Recent Articles

Fluctuations in ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}$ and ${}^{12}C$ ( ${}^{16}O$ , ${}^{8}{Be}_{g . s .}$ ) ${}^{20}{Ne}$ reactions

R. Singh, K. A. Eberhard, and R. G. Stokstad

Phys. Rev. C 22, 1971 (1980) - Published 1 November, 1980

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A statistical model analysis has been performed on the excitation functions for ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}$ ( $0^{+}$ , g.s.; $2^{+}$ , 1.37; $4^{+}$ , 4.12 +; $2^{+}$ , 4.24; $3^{+}$ , 5.24 MeV) from $E_{c . m .} = 13.17$ to $E_{c . m .} = 23.09$ MeV at $θ_{L} = 35 °$ and for ${}^{12}C$ ( ${}^{16}O$ , ${}^{8}{Be}_{g . s .}$ ) ${}^{20}{Ne}$ ( $0^{+}$ , g.s.; $2^{+}$ , 1.63; $4^{+}$ , 4.25 MeV) from $E_{c . m .} = 14.07$ to $E_{c . m .} = 23.09$ MeV (for $0^{+}$ , g.s.), $E_{c . m .} = 14.46$ to $E_{c . m .} = 23.09$ MeV (for $2^{+}$ , 1.63 MeV), $E_{c . m .} = 16.65$ to $E_{c . m .} = 23.09$ MeV (for $4^{+}$ , 4.25 MeV) at $θ_{L} = 32.5 °$ . The number of effective channels was calculated exactly. The theoretical and experimental distributions of the cross sections agree reasonably well and indicate that the fluctuating component of the experimental cross sections is consistent with statistical model predictions for these quantities.

NUCLEAR REACTIONS ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}$ , ${}^{12}C$ ( ${}^{16}O$ , ${}^{8}{Be}_{g . s .}$ ) ${}^{20}{Ne}$ , statistical model analysis of the excitation functions at $θ_{L} = 35 °$ and $θ_{L} = 32.5 °$ .

Barrier penetration and spontaneous fission in the time-dependent mean-field approximation

S. Levit, J. W. Negele, and Z. Paltiel

Phys. Rev. C 22, 1979 (1980) - Published 1 November, 1980

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A mean-field theory is obtained for the spontaneous decay of unstable nuclei by applying the stationary-phase approximation to a functional integral expression for $Tr {(H - E)}^{- 1}$ . The method is applied first to the lifetime of a metastable state in one-dimensional quantum mechanics and subsequently generalized to many-fermion systems. Solutions to the resulting nonlinear self-consistent field equations are presented for a self-bound, saturating many-body system of fermions in one spatial dimension.

NUCLEAR REACTIONS, FISSION Derivation of dynamical mean-field equations for spontaneous fission, using imaginary time stationary-phase approximation to a functional integral expression for $Tr {(H - E)}^{- 1}$ . Application to a many-fermion model in one spatial dimension.

$E 2$ giant resonances and an $M 1$ component in the photofission of ${}^{236}U$

J. D. T. Arruda-Neto, S. B. Herdade, B. L. Berman, and I. C. Nascimento

Phys. Rev. C 22, 1996 (1980) - Published 1 November, 1980

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Electrofission and photofission yields and electrofission-fragment angular distributions for ${}^{236}U$ have been measured with fission-track detectors for incident electron energies from 5.5 to 33.0 MeV. Analysis of these data with the use of virtual-photon spectra calculated in distorted-wave Born approximation, combined with the known photofission cross section, results in the simultaneous determination for this nucleus of (a) a giant isoscalar $E 2$ resonance located at 10.8±0.4 MeV, having a width of 6±1 MeV, and exhausting ∼70% of the isoscalar energy-weighted sum rule, and (b) a small $M 1$ component located at 5.8±0.2 MeV whose strength is <2% of that of the giant isoscalar $E 2$ resonance. No evidence is seen for a giant isovector $E 2$ resonance between 22 and 30 MeV.

