Electroexcitation of the Roper resonance for 1.7<Q2<4.5 GeV2 in ep→enπ+

The helicity amplitudes of the electroexcitation of the Roper resonance are extracted for 1.7 < Q(2)< 4.5 GeV2 from recent high precision JLab-CLAS cross section and longitudinally polarized beam asymmetry data for pi(+) electroproduction on protons at W=1.15-1.69 GeV. The analysis is made using two approaches, dispersion relations and a unitary isobar model, which give consistent Q(2) behavior of the helicity amplitudes for the gamma(*)p -> N(1440)P-11 transition. It is found that the transverse helicity amplitude A(1/2), which is large and negative at Q(2)=0, becomes large and positive at Q(2)similar or equal to 2 GeV2, and then drops slowly with Q(2). The longitudinal helicity amplitude S-1/2, which was previously found from CLAS ep -> ep pi(0),en pi(+) data to be large and positive at Q(2)=0.4,0.65 GeV2, drops with Q(2). Available model predictions for gamma(*)p -> N(1440)P-11 allow us to conclude that these results provide strong evidence in favor of N(1440)P-11 as a first radial excitation of the 3q ground state. The results of the present paper also confirm the conclusion of our previous analysis for Q(2)< 1 GeV2 that the presentation of N(1440)P-11 as a q(3)G hybrid state is ruled out.