It is suggested that the study of multiplicity difference correlators between two well-separated bins in high-energy heavy-ion collisions can be used as a means to detect evidence of a quark-hadron phase transition. Analytical expressions for the scaled factorial moments of multiplicity difference distribution are obtained for small bin size with mean multiplicity $\overline{s}<~0.3$ within Ginzburg-Landau description. It is shown that the scaling behaviors between the moments are still valid, though the behaviors of the moments with respect to the bin size are completely different from the so-called intermittency patterns. A universal exponent $\gamma$ is given to describe the dynamical fluctuations in the phase transition.

We study the nuclear (or $A)$ dependence of the coherent $\eta$ photoproduction reaction in a relativistic impulse approximation approach. We use a standard relativistic parametrization of the elementary amplitude, based on a set of four Lorentz- and gauge-invariant amplitudes, to calculate the coherent production cross section from ${}^4\mathrm{He}$, ${}^{12}\mathrm{C}$, and ${}^{40}\mathrm{Ca}$. In contrast to nonrelativistic treatments, our approach maintains the full relativistic structure of the process. The nuclear structure affects the process through the ground-state tensor density. This density is sensitive to relativistic effects and depends on $A$ in a different manner than the vector density used in nonrelativistic approaches. This peculiar dependence results in ${}^4\mathrm{He}$ having a cross section significantly smaller than that of ${}^{12}\mathrm{C}$—in contrast to existent nonrelativistic calculations. Distortion effects are incorporated through an $\eta$-nucleus optical potential that is computed in a simple “$t\rho$” approximation.

The neutron deficient americium isotope ${}^{236}$Am has been produced via the ${}^{235}$U${(}^6$Li, 5$n$) reaction. The reaction products were transported to an ion source of the on-line isotope separator (JAERI-ISOL) by a He/KCl aerosol jet transport system, and americium atoms were successfully ionized and mass-separated. Pu$K$ x rays associated with the EC decay of Am nuclei at the mass fraction of 236 were observed, indicating the definite identification of ${}^{236}$Am. The half-life of ${}^{236}$Am is determined to be 4.4$\pm$0.8 min and the production cross section is estimated to be about 70 $\mu$b.

The coupling constants $g_{\pi \Lambda \Sigma }$ and $g_{K\Sigma \Xi }$ are calculated in the QCD sum rule approach using the three-point function method and taking into account the SU(3) symmetry breaking effects. The pattern of SU(3) breaking appears to be different from that based on SU(3) relations.

Using an isospin-dependent transport model, we have studied the isospin and momentum relaxation times in the heavy residues formed in heavy-ion collisions at intermediate energies. It is found that only at incident energies below the Fermi energy can chemical or thermal equilibrium be reached before dynamical instability is developed in the heavy residues. Also, the isospin relaxation time is shorter (longer) than that for momentum at beam energies lower (higher) than the Fermi energy.

We propose a generalized Gibbs equation for nuclear matter in the presence of a heat flux or a viscous pressure, by using the formalism of extended irreversible thermodynamics. We study the consequences on the equations of state, with special emphasis on the compressibility. The results may be useful in the analysis of nuclear collisions.