NUCLEAR REACTIONS ${}^{236}U (e, f)$ ; measured fission-fragment yields and angular distributions, 5.5 to 33.0 MeV; deduced GQR characteristics.

Finite-size effects in trajectory calculations for $α$ particles emitted during nuclear fission

N. Cârjan and B. Leroux

Phys. Rev. C 22, 2008 (1980) - Published 1 November, 1980

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Exact calculations for the trajectories of $α$ particles emitted during the fission of ${}^{236}U$ are presented. The forces acting on the fragments and on the $α$ particles are computed taking into account the time evolution of the shape of the fissioning nucleus. The resulting final directions and kinetic energies of the $α$ particles are compared with those obtained with the traditional three-point-charge approximation. Various initial conditions, including pre-scission $α$ emissions, are considered.

RADIOACTIVITY, FISSION ${}^{235}U (n, f)$ accompanied by emission of $α$ particles; trajectory calculations taking into account the finite sizes of the fission fragments.

Geometrical aspects of relativistic nuclear collisions

G. Cecil, S. Das Gupta, and W. D. Myers

Phys. Rev. C 22, 2018 (1980) - Published 1 November, 1980

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The geometrical common to many nuclear collisional models is reformulated to permit analytical calculation of experimental observables. Nuclear diffuseness is easily incorporated. As an application, the firestreak model is used to explore the effect of diffuseness on triton and deuteron spectra in relativistic heavy ion collisions. In light colliding systems, the peripheral regions contain insufficient nuclear material to form composites, and must be excluded. The density cutoff obtained for C on C at 800 MeV/A yields a minimum tube cross section of 3.8 ${fm}^{2}$ , consistent with the nucleon-nucleon cross section.

NUCLEAR REACTIONS Relativistic nuclear collisions; nuclear diffuseness; firestreak; calculated differential cross sections of $d$ , $t$ ; comparisons with experiment.

Hypertriton as a test of theoretical hyperon-nucleon potentials. II

B. F. Gibson and D. R. Lehman

Phys. Rev. C 22, 2024 (1980) - Published 1 November, 1980

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A separable approximation to meson theoretic hyperon-nucleon potentials is made such that low-energy-scattering parameters are reproduced. Explicit $Λ N - Σ N$ coupling is neglected. The important tensor nature of triplet force is included. Several recently proposed hyperon-nucleon potentials lead to acceptable ${}_{Λ}^{3}H$ binding energy estimates.

NUCLEAR STRUCTURE ${}_{Λ}^{3}H$ , YN potentials, $B_{Λ}$ , tensor force separable potential calculation.

Optical-model potential in a relativistic quantum field model

M. Jaminon, C. Mahaux, and P. Rochus

Phys. Rev. C 22, 2027 (1980) - Published 1 November, 1980

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The average nucleon-nucleus potential at low and medium energy is investigated in the framework of a relativistic quantum field model. Using the same input parameters as Brockmann in his recent study of nuclear ground states, we calculate the self-consistent relativistic Hartree potential at positive energy in the case of infinite nuclear matter and of ${}^{16}O$ and ${}^{40}{Ca}$ . This potential is the sum of a scalar operator and of the fourth component of a vector operator. We construct its Schrödinger-equivalent potential by eliminating the small component of the Dirac spinor. The central part of this Schrödinger-equivalent potential is in fair agreement with empirical values at low and intermediate energy. Particular attention is paid to the intermediate energy domain, in which the calculated potential is repulsive in the nuclear interior and attractive at the nuclear surface. This is in keeping with some empirical evidence and is similar to results found in the framework of the nonrelativistic Brueckner-Hartree-Fock approximation. The spin-orbit potential of the relativistic Hartree model is also in good agreement with empirical values.

NUCLEAR REACTIONS Calculated average nuclear field of nuclear matter, ${}^{16}O$ and ${}^{40}{Ca}$ at positive energy from relativistic Hartree approximation.

