Conference Proceedings (Physics)

Permanent URI for this collection

https://scholar.sun.ac.za/handle/10019.1/5711

Browse

Browsing Conference Proceedings (Physics) by Author "Cowley, A. A."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Alpha-cluster structure in the ground state of 40Ca displayed in a (p,pa) knockout reaction
    (IOP Publishing, 2013) Cowley, A. A.
    The analyzing power is very sensitive to details of the reaction mechanism of (p, pα) knockout reactions in the incident energy range of approximately 100 MeV and higher. Whereas distorted wave impulse approximation calculations in the past proved to give an excellent reproduction of analyzing power angular distributions for quasifree (p, pα) reactions on light targets such as 6Li, 9Be and 12C, the situation for 40Ca was not as simple. It is now shown that the theory also offers good agreement with the experimental distribution of the heaviest target nucleus if care is taken to use proper distorted waves which treat α−36Ar properly as a system for which α–elastic scattering is anomalous. Thus it is shown that 40Ca reveals its ground state α–cluster structure in an unambiguous way similar to the light target nuclei.
  • Thumbnail Image
    Item
    Distorted-wave Born approximation study of the 11Li(p,t) 9Li reaction
    (IOP Publishing, 2016) Cowley, A. A.
    The reaction 11Li(p,t) 9Li(gs) at an incident energy of 4 MeV is treated in terms of a simplistic distorted-wave Born approximation transfer. The halo neutrons involved in the reaction are treated as a di-neutron cluster transferred in a simultaneous process. This appears to be a good approximation of the mechanism. The dominant contribution to the reaction comes from the known (1s1/2) 2 structure component of the ground state of 11Li, and the cross section angular distribution seems to be relatively insensitive to the fact that 11Li has an anomalously large radius due to its Borromean halo properties. Significantly this simple treatment of the reaction is in much better agreement with the experimental angular distribution than a more sophisticated calculation.