Quantum simulation of deep inelastic scattering in the Schwinger model

TL;DR

This paper demonstrates the use of quantum simulation techniques to compute hadronic tensors in deep inelastic scattering within the Schwinger model, showcasing a new approach to evaluate real-time observables in quantum field theories.

Contribution

It introduces quantum simulation methods for calculating hadronic tensors in DIS, providing a foundation for extending to more complex gauge theories.

Findings

Quantum simulation successfully computes the hadronic tensor in the Schwinger model.

Results agree with exact diagonalization where available.

The approach validates quantum simulation as a viable tool for nonperturbative QCD studies.

Abstract

Hadronic tensors encode the nonperturbative structure of hadrons probed in deep inelastic scattering (DIS), yet their direct evaluation requires real-time evolution that presents a challenge for traditional Euclidean lattice approaches. In this work, we present the first study of the hadronic tensors in DIS using quantum simulation in the Schwinger model, i.e (1+1)-dimensional QED. Using two complementary quantum-simulation strategies -- quantum-circuit and tensor-network methods -- we compute the real-time current-current correlator directly on the lattice and validate our results against exact diagonalization where applicable. From this correlator, we compute the hadronic tensor and determine the longitudinal structure function, the sole nonvanishing DIS observable in two space-time dimensions. Our study demonstrates that quantum simulation offers a viable complementary pathway towards the evaluation of real-time observables relevant for hadronic structure. It also provides a foundation for extending the calculations from Schwinger model to other gauge theories.