[en] The ¹⁹⁷Au electrodisintegration by neutron emission, aiming to obtain informatons about the isoscalar giant electric quadrupole resonance was studied. The cross section of the ¹⁹⁷Au (e, n)¹⁹⁶Au reaction, and the yield production of ¹⁹⁷Au (e + γ, n)¹⁹⁶Au electro + photodisintegration, in function of the energy of incident neutron, between 10 and 23 MeV were measured. A method which relates the electrodisintegration cross section with the corresponding photodisintegration cross section, by the virtual photon spectra was used in the analysis of experimental data. This analysis allows to determine the multipolar composition of photonuclear process. (author)

[en] The (e,α) cross section for ⁶⁵Cu has been measured in the electron energy range 14-34 MeV. The results have been analyzed using the distorted-wave Born approximation E1 and E2 virtual photon spectra and the E1 and E2 components of the corresponding (γ,α) cross section were obtained. To assess the accuracy of the virtual photon analysis, the (e,2n) cross section for ⁶³Cu was also measured and the obtained (γ,2n) cross section is compared with direct measurement of this cross section performed with annihilation gamma rays. (Author)

No abstract available

[en] The (e,n) cross section for ¹⁹⁷Au was measured and the results analyzed using the known (y,n) cross section and DWBA virtual photon spectra. Tuhe (y,n) cross section contains an E2 component exhausting 66+-26 percent of the isoscalar E2 sum and an M1 component in the threshold region with a strength of 18.9+-1.2Mev.mb. It is shown that the electrodisintegration cross section is very sensitive to M1 absorption and the technique can be used for other nuclei. (Author)

No abstract available

[en] The electrodisintegration of ¹⁹⁷Au was measured by residual activity from threshold to 23 MeV. The results are analysed with DWBA virtual photon spectra for finite nuclei (E1 and E2 multipoles, point DWBA for M1) to obtain M1 and E2 strengths. (author)

No abstract available

No abstract available

[en] The (e,α) cross section for ₆₅Cu has been measured in the electron energy range 14--34 MeV. The results have been analyzed using the distorted-wave Born approximation E1 and E2 virtual photon spectra and the E1 and E2 components of the corresponding (ν,α) cross section were obtained. To assess the accuracy of the virtual photon analysis, the (e,2n) cross section for ₆₃Cu was also measured and the obtained (ν,2n) cross section is compared with direct measurement of this cross section performed with annihilation gamma rays

[en] The J^π=1^-,T=0> state in ¹² C, at E_x=10.84 MeV, was investigated by inelastic electron scattering measurements at low values of momentum transfer (q<0.6 fm^-1). As well known, E1, ΔT=0 transitions are forbidden (to first order) by the isospin selection rule in self-conjugate nuclei. Nevertheless, the isospin selection rule breaks down in the presence of isospin mixing and/or away from the long wavelength limit. Therefore, instead of totally forbidden, these transitions are strongly inhibited. At low-q values, they proceed through isospin mixing which shows up as an isovector (T=1) contribution to the form factor. As previously reported, form factors were measured for incident electrons with E_i=60 MeV, at scattering angles θ=117 deg C, 135 deg C and 154 deg C. The transverse term contribution to the form factor could not be neglected and was subtracted according to Siegert's relation. In the present work, data are reanalyzed together with the complete Sendai data set, thus extending the momentum transfer range up to q ∼1.4 fm^-1. A polynomial form, derived in the framework of the harmonic oscillator shell-model, was fitted to the data. This semi-empirical expression allows for an isovector (T=1) contribution to the form factor, which interferes destructively with the isoscalar (T=0) term, resulting in a minimum for low-q values. Extrapolating to the photon-point, the transition strength was determined to be B(E1)=3.7(1.8) 10^-4 e²fm² Quantitative information on isospin mixing was obtained by calculating the Coulomb Matrix Element, <1|H_C|O> within a two-level mixing model, first assuming that the mixing occurs with the nearest T=1 level (E_x=17.23 MeV). This assumption resulted in < H_C> ≅750 (325) keV for the isospin symmetry breaking potential. Such a magnitude for < H_C> is not in good agreement with the systematics observed in isospin mixing investigations for the M1 doublet in ¹² C, E_x=12.71 and 15.11 MeV. Therefore, an admixture with the E_x=22.6 MeV (T=1) level (largest fragment of the GDR) was tried. This resulted in < H_C> ≅ 350 (175) keV which follows well the observed systematics. The results obtained in this work constitute the first investigation of isospin mixing, as well as the first determination of B(E1) for the |1^-,0> state in ¹² C. (author)