Recent Articles

Optical potential for ${}^{6}{Li}$ elastic scattering at 99 MeV

P. Schwandt, W. W. Jacobs, M. D. Kaitchuck, P. P. Singh, W. D. Ploughe, F. D. Becchetti, and J. Jänecke

Phys. Rev. C 24, 1522 (1981) - Published 1 October, 1981

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The differential cross section angular distributions for 99-MeV ${}^{6}{Li}$ elastic scattering from ${}^{12}C$ , ${}^{28}{Si}$ , ${}^{40}{Ca}$ , ${}^{58}{Ni}$ , ${}^{90}{Zr}$ , and ${}^{208}{Pb}$ have been measured for center-of-mass angles up to $θ_{max} = 43 ° - 69 °$ . The angular distributions show progressively less structure with increasing target mass which is characteristic of strongly absorbed particles. Phenomenological optical-model analyses with Woods-Saxon form factors exhibit both discrete and continuous ambiguities in the parameters which yield a good fit to the data. The $A$ dependence of several real central potential families and the effects of a surface absorption term have been investigated. A semimicroscopic single-folding ${}^{6}{Li}$ potential based on an ( $α + d$ )- cluster model for ${}^{6}{Li}$ gave a good description of the data only after renormalization of the real potential by a factor of ∼0.5.

NUCLEAR REACTIONS ${}^{12}C$ , ${}^{28}{Si}$ , ${}^{40}{Ca}$ , ${}^{58}{Ni}$ , ${}^{90}{Zr}$ , ${}^{208}{Pb}$ ( ${}^{6}{Li}$ , ${}^{6}{Li}$ ), $E_{Li} = 99$ MeV: measured elastic scattering $\frac{d σ}{d Ω}$ ; phenomenological and semimicroscopic optical model analyses.

Electromagnetic dissociation of relativistic ${}^{18}O$ nuclei

D. L. Olson, B. L. Berman, D. E. Greiner, H. H. Heckman, P. J. Lindstrom, G. D. Westfall, and H. J. Crawford

Phys. Rev. C 24, 1529 (1981) - Published 1 October, 1981

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Measurements of fragment-production cross sections have been made with ${}^{18}O$ projectiles of 1.7 GeV/nucleon incident upon targets of Be, C, Al, Ti, Cu, Sn, W, Pb, and U. We have found that the enhancement with high- $Z$ targets of cross sections for certain fragments agrees both in magnitude and $Z_{T}$ dependence with the predictions of the electromagnetic-dissociation process, which are based upon the known photonuclear cross sections and classical relativistic virtual-photon theory. We have found as well that factorization of the cross sections for nuclear processes is valid to an accuracy of better than 4%.

NUCLEAR REACTIONS Be( ${}^{18}O$ , $X$ ), $C ({}^{18}O, X)$ , Al( ${}^{18}O$ , $X$ ), Ti( ${}^{18}O$ , $X$ ), ${C u (}^{18}$ O, $X$ ), Sn( ${}^{18}O$ , $X$ ), W( ${}^{18}O$ , $X$ ), Pb( ${}^{18}O$ , $X$ ), U( ${}^{18}O$ , $X$ ), $X = {}^{6}{Li} to {}^{18}F$ , $E = 1.7$ GeV/nucleon; measured fragment-production cross sections; deduced electromagnetic-dissociation cross sections, $Z_{T}$ dependence, factorization parameters. ${}^{18}O$ fragment-production cross sections, electromagnetic dissociation, factorization, relativistic heavy ions.

${}^{230}{Th}$ fission cross section near 715 keV

L. R. Veeser and D. W. Muir

Phys. Rev. C 24, 1540 (1981) - Published 1 October, 1981

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We have used neutrons from an underground nuclear explosion to measure the differential fission cross section of ${}^{230}{Th}$ at two angles for the resonance near 715 keV. The relative energy resolution was about 1 keV. We find evidence for fine structure within the resonance, but individual peaks are not completely resolved.

NUCLEAR REACTIONS ${}^{230}{Th}$ ( $n$ , $f$ ), $E_{n} = 690 - 760$ keV; measured $σ (E_{n}, θ_{fragment})$ .

