Eur. Phys. J. C (2006) 48: 389-400
https://doi.org/10.1140/epjc/s10052-006-0048-y

Regular Article - Theoretical Physics

NLO event generation for chargino production at the ILC

¹ Fachbereich Physik, University of Siegen, 57068, Siegen, Germany
² Deutsches Elektronen-Synchrotron DESY, 22603, Hamburg, Germany

^* e-mail: tania.robens@desy.de

Received: 18 July 2006
Revised: 9 August 2006
Published online: 17 November 2006

Abstract

We present a Monte Carlo event generator for simulating chargino pair production at the International Linear Collider (ILC) at next-to-leading order in the electroweak couplings. By properly resumming photons in the soft and collinear regions, we avoid negative event weights, so the program can simulate physical (unweighted) event samples. Photons are explicitly generated throughout the range where they can be experimentally resolved. Inspecting the dependence on the cutoffs separating the soft and collinear regions, we evaluate the systematic errors due to soft and collinear approximations. In the resummation approach, the residual uncertainty can be brought down to the per-mil level, coinciding with the expected statistical uncertainty at the ILC.