Energy-energy correlators in Deep Inelastic Scattering

TL;DR

This paper introduces a new energy-energy correlator for deep-inelastic scattering, enabling precise probing of transverse momentum dependent functions with improved theoretical and simulation agreement.

Contribution

It proposes a novel EEC definition in DIS, analyzes its singular behavior using SCET, and performs high-accuracy resummation and comparison with PYTHIA simulations.

Findings

The new EEC is insensitive to pseudorapidity cuts.

Singular distributions are computed up to 73;(\u03b1_s^3) in SCET.

Resummation achieved at N3LL accuracy.

Abstract

The energy-energy correlator (EEC) is an event shape observable which probes the angular correlations of energy depositions in detectors at high energy collider facilities. It has been investigated extensively in the context of precision QCD. In this work, we introduce a novel definition of EEC adapted to the Breit frame in deep-inelastic scattering (DIS). In the back-to-back limit, the observable we propose is sensitive to the universal transverse momentum dependent (TMD) parton distribution functions and fragmentation functions, and it can be studied within the traditional TMD factorization formalism. We further show that the new observable is insensitive to experimental pseudorapidity cuts, often imposed in the Laboratory frame due to detector acceptance limitations. In this work the singular distributions for the new observable are obtained in soft collinear effective theory up to $\mathcal{O}(\alpha_s^3)$ and are verified by the full QCD calculations up to $\mathcal{O}(\alpha_s^2)$. The resummation in the singular limit is performed up to next-to-next-to-next-to-leading logarithmic accuracy. After incorporating non-perturbative effects, we present a comparison of our predictions to PYTHIA 8 simulations.