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 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: Issue: 8
  • Publication Date: 2011
  • Doi Number: 10.1007/jhep08(2011)005
  • Title of Journal : JOURNAL OF HIGH ENERGY PHYSICS
  • Keywords: Hadron-Hadron Scattering

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.