Recent Articles

Interaction of neutrons with even- $A$ tin isotopes. I. Total cross sections for $E_{n} = 0.3 - 5.0$ MeV

R. W. Harper, T. W. Godfrey, and J. L. Weil

Phys. Rev. C 26, 1432 (1982) - Published 1 October, 1982

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The neutron total cross sections of ${}^{116, 118, 120, 122, 124}{Sn}$ have been measured in the energy range $E_{n} = 0.3 - 5.0$ MeV with an energy resolution ranging from 100 keV at 0.3 MeV to 30 keV at 5 MeV. The measurements were made in good geometry using the time-of-flight method to reduce background effects, and the uncertainty in the cross sections ranges from 1.0% at low energy to 2.4% above 4 MeV. Unresolved fine structure can be seen in the cross sections of some of the isotopes below 1 MeV. Ignoring this fine structure, all the measured cross sections agree within 5% up to 2 MeV and 10% over the whole energy range with the cross section calculated from a complex potential whose real and imaginary well depths have the usual linear energy dependence, and also a neutron excess dependence. This potential was originally determined to fit the elastic scattering differential cross sections of these isotopes at a bombarding energy of 1 MeV.

NUCLEAR REACTIONS ${}^{116, 118, 120, 122, 124}{Sn}$ + $n$ , $E_{n} = 0.3 - 5.0$ MeV; measured transmission, deduced $σ_{T}$ , compared $σ_{T}$ with optical model. Isotopically enriched samples, resolution 30-100 keV, neutron time of flight.

Analyzing powers for proton inelastic scattering to unnatural-parity states in ${}^{40}{Ca}$ and ${}^{28}{Si}$

K. Hosono, N. Matsuoka, K. Hatanaka, T. Saito, T. Noro, M. Kondo, S. Kato, K. Okada, K. Ogino, and Y. Kadota

Phys. Rev. C 26, 1440 (1982) - Published 1 October, 1982

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Cross sections and analyzing powers in proton inelastic scattering leading to unnatural parity states of $2^{-}$ , $T = 0$ (6.025 and 6.75 MeV), $2^{-}$ , $T = 1$ (8.42 MeV) in ${}^{40}{Ca}$ and $6^{-}$ , $T = 0$ (11.58 MeV) and $6^{-}$ , $T = 1$ (14.36 MeV) in ${}^{28}{Si}$ were measured at 65 MeV. These states are pair states of different isospin with the same spin and parity. The analyzing powers for a pair of $T = 0$ and $T = 1$ excitations in ${}^{40}{Ca}$ show an isospin dependence not observed in ${}^{28}{Si}$ . The measured angular distributions were compared with microscopic distorted-wave Born approximation calculations using two versions of the effective nucleon-nucleon interaction. As expected, the interaction emphasizing the tensor contribution predicts analyzing powers and cross sections in better agreement with the experimental data. As factors to produce a difference in the analyzing powers between the $T = 0$ and the $T = 1$ states, the effect of two transferred orbital angular momentum amplitudes allowed in a transition and the energy dependence of the isoscalar spin-dependent terms in the effective interaction are discussed.

NUCLEAR REACTIONS ${}^{40}{Ca} (\vec{p}, p^{'}) {}^{40}{Ca}$ , ${}^{28}{Si} (\vec{p}, p^{'}) {}^{28}{Si}$ , ${}^{24}{Mg} (\vec{p}, p^{'}) {}^{24}{Mg}$ , $E = 65$ MeV, unnatural parity states of $E_{x} = 6 - 15$ MeV, measured $σ (θ)$ , analyzing power $A_{y} (θ)$ , resolution ∼35 keV, DWBA analysis.

Level structure of ${}^{97}{Tc}$ investigated via the ${}^{97}{Mo} (p, n γ)$ reaction

G. Kajrys, S. Landsberger, R. Lecomte, P. Paradis, and S. Monaro

Phys. Rev. C 26, 1451 (1982) - Published 1 October, 1982

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The level structure of ${}^{97}{Tc}$ up to 2700 keV excitation has been studied via measurements of gamma ray yields and via $n - γ$ and $γ - γ$ coincidence experiments following the ${}^{97}{Mo} (p, n γ)$ reaction with proton energies between 2.0 and 5.2 MeV. From these experiments a decay scheme of ${}^{97}{Tc}$ which includes 78 levels has been obtained. Angular distribution measurements of gamma rays deexciting and exciting these levels provided reliable multipole mixing ratios and $J^{π}$ assignments for several transitions and states.

