Abstract
Though top quark was discovered more than twenty years ago, measurement of its width is still challenging task. Most measurements either have rather low precision or they are done in assumption of the SM top quark interactions. We consider model independent parametrization of the top quark width and provide estimations on achievable accuracy using a combination of fiducial cross sections in double, single and non-resonant regions.
Highlights
The top quark is the heaviest known elementary particle
Recent results of direct measurements of the width presented by CMS and ATLAS collaborations are of 0.6 < Γt < 2.5 GeV [3] and Γt 1⁄4 1.76 Æ 0.33ðstatÞþ−00..6789ðsystÞ GeV [4]
Gauge invariant estimation of deviations of the top quark width from the standard model (SM) value is obtained in different kinematic regions
Summary
The top quark is the heaviest known elementary particle. This fact makes it along with the Higgs boson the most promising window to physics beyond the standard model (BSM). The NLO corrections to the complete 2 → 6 process involving offshell W bosons were calculated [19,20,21,22] and the k-factor for 13 TeV LHC energy was found to be 1.16 At this stage of our analysis, which aims to show the main effect caused by the width change, the complete leading order contributions have been taken into account, and the impact of the NLO corrections has been included in the assumed systematic uncertainties, as will be explained below. Decreasing in the events rate, while main declared dependencies on the width modifying parameters remains mostly unchanged This should be taken into account in the experimental analysis, since soft area cuts has a significantly greater influence on the NR region cross section than the DR one. How accurately would we be able to limit the top quark width, if we knew the corresponding fiducial sections in DR, SR, and NR regions with a given accuracy?
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have