Recent Articles

Yrast states in ${}^{62}{Zn}$

L. Mulligan, R. W. Zurmühle, and D. P. Balamuth

Phys. Rev. C 19, 1295 (1979) - Published 1 April, 1979

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High spin states in ${}^{62}{Zn}$ have been observed using the ${}^{40}{Ca}$ ( ${}^{28}{Si}$ , $α 2 p γ$ ) ${}^{62}{Zn}$ reaction at beam energies of 93.5 and 102 MeV. $γ - γ$ coincidence measurements, angular distributions, and directional correlation of oriented nuclei ratios were used to determine a likely decay scheme. Levels with probable spin as high as $J = 12$ have been observed.

NUCLEAR REACTIONS ${}^{40}{Ca}$ ( ${}^{28}{Si}$ , $α 2 p γ$ ) 93.5 and 102 MeV: measured $E_{γ}$ , $σ (E_{γ}, θ)$ , $γ - γ$ coincidence. ${}^{62}{Zn}$ deduced $E_{x}$ , $J$ , $π$ decay scheme.

Band structure in ${}^{78}{Rb}$

M. A. J. Mariscotti, G. García Bermúdez, J. C. Acquadro, A. Lepine, M. N. Rao, W. Seale, E. der Mateosian, and P. Thieberger

Phys. Rev. C 19, 1301 (1979) - Published 1 April, 1979

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A level scheme is proposed for ${}^{78}{Rb}$ , which was obtained through the ${}^{64}{Zn}$ ( ${}^{16}O$ , $np$ ) reaction at 44 and 52 MeV, by measuring $γ - γ$ coincidences and $γ$ -ray angular distributions. The isotopic identification was made by studying on- and off-beam spectra at selected time intervals, and determining the intensities of the different decay products. The main part of the level scheme comprises a $Δ I = 1$ band which shows a staggering similar to that previously found in ${}^{76}{Br}$ and ${}^{77}{Kr}$ . In addition the level energies are very close to those in ${}^{76}{Br}$ . It was not possible to establish in a conclusive manner whether the lowest state of the proposed level scheme corresponds to one or the other of the hitherto known 6 and 17.5 min isomers in ${}^{78}{Rb}$ , but the first possibility appears to be the more likely one.

NUCLEAR REACTIONS ${}^{64}{Zn}$ ( ${}^{16}O$ , $np$ ), $E = 44 and 52$ MeV; measured $σ (E_{γ}, θ)$ , $E_{γ}$ , $I_{γ}$ , $γ - γ$ coin. ${}^{78}{Rb}$ deduced levels, $I$ . Enriched ${}^{64}{Zn}$ target.

Fragmentation of relativistic ${}^{56}{Fe}$

G. D. Westfall, Lance W. Wilson, P. J. Lindstrom, H. J. Crawford, D. E. Greiner, and H. H. Heckman

Phys. Rev. C 19, 1309 (1979) - Published 1 April, 1979

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The fragmentation of ${}^{56}{Fe}$ at 1.88 GeV/nucleon has been studied on H, Li, Be, C, S, Cu, Ag, Ta, Pb, and U targets. The detection apparatus consisted of a simple transmission detector. A method is presented which eliminates the effects of multiple interactions in the targets which were typically half an interaction-length thick. Elemental production cross sections, $σ (Z)$ , were measured for $Z = 13 to 25$ . Measured charge-changing cross sections, $σ_{Δ Z \geq 1}$ , and derived mass-changing cross sections, $σ_{Δ A \geq 1}$ , are presented for each target. The $σ (Z)$ factor into a term which depends only on the target and a term which depends only on the fragment observed. The $σ_{Δ Z \geq 1}$ and $σ_{Δ A \geq 1}$ follow a simple geometric behavior. The cross section for the removal of one proton from the ${}^{56}{Fe}$ projectile is enhanced for the heavier targets. This effect is described by a model assuming Coulomb dissociation. The $σ (Z)$ for ${}^{56}{Fe}$ on the $H$ target are compared to the semiempirical formulas of Silberberg and Tsao.

