Eur. Phys. J. C (2007) 52: 999-1019
https://doi.org/10.1140/epjc/s10052-007-0434-0

Special Article - Scientific Note

Study of ATLAS sensitivity to FCNC top decays

¹ LIP – Dep. Física, Universidade de Coimbra, 3004-516, Coimbra, Portugal
² E. Andronikashvili Institute of Physics, Tbilisi, Georgia
³ High Energy Physics Institute, Tbilisi State University, Tbilisi, Georgia
⁴ Nevis Laboratories, CU, Columbia University, 136 South Broadway, P.O. Box 137, Irvington, NY, 10533, USA

^* e-mail: filipe.veloso@lipc.fis.uc.pt

Received: 29 March 2007
Revised: 13 September 2007
Accepted: 13 September 2007
Published online: 16 October 2007

Abstract

The ATLAS experiment sensitivity to top quark flavour changing neutral current (FCNC) decays was studied at LHC using tt̄ events. While one of the top quarks is expected to follow the dominant Standard Model decay t→bW, the other decays through a FCNC channel, i.e. t→Zu(c), t→γu(c) or t→gu(c). Different types of analyses, applied to each FCNC decay mode, were compared. The FCNC branching ratio sensitivity (assuming a 5σ signal significance) and 95% confidence level limits on the branching ratios (in the hypothesis of signal absence) were obtained.