UBC Theses and Dissertations
A study of the reaction ²⁸Si (p,γ) ²⁹P Lim, Sim Too
A study of the reaction ²⁸Si (p,γ) ²⁹P The giant resonance region of ²⁹P has been investigated by means of the reaction ²⁸Si (p,γ) ²⁹P. The yields have been measured for the transitions to the ground and the first five.excited states. A comparison of the (p, γ[sub o]) yield with the ²⁹Si(p,γ)²⁸Al yield show a possible isospin splitting of 2.5 MeV. Angular distributions have been. measured for the transitions to the ground, lst excited and 5th excited states. The angular distributions are interpreted in terms of the dominating dipole transitions with interference from the giant quadrupole resonance. A considerable amount of quadrupole strength is observed in the (p, γ[sub o]) and (p, γ₁) reactions. The strengths of different channels in term of the classical dipole sum are compared with the structure of the low-lying states in ²⁹P. Intermediate structure, of width Γ≈ 200 keV, observed throughout the giant, dipole resonance is compared to available 2p-lh calculations. 29 Higher excited states of ²⁹P, the region below the giant resonance, have also been investigated via the (p, γ[sub o]) reaction. Several narrow resonances with observed widths characterized by the target thickness (≈ 17 keV) are proposed to be T=3/2 states, i.e. analogs of states in ²⁹Al. Possible spin-parity assignments to these states are given. Of particular interest are the resonances, of width -150 keV, observed at E[sub p] = 7.25, 7.45 and 8.80 MeV. Evidence for possible spin- parity assignments to the 7.45 and 8.80 MeV states are given. These states are proposed as possible doorway states, such as 2p-lh states.
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