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Development of nuclear models for higher energy calculations

Description: Two nuclear models for higher energy calculations have been developed in the regions of high and low energy transfer, respectively. In the former, a relativistic hybrid-type preequilibrium model is compared with data ranging from 60 to 800 MeV. Also, the GNASH exciton preequilibrium-model code with higher energy improvements is compared with data at 200 and 318 MeV. In the region of low energy transfer, nucleon-nucleus scattering is predominately a direct reaction involving quasi-elastic collis… more
Date: January 1, 1988
Creator: Bozoian, M.; Siciliano, E. R. & Smith, R. D.
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Partner: UNT Libraries Government Documents Department
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Nuclear de-excitation processes following medium energy heavy ion collisions

Description: As heavy ion reaction studies have progressed from beam energies below 10 MeV/nucleon to higher energies, many non-equilibrium reaction phenomena have been observed. Among these are nucleon emission with velocities in excess of the beam velocity, incomplete momentum transfer to evaporation residue and fission-like fragments, ..gamma..-rays with energies in excess of 100 MeV, and ..pi../sup 0/ production when beam energies are below the threshold for production by the nucleon-nucleon collision m… more
Date: September 1, 1986
Creator: Blann, M.
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Partner: UNT Libraries Government Documents Department
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Production of high energy density in anti N-nucleus interactions

Description: The results of an investigation of anti p- (and to a lesser extent) anti d- nucleus interactions are reported. The technique involves following the classical production and propagation of mesons (..pi..,K/sup +/, K/sup 0/, K/sup -/, K/sup 0/, K*, eta, ..omega.., phi) and baryons (N,..lambda..,..sigma..) in nuclei after antiparticle annihilation. It is found that small regions of the nucleus can be raised to sufficiently high energy densities that some predictions of a quark-gluon phase transiti… more
Date: January 1, 1986
Creator: Gibbs, W.R.
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Partner: UNT Libraries Government Documents Department
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Pion-induced scattering above the 3,3 resonance

Description: Results of Gluaber model calculations of elastic, inelastic, single- and double-charge exchange reactions from light nuclei of pions having energy of 300 to 1200 MeV are presented. Experimental {pi}N phase shifts including {ell}=0 through 5 were used in the calculation. 25 refs., 6 figs.
Date: January 1, 1991
Creator: Oset, E. (Valencia Univ. (Spain)) & Strottman, D. (Los Alamos National Lab., NM (United States))
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Partner: UNT Libraries Government Documents Department
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Nucleon exchange in damped nuclear reactions

Description: Starting from the general context of one-body nuclear dynamics, the nucleon-exchange mechanism in damped nuclear reactions is discussed. Some of its characteristic effects on various dinuclear observables are highlighted and a few recent advances are described.
Date: April 1, 1986
Creator: Randrup, J.
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Partner: UNT Libraries Government Documents Department
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Antisymmetrization effects in heavy-ion potentials and their dependence on the nucleon--nucleon interaction

Description: Double-folding heavy-ion potentials are conventionally generated by folding the densities of projectile and target with a nucleon--nucleon interaction. The success of the folding method has recently been explained by Fleckner and Mosel (Nucl. Phys. A277, 170 (1977)) in terms of a cancellation effect between two types of approximations, namely, the effects of neglecting the antisymmetrization between the ions and the polarization of the densities due to the (Coulomb and nuclear) forces between t… more
Date: October 1, 1977
Creator: Schultheis, H. & Schultheis, R.
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Partner: UNT Libraries Government Documents Department
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Inclusive quasielastic and deep inelastic electron scattering at high energies

Description: With high electron energies a kinematic regime can be reached where it will be possible to separate quasielastic and deep inelastic scattering. We present a short description of these processes which dominate the inclusive spectrum. Using the highest momentum transfer data available to guide our estimates, we give the kinematic requirements and the cross sections expected. These results indicate that inclusive scattering at high q has a yet unfilled potential. 18 refs., 13 figs.
Date: January 1, 1990
Creator: Day, D.B.
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Partner: UNT Libraries Government Documents Department
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Overview of polarization in intermediate energy nucleon-nucleus inelastic scattering

Description: The general role that polarization transfer (PT) can play in the ''dissection'' of medium-energy N-nucleus inelastic reactions is reviewed, specifically concentrating on the importance of complete sets of PT observables for the study of nuclear structure. The discussion is largely in the context of plane-wave impulse approximations, with the effects of distortions considered through comparisons between simple plane-wave predictions and DWIA computations. 31 refs., 11 figs. (LEW)
Date: January 1, 1985
Creator: Carey, T.
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Partner: UNT Libraries Government Documents Department
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Classical-limit S-matrix for heavy ion scattering. [S matrix]

Description: An integral representation for the classical limit of the quantum mechanical S-matrix is developed and applied to heavy-ion Coulomb excitation and Coulomb-nuclear interference. The method combines the quantum principle of superposition with exact classical dynamics to describe the projectile-target system. A detailed consideration of the classical trajectories and of the dimensionless parameters that characterize the system is carried out. The results are compared, where possible, to exact quan… more
Date: January 1, 1977
Creator: Donangelo, R.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Nucleon Radiative Capture and the Inverse Reaction at Intermediate Energies

Description: The processes which can lead to the radiative capture of fast nucleons include direct transitions in the nuclear potential, transitions in which coherent multipole resonances are excited, transitions by nucleons which are excited in early intranuclear collisions, bremsstrahlung from nucleon-nucleon collisions and photon evaporation'' from a thermally equilibrated nucleus. Corresponding processes occur when an energetic photon ejects fast nucleons from a nucleus. As experimental information from… more
Date: January 1, 1991
Creator: Halpern, I.
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Partner: UNT Libraries Government Documents Department
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Coupled channels calculations of heavy-ion reactions near the Coulomb barrier

