Revisiting the role of grooming in DIS

TL;DR

This paper introduces a new grooming algorithm for deep inelastic scattering that isolates radiation regions, enabling precise QCD studies and hadronization analysis at HERA and EIC.

Contribution

A novel event-wide grooming procedure tailored for DIS, with a factorization theorem showing independence from initial hadronic states in certain limits.

Findings

The groomed invariant mass is studied in DIS.

The cross-section in the back-to-back limit is independent of the incoming hadronic matrix element.

Proposes using this method at HERA and EIC for probing QCD and nuclear effects.

Abstract

We introduce a novel grooming procedure, which is an extension of the modified MassDrop tagging algorithm, tailored to the needs of deep inelastic scattering (DIS). The new algorithm, which grooms the event as a whole, takes advantage of the natural separation of current and target fragmentation in the Breit frame, in order to eliminate radiation in the beam and central rapidity regions. We study the groomed invariant mass in DIS and within soft-collinear effective theory we construct a factorization theorem for the cross-section in the back-to-back limit. In this limit we show that, up to a normalization factor, the cross-section does not depend on the incoming hadronic matrix element and we propose this measurement at HERA and the future electron-ion collider (EIC) as a probe to hadronization, precision QCD, and cold nuclear matter effects. We also give an event based definition of the Winner-Take-All axis and comment on possible applications.