Reactor antineutrino spectra and their application to antineutrino-induced reactions. II

P. Vogel, G. K. Schenter, F. M. Mann, and R. E. Schenter

Phys. Rev. C 24, 1543 (1981) - Published 1 October, 1981

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The antineutrino and electron spectra associated with various nuclear fuels are calculated. While there are substantial differences between the spectra of different uranium and plutonium isotopes, the dependence on the energy and flux of the fission-inducing neutrons is very weak. The resulting spectra can be used for the calculation of the antineutrino and electron spectra of an arbitrary nuclear reactor at various stages of its refueling cycle. The sources of uncertainties in the spectrum are identified and analyzed in detail. The exposure time dependence of the spectrum is also discussed. The averaged cross sections of the inverse neutron $β$ decay, weak charged and neutral-current-induced deuteron disintegration, and the antineutrino-electron scattering are then evaluated using the resulting ${\bar{ν}}_{e}$ spectra.

RADIOACTIVITY, FISSION ${}^{235}U$ , ${}^{238}U$ , ${}^{239}{Pu}$ , ${}^{240}{Pu}$ , ${}^{241}{Pu}$ , antineutrino and electron spectra calculated. $σ$ for $\bar{ν}$ induced reactions analyzed.

Pauli blocking in pion- ${}^{4}{He}$ scattering including partial wave mixing

J. de Kam

Phys. Rev. C 24, 1554 (1981) - Published 1 October, 1981

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Detailed calculations are presented of the Pauli blocking correction in $π$ - ${}^{4}{He}$ scattering for the energy range $T_{π} = 24 - 220$ MeV. Pion-nucleon partial wave mixing which is due to the Pauli projection operator is taken into account for the first time. The first-order optical potential of Celenza, Liu, and Shakin is used. The nucleon-core interaction is simulated by means of an effective $π - N$ subenergy. Satisfactory results are obtained for the cross sections at low energies. However, at intermediate energies the elastic cross sections are overestimated by 30-40%. The partial wave mixing which is introduced by the Pauli principle generates a small correction at low energies but in the resonance region it leads to a clear increase in the cross sections by 10-20%.

NUCLEAR REACTIONS $π$ - ${}^{4}{He}$ scattering, $T_{π} = 24 - 220$ MeV, optical potential, Pauli-principle corrections.

Test of charge symmetry in the $np \to d π^{0}$ reaction at 795 MeV

C. L. Hollas, C. R. Newsom, P. J. Riley, B. E. Bonner, and G. Glass

Phys. Rev. C 24, 1561 (1981) - Published 1 October, 1981

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The angular distribution for the $np \to d π^{0}$ reaction has been measured at 795 MeV from 2° to 178° center of mass to search for direct evidence for charge symmetry breaking forces. No evidence for an asymmetry about 90° is found to the order of ±0.50% for the integrated asymmetry parameter $A_{fb}$ . Good agreement is obtained for the shape of the angular distribution with those for the $pp \to d π^{+}$ reaction near 800 MeV. Definite evidence is found for the $f$ -wave pion-deuteron final state.

NUCLEAR REACTIONS $np \to d π^{0}$ , $E = 795$ MeV; measured $σ (θ)$ deduced Legendre polynomial coefficient ratios: test of charge symmetry breaking forces of strong interaction.

Unified theory of $NN \to π d$ , $π d \to π d$ , and $NN \to NN$ reactions

B. Blankleider and I. R. Afnan

Phys. Rev. C 24, 1572 (1981) - Published 1 October, 1981

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Using a set of equations that couple the $N - N$ to the $π - d$ channel and satisfy two- and three-body unitarity, we have studied in detail the reaction $pp \to π^{+} d$ , and $π d \to π d$ and $NN \to NN$ scattering. We find that the equations give a very good description of the differential cross sections and some of the polarization data for both $\vec{p} p \to π^{+} d$ and $π d \to π \vec{d}$ over the energy region $47 < T_{π} < 256$ MeV. We observe that for $pp \to π^{+} d$ , higher partial waves ( $l_{π d} > 2$ ) contribute significantly to both the differential cross section and analyzing power. Including the $P_{11} π - N$ interaction and thus true absorption in $π - d$ elastic scattering, we find a cancellation between the pole and nonpole parts of the $P_{11}$ amplitude. A major part of the effect of true absorption is in $J^{π} = 0^{+}$ , which contributes little to the absorption cross section. The sensitivity of the results to the $D$ state of the deuteron and the choice of the $π NN$ form factor is investigated. For $N - N$ scattering the agreement with the experimental phase shifts is better in the singlet than triplet channels. This is due to the absence of vector meson exchange in the calculation. The ${}^{1}D_{2}$ phase shift exhibits resonance behavior in the absence of a pole in the amplitude.

