Energy levels of light nuclei A = 12

Nuclear collective vibrations in extended mean-field theory

Four-body adiabatic model applied to elastic scattering

Multiple scales in the fine structure of the isoscalar giant quadrupole resonance in 208Pb

Title Microscopic global optical potential for nucleon-nucleus systems in the energy range 50-400 MeV Author(s) Furumoto, Takenori; Tsubakihara, Kohsuke; Ebata, S; Horiuchi, Wataru Citation Physical Review C, 99(3), 034605 https://doi.org/10.1103/PhysRevC.99.034605 Issue Date 2019-03-06 Doc URL http://hdl.handle.net/2115/74949 Rights ©2019 American Physical Society Type article File Information PhysRevC.99.034605-1.pdf

/pdf/microscopic-global-optical-potential-for-nucleon-nucleus-2k4tvaf3yx.pdf

Microscopic global optical potential for nucleon-nucleus systems in the energy range 50-400 MeV

Measurements of the spin dependence of large l, j = l — —, ', transfer reactions at medium energies provide a stringent test of three-body reaction models. We report measurements of the cross section (da/d Q), vector ( A~ ) and tensor ( A» ) analyzing powers, and outgoing proton polarization (p) angular distributions (8, =6.9'-82. 3') for the l= 3, j"= 2 ground-state transition in Zn(d, p) Zn measured with 88.2-MeV deuterons. Adiabatic model calculations fail to describe either interference oscillations in the data or departures from the simple theoretical relationships, 1+3p +23» =0 and 2+ Ayy+3Ay 0, that are expected to hold for a far-side — dominated reaction. The quasiadiabatic model, in which the center-of-mass energy in breakup configurations is not constrained to be degenerate with the elastic channel, is able to reproduce qualitatively these features of the data.

Enhancement of the near-side component in quasiadiabatic calculations of the zn-66(d,p)zn-67 reaction

The analyzing power ${\mathit{A}}_{\mathit{y}}$ for proton elastic scattering on $^{12}\mathrm{C}$ has been precisely and absolutely determined at three scattering angles (${\mathrm{\ensuremath{\theta}}}_{\mathrm{lab}}$=16.3\ifmmode^\circ\else\textdegree\fi{}, 17.3\ifmmode^\circ\else\textdegree\fi{}, and 18.3\ifmmode^\circ\else\textdegree\fi{}) at an incident proton energy of 188.9 MeV. The technique employed requires statistically high quality polarization transfer measurements, combined with the constraints imposed on polarization observables for reactions with the spin structure 1/2+0\ensuremath{\rightarrow}1/2+0. These results represent some of the most accurately known spin observables at intermediate energies and serve as calibration points for secondary standards.

Determination of analyzing powers for 189 MeV proton elastic scattering on 12C.

Differential cross sections and analyzing powers for/sup 15/N(/ital d/rvec //,/ital t/)/sup 14/N were measured up to 25MeV excitation energy with 88 and 89 MeV polarized deuteron beams and magneticspectrographs. States of /sup 14/N up to 18.53 MeV have been studiedin two experiments with overall resolutions of 25--70 keV, and /ital j/transfers were determined from their characteristic analyzing powers. Mixturesof different /ital j/ transfers could be determined for those 1/sup +/states where mixing was significant. Exact finite-range distorted-wave Bornapproximations calculations were used to deduce /ital l/ transfers andspectroscopic strengths. The observed summed spectroscopic strength is 88% ofthe shell-model sum rule. Firm lower limits and tentative upper limits for six(/ital p//sub 1/2/p/sub 1/2/)/sub J,/ital T// and(/ital p//sub 3/2/p/sub 1/2/)/sub J,/ital T// residual two-nucleonmatrix elements are deduced. Comparison with the widely used Cohen-Kurathmatrix elements shows good agreement for four terms, but significantquantitative disagreement for the(/ital p//sub 1/2/p/sub 1/2/)/sub 0/sup +/,1/ and(/ital p//sub 1/2/p/sub 3/2/)/sub 1/sup +/,1/ terms.We also see significantly more than the predicted/ital p//sub 1/2/p/sub 3/2/ mixing for the 3.948 MeV1/sup +/,0 state. No appreciable pickup of /ital s/-/ital d/shell admixtures was seen up to 25 MeV excitation.

/sup 15/N(/ital d/rvec //,/ital t/)/sup 14/N at 89 MeV, /ital j/ dependence and /ital p/-shell matrix elements

Measurements using 200 MeV protons, of the spin-flip probability parameter {ital S}{sub {ital N}{ital N}{prime}} have been made on {sup 208}Pb covering an excitation energy range of 2 to 24 MeV for momentum transfers from 0.45 to 0.84 fm{sup {minus}1}. These data have been compared to calculations that use random-phase-approximation wave functions in an impulse approximation model. Distortions are shown to have a large effect in the calculation of {ital S}{sub {ital N}{ital N}{prime}}. The calculations describe the data well and suggest that natural parity transitions contribute significantly to the spin-flip response. A broad structure is observed near 7 MeV; calculations suggest that this structure is composed of a superposition of a number of spins and parities.

P. Li

Papers

Enhancement of the near-side component in quasiadiabatic calculations of the zn-66(d,p)zn-67 reaction

Determination of analyzing powers for 189 MeV proton elastic scattering on 12C.

/sup 15/N(/ital d/rvec //,/ital t/)/sup 14/N at 89 MeV, /ital j/ dependence and /ital p/-shell matrix elements

Spin-flip probabilities in Pb208 measured with 200 MeV protons.