Extra dimensions and dark matter

Abstract

In this paper we study the general scenario of an effective theory coming from thecompactification of a higher dimensional theory in a string inspired setting. This leads togauge coupling unification at an intermediate mass scale. After having computed all thethreshold corrections (due to Kaluza–Klein modes) to the running of the couplings of theminimal supersymmetry extension of the standard model, we embark on a detailedphenomenological analysis of the model, based on the numerical package DarkSUSY,to find constraints on the scenario from dark matter data. The mass spectrumof the theory does not have tachyons. Moreover we find that the neutralino isstill the lightest supersymmetric particle with a relic density compatible withthe most recent experimental data. We find that with respect to the standardmSUGRA scenario the neutralino is higgsino-like in most of the parameter space. Ourmodifications to the DarkSUSY package will shortly be available upon request.