The Flavour-Changing Neutral Currents Decay t-->Hq at ATLAS Experiment

Abstract

The sensitivity of the ATLAS experiment to the top-quark rare decay via flavour-changing neutral currents t --> Hq (q represents c and u quarks) has been studied at sqrt{s} = 14 TeV in the decay mode of ttbar --> HqWb --> WW*q,Wb -->l νl νj, l^{\pm} νb, (l=e, μ). The Standard Model backgrounds ttbar, ttbar H, WZ and WH have been analysed. The signal and backgrounds were generated via PYTHIA 5.7 and simulated and analysed using ATLFAST 2.51. A branching ratio for t --> Hq -->WW*q as low as 2.0x10^{-3} for m_H=150 GeV and 2.1x10^{-3} for m_H=160 GeV could be discovered at the 5 σlevel with an integrated luminosity of 100 fb^{-1}.