Recent Articles

Proton hole states in neutron rich Pd nuclei

E. R. Flynn, F. Ajzenberg-Selove, Ronald E. Brown, J. A. Cizewski, and J. W. Sunier

Phys. Rev. C 27, 2587 (1983) - Published 1 June, 1983

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The ( $\vec{t}, α$ ) reaction at 17 MeV triton energy has been used to study proton hole states in targets of ${}^{106, 108, 110}{Pd}$ . The results indicate that for the residual nuclei, ${}^{105, 107, 109}{Rh}$ , the ground states have a spin of ${\frac{7}{2}}^{+}$ , in contrast to the lighter Rh nuclei, and are not of single-particle character. Coupled-channels analysis indicates a possible particle-vibration character for these ground states. A strong neutron-proton interaction may be evident from the level systematics of Rh nuclei as the ground state spins change between $N = 58$ and $N = 60$ ( ${}^{103}{Rh}$ and ${}^{105}{Rh}$ ).

NUCLEAR REACTIONS ${}^{106, 108, 110}{Pd} (\vec{t}, α)$ , $E = 17.0$ MeV; measured $σ (θ)$ , $A_{y}$ . Deduced levels ${}^{105, 107}{Rh}$ . DWBA, CCBA analyses.

Energy dependence of the ${}^{124}{Sn} (p, t)$ reaction to the $3^{-}$ - $10^{+}$ two-quasiparticle states of ${}^{122}{Sn}$ at incident energies of 34.9, 45.1, 54.7, and 65.0 MeV

M. Matoba, K. Tsuji, K. Marubayashi, T. Shintake, K. Ohba, and T. Nomiyama

Phys. Rev. C 27, 2598 (1983) - Published 1 June, 1983

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Angular distributions for the ${}^{124}{Sn} (p, t)$ reaction to low-lying $3^{-}$ , $4^{+}$ , $5^{-}$ , $6^{+}$ , $7^{-}$ , $8^{+}$ , and $10^{+}$ two-quasiparticle states of ${}^{122}{Sn}$ were measured at $E_{p} = 34.9, 45.1, 54.7, and 65.0$ MeV and analyzed with zero-range distorted-wave Born approximation theory. The shapes of the angular distributions are reasonably well reproduced with the zero-range theory using one average optical potential set and the deduced enhancement factors are almost constant with smoothly decreasing zero-range normalization constants as a function of the incident energy.

NUCLEAR REACTIONS ${}^{124}{Sn} (p, t)$ , $E_{p} = 34.9, 45.1, 54.7, and 65.0$ MeV; measured $σ (E_{t}, θ)$ absolute. DWBA analysis, zero-range, energy dependence of enhancement factors. Enriched target.

( $n, n^{'} γ$ ) study of collective excitations in ${}^{192}{Os}$ : Comparison with the boson models for transitional nuclei

E. W. Kleppinger and S. W. Yates

Phys. Rev. C 27, 2608 (1983) - Published 1 June, 1983

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The ( $n, n^{'} γ$ ) reaction has been used to study low-lying collective excitations in ${}^{192}{Os}$ . Measurements of $γ$ -ray excitation functions at incident neutron energies from 1.0 to 3.0 MeV and detailed $γ$ -ray angular distributions at 2.5-MeV neutron energy have led to the placement of many new levels in a level scheme now incorporating 54 levels below 2.4 MeV. In many cases, the assignment of a unique spin-parity has been possible. The positive-parity states compare favorably with interacting boson approximation and boson expansion theory calculations, except for the $0_{3}^{+}$ excitation, which is inconsistent with predictions of both models. No negative-parity band structure is apparent.

NUCLEAR REACTIONS ${}^{192}{Os} (n, n^{'} γ)$ , $E_{n} = 1.0 - 3.0$ MeV; measured $E_{γ}$ , $I_{γ}$ , $σ (E, E_{γ}, θ_{γ})$ . ${}^{192}{Os}$ deduced levels, branching ratios, $J$ , $π$ . Compared levels and branching ratios to theory. Enriched target, Ge(Li) detector, time-of-flight background suppression.

