We address the question of the intrinsic quadrupole moment $Q_0$ of the nucleon in various models. All models give a positive intrinsic quadrupole moment for the proton. This corresponds to a prolate deformation. We also calculate the intrinsic quadrupole moment of the $\Delta \mathrm{}\left(1232\right).$ All our models lead to a negative intrinsic quadrupole moment of the ${\Delta }^{+}$ corresponding to an oblate deformation.

Differential cross sections for the reaction ${}^7\mathrm{Li}{\mathrm{}(p,2p)\mathrm{}}^6\mathrm{He},$ at incident proton energy of 70 MeV, were analyzed in the framework of the DWTA approach. The point-nucleon root-mean-square radius for the neutron distribution of ${}^6\mathrm{He}$ was deduced to be 2.85(7) fm.

Although the model by Korchin et al. [Phys. Rev. C 59, 1890 (1999)] for the radiative $p+d$ capture basically follows the covariant and gauge invariant approach by Nagorny et al. [Sov. J. Nucl. Phys. 49, 465 (1989); 53, 228 (1991); 55, 1325 (1992); Phys. At. Nucl. 57, 940 (1994); Phys. Lett. B 316, 231 (1993)], several inconsistencies in the model are pointed out.

In response to the preceding Comment we clarify the points raised and show that the arguments presented in the Comment are poorly substantiated.

A new measurement of the ${}^{18}\mathrm{F}(p,\alpha )$ reaction and the ${}^{18}\mathrm{F}\mathrm{}(p,p)\mathrm{}$ elastic scattering was performed at the Radioactive Ion Beam facility in Louvain-la-Neuve. Values were deduced for the resonance energy, total width, partial width, and resonance strength of the 7.07 MeV level in ${}^{19}\mathrm{Ne},$ confirming and increasing the precision of a first result obtained several years ago in the same lab.

The reaction $\overrightarrow{p}\overrightarrow{p}\mathrm{ppX}$ was studied at two energies ${(T}_p=1520\mathrm{}$ and 1805 MeV) and at several angles between $0°$ and $17°$ in the laboratory. The analyzing powers and cross sections of the $\mathrm{ABC}$ enhancement production were measured in the missing mass ${(M}_{{\pi }^0}<~M_X<~M_{\eta }).\mathrm{}$ Several substructures were observed at different angles and both energies. Substructures at $M_X\approx 310$ and 350 MeV were systematically extracted. Substructures in the higher mass range $400<~M_X<~500\hspace{0.5em}\mathrm{MeV}$ were observed but their masses were less stable. These substructure masses have been associated with $q^2-q^2$ (and $q^3-q^3)$ configurations, allowing a new assumption for the $\mathrm{ABC}$ effect description, as being colored multiquark clusters.

Relativistic kinetic theory, based on the Grad method of moments as developed by Israel and Stewart, is used to model viscous and thermal dissipation in neutron star matter and determine an upper limit on the maximum mass of neutron stars. In the context of kinetic theory, the equation of state must satisfy a set of constraints in order for the equilibrium states of the fluid to be thermodynamically stable and for perturbations from equilibrium to propagate causally via hyperbolic equations. Application of these constraints to neutron star matter restricts the stiffness of the most incompressible equation of state compatible with causality to be softer than the maximally incompressible equation of state that results from requiring the adiabatic sound speed to not exceed the speed of light. Using three equations of state based on experimental nucleon-nucleon scattering data and properties of light nuclei up to twice normal nuclear energy density, and the kinetic theory maximally incompressible equation of state at higher density, an upper limit on the maximum mass of neutron stars averaging 2.64 solar masses is derived.

A semiempirical shell model mass equation based on magic number $Z=126\mathrm{}$ and applicable to translead elements with $N<~126$ is presented. For $\alpha -\mathrm{d}\mathrm{e}\mathrm{c}\mathrm{a}\mathrm{y}$ energies the equation is shown to have a high predictive power and an rms deviation from the data of about 100 keV. The rms deviations for masses and other mass differences are between about 200 and 300 keV.

We present the observation of the first decay event of the new nuclide ${}^{292}116$ in the running experiment on the synthesis of $Z=116\mathrm{}$ nuclei in the reaction ${}^{248}\mathrm{Cm}{+}^{48}\mathrm{Ca}.$ The experiment is in progress at FLNR, JINR, Dubna.

