ELECTROMAGNETIC FORM-FACTORS OF ELECTRODISINTEGRATION OF LIGHT-NUCLEINEAR-THRESHOLD

The general structure of electromagnetic currents for electrodisintegr ation of nuclei near threshold, e(-) + A --> e(-) + A(1) + A(2) (A, A( 1) and A(2) are arbitrary nuclei or hadrons with spins 0, 1/2 and 1), are established. Considering nuclei as elementary particles with the d efinite values of spin and space parity and using the conservation of hadronic electromagnetic current and P-invariance of hadron electromag netic interaction, the spin structure of the amplitudes of the process es gamma + A --> A(1) + A(2) is derived in terms of threshold electro magnetic form factors. The present formalism is valid for any nuclear structure and any reaction mechanism. The structure functions, which c haracterize the scattering electrons on the polarized target, are calc ulated as quadratic combinations of the form factors. These structure functions are used for the analysis of the problem of complete experim ent for the full determination of all threshold form factors. P-odd pa rt of electromagnetic current, induced by P-odd nuclear forces, is par ametrized also in terms of the corresponding form factors. The process es with the following combinations of spins of hadrons e(-) + 1 --> e( -) + 0 + 0, e(-) + 1 --> e(-) + 1 + 0, e(-) + 1/2 --> e(-) + 1/2 + 1 a nd e(-) + 1/2 --> e(-) + 1/2 + 1/2, and with different combinations of space parities of nuclei A, A(1) and A(2), are examined within this a pproach. (C) 1998 Published by Elsevier Science B.V.