NEUTRALINO ANNIHILATION INTO GLUONS

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 a nnihilation of neutralinos into a gluon and quark-antiquark pair, and discuss QCD corrections to the tree-level cross sections for neutralin o annihilation into quarks. If the neutralino is lighter than the top quark, the effect of these results on high-energy neutrino signals fro m neutralino annihilation in the Sun and in the Earth can be significa nt, especially if the neutralino is primarily gaugino. On the other ha nd, our results should have little effect on calculations of the cosmo logical abundance of neutralinos. We also briefly discuss implications for cosmic-ray antiprotons from neutralino annihilation in the galact ic halo.