We analyze the chiral limit in dense isoptin-asymmetricnuclearmatter. It is shown that the pseudo-Goldstone modes in this system are qualitatively different from the case of isospin-symmetric matter. (author). 20 refs.
Asymmetricnuclearmatter is investigated by the Dirac Brueckner Hartree-Fock (DBHF) approach with a new decomposition of the Dirac structure of nucleon self-energy from the G matrix. It is found that the isospin dependence of the scalar and vector potentials is relatively weak, although both potentials for neutron (proton) become deep (shallow) in the neutron-rich nuclearmatter. The results in asymmetricnuclearmatter are rather different from those obtained by a simple method, where the nucleon self-energy is deduced from the single-particle energy. The nuclear binding energy as a function of the asymmetry parameter fulfils the empirical parabolic law up to very extreme isospin asymmetricnuclearmatter in the DBHF approach. The behaviour of the density dependence of the asymmetry energy is different from that obtained by non-relativistic approaches, although both give similar asymmetry energy at the nuclear saturation density
We have investigated the equation of state (EOS) and single particle (s.p.) properties of asymmetricnuclearmatter within the framework of the Brueckner-Bethe-Goldstone approach. We have discussed particularly the effect of microscopic three-body forces (TBF). It is shown that the TBF affects significantly the predicted properties of nuclearmatter at high densities.
The ratio of pre-equilibrium neutrons to protons from collisions of neutron-rich nuclei is studied as a function of their kinetic energies. This ratio is found to be sensitive to the density dependence of the nuclear symmetry energy, but is independent of the compressibility of symmetric nuclearmatter and the in-medium nucleon-nucleon cross sections. The experimental measurement of this ratio thus provides a novel means for determining the nuclear equation of state of asymmetricnuclearmatter.
We review the differences in first order phase transition of single and multi-component systems, and then discuss the crystalline structure expected to exist in the mixed confined deconfined phase of hadronic matter. The particular context of neutron stars is chosen for illustration. The qualitative results are general and apply for example to the vapor-liquid transition in subsaturated asymmetricnuclearmatter.
We suggest several ways to study properties of the symmetry term in the nuclear equation of state, EOS, from collective modes in beta-unstable nuclei. After a general discussion on compressibility and saturation density in asymmetricnuclearmatter we show some predictions on the collective response based on the solution of generalized Landau dispersion relations. Isoscalar-isovector coupling, disappearance of collectivity and possibility of new instabilities in low and high density regions are discussed with accent on their relation to the symmetry term of effective forces. The onset of chemical plus mechanical instabilities in a dilute asymmetricnuclearmatter is discussed with reference to new features in fragmentation reactions.
Within the Cornwall-Jackiw-Tomboulis (CJT) approach a general formalism is established for the study of asymmetricnuclearmatter (ANM) described by the four-nucleon interactions. Restricting ourselves to the double-bubble approximation (DBA), we determine the bulk properties of ANM, in particular, the density dependence of the nuclear symmetry energy, which is in good agreement with data of recent analyses.
Relativistic mean field (RMF) theory of nuclearmatter with the isovector scalar mean field corresponding to the {delta}-meson [a{sub 0}(980)] is studied. While the {delta}-meson field vanishes in symmetric nuclearmatter, it can influence properties of asymmetricnuclearmatter in neutron stars. The RMF contribution due to {delta}-field to the nuclear symmetry energy is negative. To fit the empirical value, E{sub s}{approx}30 MeV, a stronger {rho}-meson coupling is required than in absence of the {delta}-field. The energy per particle of neutron star matter is than larger at high densities than the one with no {delta}-field included. Also, the proton fraction of {beta}-stable matter increases. Splitting of proton and neutron effective masses due to the {delta}-field can affect transport properties of neutron star matter. (author). 4 refs, 6 figs.
The spectral function of protons in the asymmetricnuclearmatter is calculated in the self-consistent T-matrix approach. The spectral function per proton increases with increasing asymmetry. This effect and the density dependence of the spectral function partially explain the observed increase of the spectral function with the mass number of the target nuclei in electron scattering experiments.
We examine the model dependence of the phase diagram of inhomogeneous nulcear matter in supernova cores using the quantum molecular dynamics (QMD). Inhomogeneous matter includes crystallized matter with nonspherical nuclei -- ``pasta'' phases -- and the liquid-gas phase separating nuclearmatter. Major differences between the phase diagrams of the QMD models can be explained by the energy of pure neutron matter at low densities and the saturation density of asymmetricnuclearmatter. We show the density dependence of the symmetry energy is also useful to understand uncertainties of the phase diagram. We point out that, for typical nuclear models, the mass fraction of the pasta phases in the later stage of the collapsing cores is higher than 10-20 %.
We use a chiral SU(3) quark mean field model to study the properties of nuclear systems at finite temperature. The liquid-gas phase transition of symmetric and asymmetricnuclearmatter is discussed. For two formulations of the model the critical temperature, $T_c$, for symmetric nuclearmatter is found to be 15.8 MeV and 17.9 MeV. These values are consistent with those derived from recent experiments. The limiting temperatures for finite nuclei are in good agreement with the experimental points.
The effects of the equation of state of asymmetricnuclearmatter on the nuclear collisions are discussed based on the microscopic calculations by antisymmetrized molecular dynamics. In the calculations with the different effective interactions corresponding to different density dependence of the symmetry energy, the isospin effects in high and low density stages are seen in the collisions of neutron-rich unstable nuclei as well as in collisions of heavy stable nuclei with large N/Z.
