β Scribed by Magda Ericson
No coin nor oath required. For personal study only.
The last scientific talk of Amos de Shalit was the summary of the proceedings of the Heidelberg "International Conference on Nuclear Reactions induced by Heavy Ions."
Listing the problems still open in nuclear physics, he mentioned the behavior of the nucleons inside the nucleus. Quoting his words, "If one has a nucleus and one has nucleons in it, then one asks oneself: The nucleons in the nucleus, do they behave like the free nucleons, or differently?... In other words we want to know, Do they retain their mass? Do they retain their charge distribution? Do they retain their coupling constant to the weak field of beta decay, to the p mesons?"
This article, which addresses itself to the last question, is a tribute to a great scientist and is dedicated to the memory of a friend.
The nuclear pionic vertex and its relation to the n-nuclear (charge exchange) scattering length are investigated using dispersion techniques. The aim is to extract information on mesonic (exchange current) effects in the pionic vertex and in the axial vector current matrix element.
A sum rule is obtained: The sum of pionic vertices between the ground state and all excited nuclear states is connected to an integral of the total r-nuclear cross section in the (3,3) resonance energy and above. The exchange current effects are shown to be related in a model-independent way to shadow phenomenon in the cross section.
The Goldberger-Treiman relation extends this result to Gamow-Teller matrix elements (nuclear Adler-Weisberger sum rule). Estimates are given for the renormalization of the axial coupling constant in some nuclei.
π SIMILAR VOLUMES
Vibrational magnetic dipole transition moments, and hence rotational strengths and vibrational circular dichroism intensities, are determined by the atomic axial tensors. The electronic contributions to the latter, I&, are related via a sum rule to the paramagnetic susceptibility tensor, ,&. Their a
## Abstract The construction of layered DNAβRNA replicons has facilitated and expanded the use of alphavirus vectors to vaccine development, construction of packaging cell lines and longβterm heterologous gene expression. In these vector systems, the alphavirus replicon is under the control of a st