Exotic Nuclei - part B

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Vakinfo

This course is given by Prof. Neyens and prof. Severijns. The first part is on electromagnetic moments, the second on the (electro)weak interaction.

Examenvragen

14 juni 2012

Prof. Neyens

There were three questions, one of which was given as a take-home question based on a paper.

1. (Orally) 187Tl has spin-parity (1/2)+. This assignment is tentative.

  • Explain how one can get this spin and parity in the shell model picture.
  • What could cause the failure of the single particle shell model in this case?
  • What other configurations could occur, and what are their spins and parities?
  • What electromagnetic moment would you try and determine to get the spin and configuration of this nucleus?
  • The half life of 187Tl is 51s. What experimental method would you recommend to determine the spin of 187Tl?

2. (Written) There was a table with the spin and g-factor of several Na (Z=11) isotopes. Also given was the magnetic moment of the relevant single particle orbitals.

  • The valence protons live in the same orbital for the odd mass isopes. What orbital is this? Why can you conclude this?
  • What configuration do you suggest for (even mass isotope of Na, can't remember which one)? What is the predicted magnetic moment? Compare to the experimental value; what do you conclude?

Prof. Severijns

No oral examination.

1. The experession for the Ft value of a 0+->0+ superallowed transition was given. What do you need to do experimentally to get a value for Ft? What can we learn about the Standard Model from the Ft value?

2. These questions should be answered in less than 10 lines each. No mathematical expressions should be needed.

  • Why are there 5 components to the weak interaction? Why do we only include two of them in the standard model?
  • Why do Fermi decays only depend on the V and S interactions, and Gamow-Teller decays on T and A?
  • How can you determine the neutrino momentum in a beta decay?