We show how single top production at the LHC can be used to discover (and characterize the couplings of) B quarks, which are an essential part of many natural models of new physics beyond the Standard Model. We present the B effective model and conce
ntrate on resonant production via a colored anomalous magnetic moment. Generally, Bs preferentially decay into a single top quark produced in association with a W boson; thus, this production process makes associated single top production essential to B searches at the LHC. We demonstrate the background processes are manageable and the signal cross section is sufficient to yield a large signal significance even during the 7 TeV LHC run. Specifically, we show that B masses of 700 GeV or more can be probed. Moreover, if a B is found, then the chirality of its coupling can be determined. Finally, we present signal cross sections for several different LHC energies.
We study methods of extracting new physics signals in final states with a top-quark pair plus large missing energy at the LHC. We consider two typical examples of such new physics: pair production of a fermionic top partner (a $T$ in Little Higgs mod
els for example) and of a scalar top partner (a $tilde{t}$ in SUSY). With a commonly-adopted discrete symmetry under which non Standard Model particles are odd, the top partner is assumed to decay predominantly to a top quark plus a massive neutral stable particle $A^0$. We focus on the case in which one of the top quarks decays leptonically and the other decays hadronically, $pp to {tt} A^0A^0 X to bj_1j_2 bar bell^- bar u A^0A^0 X + c.c.$, where the $A^0$s escape detection. We identify a key parameter for the signal observation: the mass splitting between the top partner and the missing particle. We reconstruct a transverse mass for the lepton-missing transverse energy system to separate the real $W$ background from the signal and propose a definition for the reconstructed top quark mass that allows it to take unphysical values as an indication of new physics. We perform a scan over the two masses to map out the discovery reach at the LHC in this channel. We also comment on the possibility of distinguishing between scalar and fermionic top partners using collider signatures.