Using the Hugenholtz-Van Hove theorem, we derive general expressions for the quadratic and quartic symmetry energies in terms of single-nucleon potentials in isospin asymmetricnuclearmatter. These analytical relations are useful for gaining deeper insights into the microscopic origins of the uncertainties in our knowledge on nuclear symmetry energies especially at supra-saturation densities. As examples, the formalism is applied to two model single-nucleon potentials that are widely used in transport model simulations of heavy-ion reactions.
We suggest several ways to study properties of the symmetry term in the nuclear equation of state, EOS, from collective effects in medium energy heavy ion collisions with exotic beams. The onset of chemical plus mechanical instabilities in a dilute asymmetricnuclearmatter is discussed with reference to new features in fragmentation reactions. Collective flows in heavy ion collisions are shown also to be strongly dependent on the symmetry term of the EOS. (orig.) 10 refs.
A full (3+1)-dimensional calculation using Lagrangian hydrodynamics is proposed for relativistic nuclear collisions. This calculation enables us to evaluate the anisotropic flow of the hadronic matter which appears in non-central and/or asymmetrical relativistic nuclear collisions. Applying hydrodynamical calculations to the deformed uranium collisions in the AGS energy region, we discuss the nature of the space-time structure and particle distributions in detail. (orig.)
A full (3+1) dimensional calculation using Lagrangian hydrodynamics is proposed for relativistic nuclear collisions. Initial conditions for the hot fluid is given with the aid of suitable event generator instead of using Ansatz. The calculation enables us to evaluate anisotropic flow of hot and dense matter resulting from non-central and/or asymmetrical relativistic nuclear collisions. Using this model we discuss effect of phase transition to collective flow in AGS energy region. (author)
The free energy and the equation of state of isospin-asymmetricnuclearmatter are calculated at finite temperature up to three loop order in the framework of in-medium chiral perturbation theory, systematically incorporating one- and two-pion exchange dynamics to this order. Effects from the 2?-exchange with explicit ?-isobar excitation are included, as well as three-body forces. We construct the phase diagram of nuclearmatter for different proton fractions Formula Not Shown and investigate the dependence of nuclearmatter properties on the isospin-asymmetry. A detailed study of the liquid?gas phase transition is performed. For isospin-symmetric nuclearmatter we find a critical temperature of 15.1 MeV; as the isospin-asymmetry is increased, the liquid?gas coexistence region decreases un...
Within the Thomas-Fermi model for isospin asymmetricnuclearmatter, the nuclear symmetry energy can be expressed explicitly in terms of the isospin-dependence of the nucleon-nucleon strong interaction. Respective effects of the in-medium three-body interaction and the two-body short-range tensor force due to the $\\rho$ meson exchange as well as the short-range nucleon correlation on the high-density behavior of the nuclear symmetry energy are demonstrated in a transparent way. Possible physics origins of the extremely uncertain nuclear symmetry energy at supra-saturation densities are discussed.
We examine how nuclear masses are related to the density dependence of the symmetry energy. Using a macroscopic nuclear model we calculate nuclear masses in a way dependent on the equation of state of asymmetricnuclearmatter. We find by comparison with empirical two-proton separation energies that a smaller symmetry energy at subnuclear densities, corresponding to a larger density symmetry coefficient L, is favored. This tendency, which is clearly seen for nuclei that are neutron-rich, nondeformed, and light, can be understood from the property of the surface symmetry energy in a compressible liquid-drop picture.
The bulk parameters characterizing the energy of symmetric nuclearmatter and the symmetry energy defined at normal nuclear density ? 0 provide important information on the equation of state (EOS) of isospin asymmetricnuclearmatter. While significant progress has been made in determining some lower order bulk characteristic parameters, such as the energy E 0(? 0) and incompressibility K 0 of symmetric nuclearmatter as well as the symmetry energy E sym(? 0) and its slope parameter L, yet the higher order bulk characteristic parameters are still poorly known. Here, we analyze the correlations between the lower and higher order bulk characteristic parameters within the framework of Skyrme Hartree-Fock energy density functional and then estimate the values of some higher order bulk characte...
Using the Hugenholtz-Van Hove theorem, we derive analytical expressions for the nuclear symmetry energy $E_{sym}(\\rho)$ and its density slope $L(\\rho)$ in terms of the Lorentz covariant nucleon self-energies in isospin asymmetricnuclearmatter. These general expressions are useful for understanding the Lorentz structure and the microscopic origin of the nuclear symmetry energy in relativistic covariant formulism. As an example, we analyze the Lorentz covariant nucleon self-energy decomposition of $E_{sym}(\\rho)$ and $L(\\rho)$ within the nonlinear $\\sigma$-$\\omega$-$\\rho$-$\\delta$ relativistic mean field model.
We calculate the nucleon self-energies in an isospin asymmetricnuclearmatter using QCD sum rule. Taking the difference of these for the neutron and proton enables us to express an important part of the nuclear symmetry energy in terms of local operators. Calculating the operator product expansion up to mass dimension six operators, we find that the main contribution to the difference comes from the iso-vector scalar and vector operators, which is reminiscent to the case of relativistic mean field type theories where mesons with aforementioned quantum numbers produce the difference and provide the dominant mechanism for nuclear symmetry energy.
The short-range and tensor correlations associated to realistic nucleon-nucleon interactions induce a population of high-momentum components in the many-body nuclear wave function. We study the impact of such high-momentum components on bulk observables associated to isospin asymmetricmatter. The kinetic part of the symmetry energy is strongly reduced by correlations when compared to the non-interacting case. The origin of this behavior is elucidated using realistic interactions with different short-range and tensor structures.
