ISSN:
1434-601X
Keywords:
21.60.CS
;
25.30.Dh
;
27.20.+n
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The line shape and the excitation strength of the very weak first excited J π =1/2+ state at Ex=1.684 MeV in Zeitschrift für Physik Zeitschrift für Physik9Be has been investigated with high-resolution inelastic electron scattering at E0=45 and 49 MeV and scattering angles θ=105°, 117°, 129° and 165°, and with high-resolution inelastic proton scattering at E0=13MeV and θ=15° and 18°. Due to lying just above the neutron threshold the level has a strongly asymmetric line shape which in both experiments can be described consistently with a Breit-Wigner expression modified on the low energy side by the threshold behaviour of the cross section. The resonance energy is ER=1.684 ± 0.007 MeV and the width T=217± 10 keV in thec.m. system. A single particle potential model calculation reproduces the line shape and the resonance parameters fairly well. In addition, the inelastic electron scattering form factor has been measured. In the range of momentum transfersq =0.24-0.46 fm−1 it is dominated by a 0p3/2→ 1s1/2 particle-hole transition. The transition is mainly longitudinal and of isoscalar nature with a strength of B (E1)↑ =0.027 + 0.002 e2 fm2, but a small M2 contribution ofB(M2)↑=8.8 ±1.5 μ N 2 fm2 has also been detected.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01289549
Permalink
