We describe how the Feshbach-Kerman-Koonin (FKK) theory can be used to obtain residual nucleus spin distributions following preequilibrium decay, by removing the assumption of zero intrinsic spins in multistep direct reactions. By making use of parallels between the exciton model and the FKK multistep direct theory we also obtain a straightforward method for determining spin distributions in the exciton model. We compare these two approaches and apply them to high-spin isomer production cross sections in 14 MeV neutron reactions on hafnium. We obtain reasonable agreement with measurements, though there is evidence that the FKK theory underpredicts high spin transfer reactions. Comparisions with the exciton model suggest that multistep processes in FKK are underestimated, and that an FKK formulation incorporating non-normal DWBA transitions may yield results in closer agreement with the exciton model, and with experiment.

When one or two neutrons are lost in a collision between a projectile with a diffuse neutron-rich surface and a target nucleus, the transverse momentum distribution of the fragments thus produced can be fit with a double Gaussian curve in which a narrow component is superimposed on a much broader one. It is shown that this phenomenon is also observed for fragments from the ‘‘normal’’ projectile ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$. A density-dependent nucleon Fermi momentum and fragment recoil with the momentum of the lost nucleon give good agreement with experiment. The two Gaussian components do not require the presence near the nuclear surface of nucleons with two widely different binding energies, as often supposed.

The resonant ${\mathit{P}}_{33}$ single-pion electroproduction multipole amplitude ${\mathit{S}}_1^{+(3/2)\mathrm{}}$(${\mathit{q}}^2$) and the ΔNγ scalar form factor ${\mathit{G}}_{\mathit{C}}^{\mathrm{*}}$(${\mathit{q}}^2$) are calculated nonperturbatively in terms of the well-known nucleon form factors ${\mathit{g}}_{\mathit{A}}$(${\mathit{q}}^2$) and ${\mathit{G}}_{\mathit{E}}^{\mathit{V}}$(${\mathit{q}}^2$). Results are in good agreement with experiment. Our treatment is completely relativistic with current conservation guaranteed. Assuming the usual dipole behavior for ${\mathit{g}}_{\mathit{A}}$(${\mathit{q}}^2$) and ${\mathit{G}}_{\mathit{E}}^{\mathit{V}}$(${\mathit{q}}^2$), we confirm that ${\mathit{G}}_{\mathit{C}}^{\mathrm{*}}$(${\mathit{q}}^2$) falls off asymptotically at the rate ${\mathit{q}}^{\mathrm{-}6}$ as expected in perturbative QCD.

Angular distributions of the tensor analyzing powers ${\mathit{A}}_{\mathit{z}\mathit{z}}$ and ${\mathit{A}}_{\mathit{x}\mathit{x}}$-${\mathit{A}}_{\mathit{y}\mathit{y}}$ for the reactions ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(d,p${)}^3$H and ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(d,n${)}^3$He are presented at deuteron energies of 25, 40, 60, and 80 keV. The analyzing powers for the two reaction channels are quite similar at these energies. The data have been included in an R-matrix analysis of the four nucleon system. According to this analysis, transitions from entrance-channel quintet-S states are important in these reactions, so that the use of polarized fuels would not result in a neutron-lean fusion reactor.

The deep inelastic scattering on the deuteron is considered in a fully covariant field theoretical approach. All calculations are performed in the Bethe-Salpeter formalism and the Wilson operator product expansion method within an effective meson-nucleon theory. By the operator product expansion method we obtain an explicit form of the nucleon contribution and mesonic exchange corrections to moments of the deuteron structure function ${\mathit{F}}_2^{\mathit{D}}$. The structure function of the deuteron is recovered by the inverse Mellin transform of the moments and is presented as the sum of two convolution terms, viz. the nucleonic (relativistic impulse approximation) and mesonic (contribution of the meson exchange currents) ones. The sum rules for the baryon number and energy-momentum of the deuteron are derived using the normalization condition of the Bethe-Salpeter amplitude and virial theorem of field theory. The numerical estimates of the nuclear effects in the deuteron structure function in the Bethe-Salpeter formalism are also presented. It is found that the binding effects of the nucleons are significant and relativistic calculations within the Bethe-Salpeter formalism are compared with the previous nonrelativistic estimates.