NUCLEAR REACTIONS ${}^{97}{Mo} (p, n γ) {}^{97}{Tc}$ , $E = 2.0 - 5.2$ MeV; measured $E_{γ}$ , $n - γ$ , $γ - γ$ coincidences, $γ$ -ray angular distributions; ${}^{97}{Tc}$ deduced levels, $J^{π}$ ; enriched targets, Ge(Li) detectors.

High spin states and band structure in ${}^{97}{Tc}$

G. Kajrys, M. Irshad, S. Landsberger, R. Lecomte, Paul Paradis, and S. Monaro

Phys. Rev. C 26, 1462 (1982) - Published 1 October, 1982

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High spin states in ${}^{97}{Tc}$ have been populated via the ${}^{94}{Zr} ({}^{6}{Li}, 3 n γ)$ reaction. $γ - γ$ coincidence techniques have been used to determine the level scheme while excitation functions and angular distribution measurements have been used to assign spin values and to determine some multipole mixing ratios. The results are compared to recent particle-core coupling calculations.

NUCLEAR REACTIONS ${}^{94}{Zr} ({}^{6}{Li}, 3 n) {}^{97}{Tc}$ , $E = 18 - 30$ MeV; measured $E_{γ}$ , $n - γ$ , $γ - γ$ coincidences, $γ$ -ray angular distributions; ${}^{97}{Tc}$ deduced levels, $J^{π}$ ; enriched targets, Ge(Li) detectors.

Saturation analysis as a test of statistical fission in heavy ion reactions

M. Blann, D. Akers, T. A. Komoto, F. S. Dietrich, L. F. Hansen, J. G. Woodworth, W. Scobel, J. Bisplinghoff, B. Sikora, F. Plasil, and R. L. Ferguson

Phys. Rev. C 26, 1471 (1982) - Published 1 October, 1982

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Evaporation residue and binary (fissionlike) cross sections are reported for ${}^{56}{Fe}$ + ${}^{120, 122}{Sn}$ at incident ${}^{56}{Fe}$ energies between 330 and 456 MeV. The $σ_{ER}$ are compared with results for the two additional entrance channels ${}^{35}{Cl}$ + ${}^{141}\Pr$ and ${}^{86}{Kr}$ + ${}^{90}{Zr}$ producing similar compound nuclei. Comparisons of $\frac{σ_{ER}}{π λ^{2}}$ versus excitation energy (which tests the Bohr independence hypothesis) support the conclusion that the yields are limited by statistical fission decay. Similar results are shown for the entrance channels ${}^{84, 86}{Kr}$ + ${}^{65}{Cu}$ and ${}^{40}{Ar}$ + ${}^{109}{Ag}$ . It is shown that evaporation residue data of this type (where yields are limited by saturation in the fission channel) provide a good means of determining statistical fission parameters.

NUCLEAR REACTIONS Illustrate consistency of evaporation residue excitation functions formed in heavy ion reactions with Bohr independence hypothesis; illustrate that statistical parameters deduced should be valid.

Reaction cross sections for ${}^{14}N$ + ${}^{14}N$

P. A. DeYoung, J. J. Kolata, L. J. Satkowiak, and M. A. Xapsos

Phys. Rev. C 26, 1482 (1982) - Published 1 October, 1982

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Excitation functions for the yields of eleven residual nuclei from the ${}^{14}N$ + ${}^{14}N$ reaction have been measured over the range $E_{c . m .} = 7 - 25$ MeV in steps of ∼ 250 keV with $γ$ -ray techniques. The magnitude and energy dependence of the excitation functions for the partial yields are very different from those for the ${}^{12}C$ + ${}^{16}O$ system. The total fusion cross section is similar to that from ${}^{12}C$ + ${}^{16}O$ when compared at the same center of mass energy, but appears to saturate at an energy and magnitude which are lower than expected from previous systematics. Small, regular fluctuations can be seen in the fusion cross section at the 1-2% level.