The properties of ${K=0\mathrm{}}^{+}$ excitations in deformed and transitional nuclei have recently been of intense interest. We present results of a study of the deexcitations of the lowest excited $0^{+}$ state in ${}^{152}$Sm from the $\epsilon$-decay of ${}^{152}$Eu, yielding one of the few precisely known values of the branching ratio $R_{0g}^{\gamma }{=B(E2;2\mathrm{}}_{\gamma }^{+}\to 0_2^{+}{)/B(E2;2\mathrm{}}_{\gamma }^{+}\to 0_1^{+})$ =0.048(4), which is extraordinarily small. From $T_{1/2}{(2\mathrm{}}_{\gamma }^{+})$ we also obtain ${B(E2;2\mathrm{}}_{\gamma }^{+}\to 0_2^{+})$=0.17 W.u. Values of $R_{0g}^{\gamma }$ calculated in the interacting boson model (IBA) go to zero extremely rapidly, changing by orders of magnitude for a narrow range of parameter values. ${}^{152}$Sm is a rare case of a transitional nucleus that lands almost at the minimum. ${}^{152}$Sm and ${}^{154}$Gd are the only nuclei from $90<~N<~114$ where the $B\left(E2\mathrm{}\right)\mathrm{}$ values for all four transitions $2_{\gamma }^{+}\to 0_2^{+}$, $2_{\gamma }^{+}\to 0_1^{+}$, $0_2^{+}\to 2_1^{+}$, and $2_1^{+}\to 0_1^{+}$ are now known. In ${}^{152}$Sm these $B\left(E2\mathrm{}\right)\mathrm{}$ values span three orders of magnitude, from 144 to 0.17 W.u. and are reproduced to within a factor of 2–3 by the IBA. The rather strong ${B(E2;0\mathrm{}}_2^{+}\to 2_1^{+})$ value of 33 W.u. suggest that the $0_2^{+}$ level is an example of a good low energy $\beta$-vibration.

We have made improved measurements of the neutron capture and total cross sections for ${}^{137}\mathrm{Ba}$ over a sufficiently wide range of energies so that the reaction rate at $s$-process temperatures ($\mathrm{kT}$=6–23 keV) can be determined solely from the data. These rates are crucial for the interpretation of recently discovered anomalies of Ba isotopes in silicon carbide grains from the Murchison meteorite. Recent stellar models of the $s$ process are in agreement with the meteoric anomaly data for Ba only if the ${}^{137}\mathrm{Ba}(n,\gamma )$ reaction rate is 20% larger than the previously accepted rate. Our reaction rates at $s$-process temperatures are in agreement with the extrapolated reaction rate from the most recent previous measurement. Hence, our results uphold, and place on much firmer footing, the discrepancy between recent stellar models of the $s$-process and the meteoric anomaly data.

We use a recently derived result to extract from two-pion interferometry data from $p\overline{p}$ collisions, the radius of the coherent component in the source. We find a coherent source radius of about 2 fm.

Pseudospin symmetry has been invoked as a possible explanation for the “quantized alignment” observed in some superdeformed “identical” bands. The clearest case involves the $1/2\left[301\right]$ orbital (a pseudospin singlet, $\tilde{\Lambda }=0\mathrm{}$), where pseudospin alignment provides an explanation for some identical bands in the mass-150 region. Pseudospin doublets $(\Omega =\tilde{\Lambda }\pm 1/2)$ can also generate quantized alignments and such an explanation, with $\tilde{\Lambda }=1,$ has recently been proposed for the band in ${}^{191}\mathrm{Au}$ identical to ${}^{192}\mathrm{Hg}.$ The present work examines whether the data on the normally deformed nuclei support such an interpretation and concludes that pseudospin alignment is plausible for states with $\tilde{\Lambda }=0\mathrm{}$ or 1.

The differential $\mathrm{np}$ scattering cross section has been measured at 162 MeV in the angular range ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=72\mathrm{}°-180°$, using the neutron beam facility at The Svedberg Laboratory in Uppsala. Special attention was paid to the absolute normalization of the data. In the angular range $150°-180°$, the data are steeper than those of most previous measurements and predictions from energy-dependent partial-wave analyses or nucleon-nucleon potentials. At $180°$, the difference is of the order of 10–15%, an important change since this cross section is considered as a primary standard. It has also consequences for fundamental physics. Moreover, a value of the charged $\pi \mathrm{NN}$ coupling constant, $g_{{\pi }^{\pm }}^2=14.52\mathrm{}\pm 0.26\hspace{0.5em}{(f}_{{\pi }^{\pm }}^2=0.0803\mathrm{}\pm 0.0014)$, is deduced from the data, using a novel extrapolation method. This is in good agreement with the classical text book value, but higher than those determined in recent partial-wave analyses of the nucleon-nucleon data base.

