Photodisintegration studies on p-nuclei: the case of Mo and sm isotopes

Abstract

In explosive stellar environments like supernovae, the temperatures are high enough for the production of heavy neutron-deficient nuclei, the socalled p-nuclei. Up to now, the knowledge of the reaction rates of p-nuclei is based on theoretical parameterizations using statistical model calculations. At the bremsstrahlung facility of the superconducting electron accelerator ELBE of FZ Dresden-Rossendorf, we aim to measure the photodisintegration rates of heavy nuclei experimentally. Photoactivation measurements on the astrophysically relevant p-nuclei 92 Mo and 144 Sm have been performed with bremsstrahlung end-point energies from 10.0 to 16.5 MeV. First experiments on the short-lived decays following the reaction 144 Sm(γ,n) are carried out using a pneumatic delivery system for rapid transport of activated samples. The activation yields are compared with calculations using cross sections from recent Hauser-Feshbach models.

Photoactivation experiment onAu197and its implications for the dipole strength in heavy nuclei

“…The 197 Au(γ, n) reaction has been used as a photoactivation standard for the experiments discussed in Refs. [54] and [55].…”

Spectrum of Yang-Mills theory in 3 and 4 dimensions

“…In general, theoretical derivations, that are obtained straightforwardly from Yang-Mills theory, are lacking in 4 dimensions, in the low-energy limit. The situation appears rather better in 3 dimensions, where some analysis have been performed, reaching agreement with lattice computations for the string tension [13,14,15,16] and the spectrum [17,18]. A successful approach was devised by Karabali, Kim and Email address: marcofrasca@mclink.it (Marco Frasca) Nair with a set of matrix variables to work in this case to obtain a wavefunction results of the theory [19,13,14].…”

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“…Experimental veri cation of the predicted photodisintegration cross sections are clearly needed [1]. For photodisintegration reactions with charged particle emission there is only a very limited number of cases in the relevant mass and energy range where the H-F cross sections can be directly compared to experimental data [4]. Consequently, the model calculations remain mainly untested.…”