NUCLEAR REACTIONS H( ${}^{56}{Fe}$ , $S$ ), Li( ${}^{56}{Fe}$ , $X$ ), Be( ${}^{56}{Fe}$ , $X$ ), C( ${}^{56}{Fe}$ , $X$ ), S( ${}^{56}{Fe}$ , $X$ ), Cu( ${}^{56}{Fe}$ , $X$ ), Ag( ${}^{56}{Fe}$ , $X$ ) Ta( ${}^{56}{Fe}$ , $X$ ), Pb( ${}^{56}{Fe}$ , $X$ ), U( ${}^{56}{Fe}$ , $X$ ), $X = Al to Mn$ , measured elemental production cross sections; measured charge-changing cross sections and derived mass changing cross sections. Iron fragmentation cross sections, relativistic heavy ions, thick target corrections, Coulomb dissociation.

High-spin states in odd-mass ${}^{113 - 119}{Sb}$ : $Δ J = 1$ bands on $\frac{9}{2^{+}}$ proton-hole states

R. E. Shroy, A. K. Gaigalas, G. Schatz, and D. B. Fossan

Phys. Rev. C 19, 1324 (1979) - Published 1 April, 1979

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Properties of high-spin states in ${}^{113, 115, 117, 119}{Sb}$ have been studied via the ${}^{A}{Cd} ({}^{6}{Li}, 3 n) {}^{A + 3}{Sb}$ reactions. Using Ge(Li) and Si(Li) detectors, in-beam measurements of $γ$ -ray excitation functions, $γ - γ$ coincidences, $γ$ -ray angular distributions, and pulsed beam- $γ$ timing spectra were made to determine level energies, decay schemes, $γ$ -ray multipolarities, $J^{π}$ assignments, isomeric lifetimes, and a $g$ factor. Systematic $Δ J = 1$ bands built on low-lying $\frac{9}{2^{+}}$ proton-hole (2p-1h) states were observed in these nuclei. The bandheads that involve the excitation of a $1 g_{\frac{9}{2}}$ proton across the $Z = 50$ shell achieve an energy minimum near the middle of the neutron shell. The observed properties of these bands are consistent with significant prolate deformations; the band spacings imply a deformation asymmetry of $γ = 20$ in a triaxial rotor model. In addition, single-particle and single-particle plus core-excitation states were observed in these Sb nuclei. Two isomers were identified, a $\frac{19}{2^{(-)}}$ state at 2796 keV in ${}^{115}{Sb}$ ( $τ = 230 \pm 4$ ns and $g = + 0.290 \pm 0.005$ ) and a ( $\frac{27}{2^{+}}$ ) state in ${}^{119}{Sb}$ ( $τ = 1.23 \pm 0.13$ s).

NUCLEAR REACTIONS ${}^{110 - 116}{Cd}$ ( ${}^{6}{Li}$ , $3 n$ ) ${}^{113 - 119}{Sb}$ ; measured $γ - γ$ coincidences, $γ (E, θ, t)$ , spin rotation in $B = 10.3$ kG; deduced level schemes in odd-mass ${}^{113 - 119}{Sb}$ , $γ$ multipolarities, $J^{π}$ , $T_{\frac{1}{2}}$ , $g$ -factor. Enriched targets, Ge(Li) detectors.

In-beam gamma-ray spectroscopy of ${}^{74}{Se}$ following the ${}^{60}{Ni}$ ( ${}^{16}O$ , $2 p$ ), ${}^{64}{Ni}$ ( ${}^{12}C$ , $2 n$ ) and ${}^{65}{Cu}$ ( ${}^{11}B$ , $2 n$ ) reactions

R. B. Piercey, A. V. Ramayya, R. M. Ronningen, J. H. Hamilton, V. Maruhn-Rezwani, R. L. Robinson, and H. J. Kim

Phys. Rev. C 19, 1344 (1979) - Published 1 April, 1979

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The energy levels in ${}^{74}{Se}$ produced in the ${}^{60}{Ni}$ ( ${}^{16}O$ , $2 p$ ), ${}^{64}{Ni}$ ( ${}^{12}C$ , $2 n$ ) and ${}^{65}{Cu}$ ( ${}^{11}B$ , $2 n$ ) reactions were studied. An energy level scheme was deduced from $γ - γ$ coincidence measurements. Spin and parity assignments based on angular distribution and directional correlation of oriented nuclei measurements were made for most of the levels. Lifetimes of many of the transitions in ${}^{74}{Se}$ were deduced from their Doppler broadened lineshapes via the Doppler shift attenuation method. Three "rotational-like" band structures to high spin were observed and their properties investigated. A positive parity, $Δ J = 1$ , band to ( $9^{+}$ ) as well as the positive parity, $Δ J = 2$ , yrast band to ( $14^{+}$ ) were observed. In addition a negative parity, $Δ J = 2$ , band with rotational-like character was seen to ( $13^{-}$ ).

