On high-energy elastic scattering of protons by nuclei (original) (raw)
Related papers
Multiple scattering effects in proton nucleus elastic scattering at intermediate energies
Physical Review C, 1991
The second-order corrections to the Kerman-McManus-Thaler optical potential for the elastic scattering of protons from ' 0 are calculated at l35, 200, and 300 MeV incident energies, paying particular attention to the nonlocalities inherent in the potential. It is shown that these effects result in a significant reduction in the proton-target absorption. Recent detailed investigations of nucleon-nucleon (NN) transition amplitudes calculated from realistic interactions [1] have shown their onand off-shell behavior to be remarkably stable to the choice of interaction [2]. This, combined with more detailed information on nuclear wave functions now available from electron-scattering data, has stimulated a renewed interest in finite nucleus calculations of the nucleon-nucleus interaction based on the free NN transition amplitude and multiple-scattering expansions as formulated, for example, by Kerman, McManus, and Thaler (KMT) [3]. For nucleon-nucleus (NA) scattering at intermediate energies, calculations based on the KMT formalism are thus expected to be relatively insensitive to the assumed NN interaction. This is certainly not the case in the evaluation of medium eff'ects, both at low and intermediate energies, using the nuclear matter G-matrix approach [4]. Such approaches also use the local-density approximation in applying the nuclear matter results to finite nuclei, an approximation which is suspect [5].
Le Journal de Physique Colloques
Les observables de spin et la section efficace de diffusion 6lastique p + 4 0~a sont calculees dans un modsle de convolution compl&te utilisant les matrices t de l'interaction NN libre bas6es sur les potentiels de Paris et de Bonn. Les deux familles de calculs sont compar6es entre elles et aux donnEtes B 200 MeV ainsi qu'au mod6le t.rho plus conventionnel. Les calculs en convolution compl6te reproduisent beaucoup mieux les donn6es et montrent qu'A cette 6nergie un bon traitement des effets hors couche est plus important que le choix entre les d e w potentiels NN consid6r6s.
High-energy scattering of protons by nuclei
Nuclear Physics B, 1970
The theory of high-energy hadron-nucleus collisions is discussed by means of the multiple-diffraction theory. Effects of the Coulomb field are accounted for in elastic scattering by light and heavy nuclei. Inelastic scattering is treated by means of the shadowed single collision approximation at small momentum transfer and the corresponding multiple collision expansion at large momentum transfers. The theory is compared with the measurements of Bellettini et al. on proton-nucleus scattering at 20 GeV/c by finding density distributions for the nuclei which provide least-squares fits to the data. The nucleon densities found are closely comparable in dimensions to the known charge densities. The predicted sums of the angular distributions of elastic and inelastic scattering reproduce the experimental angular distributions fairly closely. × j [l+~tj(b,b')]-i d2bd2b ' .
Coupling effects in the elastic scattering of the exotic nucleus 6He on protons
Physics Letters B, 2001
Cross sections for the elastic scattering of 6 He radioactive nuclear beam on proton targets have been measured at 38.3 MeV/nucleon. With a view to test the ability of general optical potentials to reproduce the data for scattering of unstable nuclei, the present results, as well as other existing data for 6,8 He, have been analyzed within the framework of the microscopic Jeukenne-Lejeune-Mahaux nucleon-nucleus potential. The angular distributions were found to be best reproduced by reducing the real part of the optical potential. This renormalization can be seen as a consequence of the complex polarization potential produced by the coupling to the continuum due to the weakly bound nature of the unstable nuclei. This effect can be simulated in a phenomenological analysis by a surface potential. 2001 Published by Elsevier Science B.V.
Application of multiple scattering theory to lower-energy elastic nucleon-nucleus scattering
Physical Review C, 1995
The optical model potentials for nucleon-nucleus elastic scattering at 65 MeV are calculated for 12 C, 16 O, 28 Si, 40 Ca, 56 Fe, 90 Zr and 208 Pb in first order multiple scattering theory, following the prescription of the spectator expansion, where the only inputs are the free NN potentials, the nuclear densities and the nuclear mean field as derived from microscopic nuclear structure calculations. These potentials are used to predict differential cross sections, analyzing powers and spin rotation functions for neutron and proton scattering at 65 MeV projectile energy and compared with available experimental data. The theoretical curves are in surprisingly good agreement with the data. The modification of the propagator due to the coupling of the struck nucleon to the residual nucleus is seen to be significant at this energy and invariably improves the congruence of theoretical prediction and measurement.
Spin observables in quasi-elastic proton-nucleus scattering near 1 GeV
Physical Review C, 1985
The spin dependence of quasi-elastic proton-nucleus scattering is studied using Glauber s eikonal multiple scattering theory, which is extended to include multiple knockout collisions as well as the full spin dependence of the NN amplitudes. Calculations of the cross section d'or/dQdp and spin observables DAN, DLL, DSS, DSL, DLS, Ay are presented and compared to data for d o/dQdp and Ay from inclusive (p, p'} experiments on ' C at Tl,b-800 MeV. The main feature seen is a drop in the spin observables in the kinematic region where two nucleon knockout dominates the cross section. As an initial study of the contribution of quasi-free 6 production to the inclusive cross section, multiple-scattering theory is used to normalize a plane-wave impulse approximation calculation of d o. /dQdp for p+ ' C~p+m+' C .
Proton- He3 elastic scattering at intermediate energies
Physical Review C, 2021
We present a precise measurement of the cross section, proton and 3 He analyzing powers, and spin correlation coefficient C y,y for p-3 He elastic scattering near 65 MeV, and a comparison with rigorous four-nucleon scattering calculations based on realistic nuclear potentials and a model with ∆-isobar excitation. Clear discrepancies are seen in some of the measured observables in the regime around the cross section minimum. Theoretical predictions using scaling relations between the calculated cross section and the 3 He binding energy are not successful in reproducing the data. Large sensitivity to the N N potentials and rather small ∆-isobar effects in the calculated cross section are noticed as different features from those in the deuteron-proton elastic scattering. The results obtained above indicate that p-3 He scattering at intermediate energies is an excellent tool to explore nuclear interactions not accessible by three-nucleon scattering.
Microscopic model analyses of the elastic scattering of 65 MeV protons from targets of diverse mass
Physical Review C, 1998
Nonlocal coordinate space optical potentials for the scattering of 65 MeV protons from nuclei ranging in mass from 6 Li to 238 U have been defined by folding a complex, medium dependent effective interaction with the density matrix elements of each target. The effective interaction is based upon solutions of the Lippmann-Schwinger and Brueckner-Bethe-Goldstone equations having the Paris potential as input. The nuclear structure information required in our folding model are the one body density matrix elements for the target and the single nucleon bound state wave functions that they weight. For light mass nuclei, very large basis shell model calculations have been made to obtain the one body density matrix elements. For medium and heavy mass nuclei, a very simple shell model prescription has been used. The bound state single particle wave functions that complete the nuclear density matrices are either Woods-Saxon or harmonic oscillator functions. The former are employed in most cases when large basis structure is available. For light nuclei (A ≤ 16) Woods-Saxon potential parameters and harmonic oscillator lengths are determined from fits to electron scattering form factors. For all other nuclei, we use harmonic oscillator functions with the oscillator lengths set from an A 1/6 mass law. Using this microscopic model, optical potentials result from which differential cross sections, analyzing powers and spin rotations are found. In general the calculated results compare very well with data when the effective interactions are determined from a mapping of nucleon-nucleon g matrices. This is not the case when effective interactions built from a mapping of (free) t matrices are used.