Limits of stability of nuclear systems are explored within the framework of a finite-range interacting Fermi gas model and microcanonical thermodynamics in Thomas-Fermi approximation. It is found that with increasing excitation energy, infinite systems become unstable against volume boiling, while finite systems become subject to surface boiling, providing a natural explanation for the observed saturationlike patterns, or limiting temperature, in caloric curves. Boiling patterns of iso-asymmetricmatter are discussed.
We demonstrate that the instabilities of asymmetricnuclearmatter at sub-saturation densities do not present two types of instabilities as usually discussed but a unique one. The associated order parameter is everywhere dominated by the isoscalar density and so the transition is of liquid-gas type even in the so-called chemical instability region. However, the instability goes in the direction of a restoration of the isospin symmetry leading to a fractionation phenomenon. (authors)
We investigate the possible thermodynamic instability in a warm and dense nuclear medium (T<50 MeV and \\rho_0<\\rho_B< 3\\rho_0) where a phase transition from nucleonic matter to resonance-dominated Delta-matter can take place. The analysis is performed by requiring the global conservation of baryon and electric charge numbers in the framework of a relativistic equation of state. Similarly to the liquid-gas phase transition, we show that the nucleon-Delta matter phase transition is characterized by both mechanical instability (fluctuations on the baryon density) and by chemical-diffusive instability (fluctuations on the charge concentration) in asymmetricnuclearmatter. We then perform an investigation and a comparative study on the different nature of such instabilities and phase transitions.
A phenomenological momentum-independent (MID) model is constructed to describe the equation of state (EOS) for isospin asymmetricnuclearmatter, especially the density dependence of the nuclear symmetry energy E sym(?). This model can reasonably describe the general properties of the EOS for symmetric nuclearmatter and the symmetry energy predicted by both the sophisticated isospin and momentum dependent MDI model and the Skyrme-Hartree-Fock approach. We find that there exists a nicely linear correlation between K sym and L as well as between J 0/K 0 and K 0, where L and K sym represent, respectively, the slope and curvature parameters of the symmetry energy at the normal nuclear density ? 0, while K 0 and J 0 are, respectively, the incompressibility and the third-order derivative parame...
We have calculated the structural properties of a strange quark star with a static model in the presence of a strong magnetic field. To this end, we use the MIT bag model with a density dependent bag constant. To parameterize the density dependence of the bag constant, we have used our results for the lowest order constrained variational calculation of the asymmetricnuclearmatter. By calculating the equation of state of strange quark matter, we have shown that the pressure of this system increases by increasing both density and magnetic field. Finally, we have investigated the effect of density dependence of the bag constant on the structural properties of a strange quark star.
In this article we have calculated the structure properties of a strange quark star in static model in the presence of a strong magnetic field using MIT bag model with a density dependent bag constant. To parameterize the density dependence of bag constant, we have used our results for the lowest order constrained variational calculation of the asymmetricnuclearmatter. By calculating the equation of state of strange quark matter, we have shown that the pressure of this system increases by increasing both density and magnetic field. Finally, we have investigated the effect of density dependence of bag constant on the structure properties of strange quark star.
Superfluidity or superconductivity with mismatched Fermi momenta appears in many systems such as charge neutral dense quark matter, asymmetricnuclearmatter, and in imbalanced cold atomic gases. The mismatch plays the role of breaking the Cooper pairing, and the pair-breaking state cannot be properly described in the framework of standard BCS theory. I give a brief review on recent theoretical development in understanding unconventional color superconductivity, including gapless color superconductor, the chromomagnetic instabilities and the Higgs instability in the gapless phase. I also introduce a possible new framework for describing unconventional color superconductor.
pt. A. Theory of nuclearmatter EOS and symmetry energy. Constraining the nuclear equation of state from astrophysics and heavy ion reactions / C. Fuchs. In-medium hadronic interactions and the nuclear equation of state / F. Sammarruca. EOS and single-particle properties of isospin-asymmetricnuclearmatter within the Brueckner theory / W. Zuo, U. Lombardo & H.-J. Schulze. Thermodynamics of correlated nuclearmatter / A. Polls ... [et al.]. The validity of the LOCV formalism and neutron star properties / H. R. Moshfegh ... [et al.]. Ferromagnetic instabilities of neutron matter: microscopic versus phenomenological approaches / I. Vidaã. Sigma meson and nuclearmatter saturation / A. B. Santra & U. Lombardo. Ramifications of the nuclear symmetry energy for neutron stars, nuclei and heavy-ion collisions / A. W. Steiner, B.-A. Li & M. Prakash. The symmetry energy in nuclei and nuclearmatter / A. E. L. Dieperink. Probing the symmetry energy at supra-saturation densities / M. Di Toro et al. Investigation of low-density symmetry energy via nucleon and fragment observables / H. H. Wolter et al. Instability against cluster formation in nuclear and compact-star matter / C. Ducoin ... [et al.]. Microscopic optical potentials of nucleon-nucleus and nucleus-nucleus scattering / Z.-Y. Ma, J. Rong & Y.