Aspects of Track-Assisted Mass

TL;DR

This paper introduces a generalized form of track-assisted mass, enhancing its correlation with jet mass through theoretical calculations and analysis in different jet grooming scenarios, applicable at the LHC.

Contribution

It proposes a new generalization of track-assisted mass incorporating additional information, and provides resummed calculations to understand its relation to jet mass.

Findings

Resummed calculations show close correspondence between generalized track-assisted mass and jet mass.

The generalized approach improves the theoretical understanding of track-assisted mass.

Application to groomed jets demonstrates versatility in various jet analysis scenarios.

Abstract

Track-assisted mass is a proxy for jet mass that only uses direction information from charged particles, allowing it to be measured at the Large Hadron Collider with very fine angular resolution. In this paper, we introduce a generalization of track-assisted mass and analyze its performance in both parton shower generators and resummed calculations. For the original track-assisted mass, the track-only mass is rescaled by the charged energy fraction of the jet. In our generalization, the rescaling factor includes both per-jet and ensemble-averaged information, facilitating a closer correspondence to ordinary jet mass. Using the track function formalism in electron-positron collisions, we calculate the spectrum of generalized track-assisted mass to next-to-leading-logarithmic order with leading-order matching. These resummed calculations provide theoretical insight into the close correspondence between track-assisted mass and ordinary jet mass. With the growing importance of jet grooming algorithms, we also calculate track-assisted mass on soft-drop groomed jets.