Search for top squarks in multijet events with large missing momentum in proton-proton collisions at 8 TeV

A search for pairs of top squarks decaying to a top quark and a stable, weakly interacting, massive particle is presented. The search selects events containing multiple jets, with at least one identified as originating from a b-quark, and large missing transverse momentum. The search also employs a novel top quark tagging algorithm for identifying a top quark candidate decaying hadronically. It is based on 19.4 fb$^{-1}$ of proton-proton collision data collected at a center-of-mass energy of 8 TeV by the CMS detector at the Large Hadron Collider. The observed event yields are consistent with the SM expectations. Assuming both top squarks decay always into a top quark and a weakly interacting, neutral particle~($\tilde{\chi}_1^0$), the production of top squarks with mass less than 535 GeV is excluded at 95\% confidence-level for $\tilde{\chi}_1^0$ masses less than 10 GeV.