Spatial Mass

TL;DR

The paper introduces the spatial mass, an observable based on 3-vector momenta, which reduces uncertainties in multijet mass measurements at the LHC without significantly affecting sensitivity.

Contribution

It proposes the spatial mass as a new observable that is insensitive to jet mass scale and resolution uncertainties, enhancing multijet mass resolution in hadronic final states.

Findings

Spatial mass reduces uncertainty in top quark mass measurement.

Spatial mass maintains sensitivity while improving resolution.

Applicable to multijet analyses at the LHC.

Abstract

In analogy to the transverse mass constructed from two objects, we define the spatial mass constructed from the input objects 3-vector momenta. This observable is insensitive to jet mass scale and resolution uncertainties when constructed from small-radius hadronic jets. Thus it improves the effective resolution on multijet masses for searches and measurements in hadronic final states. To illustrate the efficacy of the spatial mass, we consider a top quark mass measurement at the Large Hadron Collider (LHC) in the 3-jet final state. The reduction in uncertainty comes with a negligible cost in sensitivity.