Description: A coupled channel treatment of the reaction /sup 58/Ni /plus/ /sup 64/Ni is presented. Angular distributions for ''inclusive elastic'' scattering and fusion cross sections are calculated using extended calculations which include the couplings to 1n and 2n transfer channels in a way which is consistent with a higher order vibrational model. 9 refs., 2 figs. (DWL)
Date: January 1, 1988
Creator: Esbensen, H.
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Partner: UNT Libraries Government Documents Department
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Effect of the nuclear equation of state on high-energy heavy-ion collisions

Description: The effect of the nuclear equation of state on high-energy heavy-ion collisions is studied in two separate ways on the basis of conventional nuclear fluid dynamics. The equation of state has the property that the speed of sound approaches the speed of light in the limit of infinite compression. In the first way, nonrelativistic equations of motion are solved for various values of the nuclear compressibility coefficient for the expansion of spherically symmetric nuclear matter. The matter is ini… more
Date: January 1, 1980
Creator: Nix, J. R.; Sierk, A. J. & Strottman, D.
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Partner: UNT Libraries Government Documents Department
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Meson-exchange calculation of the d(. gamma. ,p)n reaction in the GeV energy region

Description: We show that a meson-exchange model of the d({gamma},p) reaction can be constructed to reproduce the energy-dependence of the existing data for the differential cross section at 90{degree}. The prediction of the model in the GeV energy region is found to be radically different from the QCD prediction by Brodsky and Hiller. The results will be compared with the new data presented in a companion paper. 12 refs., 4 figs.
Date: January 1, 1991
Creator: Lee, T. S. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Nuclear momentum distribution and relativistic heavy-ion reactions

Description: In terms of a direction fragmentation process and a hard-scattering process, the proton-inclusive data for the reaction ..cap alpha.. + /sup 12/C ..-->.. p + X were successfully analyzed. The extracted semiempirical momentum distribution indicates possible evidence of nuclear correlations and final-state interactions. 4 figures.
Date: January 1, 1980
Creator: Wong, C.Y. & Blankenbecler, R.
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Partner: UNT Libraries Government Documents Department
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Heavy ion excitation of giant resonances: The next generation

Description: The prospects for high energy heavy ion excitation of giant resonances are discussed. A brief review is provided of the results obtained to date using low/medium energy heavy ions and it is suggested that those results show no substantial advantage of heavy ions for giant resonance excitation. Calculations are presented that show that Coulomb excitation becomes the dominant excitation mechanism of the giant resonances for heavy ions above about 100 MeV/nucleon. The Coulomb excitation provides e… more
Date: January 1, 1987
Creator: Bertrand, F.E.; Beene, J.R. & Horen, D.J.
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Partner: UNT Libraries Government Documents Department
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Scaling phenomenon in relativistic nucleus-nucleus collisions

Description: New scaling variables for proton and pion production in relativistic nucleus-nucleus collisions are introduced which are the generalizations of the Feynmann scaling variable. They allow a simple description of the cross sections at forward and backward angles. 2 figures.
Date: January 1, 1980
Creator: Wong, C.Y. & Blankenbecler, R.
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Partner: UNT Libraries Government Documents Department
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Investigation of the intermediate-energy deuteron breakup reaction

Description: The Udagawa-Tamura formalism is employed to calculate the proton singles both in the bound and unbound regions. Both the Elastic-Breakup (EB) and the Breakup-Fusion (BF) processes are considered to calculate the doubly-differential cross section for light and intermediate mass nuclei. The calculated spectra for 25 and 56 MeV deuterons reproduce the experimental spectra very well except for the spectra at large angle and at low energies, of the outgoing particle. Contributions due to precompound… more
Date: January 1, 1989
Creator: Divadeenam, M.; Ward, T.E.; Mustafa, M.G.; Udagawa, T. & Tamura, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Polarizability of nuclear wave functions in heavy ion reactions. [/sup 208/Pb(/sup 12/C,/sup 11/B)/sup 209/Be, 78 MeV]

Description: Evidence is presented for the polarizability of nuclear wave functions in heavy-ion transfer reactions. The polarization of the wave function of the transferred nucleon is largest for weakly bound nucleons, depends on the bombarding energy (being largest for low-energy (slow) collisions) and produces a shift toward forward angle. Results of an adiabatic estimate employing two-center-shell-model wave functions in a DWBA amplitude are presented. A dynamical theory is sketched which involves a sup… more
Date: August 1, 1977
Creator: Charlton, L.A.; Delic, G.; Glendenning, N.K. & Pruess, K.
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Partner: UNT Libraries Government Documents Department
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Charge exchange probes of nuclear structure and interactions with emphasis on (p,n)

Description: New results from (p,n) studies at IUCF show that it is possible to observe Gamow-Teller (GT) strength and extract GT matrix elements from (p,n) measurements. The charge exchange reactions (/sup 6/Li,/sup 6/He) and (..pi../sup +/,..pi../sup 0/) involve different projectile quantum numbers, and the relationships of these reactions to (p,n) is discussed.
Date: January 1, 1980
Creator: Goodman, C. D.
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Partner: UNT Libraries Government Documents Department
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Surface response model for quasielastic scattering

Description: The description of nucleon-nucleus inelastic scattering in terms of single-scattering has been very successful at intermediate energies. Nuclear structure is the most dominant feature at low excitations and forward scattering, and the Distorted Wave Impulse Approximation (DWIA) has been the most useful technique to extract structure information. The conventional DWIA has also been applied to quasielastic scattering. However, this method is very time-consuming at large scattering angles, since m… more
Date: January 1, 1987
Creator: Esbensen, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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