Past Events

Abstract
 

Following the observation of a Higgs Boson by ATLAS and CMS collaborations, a comprehensive programme of measurements of its properties is underway looking for deviations from the Standard Model (SM) predictions. An interesting possibility is the presence of the top quark flavor-changing neutral current (FCNC) decay into the Higgs boson and an up or charm quark.  

A search for FCNC top quark decay, t→Hq ( q=u,c), with Higgs boson decay to bottom quark pair, H→bb ̅, is present. The analysis search for top quark pair production in which one top quark decay leptonically to a W boson and a bottom quark, and the other top quark decays to qH. Data used in the search based on pp collisions at √13 TeV, is recorded by ATLAS detector at CERN Large Hadron Collider (LHC) at an integrated luminosity of 36fb^-1, and analysed in the single lepton plus at least four jets final state. A Likelihood discriminant variable is employed to distinguish the signal and background which dominated by tt ̅→WbWb decay, and a likelihood fit method is used to understand background better. Expected results of the statistical analysis are that deriving 95% CL upper limits for the t→Hc and t→Hu branch ratio respectively if no significant excess of events above the background expectation is found.

Besides, an introduction to the outlook of future study on top quark decay to a beyond Standard Model charged scalar particle and a b quark, t→bH⁺ with H⁺→cs ̅(b ̅), which has the similar final state with top quark FCNC decay, is shown.

Anyone interested is welcome to attend.