NUCLEAR REACTIONS ${}^{60}{Ni}$ ( ${}^{16}O$ , $2 p$ ), $E = 45$ MeV; ${}^{64}{Ni}$ ( ${}^{12}C$ , $2 n$ ), $E = 39$ MeV; ${}^{65}{Cu}$ ( ${}^{11}B$ , $2 n$ ), $E + 29$ MeV, ${}^{74}{Se}$ levels deduced. $γ (θ)$ , $γ - γ (θ)$ , $t_{\frac{1}{2}}$ from DSAM. Enriched targets.

Application of a band crossing model for resonances in high energy ${}^{12}C$ - ${}^{12}C$ scattering

Yosio Kondō, Yasuhisa Abe, and Takehiro Matsuse

Phys. Rev. C 19, 1356 (1979) - Published 1 April, 1979

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Resonance phenomena observed in single and mutual $2_{1}^{+}$ inelastic scattering and in $3_{1}^{-}$ inelastic scattering in the ${}^{12}C$ - ${}^{12}C$ system are investigated using a band crossing model. It is shown that characteristic features of the observed resonances can be well understood and well reproduced by the model. The coupling between wide resonances is also discussed. Another important prediction of the model, i.e., transfer of the dominant components of resonances from single and mutual $2_{1}^{+}$ excitations to the $3_{1}^{-}$ excitation with increasing scattering energy appears to be realized. These facts support the validity of the band crossing model in this system. We conclude that the prominent correlated resonances observed in high energy inelastic ${}^{12}C$ - ${}^{12}C$ scattering can be considered as a strong evidence for the existence of nuclear molecular phenomena in this energy range.

NUCLEAR REACTIONS ${}^{12}C$ ( ${}^{12}C$ , ${}^{12}C$ * ${(2}_{1}^{+}$ )) ${}^{12}C$ *( $2_{1}^{+}$ ), ${}^{12}C$ ( ${}^{12}C$ , ${}^{12}C$ ) ${}^{12}C$ *( $2_{1}^{+}$ ), ${}^{12}C$ ( ${}^{12}C$ , ${}^{12}C$ ) ${}^{12}C$ *( $3_{1}^{-}$ ), $10 \leq E_{c . m .} \leq 40$ MeV; calculated $σ (E)$ . resonance mechanism for heavy ion reactions.

Intermediate structure in ${}^{12}C$ + ${}^{12}C$ elastic scattering

Yasuhisa Abe, Takehiro Matsuse, and Yosio Kondō

Phys. Rev. C 19, 1365 (1979) - Published 1 April, 1979

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A band crossing model with a smooth-cutoff representation of absorption effects is applied to the intermediate structure observed in elastic scattering of the ${}^{12}C$ + ${}^{12}C$ system. The model is found to reproduce the experiment extremely well, which suggests strongly that the intermediate structure is a reflection of the existence of molecular resonances. The values of parameters in a smooth-cutoff representation of absorption effects are extracted by an analysis of the oscillatory fusion cross section.

NUCLEAR REACTIONS ${}^{12}C$ ( ${}^{12}C$ , ${}^{12}C$ ) ${}^{12}C$ , $6 <~ E_{c . m .} <~ 30$ MeV; $θ_{c . m .} = 90 °$ ; calculated $σ (E)$ . Resonance mechanism for Heavy Ion Reactions, absorption effects extracted from fusion data.