NUCLEAR REACTIONS $pp \leftrightarrow π d$ , $π d \to π d$ . Total and differential cross section, polarization. $47 < T_{π} < 256$ MeV. $N - N$ $I = 1$ phase shifts.

Regge trajectories for a pion-nucleus optical potential

P. Sanz, J. Sañudo, and J. Sesma

Phys. Rev. C 24, 1596 (1981) - Published 1 October, 1981

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The trajectories of the singularities of the $S$ matrix in the complex angular momentum plane, as the energy varies, are discussed for a pion-nucleus optical potential of the Kisslinger type. Special attention is paid to the existence of strongly bound states, recently suggested.

NUCLEAR REACTIONS Pion-nucleus optical potential; Regge trajectories; nuclear bound states of pions in nuclei.

Delta-hole formalism of pion-nucleus single charge exchange scattering

M. Hirata

Phys. Rev. C 24, 1604 (1981) - Published 1 October, 1981

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The pion-nucleus single charge exchange scattering matrix is described by the nonstatic theory based on the delta-hole formalism which is quite successful for the pion-nucleus elastic scattering in the (3,3) resonance energy region. The calculated excitation function of the ${}^{13}C$ ( $π^{+}$ , $π^{0}$ ) ${}^{13}N_{q . s .}$ charge exchange scattering cross section becomes flat between the pion kinetic energies 70 and 230 MeV, but the theoretical integrated cross sections are roughly a factor of 3 less than the observed ones. The observed shape of angular distribution at 150 MeV is well reproduced by our theory, although the absolute values of the calculated angular distribution are slightly smaller than the measurements.

NUCLEAR REACTIONS Pion-nucleus single charge exchange scattering. Delta-hole formalism, pion energy 70-230 MeV.

Electric monopole transitions between $O^{+}$ states in ${}^{102}{Ru}$

M. Koike, K. Komura, H. Kawakami, M. Kanbe, H. Yamada, G. Madiueme, S. Shibata, T. Fujisawa, and T. Wada

Phys. Rev. C 24, 1611 (1981) - Published 1 October, 1981

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The electric monople ( $E 0$ ) transition from the first excited $0^{+}$ state at 943.67 keV in ${}^{102}{Ru}$ is observed from the internal conversion electron studies. The dimensionless ratio of the $E 0$ to $E 2$ transition probabilities, $X (\frac{E 0}{E 2})$ , is deduced to be 0.013±0.002. The monopole moment $ρ (E 0)$ is estimated as 0.092.

RADIOACTIVITY ${}^{102}{Rh}$ [from ${}^{102}{Ru}$ ( $p$ , $n$ )]; measured $E_{ce}$ , $I_{ce}$ , $E_{γ}$ , $I_{γ}$ . ${}^{102}{Rh}$ deduced branching ratio $\frac{B (E 0)}{B (E 2)}$ , monopole moment $ρ (E 0)$ .

