Sensitivity Of Dark Matter Dectectors To Susy Dark Matter

Abstract

The sensitivity of dark matter detectors to the lightest neutralino (${\tilde {Z}_1}$) is considered within the framework of supergravity grand unification with radiative breaking of SU(2)xU(1). The relic density of the ${\tilde {Z}_1}$ is constrained to obey $0.10 \leq \Omega_{\tilde {Z}_1}h^2 \leq 0.35$, consistent with COBE data and current measurements of the Hubble constant. Detectors can be divided into two classes: those most sensitive to spin dependent incoherent scattering of the ${\tilde {Z}_1}$ (e.g. $CaF_2$) and those most sensitive to spin independent coherent scattering (high A nuclei e.g. Pb). The parameter space is studied over the range of $100GeV \leq m_0, m_{\tilde {g}} \leq 1 TeV; 2 \leq tan\beta \leq 20$; and $-2 \leq A_t/m_0 \leq 3$ and it is found that the latter type detector is generally more sensitive than the former type. Thus at a sensitivity level of $R \geq 0.1$ events/kg da, a lead detector could scan roughtly 30% of the ~parameter space studied, and an increase of ~this sensitivity by a factor of 10 ~would lead to coverage of about 70% of the parameter space. Dark matter detectors are in general more sensitive to the high $tan\beta$, low $m_{\tilde {g}}$ and low m_0 parts of the parameter space. The conditions of radiative breaking of SU(2)xU(1) enter importantly in analysing the efficiency of dark matter detectors.