-Q. Ma -- pt. B. The neutron star crust: structure, formation and dynamics. Neutron star crust beyond the Wigner-Seitz approximation / N. Chamel. The inner crust of a neutron star within the Wigner-Seitz method with pairing: from drip point to the bottom / E. E. Saperstein, M. Baldo & S. V. Tolokonnikov. Nuclear superfluidity and thermal properties of neutron stars / N. Sandulescu. Collective excitations: from exotic nuclei to the crust of neutron stars / E. Khan, M. Grasso & J. Margueron. Monte Carlo simulation of the nuclear medium: fermi gases, nuclei and the role of Pauli potentials / M. A. Pérez-García. Low-density instabilities in relativistic hadronic models / C. Providência et al. Quartetting in nuclearmatter and [symbol] particle condensation in nuclear systems / G. Röpke & P. Schuck et al. -- pt. C. Neutron star structure and dynamics. Shear viscosity of neutron matter from realistic nuclear interactions / O. Benhar & M. Valli. Protoneutron star dynamo: theory and observations / A. Bonanno & V. Urpin. Magnetic field dissipation in neutron stars: from magnetars to isolated neutron stars / J. A. Pons. Gravitational radiation and equations of state in super-dense cores of core-collapse supernovae / K. Kotake. Joule heating in the cooling of magnetized neutron stars / D. N. Aguilera, J. A. Pons & J. A. Miralles. Exotic fermi surface of dense neutron matter / M. V. Zverev, V. A. Khodel & J. W. Clark. Coupling of nuclear and electron modes in relativistic stellar matter / A. M. S. Santos et al. Neutron stars in the relativistic Hartree-Fock theory and hadron-quark phase transition / B. Y. Sun ... [et al.] -- pt. D. Prospects of present and future observations. Measurements of neutron star masses / D. G. Yakovlev. Dense nuclearmatter: constraints from neutron stars / J. M. Lattimer. Neutron star versus heavy-ion data: is the nuclear equation of state hard or soft? / J. Schaffner-Bielich ... [et al.]. Surface emission from x-ray dim isolated neutron stars / R. Turolla. High energy neutrino astronomy / E. Migneco. What gravitational waves say about the inner structure of neutron stars / V. Ferrari. Reconciling 2 M[symbol] pulsars and SN1987A: two branches of neutron stars / P. Haensel, M. Bejger & J. L. Zdunik. EOS of dense matter and fast rotation of neutron stars / J. L. Zdunik ... [et al.] -- pt. E. Quark and strange matter in neutron stars. Bulk viscosity of color-superconducting quark matter / M. Alford. Chiral symmetry restoration and quark deconfinement at large densities and temperature / A. Drago, L. Bonanno & A. Lavagno. Color superconducting quark matter in compact stars / D. B. Blaschke, T. Klähn & F. Sandin. Thermal hadronization, Hawking-Unruh radiation and e
The properties of the kaon, $K$, and antikaon, $\\kbar$, in nuclear medium are studied in the quark-meson coupling (QMC) model. Employing a constituent quark-antiquark (MIT bag model) picture, their excitation energies in a nuclear medium at zero momentum are calculated within mean field approximation. The scalar, and the vector mesons are assumed to couple directly to the nonstrange quarks and antiquarks in the $K$ and $\\kbar$ mesons. It is demonstrated that the $\\rho$ meson induces different mean field potentials for each member of the isodoublets, $K$ and $\\kbar$, when they are embedded in asymmetricnuclearmatter. Furthermore, it is also shown that this $\\rho$ meson potential is repulsive for the $K^-$ meson in matter with a neutron excess, and renders $K^-$ condensation less likely to occur.
The nuclear symmetry energy figures crucially in the structure of asymmetric nuclei and, more importantly, in the equation of state (EoS) of compact stars. At present it is almost totally unknown, both experimentally and theoretically, in the density regime appropriate for the interior of neutron stars. Based on a strong-coupled structure of dense baryonic matter encoded in the skyrmion crystal approach and resorting to the notion of generalized hidden local symmetry in hadronic interactions, we address a variety of hitherto unexplored issues of nuclear interactions associated with the symmetry energy, namely, the role of flavor symmetry such as kaon condensation and hyperons, nuclear tensor forces, the manifestation of conformal symmetry and chiral symmetry in the EoS of dense compact-star matter etc. One of the surprising results coming from the hidden local symmetry structure is the discovery that at high density, the strong short-range repulsion described in terms of $\\omega$-meson exchanges get suppresse...
Recently we have developed a novel chiral power counting scheme for an effective field theory of nuclearmatter with nucleons and pions as degrees of freedom [1]. It allows for a systematic expansion taking into account both local as well as pion-mediated multi-nucleon interactions. To implement this power counting in actual calculations we develop here a non-perturbative method based on Unitary Chiral Perturbation Theory (UCHPT) for performing the required resummations. We have applied this new method to the pion self-energy in asymmetricnuclearmatter up-to-and-including next-to-leading order contributions. We show explicitly that the contributions to the pion self-energy with in-medium nucleon-nucleon interactions at next-to-leading order cancel. Some next-to-next-to-leading order contributions to the pion self-energy in the nuclear medium are also evaluated for further illustration of our non-perturbative method.
The neutron-proton mass difference in (isospin asymmetric) nuclearmatter and finite nuclei is studied in the framework of a medium-modified Skyrme model. The proposed effective Lagrangian incorporates both the medium influence of the surrounding nuclear environment on the single nucleon properties and an explicit isospin-breaking effect in the mesonic sector. Energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels are included as well. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it markedly decreases in neutron matter. Furthermore, the possible interplay between the effective nucleon mass in finite nuclei and the Nolen-Schiffer anomaly is discussed. In particular, we find that a correct description of the properties of mirror nuclei leads to a stringent restriction of possible modifications of the nucleon's effective mass in nuclei.
We study the spinodal instabilities of asymmetricnuclearmatter at finite temperature within the microscopic Brueckner--Hartree--Fock (BHF) approximation using the realistic Argonne V18 nucleon-nucleon potential plus a three-body force of Urbana type. Our results are compared with those obtained with the Skyrme force SLy230a and the relativistic mean field models NL3 and TW. We find that BHF predicts a larger spinodal region. This result is a direct consequence of the fact that our Brueckner calculation predicts a larger critical temperature and saturation density of symmetric nuclearmatter than the Skyrme and relativistic mean field ones. We find that the instability is always dominated by total density fluctuations, in agreement with previous results of other authors. We study also the restoration of the isospin symmetry in the liquid phase, {\\it i.e.,} the so-called isospin distillation or fragmentation effect, finding that its efficiency increases with increasing proton fraction and decreases as tempera...