The enhancement in the production of $\mathrm{even}-Z$ nuclei observed in nuclear fission has also been observed in fragments produced from heavy ion collsions. Beams of ${}^{40}\mathrm{Ar},$ ${}^{40}\mathrm{Cl},$ and ${}^{40}\mathrm{Ca}$ at 25 MeV/nucleon were impinged on ${}^{58}\mathrm{Fe}$ and ${}^{58}\mathrm{Ni}$ targets. The resulting fragments were detected using the MSU $4\pi$ detector array, which had additional silicon detectors for better isotopic resolution. Comparison of the ratios of yields for each element showed enhancement of even-$Z$ fragment production. The enhancement was more pronounced for reactions with a greater difference in the $N/Z$ of the compound system. However, this effect was less for systems that were more neutron rich. The average $N/Z$ for fragments also displayed an odd-even effect with a lower average $N/Z$ for the $\mathrm{e}\mathrm{v}\mathrm{e}\mathrm{n}-Z$ fragments. This is related to the greater availability of neutron-poor isotopes for $\mathrm{e}\mathrm{v}\mathrm{e}\mathrm{n}-Z$ nuclei.

At the NIST Cold Neutron Research Facility, a multiple run neutron lifetime experiment is underway. Each run of the two-stage experiment consists of a neutron production stage and a neutron decay stage. Salient features of the experimental data are that the number N of neutrons which decay is an unobservable random variable. Also, the neutron decay events are contaminated by background events. Under the assumption that the number of trapped neutrons is a realization of a Markovian birth and death process, we deduce the distribution of N and the decay times subject to a variety of experimental constraints. These distributions serve as likelihood models for estimation of the mean neutron lifetime. The method of maximum likelihood and the method of minimum chi-square are employed and compared for estimation. For fairly large sample sizes, the minimum chi-square estimates suitable for binned decay data are shown, by simulation, to be comparable to the maximum likelihood estimates based on the data of exact decay times. But for moderate sample sizes, the former method gives smaller variances than the latter. The loss of efficiency due to using binned data rather than the complete decay time data is minimal provided the bin widths are reasonably small and the observation period for observing decay is not too short. Our systematic and unified approach facilitates the application of the developed statistical methods to similar two-stage lifetime experiments in which radioactive decay processes are studied. It also clarifies some of the ambiguities in the literature in using the conditional distributions for statistical estimation.

A model with nonuniform flow in the longitudinal direction is proposed for the relativistic heavy ion collisions and compared with the $14.6A\mathrm{}\mathrm{GeV}/c$ Si-Al and $10.8A\mathrm{}\mathrm{GeV}/c$ Au-Au collision data. The stronger influence of transparency on the distribution of heavier produced particles and the larger stopping in the heavier collision system are accounted for by using a new geometrical parametrization picture. The central dips in the proton and deuteron rapidity distributions for Si-Al collision are reproduced.

We compare three semimicroscopic theories to the first data on particle production in central Au+Au collisions taken at RHIC by the PHOBOS Collaboration as well as to existing data on central Pb+Pb collisions taken at the SPS by the NA49 Collaboration. The Linear Extrapolation of Ultrarelativistic nucleon-nucleon Scattering to nucleus-nucleus collisions (LEXUS) represents the SPS data quite well but predicts too many particles at RHIC. The wounded nucleon model predicts too few particles at both the SPS and RHIC; the collective tube model predicts fewer particles still. This suggests a transition in the dynamics of particle production between $\sqrt{s}=17\mathrm{}$ and $56A\hspace{0.5em}\mathrm{GeV}$ as one goes from the SPS to RHIC.

The spin-orbit splittings in the spectra of nuclei with mass numbers 5, 15, and 17 are studied within the framework of shell-model configuration mixing calculations including $2ħ\omega$ excitations. The contributions of the two-body spin-orbit and tensor components of the nucleon-nucleon interaction are studied in various model spaces. It is found that the effects of the two-body spin-orbit interaction are dominant and quite sensitive to the size of the model space considered. The effects of the tensor interaction are weaker. The correlations effects which are included in the larger (0+2) $ħ\omega$ shell-model space reduce the spin-orbit splitting in the case of $A=5\mathrm{}$ by 20%, and enhance it for $A=15\mathrm{}$ by about the same 20%. However, it is found that the correlations have a very small effect on the $d_{3/2}-d_{5/2}$ splitting in $A=17.\mathrm{}$

The mean lifetimes of ten states in ${}^{133}\mathrm{Nd}$ excited via the reaction ${}^{104}\mathrm{Pd}{(}^{32}\mathrm{S},2pn)$ at $E_{{32}_{\mathrm{S}}}=135\mathrm{}$ MeV were measured by means of the recoil-distance Doppler-shift method. The spectra obtained by setting a gate on the shifted component of a transition directly feeding the level of interest were analyzed within the framework of the differential decay-curve method. The intraband transition strengths are compared to calculations within the particle plus rotor model which reveal differences in the quadrupole deformations $\epsilon$ and $\gamma$ of the bands studied.

