In this paper we study the identification of the b quark inside a boosted hadronicaliy decaying top quark in the center-of-mass frame of the jet. We demonstrate that the method can be used to greatly reduce the QCD jet background even in a very high pileup condition. The method has a much smaller fake rate for QCD jets compared to typical b quark identification algorithms in jets at the same signal efficiency. When combining the b quark identification in the center-of-mass frame of the jet with jet substructure information, we can improve the rejection rate of QCD jet background by almost an order of magnitude while maintaining the same identification efficiency for the boosted top quark. [ABSTRACT FROM AUTHOR]
In this paper, we introduce a new approach to study jet substructure in the center-of-mass frame of the jet. We demonstrate that it can be used to discriminate the boosted heavy particles from the QCD jets and the method is complementary to other jet substructure algorithms. Applications to searches for hadronically decaying W/Z + jets and heavy resonances that decay to a WW final state are also discussed. [ABSTRACT FROM AUTHOR]