Abstract in english Symmetry energy coefficients of asymmetricnuclearmatter generalized are investigated as the inverse of nuclearmatter polarizabilities with two different approaches. Firstly a general calculation shows they may depend on the neutron-proton asymmetry itself. The choice of particular prescriptions for the density fluctuations lead to certain isospin (n-p asymmetry) dependences of the polarizabilities. Secondly, with Skyrme type interactions, the static limit of the dynami (more) cal polarizability is investigated corresponding to the inverse symmetry energy coefficient which assumes different values at different asymmetries (and densities and temperatures). The symmetry energy coefficient (in the isovector channel) is found to increase as n-p asymmetries increase. The spin symmetry energy coefficient is also briefly investigated.
A detailed presentation is given of estimating uncertainties in thermonuclear reaction rates for stellar nucleosynthesis involving narrow resonances, starting from random errors in measured or calculated resonance and nuclear level properties. Special attention is given to statistical matters such as probability distributions, error propagation, and correlations between errors. Interpretation of resulting uncertainties in reaction rates and the distinction between symmetric and asymmetric errors are also discussed. Computing reaction rate uncertainties is described. We give examples from explosive nucleosynthesis by hydrogen burning on light nuclei.
We present analysis of J/$\\psi$ production over the range $-1.0 < \\eta < 4.2$ in p+p and d+Au collisions using di-electron data taken during the 2008 run with the STAR experiment at Brookhaven National Laboratory. STAR's unique forward capabilities, especially the Forward Meson Spectrometer electromagnetic calorimeter, allow us the possibility of investigating the intrinsic charm components of the proton wave function using high-$x_F$ forward particles produced in asymmetric partonic collisions. Mid-rapidity measurements in d+Au collisions extend our understanding of the mechanisms underlying heavy quarkonium production and its transport through cold nuclearmatter.
The radius of interaction between the struck proton and spectator nucleons is close to the radius of short-distance two-nucleon correlations in nuclearmatter, which makes final state interaction(FSI) an important background to production of protons with large missing momentum. We present a simple classification of the dominant FSI effects in ^4He(e,e'p) scattering and identify parts of the phase space dominated by FSI. At large missing momentum, FSI leads to a striking angular anisotropy of the missing momentum distribution, which has a prominent peak in transverse kinematics and smaller, forward-backward asymmetric, peaks in parallel kinematics.
Nuclearmatter shows a tendency to cluster, i.e. to form secondary nuclei, or clusters. This property explains the fission asymmetry of actinide nuclei and the symmetric fission mode of some trans-berkelium nuclei, the two emission modes of ternary light charged particles, and two characteristic fission- properties of superheavy nuclei, namely the fission by cluster emission and a particular asymmetric mode in which the reaction entropy of internal rearrangements seems to play a role. The reality of this tendency and of its consequences can be demonstrated by thermochemical considerations. (author)
We investigate the RPA response of asymmetricnuclearmatter to external fields which induce charge exchange between nucleons, both at zero and finite temperature. Closed expressions are obtained for the RPA response in each spin channel when the nucleon-nucleon interaction is of the Skyrme type. Exchange terms are fully taken into account. We consider the transferred momentum, asymmetry and temperature as the relevant parameters of our study. Special emphasis is given to the role of neutron excess in relation to the collective states at low momentum.
We investigate the RPA response of asymmetricnuclearmatter to external fields which induce charge exchange between nucleons, both at zero and finite temperature. Closed expressions are obtained for the RPA response in each spin channel when the nucleon-nucleon interaction is of the Skyrme type. Exchange terms are fully taken into account. We consider the transferred momentum, asymmetry and temperature as the relevant parameters of our study. Special emphasis is given to the role of neutron excess in relation to the collective states at low momentum.
The R3B experiment at FAIR will offer unique opportunities worldwide to study the properties of bulk asymmetricnuclearmatter, e.g. the phase diagram, equation of state, symmetry energy, transport coefficients and in-medium cross sections. The experiment will take advantage of the intense radioactive beams produced by the SuperFRS with energies up to 2 AGeV. We will outline this physics programme and describe the detector sub-systems of R3B which will enable these measurements. Some detectors are already under construction while others are at the planning/R&D stage.
A full (3+1)-dimensional calculation using the Lagrangian hydrodynamics is proposed for relativistic nuclear collisions. The calculation enables us to evaluate anisotropic flow of hot and dense matter which appears in non-central and/or asymmetrical relativistic nuclear collisions. The relativistic hydrodynamical model is related to the equation of the state and the useful for the verification of quark-gluon plasma state. By virtue of the Lagrangian hydrodynamics we can easily trace the trajectory which corresponds to the adiabatic paths in the T-{mu} plane. We evaluate the directly of the influence of the phase transition to physical phenomena in the ultra-relativistic nuclear collisions. Using our relativistic hydrodynamical model, we discuss the effect of the phase transition on the collective flow. (author)
We have considered a hot strange star matter, just after the collapse of a supernova, as a composition of strange, up and down quarks to calculate the bulk properties of this system at finite temperature with the density dependent bag constant. To parameterize the density dependent bag constant, we use our results for the lowest order constrained variational (LOCV) calculations of asymmetricnuclearmatter. Our calculations for the structure properties of the strange star at different temperatures indicate that its maximum mass decreases by increasing the temperature. We have also compared our results with those of a fixed value of the bag constant. It can be seen that the density dependent bag constant leads to higher values of the maximum mass and radius for the strange star.
