Related papers: Insight into Emergence of Hadron Mass from $\boldm…
The $N(1440)1/2^+$ nucleon resonance, first identified in 1964 by L.D. Roper and collaborators in analyses of $\pi N$ hadroproduction data have continued to provide pivotal insights that serve to advance our understanding of nucleon excited…
Developing an understanding of phenomena driven by the emergence of hadron mass (EHM) is one of the most challenging problems in the Standard Model. This discussion focuses on the impact of results on nucleon resonance ($N^\ast$)…
Understanding the strong interaction dynamics that govern the emergence of hadron mass (EHM) represents a challenging open problem in the Standard Model. In this paper we describe new opportunities for gaining insight into EHM from results…
Studies of the nucleon resonance electroexcitation amplitudes in a wide range of photon virtualities offer unique information on many facets of strong QCD behind the generation of all prominent excited nucleon states. Advances in the…
The results on the photo- and electroexcitation amplitudes of most nucleon resonances in the mass range up to 2.0 GeV determined from the CLAS experimental data on exclusive $\pi^+\pi^-p$ photo-/electroproduction off protons in…
Studies of the spectrum of hadrons and their structure in experiments with electromagnetic probes offer unique insight into many facets of the strong interaction in the regime of large quark-gluon running coupling, {\it i.e.} the regime of…
The vast bulk of visible mass emerges from nonperturbative dynamics within quantum chromodynamics (QCD) -- the strong interaction sector of the Standard Model. The past decade has revealed the three pillars that support this emergent hadron…
Advances in the exploration of the spectrum and structure of the excited states of the nucleon from experiments with electromagnetic probes on proton targets are presented. Impressive progress has been achieved in the studies of exclusive…
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…
The bulk of visible mass is supposed to emerge from nonperturbative dynamics within quantum chromodynamics (QCD). Following years of development and refinement, continuum and lattice Schwinger function methods have recently joined in…
The bulk of visible mass is supposed to emerge from nonperturbative dynamics within quantum chromodynamics (QCD) -- the strong interaction sector of the Standard Model. Following years of development and refinement, continuum and lattice…
Exclusive $\pi^+\pi^-p$ photo- and electroproduction data from CLAS have considerably extended the information on the spectrum and structure of nucleon resonances. The data from the $\pi^+\pi^-p$ and $N\pi$ channels have provided results on…
The study of nucleon resonances in electromagnetic meson production with the CLAS detector is discussed. The electromagnetic interaction is complementary to pion scattering in the exploration of the nucleon excitation spectrum. Higher mass…
The Higgs boson, recently discovered with a mass of 125.09$\pm$0.24 GeV is known to mediate the masses of elementary particles, but only 2% of the mass of the nucleon. Extending a previous investigation [1] and including the strange-quark…
The CLAS detector at Jefferson Lab has provided the dominant part of all available worldwide data on exclusive meson electroproduction off protons in the resonance region. New results on the $\gamma_{v}pN^*$ transition amplitudes…
With discovery of the Higgs boson, science has located the source for $\lesssim 2$% of the mass of visible matter. The focus of attention can now shift to the search for the origin of the remaining $\gtrsim 98$%. The instruments at work…
Recent results on nucleon resonance studies in $\pi^{+}\pi^{-}p$ electro- production off protons with the CLAS detector are presented. The analysis of CLAS data allowed us to determine all essential contributing mechanisms, providing a…
Visible matter is characterised by a single mass scale; namely, the proton mass. The proton's existence and structure are supposed to be described by quantum chromodynamics (QCD); yet, absent Higgs boson couplings, chromodynamics is scale…
We present results on the electroexcitation of the low mass resonances Delta(1232)P33, N(1440)P11, N(1520)D13, and N(1535)S11 in a wide range of Q2. The results were obtained in the comprehensive analysis of JLab-CLAS data on differential…
The transition helicity amplitudes from the proton ground state to the $N(1440)1/2^+$, $N(1520)3/2^-$, and $\Delta(1620)1/2^-$ resonances ($\gamma_vpN^*$ electrocouplings) were determined from the analysis of nine independent one-fold…