ElectromagneticN→N*(1535)transition in the relativistic constituent-quark model

Q2independence ofQF2/F1

“…This feature leads to an analytic understanding, embodied in Eqs. (28) and (29), that QF 2 (Q 2 ) and F 1 (Q 2 ) have the same variation with Q 2 . The predicted value of the ratio QF 2 (Q 2 )/F 1 (Q 2 ) ≈ 0.8 for the values of Q 2 up to 20 GeV 2 , and drops slowly for larger values.…”

“…(3,4) the important contributions occur for a very narrow band of values close to 1 − η = x 3 = 0.145. The sharp peaking is maintained for all of the values of Q 2 considered here, and is a central reason for the qualitative success of the approximations (28,29). The small factor 1 − η multiplies the large factor Q appearing in Eq.…”

“…Such models have a long history [14][15][16], and many authors [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] have contributed to the necessary developments. Schlumpf's model is used because his power-law wave functions lead to a reasonably good description of the proton electromagnetic form factors, G E and G M , at all of the values of Q 2 where data were available as of 1992 [10][11][12].…”

Nucleon magnetic moments in light-front models with quark mass asymmetries

“…It is well known that in light-front models of the nucleon with point-like quarks, the proton and neutron magnetic moments are not reproduced simultaneously without further assumptions [1,2,3,4]. More recently, it was shown that in several nucleon light-front models, the proton and neutron magnetic moments are strongly correlated [5].…”

Nucleon electromagnetic form factors in a relativistic quark-pair-creation model

“…On the other hand, attempts to use relativized quark models combined with consistent transition operators have been carried out [4,5] and Light-Front and Point-Form studies have also been done [6,7] partially solving some of the failures of the non-relativistic approach. However, a complete understanding of the relevant ingredients in the description of electromagnetic processes has not been reached yet.…”