Multinucleon-transfer reactions between light-heavy ions

M. Sato, M. Sasagase, Y. Nagashima, J. Schimizu, T. Nakagawa, Y. Fukuchi, and T. Mikumo

Phys. Rev. C 27, 2621 (1983) - Published 1 June, 1983

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Reactions ${}^{16 - 18}O$ + ${}^{27}{Al}$ and ${}^{19}F$ + ${}^{27}{Al}$ are studied at about 5 MeV/nucleon. ${}^{16}O$ + ${}^{27}{Al}$ reactions are studied also at lower energies. General features of energy spectra, the most probable $Q$ values, which show a large energy dissipation, and, in particular, angular distributions of projectilelike products are found to be very similar to those of deep inelastic collisions of heavier systems at much higher energies. All the angular distributions in $Q$ -value intervals of 5 MeV, $\frac{d^{2} σ}{d Ω dQ}$ , exhibit forward-peaking features and are well fitted by a form $A \frac{\exp (- μ θ)}{sin θ}$ . Systematics of the variation of $μ$ vs $| Q |$ and the number of transferred nucleons, $n$ , are discussed. A picture of the rotating dinucleus model is consistent with the present observations. Cross sections of isotope production have a simple relation with $Q_{gg}$ including a nonpairing effect of the residual targetlike nucleus.

NUCLEAR REACTIONS ${}^{27}{Al} ({}^{16}O, X)$ , $E = 88, 70, 60$ MeV, ${}^{27}{Al} ({}^{17}O, X)$ , $E = 86.4$ MeV, ${}^{27}{Al} ({}^{18}O, X)$ , $E = 88$ MeV, ${}^{27}{Al} ({}^{19}F, X)$ , $E = 95$ MeV, $Z = isotopes of elements$ from $Z = 2 to Z$ (projectile), measured energy spectra, $σ$ , $σ (θ)$ , and $σ (θ, Q)$ .

Angular correlations between heavy ions and $α$ particles in ${}^{16}O$ + ${}^{27}{Al}$ collisions at 87.4 MeV: Evidence of sequential decay of projectilelike fragments

M. Sasagase, M. Sato, S. Hanashima, K. Furuno, Y. Nagashima, Y. Tagishi, S. M. Lee, and T. Mikumo

Phys. Rev. C 27, 2630 (1983) - Published 1 June, 1983

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Angular correlations have been investigated between projectilelike fragments (from Li to O) and α particles in ${}^{16}O$ + ${}^{27}{Al}$ collisions at 87.4 MeV. For C- $α$ and O- $α$ correlations, clear evidence of the sequential $α$ decays of projectilelike fragments was observed at forward angles. In ${}^{27}{Al} ({}^{16}O, {}^{12}C (g . s .) α) {}^{27}{Al} (g . s .)$ , the reaction proceeds mainly via the sequential $α$ decay of the excited ${}^{16}O$ nucleus at $E_{α} ≅ 10, 11.6, 13.2, 15.2, 16.2, and 21$ MeV. For the O- $α$ case, evidence of the sequential α decay of ${}^{20}{Ne}$ * ( $E_{x} ≅ 8.7, 12.0, and 15.2$ MeV) was observed.

NUCLEAR REACTIONS ${}^{16}O$ + ${}^{27}{Al}$ , $E_{lab} = 87.4$ MeV; measured $\frac{d^{2} σ}{d Ω_{HI} d Ω_{α}}$ , coincidence between O, N, C, B, Li, and $α$ , in-plane and out-of-plane angular correlations, ${}^{27}{Al}$ target.

Implications of angular momentum conservation for fluctuations in heavy ion reactions

L. C. Dennis

Phys. Rev. C 27, 2641 (1983) - Published 1 June, 1983

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A method is presented for calculating synthetic excitation functions and angular distributions which includes angular momentum conservation. The results of the calculations are used to study the effect of $\frac{Γ_{J}}{D_{J}}$ , the average coherence width divided by the average level density for each value of $J$ , on fluctuations, angular distributions, and changes in the angular distributions near maxima in the excitation functions. The relation between $\frac{Γ_{J}}{D_{J}}$ and the observation of resonances in heavy ion reactions is discussed. The implications of these studies on fluctuation analysis are also discussed.

