On pair production of scalar top quarks in e+e- collisions at ILC and a possibility of their mass reconstruction

TL;DR

This paper investigates the pair production of scalar top quarks in electron-positron collisions at the ILC, proposing criteria for signal-background separation and methods for top squark mass reconstruction.

Contribution

It introduces a set of criteria for distinguishing stop signals from background and demonstrates mass reconstruction of top squarks at various energies.

Findings

Effective criteria for signal separation developed.

Mass of top squark can be reconstructed with known neutralino mass.

Simulation results show feasibility at different beam energies.

Abstract

We study pair production of scalar top quarks in e+e- collisions with the subsequent decay of the top squarks into b-quarks and charginos. We simulate this process by using PYTHIA6.4 for the beam energy 2Ebeam = 350, 400, 500, 800, 1000 GeV. A set of criteria for physical variables is proposed, which provides good separation of stop signal events from top quark pair production being the main background. These criteria allow us to reconstruct the mass of the top squark with an integrared luminosity of 1000 1/fb provided that the neutralino mass is known.