NUCLEAR REACTIONS ${}^{14}N ({}^{14}N, x)$ ; $E_{c . m .} = 7 - 25$ MeV; measured excitation functions for production of $A = 16 - 27$ reaction products, observed small structures at $E_{c . m .} = 15.0, 17.1, 18.5, 20.4, and 22.0$ MeV; deduced critical angular momentum for fusion.

${}^{14}N$ + ${}^{13}C$ fusion cross sections and compound nucleus limitation in ${}^{27}{Al}$

D. E. DiGregorio, J. Gomez del Campo, Y. D. Chan, J. L. C. Ford, Jr., D. Shapira, and M. E. Ortiz

Phys. Rev. C 26, 1490 (1982) - Published 1 October, 1982

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Fusion cross sections for the ${}^{14}N$ + ${}^{13}C$ system have been measured by detecting the evaporation residues at five bombarding energies which correspond to high excitation energies in the compound nucleus: $E^{*} ({}^{27}{Al}) = 64 - 110$ MeV. The ${}^{27}{Al}$ nucleus can be populated by four different heavy-ion entrance channels— ${}^{15}N$ + ${}^{12}C$ , ${}^{16}O$ + ${}^{11}B$ , ${}^{14}N$ + ${}^{13}C$ , and ${}^{17}O$ + ${}^{10}B$ —which are accessible to experimental measurements. Comparing the present data with those already existing for the above channels, it is found that for $E^{*} > 60$ MeV the curves $E^{*}$ vs $J_{cr}$ for each system converge, which may be indicative of a limitation imposed by the compound nucleus. The data are discussed in terms of existing models for entrance channel and statistical yrast line limitations. The highest energy point also suggests the existence of a maximum absolute angular momentum limit of $\sim 28 ℏ$ .

NUCLEAR REACTIONS ${}^{14}N$ + ${}^{13}C$ $E ({}^{14}N) = 86.0, 103.8, 149.0, 161.3, and 180.0$ MeV; measured $\frac{d^{2} σ}{d Ω dE}$ for reaction products from $Z = 5 to 12$ . Extracted $σ_{fus}$ , $σ_{D}$ , $σ_{R}$ .

Mean-field effects in intermediate-energy, heavy-ion reactions

Cheuk-Yin Wong and K. T. R. Davies

Phys. Rev. C 26, 1502 (1982) - Published 1 October, 1982

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Mean-field effects in intermediate energy heavy-ion collisions are studied for ${}^{16}O$ + ${}^{40}{Ca}$ and ${}^{40}{Ca}$ + ${}^{40}{Ca}$ . At such energies, compression of nuclear matter occurs. The compressed matter produces a repulsive potential ("volcano") which acts as a divergent lens with respect to the nucleon trajectories. In consequence, one or both of the colliding nuclei may be completely disintegrated into a gas whose velocity is slightly less than the beam velocity. Theoretical signatures for the mean-field behavior of these events are presented.

NUCLEAR REACTIONS Time-dependent Hartree-Fock approximation. Heavy-ion collisions of ${}^{16}O$ + ${}^{40}{Ca}$ at 100 MeV/nucleon and 250 MeV/nucleon and ${}^{40}{Ca}$ + ${}^{40}{Ca}$ at 100 MeV/nucleon. Mean-field effects in heavy-ion collisions at intermediate energies.

One-step and two-step contributions to two-nucleon transfer reactions

B. F. Bayman and Jongsheng Chen

Phys. Rev. C 26, 1509 (1982) - Published 1 October, 1982

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Qualitative arguments are given to show that although first-order distorted-wave Born approximation calculations are adequate for the treatment of single-nucleon transfer reactions, there is little reason to trust them for two-nucleon or multinucleon transfer reactions. A first-plus-second Born approximation calculation is presented for the ${}^{208}{Pb}$ ( ${}^{16}O$ , ${}^{18}O$ ) ${}^{206}{Pb}$ ground state transition, at bombarding energies below and slightly above the Coulomb barrier. It is found that successive transfer (two-step) processes account for almost all the observed cross section.