NUCLEAR REACTIONS Statistical model calculations of $σ (θ)$ , $σ (E)$ .. Fluctuations, resonances.

Search for transfer-induced ${}^{12}C$ + ${}^{12}C$ resonances in the ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}^{*}$ reaction

J. S. Karp, D. Abriola, R. L. McGrath, and W. A. Watson, III

Phys. Rev. C 27, 2649 (1983) - Published 1 June, 1983

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Evidence for population of ${}^{12}C$ + ${}^{12}C$ resonant states in the ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}^{*}$ transfer reaction at 130 MeV incident energy was sought in carbon-carbon coincidence data. Carbon momenta were measured with position sensitive telescopes centered at + 35° and -30°. Despite the fact that the experimental configuration discriminates against the prolific projectile breakup process, few events are observed in the kinematic regions corresponding to the resonances. A Monte Carlo simulation of the ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}^{*} \to {}^{12}C + {}^{12}C$ sequential reaction indicates that the transfer production cross section of resonant states is less than one-fourth the value in the literature based on $α$ -particle singles data at 145 MeV incident energy.

NUCLEAR REACTIONS ${}^{16}O + {}^{12}C \to {}^{12}C + {}^{12}C + α$ , $E = 130$ MeV; measured coin. ${\vec{P}}_{carbon}$ ; compared Monte Carlo simulation ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}^{*} \to {}^{12}C + {}^{12}C$ reaction.

Excitation functions for production of heavy actinides from interactions of ${}^{18}O$ with ${}^{248}{Cm}$ and ${}^{249}{Cf}$

Diana Lee, Kenton J. Moody, Matti J. Nurmia, Glenn T. Seaborg, Hans R. von Gunten, and Darleane C. Hoffman

Phys. Rev. C 27, 2656 (1983) - Published 1 June, 1983

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Excitation functions have been measured for the production of isotopes of Bk through Fm in bombardments of ${}^{248}{Cm}$ with 97- to 122-MeV ${}^{18}O$ ions and of isotopes of Bk through No in bombardments of ${}^{249}{Cf}$ with 91- to 150-MeV ${}^{18}O$ ions. The cross sections and widths of the mass distributions for the actinides produced in these reactions are very similar for transfer of the same numbers of nucleons. A semiquantitative comparison of the experimental results with calculations based on a simple model shows that calculations of this type are helpful in selection of projectile-target systems and optimum energies for production of specific actinide isotopes and for synthesis of as yet unknown heavy isotopes and elements. Comparisons of experimental results with calculations show that, in general, about half of the kinetic energy of the projectile is transferred to the actinide product.

NUCLEAR REACTIONS ${}^{248}{Cm} ({}^{18}O, X)$ , $E ({}^{18}O) = 97, 104, 113, 122$ MeV; ${}^{249}{Cf} ({}^{18}O, X)$ , $E ({}^{18}O) = 91, 97, 104, 113, 122, 150$ MeV; measured $σ$ and isotopic distributions for $Z = 97 - 102$ .

Angular distributions of fragments from fission induced by 220-MeV ${}^{20}{Ne}$ on targets of ${}^{165}{Ho}$ , ${}^{197}{Au}$ , and ${}^{209}{Bi}$

H. Rossner, D. Hilscher, E. Holub, G. Ingold, U. Jahnke, H. Orf, J. R. Huizenga, J. R. Birkelund, W. U. Schröder, and W. W. Wilcke

Phys. Rev. C 27, 2666 (1983) - Published 1 June, 1983

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Fragment angular distributions are reported for 220-MeV ${}^{20}{Ne}$ induced fission of ${}^{165}{Ho}$ , ${}^{197}{Au}$ , and ${}^{209}{Bi}$ . The experimental anisotropies are underestimated and overestimated, respectively, by calculations using the moments of inertia derived from the rotating and nonrotating ( $I = 0$ ) liquid-drop models. Account is taken in the theoretical calculations of both prefission particle emission and incomplete fusion. It is possible to obtain satisfactory fits to the experimental angular distributions with spin dependent values of $\frac{I_{sph}}{I_{eff} (I)}$ if the rotating liquid-drop model condition that $\frac{I_{sph}}{I_{eff} (I)}$ goes to zero at $I_{RLDM} (B_{f} = 0)$ is relaxed. For heavy-ion induced fusion-fission reactions, as $l_{f}$ exceeds $I_{RLDM}$ and the unconditional saddle-point energy has gone to zero, the saddle-point configuration plays less and less of a role in establishing ${K_{0}}^{2}$ .