It has recently proven possible to construct an acceptable one-boson-exchange potential in which the NNπ form factor is quite soft. In order to do so it was necessary to add an effective π’ meson which increased the short-range tensor force. It is much less obvious that one can use such soft form factors if the two-pion-exchange diagrams are calculated explicitly rather than being parametrized as scalar meson exchange. Here we show that it is indeed possible to construct a model which describes nucleon-nucleon data with comparable quality as the original full Bonn potential, but in which the two pion exchange is included explicitly with consistently soft NNπ and ΔNπ vertices.

The effects of the three-body force are investigated in the three-nucleon systems. The three-body Faddeev equation is completely solved with a phenomenological three-body force which can reproduce the triton binding energy. The adopted two-body force is the PEST potential (or the Ernst-Shakin-Thaler’s separable expansion of the Paris potential) up to J=2. Calculated results of the differential cross section, and the values of the doublet and the quartet n-d scattering lengths, agree very well with the experimental data. The calculated three-body-force effects on the N-d scattering observables ${\mathit{A}}_{\mathit{y}}$, ${\mathit{iT}}_{11}$, ${\mathit{T}}_{20}$, ${\mathit{T}}_{21}$, ${\mathit{T}}_{22}$ are also discussed together with the Doleschall-type Coulomb correction.

The effects of the Coulomb interaction upon the photon cross section and analyzing power from pp bremsstrahlung have been studied in detail. Off-shell properties of the Coulomb T matrices have been considered, but the associated, Coulomb modified, hadronic T matrices are important elements in any analysis of low energy, forward proton scattering data.

A dynamical model for S- and P-wave correlated two-pion exchange between two nucleons is presented, starting from corresponding NN¯→ππ amplitudes in the pseudophysical region, which have been constructed from nucleon and Δ-isobar exchange Born terms and a meson exchange model of ππ scattering which satisfactorily describes the empirical ππ data. It is demonstrated that the results have quite different characteristics, in both strength and range, compared to (sharp mass) σ’, ρ exchange as used in the Bonn potential. Consequences for the description of high partial wave NN scattering phase shifts are discussed.

We discuss the physics of the Bochum NN potential (Ruhrpot). In contrast to conventional one-boson-exchange models (OBE) we calculate the potential within two phases which are (i) meson exchanges at long distances and (ii) direct NN interactions, coming from the intrinsic nucleon structure, at short distances. The interaction vertices are calculated in a self-consistent way. The most important resonant two- and three-π correlations are included. As the meson exchange is negligible at high ${\mathit{Q}}^2$ we have several advantages: (i) resonable meson scales, (ii) SU(6) limit for vector mesons, (iii) perturbative QCD asymptotic, (iv) no need for σ mesons, and (v) very good description of the nucleon-nucleon data.

The cross section for semi-inclusive deep-inelastic charged current neutrino scattering on hydrogen and deuterium in which a slow proton is observed in coincidence with the muon is computed as a function of Bjorken x and light-cone momentum of the detected proton. In the impulse approximation contributions from hadronization and (in case of the deuteron) the emission of a spectator nucleon are considered. In addition the probability for rescattering is computed. The results are compared to a recent analysis of the data from the WA25 (BEBC) experiment at CERN.