We study the Coulomb energy shifts in mirror nuclei with the emphasis on the halo nuclei, ${}^{11}\mathrm{Be}$ and ${}^{11}\mathrm{N}.$ We find that even in such loosely bound nuclei the second- and higher-order Coulomb contributions are relatively small and the large relative Coulomb energy shifts are due to first order effects in the Coulomb interaction.

Photoneutron cross sections were measured for ${}^9\mathrm{Be}$ in the energy range from 1.78 to 6.11 MeV with laser-induced Compton backscattered $\gamma$ rays. Resonance parameters $[E_R,B(E1\mathrm{}),{\Gamma }_n]$ for the ${1/2}^{+}$ and ${5/2}^{+}$ states were deduced from the least-squares fit to the data, while ${\Gamma }_{\gamma }$ for the ${5/2}^{-}$ state was deduced from the energy-integrated cross section. The reaction rate $〈\alpha \alpha n〉$ is discussed.

The astrophysical S factor for the proton weak capture on ${}^3\mathrm{He}$ is calculated with correlated-hyperspherical-harmonics bound and continuum wave functions corresponding to realistic Hamiltonians consisting of the Argonne $v_{14}$ or Argonne $v_{18}$ two-nucleon and Urbana-VIII or Urbana-IX three-nucleon interactions. The nuclear weak charge and current operators have vector and axial-vector components that include one- and many-body terms. All possible multipole transitions connecting any of the $p{-}^3\mathrm{He}\hspace{0.5em}S-$ and P-wave channels to the ${}^4\mathrm{He}$ bound state are considered. The S factor at a $p{-}^3\mathrm{He}$ center-of-mass energy of 10 keV, close to the Gamow-peak energy, is predicted to be $10.1\times {10}^{-20}\hspace{0.5em}\mathrm{keV}\mathrm{b}$ with the AV18/UIX Hamiltonian, a factor of $\simeq 4.5$ larger than the value adopted in the standard solar model. The P-wave transitions are found to be important, contributing about 40% of the calculated S factor. The energy dependence is rather weak: the AV18/UIX zero-energy S factor is $9.64\times {10}^{-20}\hspace{0.5em}\mathrm{keV}\mathrm{b},$ only 5% smaller than the 10 keV result quoted above. The model dependence is also found to be weak: the zero-energy S factor is calculated to be $10.2\times {10}^{-20}\hspace{0.5em}\mathrm{keV}\mathrm{b}$ with the older AV14/UVIII model, only 6% larger than the AV18/UIX result. Our best estimate for the S factor at 10 keV is therefore $(10.1\mathrm{}\pm 0.6)\times {10}^{-20}\hspace{0.5em}\mathrm{keV}\mathrm{b},$ when the theoretical uncertainty due to the model dependence is included. This value for the calculated S factor is not as large as determined in fits to the Super-Kamiokande data in which the $\mathit{hep}$ flux normalization is free. However, the precise calculation of the S factor and the consequent absolute prediction for the $\mathit{hep}$ neutrino flux will allow much greater discrimination among proposed solar neutrino oscillation solutions.

A high statistics measurement of the β decay of ${}^{187}\mathrm{Re}$ with a cryogenic microcalorimeter has been performed. The high accuracy and the calorimetric nature of the measurement allow setting a value for the end-point energy of the decay in a metallic rhenium crystal equal to $[2470\pm 1(\mathrm{stat})\pm 4(\mathrm{syst}\left)\right]$ eV. A good extrapolation of the spectrum to zero energy has also been possible thanks to the stable and well determined detector response down to the energy threshold of about 420 eV. This allows an estimate of the ${}^{187}\mathrm{Re}$ half-life of $[4.12\pm 0.02(\mathrm{stat})\pm 0.11(\mathrm{syst}\left)\right]\times {10}^{10}\mathrm{yr}.$ Both results are significantly better than the previous measurements reported in the literature.

The nucleus ${}^{68}\mathrm{Ge}$ has been studied by gamma-ray spectroscopy following its population at high spin in the reaction ${}^{40}\mathrm{Ca}{(}^{32}\mathrm{S}{,4p)}^{68}\mathrm{Ge}.$ The reaction channel was selected with the Microball array and gamma rays were detected with the Gammasphere array. The level scheme is very complex, reflecting the many different, and presumably mixed, excitation modes in this nucleus. Nevertheless, there appear to be some simplifications in the spin range above $18ħ$ where we have identified a superdeformed band and several terminating bands. The results are compared with a cranked Nilsson-Strutinsky model without pairing.