NUCLEAR REACTIONS ${}^{165}{Ho}$ , ${}^{197}{Au}$ , ${}^{209}{Bi}$ ( ${}^{20}{Ne}$ , fusion-fission), $E_{lab} = 220$ MeV. Measured fission fragment angular distributions. Theoretical calculations with RLDM and LDM ( $I = 0$ ) moments of inertia including prefission particle emission and incomplete fusion.

Compound nuclear evaporation model calculations in the mass $A \sim 50$ and $A \sim 80$ regions

L. V. Theisen, L. R. Medsker, and S. L. Tabor

Phys. Rev. C 27, 2679 (1983) - Published 1 June, 1983

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Experimental excitation functions for the products of the reactions ${}^{27}{Al}$ + ${}^{28}{Si}$ , ${}^{28}{Si}$ + ${}^{28}{Si}$ , ${}^{54}{Fe}$ + ${}^{28}{Si}$ , and ${}^{56}{Fe}$ + ${}^{28}{Si}$ were measured over the energy range from 65 to 99 MeV. The experimental excitation functions of the reaction products were then compared to the results obtained from compound nuclear evaporation model calculations. The generally better agreement obtained with one of the codes suggests the importance of angular momentum effects in the exit channel. Two-particle evaporations are badly underpredicted by both calculations in both mass regions. It is possible that part of these cross sections result from some reaction mechanism other than compound nuclear. The compound nuclear evaporation model calculations are also very sensitive to the level density parameters $a$ , which are not well known in the mass $A \sim 50$ and $A \sim 80$ regions.

NUCLEAR REACTIONS ${}^{27}{Al} ({}^{28}{Si}, xpyn γ)$ and ${}^{27}{Si} ({}^{28}{Si}, xpyn γ)$ $E_{lab} = 65 - 90$ MeV; measured $σ (E_{γ}, E)$ . ${}^{54}{Fe} ({}^{28}{Si}, xpyn γ)$ and ${}^{56}{Fe} ({}^{28}{Si}, xpyn γ)$ $E_{lab} = 80 - 99$ MeV; measured $σ (E_{γ}, E)$ . Enriched targets.

Evidence of quasimolecular states in the ${}^{16}O$ + ${}^{12}C$ system by statistical fluctuation analysis

A. De Rosa, G. Inglima, V. Russo, and M. Sandoli

Phys. Rev. C 27, 2688 (1983) - Published 1 June, 1983

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The statistical analysis of ${}^{16}O$ + ${}^{12}C$ collisions has been performed using the spectral density method. Preequilibrium and compound nucleus coherence widths are determined for successive independent energy intervals. The molecular nature of doorwaylike states giving rise to preequilibrium statistical fluctuations is suggested on the basis of coherence energy dependence on the molecular rotation period. The different behavior of elastic and reaction channels is investigated for what concerns molecular state excitation in ${}^{28}{Si}$ composite systems. The change with energy of the molecular rigid body moment of inertia is considered.

NUCLEAR REACTIONS ${}^{16}O$ ( ${}^{12}C$ , ${}^{12}C$ ), ( ${}^{12}C$ , $α$ ); analyzed excitation functions; spectral density method; deduced coherence width energy dependence; considered molecular level excitation.

Entropy and hadrochemical composition in heavy ion collision

T. Biró, H. W. Barz, B. Lukács, and J. Zimányi

Phys. Rev. C 27, 2695 (1983) - Published 1 June, 1983

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The composite particle production in a heavy ion collision is calculated in the framework of a hadrochemical model. A critical comparison is performed between the produced entropy and the observables. The entropy production during the hadrochemical processes is found to be negligible.