The asymmetricnuclearmatter equation of state at finite temperature is studied in the SU(2) chiral sigma model using mean-field approximation. The effect of temperature on effective mass, entropy, and binding energy is discussed. Treating the system to possess two conserved charges, the liquid-gas phase transition is investigated. We have also discussed the effect of the proton fraction on critical temperature with and without a {rho}-meson contribution. We also apply our model to study the structure of the proto-neutron star with neutrino free charge-neutral matter in beta equilibrium. We found that the mass and radius of the star decreases as it cools from the entropy per baryon S=2 to S=0 and the maximum temperature of the core of the star is about 62 MeV for S=2.
Asymmetricnuclearmatter equation of state at finite temperature is studied in SU(2) chiral sigma model using mean field approximation. The effect of temperature on effective mass, entropy, and binding energy is discussed. Treating the system as one with two conserved charges the liquid-gas phase transition is investigated. We have also discussed the effect of proton fraction on critical temperature with and without $\\rho$-meson contribution. We have extended our work to study the structure of proto-neutron star with neutron free charge-neutral matter in beta-equilibrium. We found that the mass and radius of the star decreases as it cools from the entropy per baryon S = 2 to S = 0 and the maximum temperature of the core of the star is about 62 MeV for S = 2.
We have calculated the nuclear symmetry energy $E_{sym}(\\rho)$ up to densities of $4 \\sim 5 \\rho_0$ with the effects from the Brown-Rho (BR) and Ericson scalings for the in-medium mesons included. Using the $V_{low-k}$ low-momentum interaction with and without such scalings, the equations of state (EOS) of symmetric and asymmetricnuclearmatter have been calculated using a ring-diagarm formalism where the particle-particle-hole-hole ring diagrams are included to all orders. The EOS for symmetric nuclearmatter and neutron matter obtained with linear BR scaling are both overly stiff compared with the empirical constraints of Danielewicz {\\it et al.} \\cite{daniel02}. In contrast, satisfactory results are obtained by either using the nonlinear Ericson scaling or by adding a Skyrme-type three-nucleon force (TNF) to the unscaled $V_{low-k}$ interaction. Our results for $E_{sym}(\\rho)$ obtained with the nonlinear Ericson scaling are in good agreement with the empirical values of Tsang {\\it et al.} \\cite{tsang09} a...
Recent calculations with an effective isospin dependent contact interaction show the possibility of the crossover from superfluidity of neutron Cooper pairs in $^1S_0$ pairing channel to Bose-Einstein condensation (BEC) of di-neutron bound states in dilute nuclearmatter. The density and spin correlation functions are calculated for a di-neutron condensate in asymmetricnuclearmatter with the aim to find the possible features of the BCS-BEC crossover. It is shown that the zero-momentum transfer spin correlation function satisfies the sum rule at zero temperature. In symmetric nuclearmatter, the density correlation function changes sign at low momentum transfer across the BCS-BEC transition and this feature can be considered as a signature of the crossover. At finite isospin asymmetry, this criterion gives too large value for the critical asymmetry $\\alpha_c^d\\sim0.9$, at which the BEC state is quenched. Therefore, it can be trusted for the description of the density-driven BCS-BEC crossover of neutron pairs...
Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation and at high nucleon momenta. In this report we present a selection of reaction observables particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS) At low energies the behavior of the symmetry energy around saturation influences dissipation and fragment production mechanisms. Predictions are shown for deep-inelastic and fragmentation collisions induced by neutron rich projectiles. Differential flow measurements will also shed lights on the controversial neutron/proton effective mass splitting in asymmetricmatter. The high density symmetry term can be derived from isospin effects on heavy ion r...
One of the main goal in nuclear physics research is the study of nuclei in extreme conditions of spin and isospin. The more performing tools for theoretical predictions in this field are microscopic methods such as the Hartree-Fock one based on independent particle approximation. The main ingredient for such an approach is the effective nucleon-nucleon interaction. The actual trend being the study of nuclei more and more far from the stability valley, it is necessary to cast doubt over the validity of usual effective interaction. This work constitute a study on the way one can construct a new interaction allowing some theoretical predictions on nuclei far from the stability. We have thus made a complete study of symmetric infinite nuclearmatter and asymmetric one up to pure neutron matter. One shows that the asymmetry coefficient, which was considered until now as fixing isospin properties, is not sufficient to have a correct description of very exotic isospin states. A new type of constraint is shown for fixing this degree of freedom: the neutron matter equation of state. One include this equation of state, taken from a theoretical model giving a good description of radii and masses of neutron stars. One can thus expect to build up new Skyrme interaction with realistic properties of ground state of very neutron-rich nuclei. (author). 63 refs., 68 figs., 15 tabs.
Auxiliary tests with asymmetric diffusers demonstrated that longi- tudinal pressure gradient, rather ..... As matters now stand, the necessity of resorting to .... the vertical plane of symmetry did not insure symmetry of the diffuser entrance - for the ...
The recently introduced cosmic sum rules combine the data from PAMELA and Fermi-LAT cosmic ray experiments in a way that permits to neatly investigate whether the experimentally observed lepton excesses violate charge symmetry. One can in a simple way determine universal properties of the unknown component of the cosmic rays. Here we attribute a potential charge asymmetry to the dark sector. In particular we provide models of asymmetric dark matter able to produce charge asymmetric cosmic rays. We consider spin zero, spin one and spin one-half decaying dark matter candidates. We show that lepton flavor violation and asymmetric dark matter are both required to have a charge asymmetry in the cosmic ray lepton excesses. Therefore, an experimental evidence of charge asymmetry in the cosmic ray lepton excesses implies that dark matter is asymmetric.
