In this talk we summarize previous work on mass bounds of a light neutralino in the Minimal Supersymmetric Standard Model. We show that without the GUT relation between the gaugino mass parameters M_1 and M_2, the mass of the lightest neutralino is essentially unconstrained by collider bounds and precision observables. We conclude by considering also the astrophysics and cosmology of a light neutralino.
Categories: hep-ph