NUCLEAR REACTIONS Ne + NaF heavy ion collision, $E = 0, 4 - 2.1$ , calculated spectra $p$ , $d$ , $π^{+}$ , van der Waals model, entropy.

Two-, three-, and four-particle exit channels in the reaction (806 MeV) Kr + U

P. A. Gottschalk, G. Grawert, P. Vater, and R. Brandt

Phys. Rev. C 27, 2703 (1983) - Published 1 June, 1983

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Mica track detectors employing the $2 π$ -geometry technique are used for coincidence measurements of multiple fragments in reactions induced by heavy ions. The nature of multiple fragment heavy ion induced reactions is shown to be binary from direct evidence. The process ${}^{84}{Kr}$ + ${}^{nat}U$ at 9.6 MeV/u is studied as an example. Heavy fragments in the two-, three-, and four-particle exit channels are identified with respect to their masses and energies. Specific fragment-fragment correlations revealed the sequential nature of the reactions. Distributions of mass, energy, and angle are presented for the different reaction steps and the different exit channels.

NUCLEAR REACTIONS ${}^{238}U + {}^{84}{Kr} \to n$ heavy fragments, $E = 806$ MeV, measured tracks in mica, deduced mass-yield curves, energy and angular distributions.

Analytically solvable model of charge dispersion in nuclear fission

D. R. Saroha, R. Aroumougame, and Raj K. Gupta

Phys. Rev. C 27, 2720 (1983) - Published 1 June, 1983

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Using the asymmetric two-center shell model potentials in parametrized forms, the time-dependent Schrödinger equation is solved analytically for the charge dispersion yields. We obtain a Gaussian function, characterized by a most probable charge and the width of the distribution. The hypothesis of an unchanged charge density and a minimum potential energy are given as limiting cases. Calculations are made for ${}^{236}U$ and ${}^{252}{Cf}$ .

NUCLEAR REACTIONS Nuclear fission, fragmentation theory, two-center shell model, time-dependent Schrödinger equation, analytical solution, Gaussian charge distribution, most-probable charge, unchanged charge density and minimum potential energy postulates, ${}^{236}U$ , ${}^{252}{Cf}$ .

Unified theory of meson and nucleon scattering by nuclei

M. Bolsterli

Phys. Rev. C 27, 2725 (1983) - Published 1 June, 1983

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In the meson-nucleon model of nuclei, the decomposition of the meson and nucleon field operators into internal and external parts provides a way of treating orthogonality effects in the scattering of hadrons by a nucleus. Under this decomposition, the Hamiltonian of the system splits into an internal part and terms that couple external modes. The internal part of the Hamiltonian is the Hamiltonian of the meson-nucleon shell model, and its eigenstates are approximations to the bound nuclear states. The rest of the Hamiltonian describes the external quanta of the fields and their interactions with the internal states. The internal mode functions are chosen so as to minimize the coupling of the external modes to the low-lying internal states. The Green's functions for the external fields and the diagrammatic representation of the perturbation series are presented and used to describe the treatment of hadron scattering in the one-external-hadron sector.

NUCLEAR STRUCTURE $π$ -nucleus and nucleon-nucleus scattering theory.

Fermi integration in the pion-nucleus optical potential

D. J. Ernst, Gerald A. Miller, and D. L. Weiss

Phys. Rev. C 27, 2733 (1983) - Published 1 June, 1983

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An efficient method for performing the Fermi integration required in the construction of the first order pion-nucleus optical potential is derived. The corrections to a factorized approximation are found to arise predominantly from the energy dependence of the pion-nucleon amplitude. The exact magnitude of these corrections and the quantitative features of cross sections are found to depend sensitively on the particular choice made for the dependence of the two-body energy on the pion and nucleon momenta.

NUCLEAR REACTIONS $π$ -nucleus elastic scattering, Fermi integration.