NUCLEAR REACTIONS Theory of one- and two-step contributions to ${}^{208}{Pb}$ ( ${}^{16}O$ , ${}^{18}O$ ) ${}^{206}{Pb}$ .

Shock waves in relativistic nuclear matter. II. Angular anisotropy in multiparticle spectra

A. M. Gleeson and S. Raha

Phys. Rev. C 26, 1521 (1982) - Published 1 October, 1982

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We look at the finite size effects in relativistic heavy ion collision phenomena. The surface effects and a realistic analysis of the hydrodynamic expansion of the nuclear fireball, when incorporated together, produce excellent, parameter free fits to experimental data. Several implications and possible modifications are also discussed.

NUCLEAR REACTIONS Relativistic heavy ion, hydrodynamic, angular distributions.

Unusually low fragment energies in the symmetric fission of ${}^{259}{Md}$

J. F. Wild, E. K. Hulet, R. W. Lougheed, P. A. Baisden, J. H. Landrum, R. J. Dougan, and M. G. Mustafa

Phys. Rev. C 26, 1531 (1982) - Published 1 October, 1982

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The 103-min isotope ${}^{259}{Md}$ has been identified as the daughter of an electron-capture decay branch of ${}^{259}{No}$ produced via the ${}^{248}{Cm} ({}^{18}O, α 3 n)$ reaction. Chemical separations were used to confirm the identity of ${}^{259}{Md}$ , which decays by spontaneous fission. The kinetic energies of coincident fission fragments were measured, corresponding to a fragment mass which is highly symmetric, similar to those of ${}^{258}{Fm}$ and ${}^{259}{Fm}$ . However, the total kinetic energy distribution for ${}^{259}{Md}$ is considerably broader (FWHM ∼60 MeV) than those of ${}^{258}{Fm}$ and ${}^{259}{Fm}$ , and peaks at 201 MeV, about 35-40 MeV lower in energy. Furthermore, the maximum total kinetic energy of 215 MeV for mass-symmetric events is about 30 MeV lower than for similar events from the spontaneous fission of ${}^{258}{Fm}$ and ${}^{259}{Fm}$ . A hypothesis that this energy difference resulted from the emission of light, hydrogen-like particles at scission in a large fraction of ${}^{259}{Md}$ spontaneous fission decays was shown to be unfounded. From experiments to observe such particles with counter telescopes, an upper limit of 5% was determined for the fraction of fission events accompanied by light-particle emission. The total kinetic energy deficit at mass symmetry must, therefore, be distributed between internal excitation energy and fragment deformation energy at scission. Although the presence of a large amount of fragment deformation energy seems incompatible with symmetric fission into spherical Sn-like fragments, we prefer this explanation because the low total kinetic energy suggests a lowered Coulomb energy resulting from greater separation of the charge centers of deformed fragments at scission.

RADIOACTIVITY, FISSION ${}^{259}{Md}$ (SF); measured $T_{\frac{1}{2}}$ , fragment-fragment coin, deduced mass, TKE distributions. ${}^{259}{No}$ ; measured EC decay to ${}^{259}{Md}$ , upper limit to SF decay.

Reactions ${}^{12}C (π^{\pm}, π^{\pm} d) {}^{10}B$ and ${}^{12}C (π^{\pm}, π^{\pm} t) {}^{9}B$

R. J. Ellis, H. J. Ziock, K. O. H. Ziock, Y. Tzeng, J. Arvieux, R. Corfu, J. Piffaretti, L. C. Liu, and E. R. Siciliano

Phys. Rev. C 26, 1544 (1982) - Published 1 October, 1982

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We have measured the angular and momentum distributions of the scattered pions from the reaction ${}^{12}C (π^{+}, π^{+} d) {}^{10}B$ in a coincidence experiment. We compare our results with two theoretical models based on the impulse approximation. We also present some data on the reactions ${}^{12}C (π^{\pm}, π^{\pm} t) {}^{9}B$ .

NUCLEAR REACTIONS ${}^{12}C (π^{\pm}, π^{\pm} d) {}^{10}B$ , ${}^{12}C (π^{\pm}, π^{\pm} t) {}^{9}B$ , $E_{π} = 130, 150$ MeV; measured $σ (p)$ , $σ (θ)$ , compared with PWIA.

