Wave functions of the nucleon and its parity partner from lattice QCD

TL;DR

This paper uses lattice QCD to compute moments of nucleon and its parity partner's distribution amplitudes, revealing insights into their internal structure and deviations from asymptotic forms.

Contribution

First lattice QCD calculations of distribution amplitude moments for the nucleon and its parity partner, showing smaller asymmetries for the nucleon and larger deviations for the parity partner.

Findings

Nucleon distribution amplitude asymmetries are smaller than sum rule predictions.

Parity partner exhibits stronger deviation from the asymptotic form.

Results improve understanding of hadron internal structure.

Abstract

We compute moments of distribution amplitudes using gauge configurations with two flavors of clover fermions from QCDSF/DIK and operators which are optimized with respect to their behavior under the lattice symmetries. The knowledge of these quantities helps in understanding the internal structure of hadrons and in the analysis of (semi-)exclusive processes. We present results for the nucleon distribution amplitude which suggest that the asymmetries (the deviations from the asymptotic form) are smaller than indicated by sum rule calculations. Using the same approach we were also able to calculate the same quantities for the $N^\star(1535)$, the parity partner of the nucleon. These results show a stronger deviation from the asymptotic form.