Pionic atoms and low energy elastic scattering

K. Stricker, J. A. Carr, and H. McManus

Phys. Rev. C 22, 2043 (1980) - Published 1 November, 1980

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A fit to pionic atom data is used to determine four of the parameters of the low energy pion-nucleus optical potential, while the other parameters are taken from theory. The resulting potential is used to predict elastic scattering from 30-50 MeV pions. The effects of extrapolating the paråmeters to 50 MeV with a simple energy dependence are examined.

NUCLEAR REACTIONS Optical potential, fit to pi-mesic atoms. Calculated elastic scattering with extrapolated potential at 30, 40, 50 MeV on individual targets.

Nucleon recoil effect in the pion-nucleon interaction

Nien-Chih Wei and Manoj K. Banerjee

Phys. Rev. C 22, 2052 (1980) - Published 1 November, 1980

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We have studied the effect of nucleon recoil on pion-nucleon interaction in the $P$ wave using the dynamical model of Chew and Low which uses the nucleon pole terms as the driving mechanism. In general, the inclusion of recoil causes sizable reduction of the rescattering terms in every channel. In the $P 33$ channel, this reduction is large enough to remove the resonance. This conclusion holds for any acceptable pion-nucleon coupling constant, and is independent of the choice of pion-nucleon form factor.

NUCLEAR REACTIONS Pion-nucleon interaction, nucleon recoil effect, static limit, Chew-Low theory, $P 33$ resonance.

Dynamical theory for the $P$ -wave pion-nucleon interaction

Nien-Chih Wei and Manoj K. Banerjee

Phys. Rev. C 22, 2061 (1980) - Published 1 November, 1980

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We present a dynamical theory of low energy $P$ -wave $π N$ interaction. The theory is an extension of the Chew-Low theory, with three additional features, namely, (1) inclusion of the full nucleon recoil effect, (2) inclusion of the $Z$ graphs, and (3) inclusion of $P 11$ channel inelasticity. The second feature is new in a $P$ -wave theory based on the Low expansion. We are able to fit the $P 33$ and the $P 11$ phase shifts in the energy region $0 < T_{π} < 250$ MeV quite well. In particular, we show that it is possible to explain the change of sign of the $P 11$ phase shift, $T_{π} \sim 150$ MeV, in terms of the strong inelasticity present in the channel. For the $P 13$ and $P 31$ channels, where the phase shifts are the smallest, we do reasonably well at threshold, but not so well as the energy increases. We have also examined the structure of the off-mass-shell amplitudes in the $P 11$ and $P 33$ channels. Only the $P 33$ channel amplitude is found to be factorable. A major result of our work is that the $P 33$ form factor is very hard. If one used a monopole form, the form factor mass should be $10 m_{π}$ or larger.

NUCLEAR REACTIONS Pion-nucleon interaction, $Z$ -graph term, sigma exchange term, $P 33$ resonance, form factor of $P 33$ amplitude, $P 11$ inelasticity, nonstatic kinematics.

