LHC top partner searches beyond the 2 TeV mass region

Backović, Mihailo (Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 76100, Israel) ; Flacke, Thomas (Department of Physics, Korea Advanced Institute of Science and Technology, 335 Gwahak-ro, Yuseong-gu, Daejeon, 305-701, South Korea) (Department of Physics, Korea University, Seoul, 136-713, South Korea) ; Lee, Seung (Department of Physics, Korea Advanced Institute of Science and Technology, 335 Gwahak-ro, Yuseong-gu, Daejeon, 305-701, South Korea) (School of Physics, Korea Institute for Advanced Study, Seoul, 130-722, South Korea) (Department of Physics, Korea University, Seoul, 136-713, South Korea) ; Perez, Gilad (Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 76100, Israel)

08 September 2015

Abstract: We propose a new search strategy for heavy top partners at the early stages of the LHC run-II, based on lepton-jet final states. Our results show that final states containing a boosted massive jet and a hard lepton, in addition to a top quark and possibly a forward jet, offer a new window to both detecting and measuring top partners of mass ∼ 2TeV. Our resulting signal significance is comparable or superior to the same sign dilepton channels for top partner masses heavier than roughly 1 TeV. Unlike the di-lepton channel, the selection criteria we propose are sensitive both to 5/3 and 1/3 charge top partners and allow for full reconstruction of the resonance mass peak. Our search strategy utilizes a simplified b -tagging procedure and the Template Overlap Method to tag the massive boosted objects and reject the corresponding backgrounds. In addition, we propose a new, pileup insensitive method, to tag forward jets which characterize our signal events. We consider full effects of pileup contamination at 50 interactions per bunch crossing. We demonstrate that even in the most pessimistic pileup scenarios, the significance we obtain is sufficient to claim a discovery over a wide range of top partner parameters. While we focus on the minimal natural composite Higgs model, the results of this paper can be easily translated into bounds on any heavy partner with a t t ¯ W j $$ t\overline{t}Wj $$ final state topology.


Published in: JHEP 1509 (2015) 022
Published by: Springer/SISSA
DOI: 10.1007/JHEP09(2015)022
arXiv: 1409.0409
License: CC-BY-4.0



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