Shoulders in the very asymmetric mass distribution for reactor-neutron-induced fission of ${}^{238}U$

V. K. Rao, V. K. Bhargava, S. G. Marathe, S. M. Sahakundu, and R. H. Iyer

Phys. Rev. C 19, 1372 (1979) - Published 1 April, 1979

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New experimental data have been obtained on the cumulative yields of some short-lived very asymmetric products in the reactor-neutron-induced fission of ${}^{238}U$ . Fission yields of ${}^{73}{Ga}$ ( $t_{\frac{1}{2}} = 4.8$ h), ${}^{167}{Ho}$ ( $t_{\frac{1}{2}} = 3.1$ h), ${}^{171}{Er}$ ( $t_{\frac{1}{2}} = 7.5$ h), ${}^{173}{Tm}$ ( $t_{\frac{1}{2}} = 8.2$ h), and ${}^{179}{Lu}$ ( $t_{\frac{1}{2}} = 4.6$ h) are reported. These yields together with those reported earlier by us for other relatively longer lived products (half-lives of the order of a few days to a week) for the mass chains 66, 67, 72, 77, 161, 172, 175, 177, 183, and 199 have been used to obtain the mass yield curve of ${}^{238}U$ which gives rise to "shoulders" in the highly asymmetric region. This is the first experimental observation of shoulders in this region of mass distribution. The data have been discussed in terms of the recent fragmentation potential calculations available in the literature. The presence of these new shoulders in the highly asymmetric mass region has been ascribed to the occurrence of a new potential energy valley in the far asymmetric mass region due to the influence of the 28-proton shell. The effect of deformed shells on mass distribution has also been discussed.

NUCLEAR REACTIONS Fission ${}^{238}U$ , reactor neutrons, fragmentation potential, 28-proton shell, deformed shells, highly asymmetric mass distribution.

Differential fragmentation cross sections for 7.3 GeV nitrogen ions incident on protons

John P. Wefel, John M. Kidd, Walter Schimmerling, and Kirby G. Vosburgh

Phys. Rev. C 19, 1380 (1979) - Published 1 April, 1979

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Differential cross sections $\frac{d σ}{d Ω}$ for the inclusive reaction ${}^{14}N$ + $p \to Z$ + anything (for $3 \leq Z \leq 6$ ) have been measured at six laboratory production angles ( $θ < 5 °$ ) for 7.3 GeV nitrogen ions interacting in liquid hydrogen. The angular distributions for C, B, and Be fragments decrease sharply with increasing angle, as expected for this type of peripheral reaction. The corresponding transverse momentum ( $p_{t}$ ) distributions for these fragments can be represented by Gaussian functions of $p_{t}$ . The Li distribution appears to be non-Gaussian, suggesting one (or more) different production mechanisms. The dependence of the widths of the momentum distributions on fragment mass is not consistent with theoretical predictions, and shows some evidence for an "effective" number of nucleons which determine the fragmentation spectrum of the nitrogen nucleus. Integration of the angular distributions gives partial production cross sections which are consistent with results at higher energy. This energy-independent behavior implies that limiting fragmentation is applicable down to energies of 0.5 GeV/nucleon.

NUCLEAR REACTIONS Relativistic heavy ions; fragmentation of 7.3 GeV nitrogen on protons.

Kaon inelastic scattering and charge exchange on nuclei

C. B. Dover and G. E. Walker

Phys. Rev. C 19, 1393 (1979) - Published 1 April, 1979

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We present the results of calculations of kaon inelastic and charge exchange reactions on nuclei, based on the microscopic particle-hole shell model. Both $K^{+}$ and $K^{-}$ inelastic scattering on ${}^{12}C$ are discussed for incident momenta $p_{lab} = 300 MeV / c and 800 MeV / c$ . In addition, we examine the charge exchange process ${}^{30}{Si}$ ( $K^{-}$ , ${\bar{K}}^{0}$ ) ${}^{30}{Al}$ at 300 MeV/c. We employ the distorted wave impulse approximation, using a transition operator constructed from free space $K^{\pm}$ -nucleon amplitudes taken from analyses of two-body data. For the off-shell extrapolation of the two-body $t$ matrix, required in the many-body problem, we use a separable form factor obtained by solving the inverse scattering problem. The inelastic scattering results are found to be insensitive to the presence of the off-shell form factor. We find that normal parity $T = 0 and 1$ states dominate the nuclear response to both $K^{+}$ and $K^{-}$ . At 300 MeV/c, some qualitative differences in the inelastic scattering predictions arise from choosing different elementary amplitudes from the literature. Thus kaon-nucleus scattering may shed some light on ambiguities in the low energy free space interactions of kaons. At 800 MeV/c, there is much less uncertainty in the two-body $t$ matrix, so we can focus our attention on nuclear structure aspects. We compare the kaons with pions, electrons, protons, and $α$ in terms of their inelastic scattering and charge exchange properties. By emphasizing nuclear structure aspects such as the excitation of high spin states and the splitting of the $T_{<}$ and $T_{>}$ components of giant resonances, we show that kaons are very promising as a nuclear probe.

