(N)LO Simulation of Chargino Production and Decay

TL;DR

This paper develops an NLO Monte Carlo simulation for chargino production and decay at the ILC, incorporating photonic corrections with fixed order and resummation methods, and assesses the precision of sneutrino mass determination.

Contribution

It introduces an NLO extension of the Whizard event generator for chargino processes, including a resummation approach to handle photonic corrections and negative event weights.

Findings

Resummation method avoids negative event weights.

Cross sections and event generation results are provided for both methods.

Sneutrino mass can be measured with percent-level accuracy.

Abstract

We consider NLO chargino production and decays at the ILC. For this, we present an NLO extension of the Monte Carlo Event Generator Whizard including the NLO production. For photonic corrections, we use both a fixed order and a resummation approach. The latter method evades the problem of negative event weights and automatically includes leading higher order corrections. We present results for cross sections and event generation for both methods. As a first step towards a full NLO Monte Carlo, we consider a LO implementation of the chargino production and subsequent leptonic decay and investigate the precision of the sneutrino mass determination by means of lepton energy distributions in chargino decays. The SM and SUSY backgrounds are included in our study using full matrix elements as well as smearing effects from ISR and beamstrahlung. Without using energy distribution fits, the sneutrino mass can be determined with an error in the percent regime.