Search for same-sign top-quark pair production at root s=7 TeV and limits on flavour changing neutral currents in the top sector


Chatrchyan S., Khachatryan V., Sirunyan A. M., Tumasyan A., Adam W., Bergauer T., ...More

JOURNAL OF HIGH ENERGY PHYSICS, no.8, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: Issue: 8
  • Publication Date: 2011
  • Doi Number: 10.1007/jhep08(2011)005
  • Journal Name: JOURNAL OF HIGH ENERGY PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: Hadron-Hadron Scattering
  • Middle East Technical University Affiliated: Yes

Abstract

An inclusive search for same-sign top-quark pair production in pp collisions at root s = 7 TeV is performed using a data sample recorded with the CMS detector in 2010, corresponding to an integrated luminosity of 35 pb(-1). This analysis is motivated by recent studies of p (p) over bar -> t (t) over bar reporting mass-dependent forward-backward asymmetries larger than expected from the standard model. These asymmetries could be due to Flavor Changing Neutral Currents (FCNC) in the top sector induced by t -channel exchange of a massive neutral vector boson (Z'). Models with such a Z' also predict enhancement of same-sign top-pair production in pp or pp collisions. Limits are set as a function of the Z' mass and its couplings to u and t quarks. These limits disfavour the FCNC interpretation of the Tevatron results.