B's with Direct Decays: Tevatron and LHC Discovery Prospects in the bbar{b}+MET Channel

We explore the discovery prospects for B'\bar{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 b\bar{b}+MET 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 b\bar{b}+MET cross section required for exclusion and discovery.