Decay of ${}^{121}{Cs}^{m, g}$ and ${}^{123}{Cs}$

K. Sofia, B. N. Subba Rao, and J. E. Crawford

Phys. Rev. C 24, 1615 (1981) - Published 1 October, 1981

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Radiations from ${}^{121}{Cs}^{m, g}$ and ${}^{123}{Cs}$ , produced by bombarding 41% enriched ${}^{124}{Xe}$ gas targets with protons, have been investigated with several Ge detectors in singles, two parameter $γ - γ$ and $β - γ$ coincidence, and multispectrum modes. Two groups of gamma rays with slightly different half-lives are observed in ${}^{121}{Cs}^{m} ({\frac{9}{2}}^{+})$ to decay to high spin levels with a half-life of 121±3 sec, and ${}^{121}{Cs}^{g} ({\frac{3}{2}}^{+})$ to low spin levels with 136±3 sec half-life. The decay energy of ${}^{121}{Cs}^{g} \to {}^{121}{Xe}^{g}$ was measured to be 5.40±0.02 MeV and that of ${}^{123}{Cs}$ (365±4 sec) to be 4.0±0.1 MeV. $K$ -conversion coefficients determined by the $\frac{x}{γ}$ method are 11±1 for the 38.38 keV transition of ${}^{121}{Cs}^{m}$ , and 1.3±0.1 and 0.9±0.1 for the 83.38 and 97.39 keV transitions of ${}^{123}{Cs}$ , requiring these transitions to be $40 % M 1 + 60 % E 2$ , $90 % M 1 + 10 % E 2$ , and $80 % M 1 + 20 % E 2$ , respectively. The $log ft$ values, the above multipolarities, and the branchings of electromagnetic transitions enable a few spin and parity assignments to levels in ${}^{121}{Xe}$ and ${}^{123}{Xe}$ . Decay schemes of ${}^{121}{Cs}^{m} ({\frac{9}{2}}^{+})$ , ${}^{121}{Cs}^{g} ({\frac{3}{2}}^{+})$ , and ${}^{123}{Cs}$ ( $½^{+}$ ) are deduced from these observations. Some of the levels of ${}^{121}{Xe}$ and ${}^{123}{Xe}$ can be identified with low lying excitations of intrinsic states of the Nilsson model with deformation parameter $β = + 0.16 to + 0.19$ .

RADIOACTIVITY ${}^{124}{Xe}$ ( $p$ , $2 n$ ) ${}^{123}{Cs}$ , $E_{p} = 33$ MeV; ${}^{124}{Xe}$ ( $p$ , $4 n$ ) ${}^{121}{Cs}$ , $E_{p} = 52$ MeV; measured $E_{γ}$ , $I_{γ}$ , $γ - γ$ coincidence, ICC, $Q_{EC}$ ; deduced ${}^{121}{Xe}$ , ${}^{123}{Xe}$ levels, $log ft$ , $I$ , $π$ ; enriched Xe gas targets. In-beam ${}^{122}{Te}$ ( $α$ , $5 n γ$ ) ${}^{121}{Xe}$ , $E_{\propto} = 69$ MeV, $γ - γ$ coincidence, enriched Te targets.

Nuclear levels in ${}^{176}{Lu}$

R. A. Dewberry, R. K. Sheline, R. G. Lanier, L. G. Mann, and G. L. Struble

Phys. Rev. C 24, 1628 (1981) - Published 1 October, 1981

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The nuclear structure of ${}^{176}{Lu}$ has been studied with the ( $t$ , $α$ ) reaction on an isotopically enriched target of ${}^{177}{Hf}$ using a 17 MeV triton beam and a quadrupole-triple-dipole-type spectrometer. These measurements were combined with published ( $n$ , $γ$ ), ( $n$ , $e^{-}$ ), and ( $d$ , $p$ ) data to construct a level scheme for ${}^{176}{Lu}$ . The Nilsson model including Coriolis coupling calculations has been used to interpret the level structure. The previously known Nilsson configurations $\frac{7}{2^{+}} [404] + \frac{7}{2^{-}} [514]$ , $\frac{7}{2^{+}} [404] - \frac{7}{2^{-}} [514]$ , $\frac{7}{2^{+}} [404] - \frac{9}{2^{+}} [624]$ , and $\frac{9}{2^{-}} [514] - \frac{7}{2^{-}} [514]$ with bandhead energies 0, 240.56, 198.01, and 342.48 keV, respectively, have been populated in the ( $t$ , $α$ ) reaction. Proposed new Nilsson configurations and bandhead energies are: $\frac{5}{2^{+}} [402] - \frac{7}{2^{-}} [514]$ at 390.21 keV, $\frac{9}{2^{-}} [514] + \frac{7}{2^{-}} [514]$ at 485.7 keV, $\frac{5}{2^{+}} [402] + \frac{7}{2^{-}} [514]$ at 563.89 keV, $\frac{1}{2^{+}} [411] + \frac{7}{2^{-}} [514]$ at 726.51 keV, $\frac{1}{2^{+}} [411] - \frac{7}{2^{-}} [514]$ at 838.36 keV, $\frac{7}{2^{-}} [523] + \frac{7}{2^{-}} [514]$ at 1273 keV, and $\frac{3}{2^{+}} [411] + \frac{7}{2^{-}} [514]$ at 1390.67 keV. The five new values of the singlet-triplet splitting energies and one new $K = 0$ odd-even shift observed in this study are compared with theory.