Asymmetries and cross sections for the reaction $\vec{p} + p \to p + π^{+} + n$ at 800 MeV

A. D. Hancock, R. W. Hackenburg, E. V. Hungerford, B. W. Mayes, L. S. Pinsky, J. C. Allred, T. M. Williams, S. D. Baker, J. A. Buchanan, J. M. Clement, M. Copel, I. M. Duck, G. S. Mutchler, G. P. Pepin, E. A. Umland, G. C. Phillips, M. W. McNaughton, C. Hwang, and M. Furić

Phys. Rev. C 27, 2742 (1983) - Published 1 June, 1983

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Kinematically complete data (analyzing powers and polarized cross sections) for the reaction $\vec{p} + p \to p + π^{+} + n$ at 800 MeV have been accumulated at twelve angle pairs with polarized beam and unpolarized target. Analyzing powers as large as 0.6 are observed in the regions of phase space where the $Δ^{+ +}$ resonant state can be produced. The four-momentum transfer to the proton-pion $Δ^{+ +}$ resonance varied between 0.09 ${(G e V / c)}^{2}$ to 0.81 ${(G e V / c)}^{2}$ . Current theories are not capable of reproducing these results in detail.

NUCLEAR REACTIONS $\vec{p} (p, n) π^{+} p$ , measured $\frac{d^{3} σ}{d p_{1} d Ω_{1} d Ω_{2}}$ and analyzing power.

Positive-pion-nucleus elastic scattering at 20 MeV

Felix E. Obenshain, F. E. Bertrand, E. E. Gross, N. W. Hill, J. R. Wu, R. L. Burman, M. Hamm, M. J. Leitch, R. D. Edge, B. M. Preedom, M. A. Moinester, M. Blecher, and K. Gotow

Phys. Rev. C 27, 2753 (1983) - Published 1 June, 1983

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Measurements of positive-pion elastic scattering cross sections at 20 MeV have been made in the angular range 30°-150°. Angular distributions were obtained for targets of ${}^{12}C$ , ${}^{16}O$ , ${}^{40}{Ca}$ , ${}^{90}{Zr}$ , ${}^{120}{Sn}$ , and ${}^{208}{Pb}$ . The data were fit with a phenomenological optical model potential calculation to obtain the real and imaginary $s$ - and $p$ -wave strength parameters. These parameters are compared to those obtained from data at 30, 40, and 50 MeV. Cross sections calculated from an optical model potential based on pionic atom data are in good agreement with our data at 20 MeV.

NUCLEAR REACTIONS Elastic scattering of 20-MeV $π^{+}$ from ${}^{12}C$ , ${}^{16}O$ , ${}^{40}{Ca}$ , ${}^{90}{Zr}$ , ${}^{120}{Sn}$ , and ${}^{208}{Pb}$ . Angular distributions $30 ° \leq θ_{L} \leq 160 °$ . Optical model analysis of differential cross sections.

Exchange effects and large angle proton scattering on light nuclei at intermediate energies: Formalism and application to $p$ + ${}^{4}{Hescattering}$

H. S. Sherif, M. S. Abdelmonem, and R. S. Sloboda

Phys. Rev. C 27, 2759 (1983) - Published 1 June, 1983

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The amplitude for elastic scattering of protons on a light nucleus is treated in a manner which takes into account the indistinguishability of the incident and target protons. We propose a simple model in which the direct and knockout amplitudes are represented by an optical potential amplitude. The rest of the exchange amplitude is cast in a form which represents the exchange of a heavy cluster between projectile and target; the heavy particle stripping amplitude. A modified distorted wave Born approximation appropriate for such elastic channel rearrangement is developed. This approximation simplifies the handling of finite range and recoil effects. The calculation of the heavy particle stripping amplitude requires knowledge of the proton-cluster overlap function of the target nucleus. The present model is applied to the scattering of protons on ${}^{4}{He}$ in the energy range 0.1—1.2 GeV. Several overlap functions derived from fits to the charge form factor of ${}^{4}{He}$ are used in the calculations. The general behavior of the large angle cross section is reproduced by our model. Of particular importance is the finding that the results are rather sensitive to the large momentum behavior of the overlap function. Moreover, functions that are derived from the charge form factor after correcting for meson exchange current effects appear to do better at higher energies than those with no correction. Good qualitative agreement with the 180° excitation function is obtained and the calculations predict a second shoulder near 1.1 GeV. We have also investigated the effect of the heavy particle stripping amplitude on the calculation of the large angle polarization.