NUCLEAR REACTIONS, NUCLEAR STRUCTURE ${}^{12}C$ ( $K^{\pm}$ , $K^{\pm'}$ ) ${}^{12}C$ * $p_{lab} \approx 300 - 800$ MeV/c; ${}^{30}{Si}$ ( $K^{-}$ , ${\bar{K}}^{0}$ ) ${}^{30}{A 1}$ *, $p_{lab} = 300$ MeV/c theoretical estimates based on DWIA for kaon inelastic and charge exchange $\frac{d σ}{d Ω}$ ; virtues of kaons as nuclear structure probe.

Nuclear fragment production from 720-MeV alpha-induced reactions

T. C. Schweizer, R. R. Doering, S. T. Thornton, L. C. Dennis, K. R. Cordell, and R. L. Parks

Phys. Rev. C 19, 1408 (1979) - Published 1 April, 1979

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Heavy-fragment ( $Z > 2$ ) energy spectra from 720-MeV $α$ -induced nuclear reactions on Al, Ag, and Ta have been measured at 30°, 60°, 90°, and 120°. The angular distributions are not well reproduced by thermodynamic evaporation medels with either one or two emitting sources. The anisotropy of the low- $Z$ fragments is, however, better described by three sources whose evenly spaced velocities and temperatures indicate that the three sources may represent a discrete approximation to an actual continuum of sources. The observed anisotropy may also be a manifestation of large contributions to the forward-angle cross sections from pre-equilibrium fragment emission. Extension of this analysis to our hydrogen- and helium-isotope data indicates that the light fragments continue the trends exhibited by the heavy-fragment data. A comparison with data from proton-induced reactions indicates that the anisotropy observed may be a manifestation of higher energy and momentum deposition in the target nucleus by $α$ -particles than by protons.

NUCLEAR REACTIONS Al, Ag, Ta ( $α$ , $X$ ), $E = 720$ MeV; measured $σ (E, θ)$ , $X = Li to O$ . Thermodynamic models, evaporation, firestreak, pre-equilibrium emission.

Positive-pion photoproduction on ${}^{12}C$ near threshold

F. L. Milder, E. C. Booth, B. Chasan, A. M. Bernstein, J. Comuzzi, G. Franklin, A. Nagl, and H. Uberall

Phys. Rev. C 19, 1416 (1979) - Published 1 April, 1979

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The $π^{+}$ photoproduction on ${}^{12}C$ has been measured relative to the proton from 0-20 MeV above threshold. Total cross sections from 0-12 MeV, summed over states in ${}^{12}B$ have been extracted with accuracies between 5% and 8% relative to the proton photoproduction cross section. Distorted wave impulse approximation calculations have been performed and show good agreement with the data. The yield from 0-3 MeV above threshold is well described by a one parameter fit for the ground state cross section using only the $\vec{σ} \cdot \vec{ε}$ term of the Hamiltonian.

NUCLEAR REACTIONS ${}^{12}C$ ( $γ$ , $π^{+}$ ) ${}^{12}B$ , bremsstrahlung endpoint energies to 175 MeV, deduced $σ (E)$ ; calculated $σ (E)$ , DWIA.

Energy dependence of the absorptive $S$ -wave pion-nucleus optical potential

J. Chai and D. O. Riska

Phys. Rev. C 19, 1425 (1979) - Published 1 April, 1979

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It is shown that the simplest two-body pion rescattering model for pion absorption in nuclei leads to a rapid increase with pion energy for the absorptive part of the $S$ -wave pion-nucleus optical potential proportional to $p^{2}$ . The energy dependence is almost entirely due to the pion-nucleon rescattering amplitude and not to nuclear structure effects.

NUCLEAR REACTIONS Absorptive part of $S$ -wave pion nucleus optical potential calculated as a function of pion energy.

