Authors: M A Fawzi
Publish Date: 1972/04/01
Volume: 250, Issue: 2, Pages: 120-144
Abstract
Alpha particle unstable states in12C have been investigated using the three reactions14Nd α′12C14Nd α′α8Be and12Cα α′12C Excitation cross sections and angular distributions have been measured for the reactions14Nd α′ at 52 MeV and12Cα α′ at 90 MeV For a few angle pairs the αdecay of excited states in12C have been observed in a14Nd α′α correlation measurement The reactions selectively excite onlyT=0 states A previously undetected level with a large αdecay width Γ=12 MeV has been observed at 1562 MeV excitation This level shows up clearly in both reactions and is further distinguished from the nearby 1408 state in the correlation measurement because of the distinctly different energy distributions of the decay productsOn the basis of a particle angular distributions the 1562 MeV level was assigned spin and parity 4+ and the level at 1408 was assigned 3− The latter differs from the value suggest by earlier work Comparison with DWBA calculations indicates that angular distributions of all other prominent levels are in agreement with their earlier assignmentsThe author wants to express his gratitude to Prof A Citron Prof W Heinz and Prof H Schopper for their encouragement and support I wish to record my deep appreciation to Dr E L Haase and Dr D P Saylor for their continuous help and many helpful discussions on the various theoretical problems I should also like to thank Dr R Hagelberg and Mr M Straub for help with the experiment and the programming and Mr Siebert for making available his data I am indebted to the Deutscher Akademischer Austauschdienst DAAD for financial grant during my stay in Germany
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