Hypernuclear physics with pions

C. B. Dover, L. Ludeking, and G. E. Walker

Phys. Rev. C 22, 2073 (1980) - Published 1 November, 1980

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We investigate the possibility of producing hypernuclei with energetic pion beams via the ( $π^{+}, K^{+}$ ) reaction. Due to the high momentum transfer involved ( $q \approx 300$ MeV/c), even in the forward direction, the ( $π^{+}, K^{+}$ ) reaction preferentially populates high spin natural parity configurations obtained by coupling a $Λ$ particle to a neutron hole. We present differential cross section calculations utilizing the plane wave approximation (PWA), the distorted wave impulse approximation (DWIA) using fully distorted waves, and the eikonal approximation (EIK) to approximate distortion effects. The DWIA and EIK results are in agreement, and lead to cross sections typically a factor of 5-10 lower than the PWA results, due to absorptive effects. Cross sections of 5-20 μb/sr at 0° are obtained in the DWIA for high spin natural parity "stretched configurations," for example ${({}_{Λ}d_{\frac{3}{2}, \frac{5}{2}} \otimes {}_{n}f_{\frac{7}{2}}^{- 1})}^{5_{-}}$ or ${({}_{Λ}f_{\frac{5}{2}, \frac{7}{2}} \otimes {}_{n}f_{\frac{7}{2}}^{- 1})}^{6_{+}}$ in ${}_{Λ}^{48}{Ca}$ , for pion lab momentum $p_{π}$ in the range 1.02-1.1 GeV/c, where the elementary cross section for $K^{+} n \to π^{+} Λ$ has its peak values. The cross sections for the population of the natural parity ground-state levels ${({}_{Λ}S_{\frac{1}{2}} \otimes {}_{n}{l_{l + \frac{1}{2}}}^{- 1})}_{J = l}$ with closed shell targets remain above 2 μb/sr at 0° for systems lighter than $A \approx 50$ . The cross sections drop rapidly below $p_{π} = 1.02$ GeV/c, due to threshold effects. Results are presented for the calculated quasielastic (quasifree) continuum background for the ( $π^{+}, K^{+}$ ) reaction as a function of $θ_{1 a b}$ and hypernuclear excitation energy. Because of the higher momentum transfer the quasielastic background is broader and significantly less in magnitude than that obtained in the ( $K^{-}, π^{-}$ ) reaction at 0°. Thus it should be possible to measure cross sections of a few μb/sr associated with particle-hole states using existing pion beams in the 1-1.5 GeV/c momentum range, for instance at the Brookhaven AGS. The class of hypernuclear states populated at 0° in a ( $π^{+}, K^{+}$ ) reaction is complementary to those seen in the "crossed" ( $K^{-}, π^{-}$ ) reaction at 0°, the latter being sensitive only to low spin states. Thus the ( $π^{+}, K^{+}$ ) reaction offers unique possibilities for extending our knowledge of hypernuclear structure.

NUCLEAR STRUCTURE Excitation of high spin states in ( $π, K$ ) reaction. DWIA and PWA estimates of cross sections.

Comprehensive relations for hadron-nucleus inelastic excitations in terms of elastic scattering

R. D. Amado, F. Lenz, J. A. McNeil, and D. A. Sparrow

Phys. Rev. C 22, 2094 (1980) - Published 1 November, 1980

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We obtain closed form asymptotic approximations to the eikonal form for inelastic hadron-nucleus scattering to strongly excited nuclear states. These forms exploit the dominance of the nuclear geometry recently used by us to obtain the elastic scattering amplitudes. Our forms agree well with the data. We find that the inelastic scattering can be written in terms of the elastic scattering cross section. These data-to-data forms agree remarkably well with experiment and serve to emphasize the geometric unity of the reactions. The simplicity of these expressions and relations should make them useful in medium energy phenomenology.

NUCLEAR REACTIONS Closed form eikonal amplitude for hadron-nucleus inelastic scattering. Data-to-data form relating inelastic and elastic scattering.

Recoil properties of nuclei produced in the interaction of protons with ${}^{27}{Al}$

L. Winsberg, E. P. Steinberg, D. Henderson, and A. Chrapkowski

Phys. Rev. C 22, 2108 (1980) - Published 1 November, 1980

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Recoil properties of ${}^{7}{Be}$ , ${}^{11}C$ , and ${}^{18}F$ produced in the interaction of 1-11.5 GeV protons with ${}^{27}{Al}$ were measured in a stack of aluminum foils. A difference method was employed to determine the fraction of recoil loss in the forward (beam) and backward directions ( $F$ and $B$ , respectively). The values of $\frac{F}{B}$ and the recoil ranges were combined with previous data on ${}^{8}{Li}$ , ${}^{22}{Na}$ , and ${}^{24}{Na}$ and with counter-experiment measurements in a systematic analysis of the reaction mechanism, based on the two-velocity reaction model. The analysis indicates that the same processes occur in ${}^{27}{Al}$ as in heavier target nuclei. The mechanism of formation of the products from ${}^{27}{Al}$ , that were measured, appears to be independent of the energy of the incident proton in the GeV energy region.

