Title: Metastability bounds on Dark Matter Models

Speaker: Dr. Najimuddin Khan, PRL Ahmedabad

Abstract: We add new particles to the Standard Model at TeV scale, e.g., new particles of a SU(2) complex scalar doublet. We have imposed a discrete symmetry Z2 on the extended scalar such that odd number of scalar fields do not couple with the SM particles. The lightest neutral scalar particle becomes stable. This scalar field can be taken as a viable dark matter candidate which saturates the relic abundance of the Universe. We have shown various phase diagrams and point out the regions of absolute stability, meta-stability and instability for the electroweak vacuum and review the bounds on the models. We graphically demonstrate how the confidence level, at which stability of electroweak vacuum is excluded, depends on such new physics parameters.