NUCLEAR REACTIONS ${}^{20}{Ne}$ + ${}^{238}U$ , $E_{lab} = 400$ MeV/nucleon fluid dynamics, viscosity, heat conduction, cross sections.

Nuclear levels in ${}^{170}{Tm}$

Raymond A. Dewberry, Raymond K. Sheline, Robert G. Lanier, Gordon L. Struble, and Lloyd G. Mann

Phys. Rev. C 24, 1643 (1981) - Published 1 October, 1981

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Levels in ${}^{170}{Tm}$ have been observed up to an excitation energy of 1900 keV using the ${}^{171}{Yb}$ ( $t$ , $α$ ) ${}^{170}{Tm}$ reaction. Many of the observed levels can be assigned as the successive coupling of the $\frac{1}{2^{+}} [411 ↓]$ , $\frac{7}{2^{+}} [404 ↓]$ , $\frac{5}{2^{+}} [402 ↑]$ , $\frac{3}{2^{+}} [411 ↑]$ , $\frac{7}{2^{-}} [523 ↑]$ , and $\frac{5}{2^{+}} [413 ↓]$ protons to the $\frac{1}{2^{-}} [521 ↓]$ neutron. The following levels (denoted by bandhead energy in keV or energy of lowest spin member observed, spins assigned, $K^{π}$ , and Nilsson configuration) have been assigned: 644, $I = 4$ , $4^{-}$ [404↓ + 521↓]; 716, $I = 2$ , $2^{-}$ [402↑ - 521↓]; $I = 2$ level at 744, $I = 2 and 3$ , $1^{-}$ [411↑ - 521↓]; 774, $I = 3$ , $3^{-}$ [404↓ - 521↓]; $I = 5$ level at 829, $I = 5 and 6$ , $4^{+}$ [523↑ + 521↓]; 851, $I = 2 and 3$ , $2^{-}$ [411↑ + 521↓]; 867, $I = 3$ , $3^{-}$ [402↑ + 521↓]; $I = 5$ level at 891, $I = 5 and 6$ , $3^{+}$ [523↑ - 521↓]; 1213, $I = 3 and 4$ , $3^{-}$ [413↓ + 521↓]; 1382, $I = 2 to 4$ , $2^{-}$ [413↓ - 521↓]. In addition, higher spin members of the [411↓ ± 521↓] ground state configuration and the $K^{π} = 1^{-}$ $γ$ -vibrational band built on the ground state have been proposed. Coriolis coupling calculations were performed, and anomalous experimental ( $t$ , $α$ ) intensities were interpreted in terms of this interaction. Anomalous population of the previously known [411↓ ± 512↑] neutron excited state configuration has been observed and interpreted in terms of the residual neutron-proton interaction.

NUCLEAR REACTIONS ${}^{171}{Yb}$ ( $t$ , $α$ ) ${}^{170}{Tm}$ with isotopically enriched target; $E_{t} = 17.0$ MeV; measured $E_{α}$ and $σ (θ)$ with Q3D spectrometer; DWBA analysis; deduced levels $I^{π}$ , $K$ . NUCLEAR STRUCTURE ${}^{170}{Tm}$ assigned Nilsson configurations; mixed bands $K^{'}$ of neutron excited state configuration with bands $K$ of proton excited state configuration satisfying condition $δ_{K^{'}, K}$ .

Low-lying spectra of transitional odd-mass nuclei described in angular momentum projected one-quasiparticle states

Akitsu Ikeda

Phys. Rev. C 24, 1656 (1981) - Published 1 October, 1981

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A previously proposed model of a particle coupled to a soft rotor is extended in order that both of the unique parity and the normal parity orbits can be indiscriminately treated in the same framework. Numerical calculations are performed for the odd-mass La and Pd isotopes. The low-lying energy spectra and variation of the spectra with mass number are well reproduced.

NUCLEAR STRUCTURE ${}^{127, 129, 131, 133, 135}{La}$ , ${}^{101, 103, 105, 107, 109}{Pd}$ ; calculated levels, $J$ , $π$ . Approximate angular momentum projection out of one-quasiparticle states.

