Neutralino-neutralino annihilation to photon and gluon pairs in MSSM models

A complete one-loop computation of the processes ((chi) over tilde (0)(i)(chi) over tilde (0)(j)<---->gammagamma,gg), for any pair of the four minimal supersymmetric standard model (MSSM) neutralinos, has been performed for an arbitrary c.m. energy. As a first application suitable for dark matter (DM) searches neutralino-neutralino annihilation is studied at relative velocities v/csimilar or equal to10(-3), describing the present DM distribution in the galactic halo, and v/csimilar or equal to0.5, determining neutralino relic density contributions. Numerical results are presented for 31 MSSM benchmark models indicating considerable sensitivity to the input parameters. Numerical codes are released, which may be used for the computation of the annihilation of any two neutralinos to two photons or two gluons at the aforementioned v/c values. In the near future, we intend to complement them with codes for the inverse process gammagamma-->(chi) over tilde (0)(i)(chi) over tilde (0)(j), observable at future high energy linear colliders.