Local density approximation for the relativistic nucleon-nucleus potential

M. Jaminon

Phys. Rev. C 26, 1551 (1982) - Published 1 October, 1982

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We investigate the relativistic Hartree-Fock single-particle potential in the framework of a local density approximation and of an improved local density approximation. In most cases the latter yields a better agreement between theoretical and experimental results for quantities which are characteristic of the nuclear surface. In the case of ${}^{40}{Ca}$ , the energy dependence of the ratio of the strengths of the scalar and vector components of the relativistic potential in the center-of-mass system is in good agreement with that determined by the elastic scattering data analyses. In keeping with recent experimental evidence, the calculated central part of the optical-model potential has a wine-bottle bottom shape at intermediate energy. Both approximations provide a strong spin-orbit component.

NUCLEAR REACTIONS Improved local density approximation for the relativistic Hartree-Fock single-particle potential in ${}^{40}{Ca}$ .

Single particle intranuclear "cascade" and pion production

David G. Long and Morton M. Sternheim

Phys. Rev. C 26, 1558 (1982) - Published 1 October, 1982

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A single particle intranuclear cascade code has been developed to determine the importance of multiple scattering, various nuclear medium corrections, and pion absorption inputs in medium energy nuclear physics. Reasonable agreement with experimental data for pion production by 740 MeV protons is obtained with all the input parameters taken from experimental free two-body data. Through a detailed study of the pions produced in Pb, it is determined that most of the pions (∼ 85%) which exit the nucleus have scattered at most once, and that the results are very sensitive to the nuclear density and the pion absorption models used.

NUCLEAR REACTIONS New cascade model; compared to $π$ production data. Relative importance of pion absorption model inputs, multiple scattering, nuclear medium corrections studied.

Yields of two-nucleon-out residual products from stopped $π^{-}$ reactions

C. J. Orth, B. J. Dropesky, G. C. Giesler, L. -C. Liu, R. S. Rundberg, and V. L. Rundberg

Phys. Rev. C 26, 1571 (1982) - Published 1 October, 1982

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Yields of two-nucleon-out products from stopped $π^{-}$ reactions in ${}^{26}{Mg}$ , ${}^{74}{Ge}$ , ${}^{97}{Mo}$ , ${}^{114}{Cd}$ , ${}^{142}{Ce}$ , and ${}^{174}{Yb}$ have been measured by activation techniques. These products result predominantly from pion absorption at the nuclear surface when the absorbing pair of nucleons escapes the nucleus leaving behind very little excitation energy (≲8 MeV). The ratios of the yields of the $nn$ -out to the $np$ -out products following stopped $π^{-}$ absorption increase monotonically from 6.8 for ${}^{26}{Mg}$ to 18.2 for ${}^{174}{Yb}$ . The data have been fitted using a pion absorption model that uses separate density distributions for neutrons and protons, and a three to five percent greater root-mean-square radius for neutrons is indicated.

NUCLEAR REACTIONS Stopped $π^{-}$ reactions in enriched targets of ${}^{26}{Mg}$ , ${}^{74}{Ge}$ , ${}^{97}{Mo}$ , ${}^{114}{Cd}$ , ${}^{142}{Ce}$ , and ${}^{174}{Yb}$ . Measured yields of $Δ A = 2$ products by activation. Compared results with calculations.

Distortion effects in ( $π, π p$ ) quasifree knockout reactions

L. Rees, N. S. Chant, and P. G. Roos

Phys. Rev. C 26, 1580 (1982) - Published 1 October, 1982

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Distorted wave impulse approximation calculations for the ( $π, π p$ ) quasifree knockout reaction on ${}^{16}O$ and ${}^{40}{Ca}$ have been carried out for a variety of bombarding energies and angle pairs. In general, the distortion effects arising from the interaction of the pions and protons with the target core are strong and vary with bombarding energy. The results emphasize the need to include these interactions properly in any analysis of experimental data.

NUCLEAR REACTIONS DWIA reaction theory of proton knockout from nuclei ${}^{16}O$ , ${}^{40}{Ca} (π^{+}, π^{+} p)$ , $T_{π} = 100 - 300$ MeV, calculate $σ (θ_{1}, θ_{2}, E_{1})$ .