The Landau Fermi Liquid parameters are calculated for charge neutral asymmetricnuclearmatter in beta equilibrium at zero temperature in the presence of a very strong magnetic field with relativistic mean-field models. Due to the isospin structure of the system, with different populations of protons and neutrons and spin alignment to the field, we find non-vanishing Landau mixing parameters. The existence of quantized Landau levels for the charged sector has some impact on the Landau parameters with the presence of discretized features in those involving the proton sector. Using the Fermi liquid formalism singlet and triplet excited quasiparticle states are analyzed, and we find that in-medium effects and magnetic fields are competing, however, the former are more important in the interaction energy range considered. It is found that for magnetic field strengths Log$_{10}$ B (G) $\\le 17$ the relative low polarization of the system produces mild changes in the generalized Landau parameters with respect to the...
Using the large acceptance apparatus FOPI, we study central and semi-central collisions in the reactions (energies in Formula Not Shown are given in parentheses): 40Ca+40Ca (0.4, 0.6, 0.8, 1.0, 1.5, 1.93), 58Ni+58Ni (0.15, 0.25, 0.4), 96Ru+96Ru (0.4, 1.0, 1.5), 96Zr+96Zr (0.4, 1.0, 1.5), 129Xe+CsI (0.15, 0.25, 0.4), 197Au+197Au (0.09, 0.12, 0.15, 0.25, 0.4, 0.6, 0.8, 1.0, 1.2, 1.5). The observables include directed and elliptic flow. The data are compared to earlier data where possible and to transport model simulations. A stiff nuclear equation of state is found to be incompatible with the data. Evidence for extra-repulsion of neutrons in compressed asymmetricmatter is found.
We study the effects of momentum dependent interactions on the single-particle properties of hot asymmetricnuclearmatter. In particular, the single-particle potential of proton and neutron as well the symmetry potential, are studied within a self-consistent model using a momentum dependent effective interaction. In addition, the isospin splitting of the effective mass is derived from the above model. In all the cases, temperature effects are included and analyzed. The role of the specific parametrization of the effective interaction used in the present work is investigated. It is concluded that the behavior of the symmetry potential depends strongly on the parametrization of the interaction part of the energy density as well as the momentum dependence regulator function. The effects of the parametrization are less pronounced on the isospin mass splitting.
The observational relation between the density of baryon and dark matter in the Universe, ?DM/?B?5, is one of the most difficult problems to solve in modern cosmology. We discuss a scenario that explains this relation by combining the asymmetric dark matter scenario and the spontaneous baryogenesis associated with the flat direction in the supersymmetric standard model. A part of baryon asymmetry is transferred to charge asymmetry D that dark matter carries, if a symmetry violating interaction that works at high temperature breaks not only B-L but also D symmetries simultaneously. In this case, the present number density of baryon and dark matter can be same order if the symmetric part of dark matter annihilates sufficiently. Moreover, the baryon number density can be enhanced as compared to that of dark matter if another B-L violating interaction is still in thermal equilibrium after the spontaneous genesis of dark matter, which accommodates a TeV scale asymmetric dark matter model.
We investigate hyperon potentials in nuclearmatter through hyperon production reactions, and construct several sets of equation of state (EOS) of nuclearmatter including hyperons for numerical simulations of core collapse supernovae.
The kaon-nucleon interaction in nuclearmatter is considered by taking into account tree graphs, p-wave interaction, pionic intermediate states and some residual interaction constrained by Adler`s consistency condition. The kaon spectra in nuclearmatter are discussed as well as the possibility of K{sup -} and anti K{sup 0} condensation in dense nuclearmatter. (orig.)
Pulse shaping of femtosecond lasers causes frequency and intensity changes in the electromagnetic field; these changes can be symmetric or asymmetric with respect to time. Within the first few femtosecond, the nonlinear optical response is purely electronic. The nuclear response follows soon after that and continues for hundreds of femtoseconds. Differences in the nonlinear optical response caused by time inversion of laser pulses are explored here on a number of different systems. The change in behavior is first probed in a solution of IR144 for different laser intensities which shows a distinctive asymmetry upon time inversion in the fluorescence signal above the linear response regime. Two-photon induced fluorescence of a rhodamine B solution at high intensities is found to have a symmetric phase dependence which becomes asymmetric because of self phase modulation and self focusing at higher laser intensities. Surprisingly, the fragmentation and ionization of isolated para-nitrotoluene molecules was found not to depend on time inversion of the shaped laser pulses. However, from pulse shaping experiments we can glean the relative timing of the fragmentation processes. Results from this study show that the response of a system to time inversion of shaped femtosecond pluses provides an internal clock for ultrafast physicochemical processes occurring during laser matter interactions.
...Matter of Entergy Nuclear Operations; Vermont Yankee Nuclear Power Station; Demand for Information...license authorizes the operation of the Vermont Yankee Nuclear Power Station (Vermont Yankee) in accordance with conditions specified...
The quark-meson coupling (QMC) model for nuclearmatter, which describes nuclearmatter as non-overlapping MIT bags bound by the self-consistent exchange of scalar and vector mesons is modified by the introduction of a density dependent bag constant. It is found that when the bag constant is significantly reduced in nuclear medium with respect to its free space value, large canceling isoscalar Lorentz scalar and vector potentials for the nucleon in nuclearmatter emerge naturally. Such potentials are comparable to those suggested by relativistic nuclear phenomenology. This suggests that the modification of the bag constant in the nuclear medium may play an important role in low- and medium-energy nuclear physics.
