First Lattice Study of the $N$-$P_{11}(1440)$ Transition Form Factors

TL;DR

This paper presents the first lattice QCD study of the $N$-$P_{11}(1440)$ transition form factors, providing a model-independent insight into nucleon resonance properties from nonperturbative QCD.

Contribution

It introduces the first lattice QCD calculation of the Roper-nucleon transition form factor, advancing understanding of nucleon resonances from fundamental theory.

Findings

First lattice QCD results for the $N$-$P_{11}(1440)$ transition form factors.

Insights into the $Q^2$ dependence of nucleon resonance amplitudes.

Provides a benchmark for future experimental and theoretical studies.

Abstract

Experiments at Jefferson Laboratory, MIT-Bates, LEGS, Mainz, Bonn, GRAAL, and Spring-8 offer new opportunities to understand in detail how nucleon resonance ($N^*$) properties emerge from the nonperturbative aspects of QCD. Preliminary data from CLAS collaboration, which cover a large range of photon virtuality $Q^2$ show interesting behavior with respect to $Q^2$ dependence: in the region $Q^2 \le 1.5 {GeV}^2$, both the transverse amplitude, $A_{1/2}(Q^2)$, and the longitudinal amplitude, $S_{1/2}(Q^2)$, decrease rapidly. In this work, we attempt to use first-principles lattice QCD (for the first time) to provide a model-independent study of the Roper-nucleon transition form factor.