A hybrid method for determining particle masses at the Large Hadron Collider with fully identified cascade decays

TL;DR

This paper introduces a hybrid kinematic fitting method that combines event-specific constraints and invariant mass end-points to improve the precision of SUSY particle mass measurements at the LHC, reducing uncertainties by about 30%.

Contribution

The paper presents a novel hybrid technique that enhances mass measurement accuracy by integrating multiple constraints in SUSY decay event analysis.

Findings

Mass measurement uncertainties reduced by ~30%.

Method improves precision over conventional end-point fitting.

Effective for fully identified cascade decays.

Abstract

A new technique for improving the precision of measurements of SUSY particle masses at the LHC is introduced. The technique involves kinematic fitting of events with two fully identified decay chains. We incorporate both event ETmiss constraints and independent constraints provided by kinematic end-points in experiment invariant mass distributions of SUSY decay products. Incorporation of the event specific information maximises the information used in the fit and is shown to reduce the mass measurement uncertainites by ~30% compared to conventional fitting of experiment end-point constraints for the SPS1a benchmark model.