Electromagnetic Inelastic Form Factors of Processesep→eN^*in a Relativistic Extended Particle Model Based on the Quark Model

Abstract

193The electromagnetic inelastic form factors of ep.....o;eN* are calculated in a covariant way, on the basis of a relativistic extended-particle model introduced as a straight-forward extension of the nonrelativistic quark model. It is shown that the inelastic form factors have the same q2-dependence as the elastic one at higher momentum transfers, that is,for q2 larger than the nucleon mass. This theoretical result, coming mainly from the Lorentz contraction of the nucleon as an extended particle, is consistent with recent experiment.The nucleon elastic form factors are also discussed in the same framework of the model. In particular it is shown that the neutron electric form factor appearing as a relativistic effect is consistent with existing experimental data. of N* (or N), Nand photon, respectively. For q 2 > M 2 (M being the nucleon mass), that is, lqi?: M, one of N* (or N) and N or both should be relativistic.Observing the vertex in the rest system of the N*, for instance, we have the relativistic initial nucleon with momentum P 1 = -q and Lorentz factor rz

On the six-quark structure in the deuteron form factor

“…To calculate the third part of form factor (20) related to the purely six-quark contribution we use the relativistic determination 9 ~ Q~ exp( -iq x~(r O6q(~t, ..., is; Pout) (22) J where xi are quark coordinates transformed through Jacobi coordinates r and we take the wave function as a solution of the relativistic harmonic oscillator [14] F~a are the charge (quadrupole) form factors calculated with the RSC wave function [11], and relativistic recoil effects are taken into account [13]; Fe, 6q the six-quark charge form factor, Fc, int, FQ,~n t the interference terms between the nucleon part (RSC) and six-quark part of wave function of the deuteron Substituting (23) into (22) one can obtain…”

New Properties of Nuclei: Signals from Kaons, Quarks And α ‐ Scattering

“…The second reason is that the simple form of the wave functions [Eqs. (21)(22)(23)(24)(25)] allows us to express the form factor through the experimentally known distributions of the nuclear charge density and the form factors of simpler systems. Moreover, we consider that the contributions from the colored clusters configurations (e.g.…”

“…The Klein-Gordon equation of a system of "k" nucleons, composed of N=3k quarks moving in the potential of a relativistic harmonic oscillator [25] can be written in the form, 0 ) ,..., ( ) ( where the tensor K µν is defined through the metric tensor g µν . In addition, the form factor of the Nq-system has the form, where M k is the parameter relating the internal motion of quarks in 3kq system with the motion of this system as a whole.…”

“…The parameters α k , M k can be found by fitting Eq. (38) with the nucleon form factor [25], the analysis of the elastic electron-deuteron scattering [25] and from the comparison made in Ref. [26] with the calculations based on the model of "chain quarks" [27].…”

Electromagnetic Elastic Nucleon Form Factors in a Relativistic Quark Model

“…1 l-sl In order to understand the essential features of such models, it is very important to treat every specific problem in a consistent way within the model. This is the reason why we have chosen normalizable solutions of the wave equation 1 l-sl, 5 l and minimal electromagnetic interaction.…”