Sensitivity of CLIC at 380 GeV to the top FCNC decay $t\to cH$

Abstract

In the Standard Model (SM), flavour changing neutral current (FCNC) top decays, possible at loop level only, are very strongly suppressed. Observation of any such decay would be a direct signature of physics beyond the SM. Large enhancements are possible in many "new physics" scenarios and the largest enhancement is in most cases expected for the $t\to cH$ decay. A full study for CLIC was based on the WHIZARD simulation of FCNC top decays within the 2HDM(III) model. Beam polarization and beam-induced background were taken into account. Top pair production events with the FCNC decay $t\to cH$ can be identified based on kinematic constrains and flavour tagging information. Due to a large overlap in the kinematic space with standard top pair events, the final signal selection-efficiency is small, at the 10% level. Expected limits on $BR(t\to cH)\times BR(H\to b\bar{b})$ are compared with earlier results based on parton level simulation.

11 pages, 6 figures. Talk presented at the International Workshop on Future Linear Colliders (LCWS2016), Morioka, Japan, 5-9 December 2016. C16-12-05.4. Presented on behalf of the CLICdp Collaboration

References in corpus (2)

• LCFIPlus: A Framework for Jet Analysis in Linear Collider Studies
• Top physics at high-energy lepton colliders

Cited by in corpus (3)

• Top quark anomalous FCNC production via $tqg$ couplings at FCC-hh
• Probing anomalous $tq\gamma$ and $tqg$ couplings via single top production in association with photon at FCC-hh
• Flavour-changing neutral scalar interactions of the top quark