Speaker
Description
In this talk I will discuss a new technique for the next-to-leading order accurate simulation of $e^+e^- \to t\bar{t}$ that respects the resonant nature of the process above and near the top-quark pair production threshold.
Standard parton shower simulations do not account for resonances appearing in the hard process when simulating the radiation of soft gluons from external legs, neither preserving their on-shellness in the distribution of recoil, nor taking into account width suppressed effects in the splitting kernels.
I discuss the implementation of a new method, solving both problems at NLO close to the threshold, in the Alaric parton shower within the Sherpa framework, as well as the application to $e^+e^- \to t\bar{t}$ at a future FCC-ee at $\sqrt{s} = 365$ GeV.