NUCLEAR REACTIONS ${}^{27}{Al} (p, x) {}^{7}{Be}$ to ${}^{24}{Na}$ , $E_{p} <~ 400$ GeV; analyzed recoil properties as evidence for reaction mechanism.

Systematics of particle-nucleus reactions. I. Parameters

Lester Winsberg

Phys. Rev. C 22, 2116 (1980) - Published 1 November, 1980

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A set of parameters for studying the systematics of nuclear recoil, induced by high-energy protons, is proposed. A simple version $V_{0}$ of the two-velocity model is the basis of this analysis. The velocity of the observed recoil nucleus is assumed to be the vector sum of an initial velocity $v$ , which is constant and in the forward direction from the first step of the reaction, and a velocity $V$ , which has a distribution of values and is isotropic from the second step. The evaluation of recoil experiments yields values of $v$ and $\frac{p}{p_{CN}}$ (the fractional momentum transfer) for the first step of the reaction; $〈 T 〉 = \frac{1}{2} M_{REC} 〈 V^{2} 〉$ , $ε_{S}$ and $ε_{F}$ for the second step; and $\frac{T_{max}}{〈 T 〉}$ and $P_{max}$ for the overall reaction. The mass of the observed recoil nucleus is $M_{REC}$ ; $ε_{S}$ and $ε_{F}$ are the average kinetic energy of the emitted particles in a random-walk process or in two-fragment breakup, respectively; $T_{max}$ is the maximum value of $T$ for a given reaction mode, and $P_{max}$ is the upper limit to the probability of this reaction mode. The combination of the single-collision model and the $V_{0}$ approximation results in the additional parameter $E_{0}^{*} = \frac{p E_{CN}}{p_{CN}}$ for the first step of the reaction, where $E_{CN}$ is the excitation energy plus a small kinetic energy in a compound-nucleus reaction. An analysis based on the collision-tube model, in which one or more nucleons may be emitted in the first step, gives the excitation energy $E^{*}$ , $\frac{E^{*}}{Δ A}$ , the mass $Δ m$ of the effective target, and $\frac{Δ A}{Δ m}$ . The value of $E^{*}$ includes the kinetic energy of the excited nucleus and the separation energy of the nucleons emitted in the first step. The total number of nucleons emitted in the reaction is $Δ A$ .

NUCLEAR REACTIONS Proton induced; introduction to recoil systematics.

Systematics of particle-nucleus reactions. II. Nuclear recoil in nonfission reactions induced by 1-GeV to 400-GeV protons

Lester Winsberg

Phys. Rev. C 22, 2123 (1980) - Published 1 November, 1980

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Experimental results from nonfission reactions, induced by protons with energies of 1 GeV or more, were analyzed by simple nuclear-reaction models. A set of parameters, described in the preceding paper, was obtained from this analysis for the purpose of studying the systematics of nuclear recoil in these reactions. Spallation reactions were assumed to occur in two steps: an initial fast process in which momentum is transferred to the struck nucleus in the forward direction, followed by an isotropic random-walk process. In another possible type of reaction-fragmentation-the observed nucleus is formed in a single fast event, corresponding to the first step of a spallation reaction. Since a model for determining the parameters of a fragmentation reaction from the experimental data was lacking, all of the results were analyzed by the two-step model. The parameters were divided into three groups. The first two sets of parameters correspond to the two steps described above, and the third is based on an overall energy inventory of each reaction. The general properties of the reactions studied are indicated by the systematics of these parameters. Criteria are presented for distinguishing between spallation, fragmentation, and fission. More detailed information about possible mechanisms for specific reactions is given.

NUCLEAR REACTIONS Proton induced; recoil systematics at $E_{p} = 1 - 400$ GeV.

