E. Sugarbaker

Charge exchange spin observable measurements on Pb at 795 MeV in the giant resonance region

We examine a new feature of the 0° (p,n) cross section spectra that appears at 35 MeV energy loss in Pb and Zr. To further investigate this structure we have measured a complete set of spin transfer observables for natPb at 0° using the (p↘,n↘) reaction at 795 MeV.

A study of the Fermi (0+) transition in 14C(p↘,n)14N at 495 MeV

Differential cross sections and analyzing powers have been measured for the 14C(p↘,n)14N*(IAS) reaction at a proton energy of 495 MeV. The data were obtained at the LAMPF Neutron Time‐of‐Flight Facility (NTOF) using a flight path of 400 meters over an angular distribution of θlab=0° to 10° (q=0.0 to 0.956fm−1). Previous Ay results for targets with mixed Fermi (ΔJπ=0+) and Gamow‐Teller (ΔJπ=1+) transitions are not reproduced with either DWIA or RIA calculations. The 14C target offers the best opportunity to study a pure Fermi transition (2.31 MeV) resolved from the nearest Gamow‐Teller (GT) strength (3.95 MeV). The results compare favorably with DWIA and RIA calculations. Thus the discrepancies for mixed Fermi and GT states most likely arise from either failure to understand nuclear structure effects or the nuclear distortion factors.

Evidence for pionic enhancement in quasifree Δ production in the 12C(p↘,n↘) reaction

We present (p↘,n↘) spin observable measurements in the quasielastic and quasifree delta region of excitation taken on the targets 2H and 12C at 0° and 795 MeV proton energy. These observables have been used to form the spin–longitudinal (σ⋅q) and spin–transverse (σ×q) cross sections. Good agreement is found between experiment and theory in the spin–longitudinal channel.