Measurement of the W boson helicity in events with a single reconstructed top quark in pp collisions at √s = 8 TeV

• Main Authors: Apyan, Aram (Contributor), Barbieri, Richard Alexander (Contributor), Bauer, Gerry P. (Contributor), Busza, Wit (Contributor), Cali, Ivan Amos (Contributor), Chan, Matthew Hans (Contributor), Di Matteo, Leonardo (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Goncharov, Maxim (Contributor), Gulhan, Doga Can (Contributor), Klute, Markus (Contributor), Lai, Yue Shi (Contributor), Lee, Yen-Jie (Contributor), Levin, Andrew Michael (Contributor), Luckey, P. David, Jr (Contributor), Ma, Teng (Contributor), Paus, Christoph M. E. (Contributor), Ralph, Duncan Kelley (Contributor), Roland, Christof E. (Contributor), Roland, Gunther M. (Contributor), Stephans, George S. F. (Contributor), Stockli, Fabian (Contributor), Sumorok, Konstanty C. (Contributor), Velicanu, Dragos Alexandru (Contributor), Veverka, Jan (Contributor), Wyslouch, Boleslaw (Contributor), Yang, Mingming (Contributor), Zanetti, Marco (Contributor), Zhukova, Victoria (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor), Massachusetts Institute of Technology. School of Science (Contributor)
• Format: Article
• Language: English
• Published: Springer-Verlag, 2015-04-28T20:04:47Z.
• Subjects: Article
• Online Access: Get fulltext

 A measurement of the W boson helicity is presented, where the W boson originates from the decay of a top quark produced in pp collisions. The event selection, optimized for reconstructing a single top quark in the final state, requires exactly one isolated lepton (muon or electron) and exactly two jets, one of which is likely to originate from the hadronization of a bottom quark. The analysis is performed using data recorded at a center-of-mass energy of 8 TeV with the CMS detector at the CERN LHC in 2012. The data sample corresponds to an integrated luminosity of 19.7 fb[superscript −1]. The measured helicity fractions are F [subscript L] = 0.298 ± 0.028 (stat) ± 0.032(syst), F [subscript 0] = 0.720 ± 0.039 (stat) ± 0.037(syst), and F [subscript R] = −0.018 ± 0.019 (stat) ± 0.011(syst). These results are used to set limits on the real part of the tWb anomalous couplings, g [subscript L] and g [subscript R].