The elastic proton-deuteron backward reaction is analyzed within a covariant approach based on the Bethe-Salpeter equation with realistic meson-exchange interaction. Lorentz boost and other relativistic effects in the cross section and spin correlation observables, such as tensor analyzing power and polarization transfer, etc., are investigated in explicit form. Results of numerical calculations for a complete set of polarization observables are presented.

We report experimental measurements in ${}^{241}\mathrm{Pu}$ of the following: primary and secondary $\gamma$ rays and conversion electrons from thermal neutron capture in ${}^{240}\mathrm{Pu};\gamma$ rays from ${}^{245}\mathrm{Cm}$ α decay; proton and triton spectra, respectively, from $\mathrm{}(d,p)\mathrm{}$ and $\mathrm{}(d,t)\mathrm{}$ reactions on ${}^{240}\mathrm{Pu}$ and ${}^{242}\mathrm{Pu}$ targets. From these data and those of other investigations, we have identified 53 excited levels in ${}^{241}\mathrm{Pu}$ below 1400 keV. Of these, 44 are placed in 10 rotational bands (with connecting transitions) that have been assigned Nilsson configurations. For the bands below 1 MeV in ${}^{241}\mathrm{Pu}$ that are largely of single-particle character, there is good correspondence with similar bands in ${}^{239}\mathrm{U}$ and with the theoretical model of Gareev et al. For those bands in ${}^{241}\mathrm{Pu}$ where there is mixing between single-particle and vibrational modes, we find some significant deviations from theoretical predictions. For example, the $\frac{5}{2}\left[622\right]\otimes 0^{-}$ state at 519 keV appears to mix less with other states than predicted, while a trio of $K^{\pi }={\frac{1}{2}}^{-}$ bands show unexpected mixing patterns.

The giant resonance region in ${}^{28}\mathrm{Si}$ was studied with inelastic scattering of 240 MeV α particles at small angles including 0°. The giant resonance peak extended from $E_x=12\mathrm{}\mathrm{MeV}$ to 35 MeV and $E0\mathrm{}$ strength corresponding to $54\pm 6\%$ of the isoscalar $E0\mathrm{}$ energy weighted sum rule was identified between $E_x=11\mathrm{}–35\mathrm{MeV}$ with a centroid of $21.5\pm 0.3\mathrm{MeV}$ and an rms width of $5.9\pm 0.2\mathrm{MeV}.$ $E2\mathrm{}$ strength corresponding to $32\pm 5\%$ of the isoscalar $E2\mathrm{}$ sum rule was identified with a centroid of $E_x=19.0\mathrm{}\pm 0.2\mathrm{MeV}$ and rms width of $1.7\pm 0.2\mathrm{MeV}.$ Elastic scattering was measured from ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=3\mathrm{}°$ to 47° and optical parameters obtained. Inelastic scattering to states at 1.78, 6.88, 10.2, and 11.1 MeV was measured and deformation lengths and $L$ components extracted.

Sources of ${}^{230}\mathrm{U}$ were prepared using the ${\beta }^{-}$ decay of ${}^{230}\mathrm{Pa}$ produced in the reaction ${}^{232}\mathrm{Th}$ $\mathrm{}(p,3n)\mathrm{}$ with 34-MeV protons. These sources were used to determine the half-life of the $1^{-}$ state at 230.4 keV in ${}^{226}\mathrm{Th}$ using the Doppler shift method following α decay of ${}^{230}\mathrm{U}$. An average value of the half-life of 3.5±1.2 ps was observed. The half-life of the 226.4-keV $4^{+}$ state in ${}^{226}\mathrm{Th}$ was also measured to be 145±20 ps. The absolute transition probabilities in Weisskopf units of the 230- and 158-keV transitions depopulating the $1^{-}$ state were determined as (2.50±0.86)$\times {10}^{-3}$ and (4.54±1.55)$\times {10}^{-3}$, respectively. These experimental values are compared with experimental values of ${}^{223}\mathrm{Ra}$ and theoretical calculations. Finally, experimental values of the intrinsic dipole moment $D_0$ and the ratio of the intrinsic dipole moment to the intrinsic quadrupole moment $D_0{/Q}_0$ were determined as 0.27±0.05 $e$ fm and (3.5±1.0)$\times {10}^{-4}$ ${\mathrm{fm}}^{-1}$ respectively, and compared with various theories and experiments.

