QCD Instanton-induced Processes in Deep-Inelastic Scattering - Search Strategies and Model Dependencies

TL;DR

This paper explores strategies to identify QCD-instanton induced processes in deep-inelastic scattering at HERA, focusing on optimized cuts and model dependency analysis to distinguish signal from background.

Contribution

It introduces a multi-dimensional cut approach using six sensitive observables and assesses the stability of results against different hadronization models and parameters.

Findings

Potential to isolate instanton-enriched samples with optimized cuts.

Normal DIS background more sensitive to model variations than instanton signals.

Results are robust within the considered model variation bandwidth.

Abstract

We investigate possible search strategies for QCD-instanton induced processes at HERA in the deep-inelastic scattering (DIS) regime. Our study is based on the Monte Carlo generator QCDINS for instanton-induced events and the standard generators for normal DIS events. It appears possible to isolate an instanton enriched data sample via an optimized multi-dimensional cut scenario for a set of six most instanton-sensitive DIS observables. As a further central point, we investigate the stability of our results with respect to a variation of the (hadronization) models available for the simulation of both normal DIS and instanton-induced events. Dependencies on the variation of certain inherent parameters are also studied. Within the ``bandwidth'' of variations considered, we find that the normal DIS background is typically much more sensitive to model variations than the I-induced signal.