Nuclear excitation function and particle emission from complex nuclei following muon capture

Mordechai Lifshitz and Paul Singer

Phys. Rev. C 22, 2135 (1980) - Published 1 November, 1980

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A model for the calculation of the nuclear excitation function following muon capture in complex nuclei and of the ensuing emission is presented. The capturing nucleus is treated as consisting of quasifree nucleons moving in a momentum-dependent potential and having an effective nucleon-momentum distribution. The emission of protons, deuterons, $α$ particles, and neutrons is calculated by considering both pre-equilibrium and compound-nucleus emission. The model accounts well for the observed charged particles emission rates from capturing nuclei over the wide range $23 \leq A \leq 209$ . The proton emission is shown to become mainly of pre-equilibrium nature for the heavier nuclei. The results for neutron emission are also in satisfactory agreement with experimentally measured multiplicities and spectra.

NUCLEAR REACTIONS Calculated probabilities of ( $μ^{-}, pxn$ ), ( $μ^{-}, α$ ) $E_{μ} = 0$ reactions for various targets with $23 <~ A <~ 209$ ; inclusive and exclusive channels; pre-equilibrium emission; compound-nucleus emission; neutron multiplicities; nuclear excitation distribution following $μ$ capture.

Pion coupling to the $A = 6$ , $A = 12$ , and $A = 14$ nuclei

Olgierd Dumbrajs

Phys. Rev. C 22, 2151 (1980) - Published 1 November, 1980

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The values of the coupling constants ${f_{π {}^{6}{Li} {}^{6}{Be}}}^{2} = 0.07$ , ${f_{π {}^{12}C {}^{12}N}}^{2} = 0.004$ , and ${f_{π {}^{14}N {}^{14}O}}^{2} = 0.00014$ have been extracted from the pological treatment of the ${}^{6}{Li} (p, n) {}^{6}{Be}$ , ${}^{12}C (p, n) {}^{12}N$ , and ${}^{14}N (p, n) {}^{14}O$ reactions. A critical discussion of our present knowledge of the pion couplings to these nuclei and of existing methods of their determination is given.

NUCLEAR REACTIONS Initial nucleus-pion-final nucleus coupling constants. PCAC hypothesis. Analyticity. ${}^{6}{Li} (p, n) {}^{6}{Be}$ , ${}^{12}C (p, n) {}^{12}N$ , ${}^{14}N (p, n) {}^{14}O$ at 0.144 GeV.

Comparison between $NN$ potential derived from dispersion relations and a model field theory

A. S. Rinat

Phys. Rev. C 22, 2156 (1980) - Published 1 November, 1980

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We compare the solution of a model field theory which relates off-shell amplitudes for elastic $NN$ and $π N$ scattering to a similar relation between on-shell amplitudes derived from a dispersive approach. The first is a dynamical realization of $s$ -channel unitarity, whereas the second starts with and exploits $t (u)$ channel unitarity. Provided that $T_{NN}$ satisfies a Mandelstam representation, equivalent approximations ought to produce equivalent results and we perform the comparison for the actually calculated $T_{NN}$ and the subsequently extracted potentials $V_{NN}$ . Interpreting $V_{NN}$ we caution against the simultaneous retention of contributions with pions (crossed and uncrossed) linking intermediate nucleons as well as nucleons and physical isobars.

NUCLEAR REACTIONS $NN$ scattering, comparison between elastic amplitude and potential derived from model field theory and dispersive approach.

Energy levels of ${}^{127, 129, 131}{Sn}$ populated in the $β^{-}$ decay of ${}^{127, 129, 131}{In}$

L. -E. De Geer and G. B. Holm

Phys. Rev. C 22, 2163 (1980) - Published 1 November, 1980

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The decay of 0.27 s ${}^{131}{In}$ to levels in the single hole nucleus ${}^{131}{Sn}$ have been studied using an on-line isotope separator. The $s_{\frac{1}{2}}$ and $g_{\frac{7}{2}}$ levels are found at 332.8 and 2433 keV excitation, respectively. The $Q_{β^{-}}$ of ${}^{131}{In}$ has been determined to be 8.82±0.20 MeV. To complete the series of heavy odd-mass isotopes of Sn, levels in the ${}^{127, 129}{Sn}$ nuclei, which are populated in the decay of ${}^{127, 129}{In}$ also have been studied. Decay schemes are proposed for the decay of two ${}^{127}{In}$ isomers of half-lives 1.15±0.05 s and 3.7±0.1 s and for the decay of two ${}^{129}{In}$ isomers of half-lives 0.59±0.03 s and 1.20±0.05 s. Low lying negative parity states of three quasiparticle character have been observed in ${}^{127, 129}{Sn}$ where $μ s$ isomers due to the low energy $h_{\frac{11}{2}}$ orbit are also suggested.