A high statistics experiment performed on Gd nuclei with the use of the EUROGAM II array resulted in the discovery of twelve new superdeformed (SD) bands. Three of them have been assigned to ${}^{148}\mathrm{Gd}$ and seven to ${}^{149}\mathrm{Gd}$ giving a total of thirteen SD bands now known in this last nucleus. The close relationship in transition energies between these bands and those in neighboring nuclei has been used to suggest configurations. Most of the new bands exhibit more or less pronounced irregularities in their dynamical moments of inertia with consequences on their identities with other bands.

The ${\beta }^{+}$/EC decay of mass-separated $A=80\mathrm{}$ nuclei was studied by means of $\beta$- and $\gamma$-ray spectroscopy after the bombardment of a ${}^{24}$Mg target with ${}^{58}$Ni ions at 190 MeV. A new 1${}^{-}$ isomer at 228.5(1) keV has been identified in ${}^{80}$Y with a half-life of 4.7(3) s. This new isomer decays to the 4${}^{-}$ ground state with an 81(2)$\%$ branch and by ${\beta }^{+}$/EC transitions to levels in ${}^{80}$Sr with a 19(2)$\%$ branch. The half-life of the ${}^{80}$Y ground-state decay has been remeasured to be 30.1(5) s. A level scheme for the low-lying states in ${}^{80}$Y is presented. Hartree-Fock-Bogolyubov calculations show a large prolate deformation for these states, and two-quasiparticle + rotor model calculation results suggest that the low-lying states can be reproduced by inclusion of an effective proton-neutron residual interaction. The dominating Nilsson configurations for the 4${}^{-}$ ground state and the 1${}^{-}$ isomeric state have been found to originate from the parallel and antiparallel coupling of the proton [422]5/2${}^{+}$ and the neutron [301]3/2${}^{-}$ orbitals.

We show that the occurrence of approximate pseudospin symmetry in nuclei is connected with certain similarities in the relativistic single-nucleon wave functions of the corresponding pseudospin doublets. We perform a case study in which several examples and the systematics of this connection are explored.

We consider ${}^1{S}_0$ pairing in infinite neutron matter and nuclear matter and show that in the lowest order approximation, where the pairing interaction is taken to be the bare nucleon-nucleon interaction in the ${}^1{S}_0$ channel, the pairing interaction and the energy gap can be determined directly from the ${}^1{S}_0$ phase shifts. This is due to the almost separable character of the nucleon-nucleon interaction in this partial wave. These results put an interaction-independent upper limit on the value of the gap, and on the density where ${}^1{S}_0$ superfluidity disappears in neutron matter and nuclear matter.

We calculate the binding energy of two $\Lambda$ hyperons bound to a nuclear core within the relativistic mean field (RMF) theory. The starting point is a two-body relativistic equation of the Breit type suggested by the RMF theory, and corrected for the two-particle interaction. We evaluate the 2 $\Lambda$ correlation energy and estimate the contribution of the ${\sigma }^{*}$ and $\Phi$ mesons, acting solely between hyperons, to the bond energy $\Delta B_{\Lambda \Lambda }$ of ${}_{\Lambda \Lambda }^6\mathrm{He}$, ${}_{\Lambda \Lambda }^{10}\mathrm{Be}$, and ${}_{\Lambda \Lambda }^{13}\mathrm{B}$. Predictions of the $\Delta B_{\Lambda \Lambda }\hspace{0.5em}A$ dependence are made for heavier $\Lambda$ hypernuclei.