Expressions for the P,T-violating NN potentials are derived for π, ρ, and ω exchange. The nuclear matrix elements for ρ and ω exchange are shown to be greatly suppressed, so that, under the assumption of comparable coupling constants, π exchange would dominate by two orders of magnitude. The ratio of P,T-violating to P-violating matrix elements is found to remain approximately constant across the nuclear mass table, thus establishing the proportionality between time-reversal-violation and parity-violation matrix elements. The calculated values of this ratio suggest a need to obtain an accuracy of order 5×${10}^{\mathrm{-}4}$ for the ratio of the PT-violating to P-violating asymmetries in neutron transmission experiments in order to improve on the present limits on the isovector pion coupling constant.

The excitation function for emission of 2.30 MeV gamma rays from the 4.51 MeV (11/$2^{+}$) state of ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$ formed in inelastic proton scattering has been measured for proton energies from 5.6 to 7.3 MeV. A resonance previously seen in both inelastic electron and proton scattering from ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ at 17.35 MeV has been observed as a resonance in the excitation function, as well as seven other resonances, all of which are narrow (i.e., less than 100 keV wide). It is suggested that these may represent fragments of $6^{\mathrm{-}}$ strength in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, as calculated by Carr et al.

The threshold energy of the ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$(p,n${)}^{26}$${\mathrm{Al}}^{\mathit{m}}$ reaction has been measured to be 5209.46±0.12 keV, using a 1 V standard as reference, and taking account of effects due to finite beam energy spread, nonuniform proton energy loss in the target, and ionization of the magnesium atoms. The Q value derived for the ${}_{}{}^{26}{}_{}{}^{}\mathrm{Al}_{}^{\mathit{m}}{}_{}{}^{}$ beta decay then becomes 4232.17±0.12 keV, which is in clear disagreement with the most precise of the existing measurements. A further measurement is proposed.

Baryon-number-violating nucleon decays were studied by searching for x and γ rays associated with radioactive residual nuclei produced by single- and multinucleon decays in ${}_{}{}^{127}{}_{}{}^{}\mathrm{I}$. Large volume NaI(Tl) detectors were used for the study. New lower limits of τ(n)>4.7×${10}^{24}$ yr and τ(p)>3.0×${10}^{24}$ yr were obtained on the mode-independent mean lives for the neutron and proton decays in ${}_{}{}^{127}{}_{}{}^{}\mathrm{I}$, respectively. Lower limits of τ(nn)>2.1×${10}^{24}$ yr, τ(nnn)>1.8×${10}^{23}$ yr, and τ(nnnn)>1.4×${10}^{23}$ yr were deduced for the first time on the mode-independent mean lives for dineutron, trineutron, and tetraneutron decays in ${}_{}{}^{127}{}_{}{}^{}\mathrm{I}$, respectively.

Reanalysis of ichproductsofbinaryreactio nsof${\mathrm{\$}}^{34}$S, ${}_{}{}^{36}{}_{}{}^{}\mathrm{S}$, and ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$ beams on ${}_{}{}^{160}{}_{}{}^{}\mathrm{Gd}$ targets. Gates set on known amma$raysin$A∼160 products selected individual react ion channels and identified coincident amma$raysin$A∼36 partner products. Transfers of protons from projectile to target and of neutrons from target to projectile were generally favored, leading to excited neutron-rich light nuclei, including some difficult to reach by other means. Notable results include the observation of amma$${\mathit{raycascadesup}}^{\mathit{t}\mathit{h}\mathit{e}}$high e stknownyraststatesinfour$N=20 isotones. In two N=19 nuclei, ${}_{}{}^{33}{}_{}{}^{}\mathrm{Si}$ and ${}_{}{}^{34}{}_{}{}^{}\mathrm{P}$, the two N=22 nuclei, ${}_{}{}^{38}{}_{}{}^{}\mathrm{S}$ and ${}_{}{}^{39}{}_{}{}^{}\mathrm{Cl}$, previously unknown yrast states were identified.