Muonic x-ray study of the even Os nuclei

M. V. Hoehn, E. B. Shera, H. D. Wohlfahrt, Y. Yamazaki, R. M. Steffen, and R. K. Sheline

Phys. Rev. C 24, 1667 (1981) - Published 1 October, 1981

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Precision measurements have been made of the muonic x-ray spectra of the transitional nuclei ${}^{186, 188, 190, 192}{Os}$ . Equivalent Barrett radii and isotope shifts have been determined, as have isomer shifts of the first excited $2^{+}$ states. These results are compared with other experiments and with theoretical calculations. The systematics of isotope shifts in the deformed nuclei are also discussed. Generalized $E 2$ moments of the charge distribution have been extracted in a nearly model-independent way and conventional electromagnetic moments have been deduced by assuming a specific transition charge density model. The latter are in good agreement with recent calculations of both the interacting boson approximation and the boson expansion theory. However, a serious discrepancy in the values of the quadrupole moments determined from the muonic and Coulomb excitation experiments is apparent. The model dependence of the muonic results (including the effect of a triaxial model charge distribution) is explored as a possible cause of the discrepancy; however, no effect large enough to explain the discrepancy is found. Furthermore, no feature of the muonic spectra was found which could be used to distinguish between a triaxial and an axially symmetric charge distribution.

NUCLEAR STRUCTURE ${}^{186, 188, 190, 192}{Os}$ ; measured muonic x-ray spectra; deduced monopole and quadrupole charge parameters, isotope and isomer shifts.

Pion-condensation threshold in nuclear matter and thermal $Δ$ isobars

P. Hecking

Phys. Rev. C 24, 1691 (1981) - Published 1 October, 1981

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The pion-condensation threshold in symmetric ( $N = Z$ ) nuclear matter at finite temperatures $0 \leq k_{B} T \leq 100$ MeV is calculated. The influence of thermally excited $Δ$ isobars—present in the nucleon medium—on the threshold is investigated and found to be moderately repulsive (i.e., raising the threshold density).

NUCLEAR STRUCTURE Pion condensation in nuclear matter, thermal $Δ$ isobars at finite temperature.

Nuclear structure of even- $A$ chromium isotopes in the band-mixed projected Hartree-Fock model

Surender Saini and M. R. Gunye

Phys. Rev. C 24, 1694 (1981) - Published 1 October, 1981

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Nuclear structure calculations for the states in even- $A$ isotopes ${}^{48 - 54}{Cr}$ are performed in the framework of the projected Hartree-Fock model by employing a realistic nucleon-nucleon interaction. An inert ${}^{40}{Ca}$ core is assumed and all the valence nucleons are treated explicitly in the configuration space of the full $fp$ shell. The energy levels, static electromagnetic moments, and transition probabilities are evaluated from the band mixing calculations wherein a large number of energetically close intrinsic states of the nuclei are taken into account. These calculations yield a $K^{π} = 2^{+}$ and $K^{π} = 4^{+}$ highly deformed band for ${}^{50}{Cr}$ and ${}^{52}{Cr}$ , respectively, when a neutron from the predominantly ${(f_{\frac{7}{2}})}^{n}$ lowest prolate intrinsic configuration is promoted to the higher unoccupied ( $fp$ ) orbits. The results of the present calculations are in fairly good agreement with the available experimental data.

NUCLEAR STRUCTURE Even- $A$ chromium isotopes. Calculated spectra, static moments, transition strengths $B (E 2)$ and $B (M 1)$ . Projected Hartree-Fock model with band mixing, ${(fp)}^{n}$ model space, modified Kuo-Brown interaction.

Interacting boson approximation description of the collective states of ${}^{168}{Er}$ and a comparison with geometrical models

D. D. Warner, R. F. Casten, and W. F. Davidson

Phys. Rev. C 24, 1713 (1981) - Published 1 October, 1981

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The interacting boson approximation has been used to calculate the positive parity states of ${}^{168}{Er}$ below 2 MeV. A simple parametrization has been used which corresponds to a description close to the SU(3) limit of the model. The predictions have been compared with new results available from a recent experimental study. Particular attention has been paid to the absolute magnitude of predicted $B (E 2)$ values in assessing the significance of discrepancies between theory and experiment. Estimates of absolute strengths have also been obtained for $M 1$ transitions in the scheme. The calculations correctly reproduce the complete sequence of $K^{π} = 0^{+} and 2^{+}$ bands below the pairing gap and provide an excellent overall description of their decay properties. Most importantly, the predicted dominance of the decay from the $β$ to the $γ$ band, over that to the ground state band, which represents a fundamental characteristic of the model in this region, is reflected by the experimental data. The reproduction of this feature from a band mixing approach in the framework of the geometrical description is also discussed, and the connection between the two descriptions is explored.

