UBC Theses and Dissertations
Final state interactions in the reactions He3(He3,2p)He4 and T(He3,np)He4 Blackmore, Ewart William
Final state interactions in the p-p and p-n systems corresponding to the formation of the singlet states of the di-proton and the deuteron have been observed in the reactions He³(He³,2p)He⁴ and T(He³,np)He⁴, by measuring the energy spectra of two of the final state particles detected in coincidence. These interactions appear as regions of high density of events along the kinematic contours in two dimensional energy space. Both p-p and p-He⁴ coincidences from the reaction He³(He³,2p)He⁴ and p-He⁴ coincidences from the reaction T(He³,np)He⁴ were studied. The dominant mechanism producing the three particle final states was found to be the sequential breakup through the states of Li⁵ and He⁵, in agreement with the results of previous experiments. The interaction between the two nucleons affects the distribution of coincidence events only in the region of two dimensional energy space corresponding to a breakup in which the two nucleons emerge with low relative energy. The relative contributions of the different processes in the reaction He³(He³,2p)He⁴ was determined for incident He³ energies from 1.15 MeV to 5.0 MeV. It was found that the nucleon-nucleon interaction becomes less important as the incident energy increases. The validity of two approximate theories of final state interactions, the Watson theory and the Phillips, Griffy and Biedenharn density of states formalism, was checked by comparing their predictions with the observed energy spectra.
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