RADIO ACTIVITY ${}^{127, 129, 131}{In}$ from ${}^{235}U (n, f)$ , isotopically separated sources: measured $T_{\frac{1}{2}}$ , $E_{γ}$ , $I_{γ}$ , $E_{β}$ , $E_{ce}$ , $I_{ce}$ , $γ γ$ -coinc., $β γ$ -coinc. ${}^{127, 129, 131}{Sn}$ deduced levels, $I$ , $π$ , $log ft$ . Ge(Li), Si(Li), plastic and anthracene detectors, Ge(Li)-Ge(Li) and Ge(Li) - anthracene coinc., plastic detector - Ge(Li) delay.

Decay of mass-separated ${}^{78}{Ga}$ to levels in even-even ${}^{78}{Ge}$

D. A. Lewis, John C. Hill, F. K. Wohn, and M. L. Gartner

Phys. Rev. C 22, 2178 (1980) - Published 1 November, 1980

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The decay of mass-separated ${}^{78}{Ga}$ produced in the thermal neutron fission of ${}^{235}U$ was studied and a decay scheme was deduced from results of $γ$ -singles and coincidence measurements. The ${}^{78}{Ga}$ half-life was determined to be 5.49±0.25 s and 45 $γ$ transitions were placed in a level scheme for ${}^{78}{Ge}$ including 19 excited states up to 5078 keV. Observation of a level at 1644 keV with a probable $J^{π}$ of $3^{+}$ completes a level structure which is in good agreement up to 2 MeV with a dynamic deformation calculation.

RADIO ACTIVITY ${}^{78}{Ge}$ [from ${}^{235}U (n, f)$ ]; measured $T_{\frac{1}{2}}$ , $E_{γ}$ , $I_{γ}$ , $γ γ$ -coin, Ge(Li) detectors; ${}^{78}{Ga}$ deduced levels, $J$ , $π$ , $log ft$ , $Q_{β}$ . Mass-separated ${}^{78}{Ga}$ activity.

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Fluctuations in ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}$ and ${}^{12}C$ ( ${}^{16}O$ , ${}^{8}{Be}_{g . s .}$ ) ${}^{20}{Ne}$ reactions

Barrier penetration and spontaneous fission in the time-dependent mean-field approximation

$E 2$ giant resonances and an $M 1$ component in the photofission of ${}^{236}U$

Finite-size effects in trajectory calculations for $α$ particles emitted during nuclear fission

Geometrical aspects of relativistic nuclear collisions

Hypertriton as a test of theoretical hyperon-nucleon potentials. II

Optical-model potential in a relativistic quantum field model

Pionic atoms and low energy elastic scattering

Nucleon recoil effect in the pion-nucleon interaction

Dynamical theory for the $P$ -wave pion-nucleon interaction

Hypernuclear physics with pions

Comprehensive relations for hadron-nucleus inelastic excitations in terms of elastic scattering

Recoil properties of nuclei produced in the interaction of protons with ${}^{27}{Al}$

Systematics of particle-nucleus reactions. I. Parameters

Systematics of particle-nucleus reactions. II. Nuclear recoil in nonfission reactions induced by 1-GeV to 400-GeV protons

Nuclear excitation function and particle emission from complex nuclei following muon capture

Pion coupling to the $A = 6$ , $A = 12$ , and $A = 14$ nuclei

Comparison between $NN$ potential derived from dispersion relations and a model field theory

Energy levels of ${}^{127, 129, 131}{Sn}$ populated in the $β^{-}$ decay of ${}^{127, 129, 131}{In}$

Decay of mass-separated ${}^{78}{Ga}$ to levels in even-even ${}^{78}{Ge}$

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