively free from systematics and backgrounds. Analysis of the spectra reveals a well-resolved electron-positron annihilation line at 511 keV and the associ...

We discuss the decay of Bc mesons into two light mesons (π,K (∗), η(′), ρ, ω, φ). All these decay channels come from a single type of diagram, namely tree annihilation. This allows us to derive extremely simple SU(3) relations among these processes. The size of annihilation contributions is an important issue in B physics, and we provide two different estimates in the case of non-leptonic charm...

Hara and Massey [1] have investigated the annihilation of positrons in Ar-CO mixtures while the present author studied the behaviour of positrons in the noble gas mixtures (Ne + Ar) [2] and (He-)-Ar) [3]. It has been found that the annihilation decay constant, A, depends quite sensitively on the nature of the gas mixture. Our calculations [3] indicate that it will be quite interesting to explor...

An explicit solution for the generating functional of n-point functions in the planar approximation is given in terms of two sets of free-algebraic annihilation and creation operators.

The recently introduced Sommerfeld enhancement of the dark matter annihilation cross section has important implications for the detection of dark matter annihilation in subhalos in the Galactic halo. In addition to the boost to the dark matter annihilation cross section from the high densities of these subhalos with respect to the main halo, an additional boost caused by the Sommerfeld enhancem...

We present the result of an indirect search for high energy neutrinos from WIMP annihilation in the Sun and in the Earth using upward-going muon events at Super-Kamiokande. Datasets from SKI-SKIII (3109.6 days) were used for the analysis. We looked for excesses of neutrino signal from the Sun and the Earth as compared with the expected atmospheric neutrino background in three types of upward-go...

The aim of this work is to identify the mechanisms responsible for very large rates and other peculiarities observed in low-energy positron annihilation on molecules. The two mechanisms considered are: (i) Direct annihilation of the incoming positron with one of the molecular electrons. This mechanism dominates for atoms and small molecules. I show that its contribution to the annihilation rate...

We study a simple one-dimensional model of ballisticaly-controlled annihilation in which the two annihilating species are initially spatially separated. The time dependent properties of the annihilation front are exactly derived. It is shown that the front wanders in a brownian fashion around its average value.

We calculate total and differential cross sections for sfermion production in e+e− annihilation and in photon-photon collisions with arbitrary photon polarization. The total cross section at a polarized photon collider is shown to be larger than the e+e− annihilation cross section up to the kinematic limit of the photon collider.

We use classical or large N c QCD to describe the mesons (π, ρ, ω) coming from proton-antiproton annihilation at rest as classical fields, which we then quantize as coherent states. This treatment gives a nearly parameter free account of the pion branching ratios in annihilation.