Analysis of $0^{-}$ ↔ $0^{+}$ beta decay and muon capture in the $A = 16$ nuclei

Barry R. Holstein and C. W. Kim

Phys. Rev. C 19, 1433 (1979) - Published 1 April, 1979

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The muon capture $μ^{-}$ + ${}^{16}O$ → ${}^{16}N$ *( $0^{-}$ )+ $ν_{μ}$ and the beta decay ${}^{16}N$ *( $0^{-}$ )→ ${}^{16}O$ + $e^{-} + {\bar{ν}}_{e}$ are analyzed in the elementary particle approach supplemented by some minimal dynamical assumptions. Predictions are found to be consistent with experiment without the need for substantial meson excahnge contributions.

NUCLEAR REACTIONS ${}^{16}O$ ( $μ$ , $ν_{μ}$ ) ${}^{16}N$ *( $0^{-}$ ), calculated capture rate; ${}^{16}N$ *( $0^{-}$ ), calculated beta decay rate.

Inelastic $α$ -particle scattering at intermediate energy

T. S. Bauer, R. Beurtey, A. Boudard, G. Bruge, H. Catz, P. Couvert, J. L. Escudié, J. M. Fontaine, M. Garçon, J. C. Lugol, M. Matoba, S. Platchkov, M. Rouger, and Y. Terrien

Phys. Rev. C 19, 1438 (1979) - Published 1 April, 1979

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The rigid body approximation is used to extend the Glauber formalism to the analysis of inelastic scattering of 1.37 GeV $α$ particles by ${}^{24}{Mg}$ and ${}^{58}{Ni}$ . Angular distributions for low-lying states in ${}^{24}{Mg}$ and ${}^{58}{Ni}$ are analyzed in this framework together with previously published data for Ca isotopes. Intermediate energy $α$ particle scattering is tested as a tool to observe the isoscalar giant quadrupole resonance. Energy weighted sum rules are drawn from the analysis of $L = 2$ angular distributions measured in the proper energy range. Comparison is made with existing data.

NUCLEAR REACTIONS ${}^{40, 42, 44}{Ca}$ ( $α$ , $α^{'}$ ), ${}^{24}{Mg}$ ( $α$ , $α^{'}$ ), ${}^{58}{Ni}$ ( $α$ , $α^{'}$ ), $E_{α} = 1.370$ GeV. Measured $σ (θ)$ , Glauber type analysis. Isoscalar resonances. Deduced ${β_{L}}^{2}$ .

Formalism for including the $Δ (1236)$ resonance in bound trinucleon systems

E. P. Harper, Y. E. Kim, and A. Tubis

Phys. Rev. C 19, 1450 (1979) - Published 1 April, 1979

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We present a generalized formulation and angular momentum reduction of the Faddeev equations in momentum space. This permits the consideration of nucleon-isobar configurations generated in the bound trinucleon system through the agency of transition potentials which connect nucleon-nucleon to nucleon-isobar and isobar-isobar two-body states. We show that the exact model equations can be made numerically tractable by dropping small terms in the coupled channel equations and that this then leads to a set of equations not significantly more difficult to solve than the usual Faddeev equations for the nucleon configurations alone. To accomplish this we have carried out a complete angular momentum reduction of the equations which enables us to identify the dominant terms. The procedure can easily be extended, at the cost of more tedious algebra, to allow for the inclusion of the smaller terms, but we believe that the system of equations presented here will account for the major part of the effects of the $Δ (1236)$ resonance in bound trinucleon systems.

NUCLEAR STRUCTURE Three nucleon bound state, coupled-channel formalism for inclusion of $Δ (1236)$ , $NN \leftrightarrow N Δ$ and $NN \leftrightarrow Δ Δ$ transition potentials

Superallowed Fermi decay of ${}^{62}{Ga}$

C. N. Davids, C. A. Gagliardi, M. J. Murphy, and E. B. Norman

Phys. Rev. C 19, 1463 (1979) - Published 1 April, 1979

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The superallowed $β^{+}$ decay of ${}^{62}{Ga}$ has been studied, using plastic and semiconductor $Δ E - E$ telescopes. The reaction ${}^{58}{Ni}$ ( ${}^{6}{Li}$ , $2 n$ ) ${}^{62}{Ga}$ was used to produce ${}^{62}{Ga}$ , with $E_{{}^{6}{Li}} = 25$ MeV. A half-life of 116.34±0.35 ms was obtained, and the total decay energy $Q_{EC}$ was measured to be 9171±26 keV. After applying radiative and charge-dependent corrections, the "corrected" $ft$ value $F t = 3081 \pm 47$ s was obtained, in excellent agreement with the value from Fermi decays in $A \leq 54$ nuclei.

