B′s with direct decays: Tevatron and LHC discovery prospects in the bb̄+E□_T channel

We explore the discovery prospects for B′B^̄′ pair production followed by direct decays B′→bX, where B′ is a new quark and X is a long-lived neutral particle. We develop optimized cuts in the (m_B′,m_X) plane and show that the 7 TeV LHC with an integrated luminosity of 1(10)fb^-1 may exclude masses up to m _B′∼620(800)GeV, completely covering the mass range allowed for new quarks that get mass from electroweak symmetry breaking. This analysis is applicable to other models with bb̄E□_T signals, including supersymmetric models with bottom squarks decaying directly to neutralinos, and models with exotic quarks decaying directly to GeV-scale dark matter. To accommodate these and other interpretations, we also present model-independent results for the bb̄E□_T cross section required for exclusion and discovery.