相关论文: Electroexcitation of the Roper resonance from CLAS…
The helicity amplitudes of the electroexcitation of the Roper resonance are extracted for 1.7 < Q2 < 4.5 GeV2 from recent high precision JLab-CLAS cross section and longitudinally polarized beam asymmetry data for pi+ electroproduction on…
The amplitudes of the transition gamma* N -> P11(1440) are calculated within light-front relativistic quark model assuming that the P11(1440) is the first radial excitation of the 3q ground state. The results are presented along with the…
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…
We review recent progress in the investigation of the electroexcitation of nucleon resonances, both in experiment and in theory. The most accurate results have been obtained for the electroexcitation amplitudes of the four lowest excited…
The transition helicity amplitudes from the proton ground state to the $P_{11}(1440)$ and $D_{13}(1520)$ excited states ($\gamma_{v}pN^*$ electrocouplings) were determined from the analysis of nine independent one-fold differential $\pi^{+}…
The electroexcitation amplitudes or $\gamma_vpN^*$ electrocouplings of the $N(1440)1/2^+$, $N(1520)3/2^-$, and $\Delta(1600)3/2^+$ resonances were obtained for the first time from the $ep \to e'\pi^+\pi^-p'$ differential cross sections…
Using two approaches: dispersion relations and isobar model, we have analyzed recent high precision CLAS data on cross sections of \pi^0, \pi^+, and \eta electroproduction on protons, and the longitudinally polarized electron beam asymmetry…
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…
Data on single- and double-charged pion electroproduction off protons are successfully described in the second and third nucleon resonance regions with common N* photocouplings. The analysis was carried out using separate isobar models for…
We utilize a light-front relativistic quark model to predict the 3q core contribution to the electroexcitation of nucleon resonances of the [70,1-] multiplet on the proton and neutron at Q2 < 5GeV2. The investigation is stimulated in large…
Recent JLab data of the differential cross section for the reaction p(e,e'p)pi0 in the invariant mass region of 1.1 < W < 1.4 GeV at four-momentum transfer squared Q^2= 2.8 and 4.0 (GeV/c)$^2$ are analyzed with two models, both of which…
A description of the Roper using the chiral chromodielectric model is presented and the transverse $A_{1/2}$ and the scalar $S_{1/2}$ helicity amplitudes for the electromagnetic Nucleon--Roper transition are obtained for small and moderate…
Transition helicity amplitudes $\gamma_{v}NN^*$ (electrocouplings) were determined for prominent excited proton states with masses below 1.8 GeV in independent analyses of major meson electroproduction channels: $\pi^{+}n$, $\pi^0p$ and…
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…
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…
We report on the determination of the electrocouplings for the transition from the proton to the $N(1675){\frac{5}{2}}^-$ resonance state using recent differential cross section data on $e p \rightarrow e\pi^+ n$ by the CLAS collaboration…
Recent measurements of nucleon resonance transition form factors with CLAS at Jefferson Lab are discussed. The new data resolve a long-standing puzzle of the nature of the Roper resonance, and confirm the assertion of the symmetric…
The Roper resonance, the first excited state of the nucleon, Is one of the best-established baryon resonances. Yet, its properties have not been consistently explained by effective models of QCD, such as the non-relativistic quark model. In…
A workable basis of quark configurations $s^3$, $s^2p$ and $sp^2$ at light front has been constructed to describe the high-$Q^2$ behavior of transition form factors and helicity amplitudes in the electroproduction of the lightest nucleon…
$\gamma_{v}NN^*$ transition helicity amplitudes (electrocouplings) of several prominent excited proton states are determined for the first time in independent analyses of $\pi^+n$, $\pi^0p$, and $\pi^+\pi^-p$ electroproduction off protons.…