NUCLEAR STRUCTURE Interacting boson approximation applied to ${}^{168}{Er}$ . Calculated levels, $B (E 2)$ , branching ratios. Single particle estimates of $B (M 1)$ , $B (E 2)$ . Comparison with experimental and bandmixing formalism in rotational model.

Tensor polarization and magnetic form factor and the percentage $D$ state of the deuteron

L. J. Allen and H. Fiedeldey

Phys. Rev. C 24, 1734 (1981) - Published 1 October, 1981

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The elastic electron-deutron electric and magnetic form factors $A (q)$ and $B (q)$ and tensor polarization $T_{2 \pm 1}$ have been calculated for a family of phase equivalent deuteron wave functions with a percentage $D$ state $P_{D}$ varying from 4.5 to 7.5% (generated by unitary transformation from the super-soft-core potential of de Tourreil and Sprung). It is demonstrated that measurements of $T_{2 \pm 1}$ for momentum transfers in the range $0 ≲ q ≲ 6$ ${fm}^{- 1}$ would not allow us to discriminate between all physically reasonable deuteron wave functions with different $P_{D}$ . We also find that accurate measurements of $B (q)$ in the region $4 ≲ q ≲ 6$ ${fm}^{- 1}$ are likely to narrow down the allowable range of values of $P_{D}$ a priori, without the need of difficult measurements of $T_{2 \pm 1}$ .

NUCLEAR STRUCTURE ${}^{2}H$ electric, magnetic form factors, tensor polarization calculated: phase equivalent deuteron wave functions; $P_{D}$ of deuteron wave function.

Path integrals for the nuclear many-body problem

J. P. Blaizot and H. Orland

Phys. Rev. C 24, 1740 (1981) - Published 1 October, 1981

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We present a general method for constructing path intergrals for the nuclear many-body problem. This method uses continuous and overcomplete sets of vectors in the Hilbert space. The state labels play the role of classical coordinates which are quantized as bosons. The equations of motion for the classical coordinates are obtained by calculating the functional integral in the saddle point approximation. In the particular case where the over-complete set considered is the set of all Slater determinants, the classical equations of motion are the time-dependent Hartree-Fock equations. The functional integral provides a way of requantizing these classical equations. This quantization involves boson degrees of freedom and is in some cases very similar to the method of boson expansion. It is shown that the functional integral formalism provides a unifying framework to describe various approaches to the nuclear many-body problem.

NUCLEAR STRUCTURE Functional integrals on continuous over-complete sets. Time-dependent Hartree and Hartree-Fock theories. Boson representations for fermion systems.

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Optical potential for ${}^{6}{Li}$ elastic scattering at 99 MeV

Electromagnetic dissociation of relativistic ${}^{18}O$ nuclei

${}^{230}{Th}$ fission cross section near 715 keV

Reactor antineutrino spectra and their application to antineutrino-induced reactions. II

Pauli blocking in pion- ${}^{4}{He}$ scattering including partial wave mixing

Test of charge symmetry in the $np \to d π^{0}$ reaction at 795 MeV

Unified theory of $NN \to π d$ , $π d \to π d$ , and $NN \to NN$ reactions

Regge trajectories for a pion-nucleus optical potential

Delta-hole formalism of pion-nucleus single charge exchange scattering

Electric monopole transitions between $O^{+}$ states in ${}^{102}{Ru}$

Decay of ${}^{121}{Cs}^{m, g}$ and ${}^{123}{Cs}$

Nuclear levels in ${}^{176}{Lu}$

Nuclear levels in ${}^{170}{Tm}$

Low-lying spectra of transitional odd-mass nuclei described in angular momentum projected one-quasiparticle states

Muonic x-ray study of the even Os nuclei

Pion-condensation threshold in nuclear matter and thermal $Δ$ isobars

Nuclear structure of even- $A$ chromium isotopes in the band-mixed projected Hartree-Fock model

Interacting boson approximation description of the collective states of ${}^{168}{Er}$ and a comparison with geometrical models

Tensor polarization and magnetic form factor and the percentage $D$ state of the deuteron

Path integrals for the nuclear many-body problem

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