RADIOACTIVITY ${}^{62}{Ga}$ , measured $T_{\frac{1}{2}}$ , $E_{β^{+}}$ ; deduced $Q_{EC}$ , $ft$ . High purity Ge, Si(Li), plastic detectors.

Electromagnetic effects and weak form factors

Barry R. Holstein

Phys. Rev. C 19, 1467 (1979) - Published 1 April, 1979

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Problems in determining nuclear bound state wave functions

R. D. Amado

Phys. Rev. C 19, 1473 (1979) - Published 1 April, 1979

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The interior part of a bound state is difficult to determine empirically. We use momentum space singularity structure to show that final state interactions, rescattering, exchange currents, etc., always act so as to obscure the bound state interior. The asymptotic part of the bound state can be measured for sufficiently "light" components. We apply these results to explain why the deuteron $D$ -state probability cannot be fixed and why it is difficult to give meaning to the idea of $π - N$ resonances in the nucleus. We treat bound state breakup, elastic scattering, and form factors.

NUCLEAR STRUCTURE Difficulties in empirical determination of bound state interiors. Application to deuteron $D$ -state and $N^{*}$ in nuclei.

Large scale shell-model calculations in the upper part of the $sd$ shell: General description and energy levels for $A = 36 - 39$

H. Hasper

Phys. Rev. C 19, 1482 (1979) - Published 1 April, 1979

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Results are presented of shell-model calculations for even and odd parity states in nuclei in the mass region $A = 36$ through $A = 39$ . In the model space used particles in the $2 s_{\frac{1}{2}}$ , $1 d_{\frac{3}{2}}$ , $1 f_{\frac{7}{2}}$ , and $2 p_{\frac{3}{2}}$ shells have been treated as active. The model space was truncated by a new method of diagonal percentage truncation. An effective Hamiltonian was employed, calculated by fitting to the binding energies of a number of reference levels. The calculated level schemes are compared with experimental data and discussed. The calculations yield good agreement with known data. Several $fp$ intruder states are located. On the basis of the calculations several predictions of angular momenta and parity of observed states have been made, as well as predictions of the excitation of not yet observed yrast states.

NUCLEAR STRUCTURE Calculated energy levels and effective interaction, $A = 36 - 39$ shell model.

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Yrast states in ${}^{62}{Zn}$

Band structure in ${}^{78}{Rb}$

Fragmentation of relativistic ${}^{56}{Fe}$

High-spin states in odd-mass ${}^{113 - 119}{Sb}$ : $Δ J = 1$ bands on $\frac{9}{2^{+}}$ proton-hole states

In-beam gamma-ray spectroscopy of ${}^{74}{Se}$ following the ${}^{60}{Ni}$ ( ${}^{16}O$ , $2 p$ ), ${}^{64}{Ni}$ ( ${}^{12}C$ , $2 n$ ) and ${}^{65}{Cu}$ ( ${}^{11}B$ , $2 n$ ) reactions

Application of a band crossing model for resonances in high energy ${}^{12}C$ - ${}^{12}C$ scattering

Intermediate structure in ${}^{12}C$ + ${}^{12}C$ elastic scattering

Shoulders in the very asymmetric mass distribution for reactor-neutron-induced fission of ${}^{238}U$

Differential fragmentation cross sections for 7.3 GeV nitrogen ions incident on protons

Kaon inelastic scattering and charge exchange on nuclei

Nuclear fragment production from 720-MeV alpha-induced reactions

Positive-pion photoproduction on ${}^{12}C$ near threshold

Energy dependence of the absorptive $S$ -wave pion-nucleus optical potential

Analysis of $0^{-}$ ↔ $0^{+}$ beta decay and muon capture in the $A = 16$ nuclei

Inelastic $α$ -particle scattering at intermediate energy

Formalism for including the $Δ (1236)$ resonance in bound trinucleon systems

Superallowed Fermi decay of ${}^{62}{Ga}$

Electromagnetic effects and weak form factors

Problems in determining nuclear bound state wave functions

Large scale shell-model calculations in the upper part of the $sd$ shell: General description and energy levels for $A = 36 - 39$

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