M. A. Oothoudt

The (p, t) reactions on nuclei in the rare earth region

Abstract The (p, t) reactions on isotopic targets of 178, 180 Hf and all the stable isotopes of Yb and on natural targets of Gd, Dy, Er, Hf, Ta, W, Os and Au were studied at a beam energy of 19 MeV with an average resolution of 12 keV. A split-pole magnetic spectrometer was used to measure (p, t) Q -values and absolute differential cross sections. On the basis of angular distribution shapes definite 0 + and tentative 2 + assignments were made. Rotational bands were identified assuming an I ( I +1) spacing. The (p, t) reaction populates excited 0 + states strongly in 174 Yb, 176 Hf, 166 Yb and several Gd, Dy and Er isotopes. The 174 Yb and 176 Hf 0 + states are discussed in terms of the pairing phase transition and in terms of Nilsson orbitals with unequal (p, t) reaction amplitudes. Members of gamma and octupole vibrational bands were observed in the even- N nuclei. The lowest L = 0 transfers to states in 169, 171 Yb were found to have less than 55% of the strength to ground states in adjacent even- N nuclei. A strong L = 0 transfer to a state at 1513 keV in 171 Yb indicates the presence of a possible K = 0 core vibration coupled to the unpaired 5 2 [512] neutron. The natural targets have furnished information on trends in cross sections for members of ground bands, gamma bandheads, 3 − octupole states, and strongly excited 0 + states.

Elastic differential cross sections and analyzing powers for p+40,42,44,48Ca at 0.8 GeV☆

Abstract Differential cross sections and analyzing powers for the elastic scattering of 800 MeV polarized protons from 40,42,44,48Ca are reported. A first-order, spin-dependent KMT optical potential analysis is presented from which the rms radii of the neutron densities are deduced. A comparison of these results with other determinations and with various theoretical predictions is given.

Elastic scattering of 0.8-GeV protons from C12, Ni58, and Pb208

Differential cross sections for elastic scattering of 0.8-GeV protons from /sup 12/C, /sup 58/Ni, and /sup 208/Pb have been measured. Preliminary analysis of the data in terms of the Kerman-McManus-Thaler formalism with spin-dependent nucleon-nucleon amplitudes shows sensitivity to details of proton and neutron matter distributions.

Elastic differential cross sections and analyzing powers for p + 54Fe, 58,64Ni at 800 MeV

Abstract Elastic scattering analyzing powers and differential cross sections for 800 MeV → p + 54Fe, 58,64Ni are reported. An approximately mode-independent technique is used to extract information concerning the neutron density distributions of these nuclei.

Analysis of elastic scattering of 0.8 GeV polarized protons from 116Sn and 124Sn

Abstract Differential cross section and analyzing power data for elastic scattering of 0.8 GeV polarized protons from 116Sn and 124Sn are analyzed in terms of a spin-dependent Kerman-McManus-Thaler formalism. Neutron matter densities and rms radii are deduced with careful attention to sources of error, and found to be in good agreement with Hartree-Fock predictions.

Coupled-channels effects in 0.8 GeV proton inelastic scattering from 58Ni

Abstract New differential cross sections for 0.8 GeV proton inelastic excitation of the first 2+ and 4+ states in 58Ni are compared with distorted wave Born approximation and coupled-channels predictions. Multistep processes and multi-phonon mixing are both shown to be important in describing the excitation of the 4+ state.

p-4He elastic scattering at 788 MeV

Abstract The p- 4 He elastic cross section at 788 MeV has been measured for laboratory angles between 13.3° and 165.5° corresponding to a range of four-momentum-transfer, − t , from 0.11 to 4.19 GeV 2 / c 2 . Evidence is presented for a backward diffraction-like structure not previously observed (3.4 t 2 / c 2 ). In the region (1.6 t 2 / c 2 ) a smooth fall off from the shoulder due to triple scattering is observed with no evidence for quadrupole scattering.

Elastic Scattering of 0.8-GeV Protons fromC12,Ni58, andPb208

Differential cross sections for elastic scattering of 0.8-GeV protons from /sup 12/C, /sup 58/Ni, and /sup 208/Pb have been measured. Preliminary analysis of the data in terms of the Kerman-McManus-Thaler formalism with spin-dependent nucleon-nucleon amplitudes shows sensitivity to details of proton and neutron matter distributions.