TeV Scale Theory for Cold and Hot Dark Matter

We show that an extension of the minimal supersymmetric standard model where neutrino mass arises from the spontaneous breakdown of global $B-L$ symmetry can provide a scenario for both cold (CDM) and hot dark matter (HDM) where (i) both the CDM (which in our case is the superpartner of the majoron) and the HDM (which is the massive neutrino) owe their origin to the same new physics connected with global $B-L$ symmetry; (ii) the stability of the cold dark matter particle is guaranteed by the $B-L$ symmetry even after its spontaneous breakdown; and (iii) the desired relative abundances of C + HDM emerge when the scale of $B-L$ symmetry breaking is in the TeV range.