Spectroscopy of light nuclei by low energy (< 70 MeV) inelastic electron scattering

Electroexcitation of magnetic dipole and other modes in46Ti and48Ti

“…q<0.7fm -1, the first three terms of the series in (2.1) can be used to determine the transition strengths B(XL)'f at the photon point [17] (2.4) with the two free parameters B(XL, O)~ and Rtr(XL), which are to be determined by adjusting (2.4) to the experimental data. In the case of electric (E) transition the transverse contribution must be taken into account.…”

“…The reduced strength of a longitudinal electric (C) or of a transverse magnetic (M) transition of multipolarity L as function of the momentum transfer q may be written in plane wave Born approximation (PWBA) as power series [17] (XL, q) "r…”

“…In the case of electric (E) transition the transverse contribution must be taken into account. This was done by the help of the Siegert theorem [17] B(EL, q)'[ ~f~2 B(CL, q) T, (2.5) where k=Ex/hc is the wavenumber of the exchanged photon. The Siegert theorem is valid near the photon point, but the validity is still rather approximate.…”

Line shape and excitation strength of the first excited state in9Be

“…where ,~= 1/k and k is the photon wave number, g =(2J + 1)/[2(21+ 1)] with J= 1/2 and I-3/2 for the excited state and ground state spins, respectively, and E R is the resonance energy. The ground state radiative width F~ is given by [19] 16~ 2 g=~c~(hc)- (2) where c~ is the fine structure constant and B(E1, k) the reduced transition strength at the photon point. Near threshold, the width F, for neutron emission behaves as …”

“…Under the assumption that q stays constant over the width of the resonance the (e, e') cross section can be extrapolated to the photon point with a known transition radius Rtr (see [19]). The single-level Breit-Wigner expression of the cross section modified for the threshold behaviour in form of Eq.…”