Inelastic electron scattering from ${}^{3}{He}$ and ${}^{4}{He}$ in the threshold region at high momentum transfer

S. Rock, R. G. Arnold, B. T. Chertok, Z. M. Szalata, D. Day, J. S. McCarthy, F. Martin, B. A. Mecking, I. Sick, and G. Tamas

Phys. Rev. C 26, 1592 (1982) - Published 1 October, 1982

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The cross section for inclusive inelastic electron scattering from the helium isotopes has been measured at momentum transfers squared of $0.8 \leq Q^{2} \leq 5.0$ ${(G e V / c)}^{2}$ for ${}^{3}{He}$ and $0.8 \leq Q^{2} \leq 2.4$ ${(G e V / c)}^{2}$ for ${}^{4}{He}$ . The data were taken at 8° and cover the range $0.6 < x < 1$ , where $x = \frac{Q^{2}}{2 M_{He} ν}$ , which includes the elastic peak, nuclear breakup threshold, the high momentum tail of the quasielastic scattering, and pion production. The structure function, $ν W_{2}$ , derived from the data, is approaching a scaling limit at high $Q^{2}$ . It can be factored into a product of functions of $Q^{2}$ and of $x$ as predicted by some models.

NUCLEAR REACTIONS ${}^{3}{He}$ , ${}^{4}{He} (e, e^{'}) X$ ; $E = 6.4 - 16.5$ GeV; $θ_{e} = 8 °$ ; measured $\frac{d σ}{d Ω d E^{'}}$ ; deduced $ν W_{2}$ at threshold.

Electroproduction of $π^{+}$ from ${}^{10}B$ and its relation to electron scattering

B. W. Zulkoskey, R. M. Sealock, H. S. Caplan, and J. C. Bergstrom

Phys. Rev. C 26, 1610 (1982) - Published 1 October, 1982

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The electroproduction of 12.3±0.7 MeV positive pions from ${}^{10}B$ , leading to low-lying states in ${}^{10}{Be}$ , has been measured in the angular range $θ_{π} = 30 ° - 140 °$ for incident electron energies $E_{e} = 158.5 - 165.0$ MeV. The unique character of $M 3$ transitions in the $p$ shell permits a direct comparison of $\frac{d^{2} σ}{d E_{π} d Ω_{π}}$ with the analog electron scattering form factors in ${}^{10}B$ , assuming the strong $π$ -nucleus interaction can be neglected. For the two lowest $T = 1$ states, the ( $e, π^{+}$ ) angular distributions agree with the $M 3$ form factors. The convective term in the $M 1$ form factor for the third $T = 1$ state is deduced from a comparison of the ( $e, π^{+}$ ) and ( $e, e^{'}$ ) data and is in good agreement with recent radiative pion capture results. The photoproduction cross section leading to the ${}^{10}{Be}$ ground state is estimated.

NUCLEAR REACTIONS ${}^{10}B (e, π^{+}) e^{'} {}^{10}{Be}$ ; $E_{e} = 158.5 - 165.0$ MeV; $E_{π} = 12.3$ MeV; measured $σ (E_{π}, θ_{π})$ ; $θ_{π} = 30 ° - 140 °$ ; compare to electron scattering, radiative pion capture, and photoproduction.

Intranuclear cascade calculation of pion-nucleus reactions in the resonance region