High-spin states in the odd-odd nucleus ${}_{}{}^{72}{}_{}{}^{}\mathrm{As}$ were investigated by means of coincidence measurements via the ${}_{}{}^{59}{}_{}{}^{}\mathrm{Co}$${(}^{19}$F,αpn) and the ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$${(}^{12}$C,αn) reactions at beam energies of 55 MeV and 50 MeV, respectively. Two new rotational-like level sequences of probably opposite parities have been found to feed into the known $7^{\left(\mathrm{-}\right)}$ isomer at 562.8 keV. Lifetime measurements for some states of the positive-parity sequence using the Doppler shift attenuation method revealed transition strengths of B(E2)≊40 Weisskopf units. Thus, this band is interpreted as a collective structure built on the two-quasiparticle intruder configuration (π${\mathit{g}}_{9/2}$⊗ν${\mathit{g}}_{9/2}$).

High-spin states of the doubly-odd ${\mathrm{nucleus}}^{86}$Rb containing 37 protons and 49 neutrons have been investigated via the reaction ${}_{}{}^{82}{}_{}{}^{}\mathrm{Se}$${(}^7$Li,3n) using ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ ions with energies between 30 and 35 MeV. The new level scheme is based on prompt γγ coincidences, angular distributions and directional correlation orientation ratios of γ rays as well as on linear polarizations of some strong γ rays and contains levels with excitation energies up to 7.9 MeV and tentative spins up to 16ħ. For fifteen of the levels lifetimes in the ps region have been determined by analyzing the Doppler shift of γ rays. Several fast M1 transitions with B(M1)≳0.3W.u. have been identified. The new high-spin level scheme of ${}_{}{}^{86}{}_{}{}^{}\mathrm{Rb}$ is interpreted on the basis of shell-model calculations in the configuration space 1${\mathit{p}}_{3/2}$, 0${\mathit{f}}_{5/2}$, 1${\mathit{p}}_{1/2}$, and 0${\mathit{g}}_{9/2}$ for the protons and 1${\mathit{p}}_{1/2}$, 0${\mathit{g}}_{9/2}$, and 1${\mathit{d}}_{5/2}$ for the neutrons. The energies of the observed levels with I>5 as well as most of the observed electromagnetic transition probabilities could be well described. The excitation of a 0${\mathit{g}}_{9/2}$ neutron over the N=50 shell gap into the ${\mathit{d}}_{5/2}$ orbital is predicted to cause remarkable alterations only for states with ${\mathit{I}}^{\mathrm{\pi }}$≥${15}^{+}$. Some of the reduced M1 transition probabilities calculated within the shell model are found to depend critically on the parametrization used to describe the residual interaction.

The isotope ${}_{}{}^{52}{}_{}{}^{}\mathrm{Ni}$ has been produced by fragmentation of a ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ beam at 68 MeV/nucleon on a nickel target and separated using the LISE spectrometer at GANIL. We have measured the half-life of ${}_{}{}^{52}{}_{}{}^{}\mathrm{Ni}$ and the energies of β-delayed protons emitted during the decay. Two proton lines have been observed at ${\mathit{E}}_{\mathit{p}}$=1.06±0.05 MeV and 1.34±0.06 MeV with branching ratios of 0.06±0.01 and 0.11±0.01, respectively. The measured half-life of ${}_{}{}^{52}{}_{}{}^{}\mathrm{Ni}$ is ${\mathit{T}}_{1/2}$=38±5 ms. A partial decay scheme is proposed.

The neutron decay of high-lying single-particle states in ${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$ excited by means of the (α${,}^3$He) reaction has been investigated at 122 MeV incident energy using a multidetector array. The high spin values of these states, inferred from previous inclusive experiments, are confirmed by the present data involving angular correlation measurements and the determination of branching ratios to low lying levels in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. The structure located between 8.5 and 12 MeV excitation energy in ${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$ displays large departures from a pure statistical decay with significant direct feeding of the low-lying collective states ($3^{\mathrm{-}}$,$5^{\mathrm{-}}$) of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. At higher excitation energy up to 20 MeV, the measured neutron decay is in agreement with the predictions of the statistical model.