Direct observation of quark-hadron duality in the free neutron F_2 structure function

TL;DR

This study provides the first direct evidence of quark-hadron duality in the neutron F_2 structure function by analyzing data from Jefferson Lab's BONuS experiment, revealing duality's validity in specific resonance regions.

Contribution

It introduces a novel spectator tagging technique to measure the neutron F_2 structure function and demonstrates quark-hadron duality in the neutron for the first time.

Findings

Quark-hadron duality holds locally in the neutron for the second and third resonance regions.

Duality is observed down to Q^2 ~ 1 GeV^2.

Possible violations up to 20% are seen in the first resonance region.

Abstract

Using data from the recent BONuS experiment at Jefferson Lab, which utilized a novel spectator tagging technique to extract the inclusive electron-free neutron scattering cross section, we obtain the first direct observation of quark-hadron duality in the neutron F_2 structure function. The data are used to reconstruct the lowest few (N=2, 4 and 6) moments of F_2 in the three prominent nucleon resonance regions, as well as the moments integrated over the entire resonance region. Comparison with moments computed from global parametrizations of parton distribution functions suggest that quark--hadron duality holds locally for the neutron in the second and third resonance regions down to Q^2 ~ 1 GeV^2, with violations possibly up to 20% observed in the first resonance region.