New limits on top squark NLSP from ATLAS 4.7 $fb^{-1}$ data

Abstract

Using the ATLAS 4.7 $fb^{-1}$ data on new physics search in the jets + $\met$ channel, we obtain new limits on the lighter top squark ($\tilde t_1$) considering all its decay modes assuming that it is the next to lightest supersymmetric particle (NLSP). If the decay $\lstop$ $\ra c \lspone$ dominates and the production of dark matter relic density is due to NLSP - LSP co-annihilation then the lower limit on $\mlstop $ is 240 GeV. The limit changes to 200 GeV if the decay $\lstop$ $\ra b W \lspone$ dominates. Combining these results it follows that $\lstop $ NLSP induced baryogenesis is now constrained more tightly.