Z. Fraenkel, E. Piasetzky, and G. Kalbermann

Phys. Rev. C 26, 1618 (1982) - Published 1 October, 1982

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The predictions of the intranuclear cascade model are compared with experimental inclusive pion-nucleus inelastic scattering and absorption cross sections in the $Δ$ -resonance region as a function of bombarding energy and target mass and with the results of recent measurements of ( $π, π p$ ) and ( $π^{+}, 2 p$ ) for ${}^{12}C$ and ${}^{209}{Bi}$ at $E_{lab} = 245$ MeV in which the two outgoing particles were measured in coincidence. The calculations reproduce well the mass dependence of the inclusive cross sections; however, the calculated bombarding energy dependence is flatter for the inelastic cross section and more peaked for the absorption cross section than the experimental energy dependence. The calculations for ${}^{12}C$ were made with two assumptions regarding the momentum distribution of the nucleons in the nucleus: (1) the "usual" local degenerate Fermi gas; (2) a momentum distribution based on an harmonic-oscillator shell model. The angular correlations for ${}^{12}C (π^{+}, π^{+} p)$ and ${}^{12}C (π^{+}, 2 p)$ are shown to provide a sensitive test for the momentum distribution, with the harmonic-oscillator shell model giving better agreement with the experimental results. The calculations show that multiple scattering of the pion and final state interactions of the outgoing proton contribute approximately equally to the nonquasifree part of the ( $π^{+}, π^{+} p$ ) cross section. The calculated number of nucleons $N$ taking part in the pion absorption process has a rather wide distribution which is generally peaked at the minimum number, $N = 2$ . The calculated $\frac{(π^{-}, π^{-} p)}{(π^{+}, π^{+} p)}$ cross section ratio for the quasifree peak at 245 MeV is larger than the free ratio in contradiction with the experimental results. This may be an indication of coherent effects which are not included in the intranuclear cascade model.

NUCLEAR REACTIONS Compared predictions of intranuclear cascade model for pion-nucleus reactions with experimental results for inclusive inelastic scattering and true absorption and for angular correlations for the ( $π, π p$ ) and ( $π^{+}, 2 p$ ) processes. $E_{π} = 85 - 315$ MeV, $A = 7 - 209$ .

Three-body kinematics for the binding effect in pion-nucleus elastic scattering

K. Nakano

Phys. Rev. C 26, 1628 (1982) - Published 1 October, 1982

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A simple and effective method to include the nucleon binding effect in pion-nucleus elastic scattering by using the three-body kinematics is proposed. It will be shown that the binding effect can be incorporated into the usual form of the first order optical potential calculation by making the two-body energy argument a variable parameter depending not only on the energy, but also on the nucleon Fermi momentum. Numerical examinations of the binding effect are carried out by $π$ - ${}^{12}C$ elastic scattering and the binding effect will be shown to have significant implications over the entire energy range considered, from low through resonance to above resonance regions.

NUCLEAR REACTIONS Calculated $σ (θ)$ for ${}^{12}C (π, π)$ , $E = 50 - 250$ MeV. Binding effect. Three-body kinematics. Importance of the Fermi motion.

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Recent Articles

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Recent Issues

Interaction of neutrons with even- $A$ tin isotopes. I. Total cross sections for $E_{n} = 0.3 - 5.0$ MeV

Analyzing powers for proton inelastic scattering to unnatural-parity states in ${}^{40}{Ca}$ and ${}^{28}{Si}$

Level structure of ${}^{97}{Tc}$ investigated via the ${}^{97}{Mo} (p, n γ)$ reaction

High spin states and band structure in ${}^{97}{Tc}$

Saturation analysis as a test of statistical fission in heavy ion reactions

Reaction cross sections for ${}^{14}N$ + ${}^{14}N$

${}^{14}N$ + ${}^{13}C$ fusion cross sections and compound nucleus limitation in ${}^{27}{Al}$

Mean-field effects in intermediate-energy, heavy-ion reactions

One-step and two-step contributions to two-nucleon transfer reactions

Shock waves in relativistic nuclear matter. II. Angular anisotropy in multiparticle spectra

Unusually low fragment energies in the symmetric fission of ${}^{259}{Md}$

Reactions ${}^{12}C (π^{\pm}, π^{\pm} d) {}^{10}B$ and ${}^{12}C (π^{\pm}, π^{\pm} t) {}^{9}B$

Local density approximation for the relativistic nucleon-nucleus potential

Single particle intranuclear "cascade" and pion production

Yields of two-nucleon-out residual products from stopped $π^{-}$ reactions

Distortion effects in ( $π, π p$ ) quasifree knockout reactions

Inelastic electron scattering from ${}^{3}{He}$ and ${}^{4}{He}$ in the threshold region at high momentum transfer

Electroproduction of $π^{+}$ from ${}^{10}B$ and its relation to electron scattering

Intranuclear cascade calculation of pion-nucleus reactions in the resonance region

Three-body kinematics for the binding effect in pion-nucleus elastic scattering

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