NUCLEAR REACTIONS Large angle $p$ + ${}^{4}{He}$ scattering ( $T_{p} = 0.1 - 1.2$ GeV). Exchange effects, heavy particle stripping, modified DWBA. Calculated $σ (θ)$ , $P (θ)$ . Compare different ${}^{4}{He}$ overlap wave functions.

$M 2$ states in $A = 15$ : ${}^{15}N (π^{-}, γ) {}^{15}C$

U. Straumann, M. Lebrun, C. J. Martoff, P. Truöl, H. R. Kissener, J. P. Perroud, C. Joseph, W. Dahme, and K. M. Crowe

Phys. Rev. C 27, 2771 (1983) - Published 1 June, 1983

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Radiative pion capture in a liquid ${}^{15}N$ $H_{3}$ target has been measured with a high-resolution photon detector. Evidence for $J^{π} = {\frac{5}{2}}^{+}$ , $T = \frac{3}{2}$ giant magnetic quadrupole states has been found. Results of a shell model calculation are given which represent the experimental spectrum satisfactorily. For the $J^{π} = {\frac{5}{2}}^{+}$ , $E^{*} ({}^{15}C) = 0.75$ MeV level and the total spectrum the measured branching ratios are (9.6±2.4) × $10^{- 4}$ and (2.4±0.6) × $10^{- 2}$ , respectively.

NUCLEAR REACTIONS ${}^{15}N (π^{-}, γ) {}^{15}C$ , ( $E_{x} < 25$ MeV), $E_{π} = 0$ MeV, measured photon spectra, pair spectrometer, compared with shell model calculations.

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Proton hole states in neutron rich Pd nuclei

Energy dependence of the ${}^{124}{Sn} (p, t)$ reaction to the $3^{-}$ - $10^{+}$ two-quasiparticle states of ${}^{122}{Sn}$ at incident energies of 34.9, 45.1, 54.7, and 65.0 MeV

( $n, n^{'} γ$ ) study of collective excitations in ${}^{192}{Os}$ : Comparison with the boson models for transitional nuclei

Multinucleon-transfer reactions between light-heavy ions

Angular correlations between heavy ions and $α$ particles in ${}^{16}O$ + ${}^{27}{Al}$ collisions at 87.4 MeV: Evidence of sequential decay of projectilelike fragments

Implications of angular momentum conservation for fluctuations in heavy ion reactions

Search for transfer-induced ${}^{12}C$ + ${}^{12}C$ resonances in the ${}^{12}C ({}^{16}O, α) {}^{24}{Mg}^{*}$ reaction

Excitation functions for production of heavy actinides from interactions of ${}^{18}O$ with ${}^{248}{Cm}$ and ${}^{249}{Cf}$

Angular distributions of fragments from fission induced by 220-MeV ${}^{20}{Ne}$ on targets of ${}^{165}{Ho}$ , ${}^{197}{Au}$ , and ${}^{209}{Bi}$

Compound nuclear evaporation model calculations in the mass $A \sim 50$ and $A \sim 80$ regions

Evidence of quasimolecular states in the ${}^{16}O$ + ${}^{12}C$ system by statistical fluctuation analysis

Entropy and hadrochemical composition in heavy ion collision

Two-, three-, and four-particle exit channels in the reaction (806 MeV) Kr + U

Analytically solvable model of charge dispersion in nuclear fission

Unified theory of meson and nucleon scattering by nuclei

Fermi integration in the pion-nucleus optical potential

Asymmetries and cross sections for the reaction $\vec{p} + p \to p + π^{+} + n$ at 800 MeV

Positive-pion-nucleus elastic scattering at 20 MeV

Exchange effects and large angle proton scattering on light nuclei at intermediate energies: Formalism and application to $p$ + ${}^{4}{Hescattering}$

$M 2$ states in $A = 15$ : ${}^{15}N (π^{-}, γ) {}^{15}C$

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