Spherical harmonics for multiparticle final states

TL;DR

This paper introduces a spectral power method using spherical harmonics for analyzing collider physics, enabling improved jet reconstruction and pileup subtraction by leveraging more detector information than traditional methods.

Contribution

It presents a novel jet definition based on spectral power H_l, demonstrating its effectiveness in reconstructing particle collision events and handling pileup.

Findings

H_l spectral power effectively reconstructs e+e- > qqg and e+e > tt events.

Pileup can be trivially subtracted if its shape is known.

Future improvements include adding degrees of freedom for jet shape analysis.

Abstract

We examine collider physics via the spectral power H_l, which utilizes much more detector information than sequential jet reconstruction. We use H_l to define a novel jet definition and use it to reconstruct both e+e- > qqg and e+e > tt final states. We find that a significant amount of pileup can be trivially subtracted from H_l jets, provided that the "shape" of pileup can be determined ahead of time. Finally, we find that future progress with H_l jets will require the addition of degrees of freedom accounting for jet "shape" (e.g. radial energy distribution). This should allow the measurement of jet shapes using much more information than traditional techniques.