Updates on the Studies of $N^*$ Structure with CLAS and the Prospects with CLAS12

TL;DR

This paper reviews recent CLAS results on nucleon resonance structures and discusses future CLAS12 experiments aiming to explore nucleon excited states at various Q^2 scales, addressing fundamental QCD questions.

Contribution

It provides an overview of recent experimental findings and outlines future measurements with CLAS12 to probe nucleon structure at unprecedented energy scales.

Findings

Recent CLAS data on $ ext{N}^*$ electrocouplings

Future CLAS12 measurements at low and high Q^2

Implications for understanding QCD and hadron mass

Abstract

The recent results on $\gamma_vpN^*$ electrocouplings from analyses of the data on exclusive meson electroproduction off protons measured with the CLAS detector at Jefferson Lab are presented. The impact of these results on the exploration of the excited nucleon state structure and non-perturbative strong interaction dynamics behind its formation is outlined. The future extension of these studies in the experiments with the CLAS12 detector in the upgraded Hall-B at JLab will provide for the first time $\gamma_vpN^*$ electrocouplings of all prominent resonances at the still unexplored distance scales that correspond to extremely low (0.05 GeV$^2 < Q^2 <$ 0.5 GeV$^2$) and the highest photon virtualities (5.0 GeV$^2 < Q^2 <$ 12.0 GeV$^2$) ever achieved in the exclusive electroproduction measurements. The expected results will address the most important open problems of the Standard Model: on the nature of more than 98\% of hadron mass, quark-gluon confinement and emergence of the excited nucleon state structure from the QCD Lagrangian, as well as allowing a search for the new states of hadron matter predicted from the first principles of QCD, the so-called hybrid baryons.