We study the phase transition from nuclearmatter to quark matter within the SU(3) quark mean field model and NJL model. The SU(3) quark mean field model is used to give the equation of state for nuclearmatter, while the equation of state for color superconducting quark matter is calculated within the NJL model. It is found that at low temperature, the phase transition from nuclear to color superconducting quark matter will take place when the density is of order 2.5?0 - 5?0. At zero density, the quark phase will appear when the temperature is larger than about 148 MeV. The phase transition from nuclearmatter to quark matter is always first order, whereas the transition between color superconducting quark matter and normal quark matter is second order.
We discuss the possibility of the cosmic coincidence generating the ratio of baryon asymmetry to dark matter in a Stueckelberg U(1) extension of the standard model and of the minimal supersymmetric standard model. For the U(1), we choose L?-L? which is anomaly free and can be gauged. The dark matter candidate arising from this extension is a singlet of the standard model gauge group but is charged under L?-L?. Solutions to the Boltzmann equations for relics in the presence of asymmetric dark matter are discussed. It is shown that the ratio of the baryon asymmetry to dark matter consistent with the current WMAP data, i.e., the cosmic coincidence, can be successfully explained in this model with the depletion of the symmetric component of dark matter from resonant annihilation via the Stueckelberg gauge boson. For the extended minimal supersymmetric standard model model, it is shown that one has a two-component dark matter picture with asymmetric dark matter being the dominant component and the neutralino being the subdominant component (i.e., with relic density a small fraction of the WMAP cold dark matter value). Remarkably, the subdominant component can be detected in direct detection experiments such as SuperCDMS and XENON-100. Further, it is shown that the class of Stueckelberg models with a gauged L?-L? will produce a dramatic signature at a muon collider with the ?(?+?-??+?-,?+?-) showing a detectable Z' resonance while ?(?+?-?e+e-) is devoid of this resonance. Within the above frameworks, we discuss several broad classes of models both above and below the electroweak phase transition temperature. Asymmetric dark matter arising from a U(1)B-L Stueckelberg extension is also briefly discussed. Finally, in the models we propose the asymmetric dark matter does not oscillate and there is no danger of it being washed out from oscillations.
Nuclear and astrophysical evidence on the equation of state of dense matter is examined. The role of hyperonization of matter in the development of proto-neutron stars is briefly discussed. 7 refs., 4 figs.
The two recent density-dependent versions of the finite-range M3Y interaction (CDM3Yn and M3Y-Pn) have been probed against the bulk properties of asymmetricnuclearmatter (NM) in the nonrelativistic Hartree-Fock (HF) formalism. The same HF study has also been done with the famous Skyrme (SLy4) and Gogny (D1S and D1N) interactions that were well tested in the nuclear structure calculations. Our HF results are compared with those given by other many-body calculations like the Dirac-Brueckner Hartree-Fock approach or ab initio variational calculations using free nucleon-nucleon interaction and by both the nonrelativistic and relativistic mean-field studies using different model parameters. Although the two considered density-dependent versions of the M3Y interaction were proven to be quite realistic in the nuclear structure or reaction studies, they give two distinct behaviors of the NM symmetry energy at high densities, like the Asy-soft and Asy-stiff scenarios found earlier with other mean-field interactions. As a consequence, we obtain two different behaviors of the proton fraction in the {beta}-equilibrium that in turn can imply two drastically different mechanisms for the neutron star cooling. While some preference of the Asy-stiff scenario was found based on predictions of the latest microscopic many-body calculations or empirical NM pressure and isospin diffusion data deduced from heavy-ion collisions, a consistent mean-field description of nuclear structure database is more often given by some Asy-soft type interaction like the Gogny or M3Y-Pn ones. Such a dilemma poses an interesting challenge to the modern mean-field approaches.
Using the volume coupling version of the cloudy bag model, the quark-meson coupling model is extended to study the role of pion field and the properties of nuclearmatter. The extended model includes the effect of gluon exchange as well as the pion-cloud effect, and provides a good description of the nuclearmatter properties. The relationship between the extended model and the EFT approach to nuclearmatter is also discussed.
The understanding of the interaction of nucleons in nuclear and neutron-rich matter at non-zero temperature is important for a variety of applications ranging from heavy-ion collisions to nuclear astrophysics. In this papre we apply the Dirac-Brueckner-Hartree-Fock method along with the Bonn B potential to predict single-particle properties in symmetric nuclearmatter and neutron-rich matter at finite temperature. It is found that temperature effects are generally small but can be significant at low density and momentum.
We develop a nonperturbative technique in field theory to study properties of infinite nuclearmatter at zero temperature as well as at finite temperatures. Here we dress the nuclearmatter with off-mass shell pions. The techniques of thermofield dynamics are used for finite temperature calculations. Equation of state is derived from the dynamics of the interacting system in a self consistent manner. The transition temperature for nuclearmatter appears to be around 15 MeV.
The bulk properties of nuclearmatter are studied within the Brueckner-Hartree-Fock (BHF) and extended Brueckner-Hartree-Fock (EBHF) approaches using different realistic nucleon-nucleon interactions. Nuclearmatter saturation points, incompressibility, chemical potential and speed of sound are calculated and analysed as functions of the density, for nuclearmatter. We found that both the BHF and the EBHF approaches fail to reproduce the empirical saturation point of nuclearmatter. Also, we found that the EBHF approach leads to a slightly smaller chemical potential compared to the BHF approximation. This effect becomes more pronounced as the density is increased further.
The input parameters for a set of codes that calculate nuclear single-particle levels and total potential energies as functions of shape are discussed. These codes were developed in Lund. In the codes, the macroscopic-microscopic method is used to calculate the total energy. The single-particle potential is a modified-oscillator potential. The macroscopic energy is calculated for both a liquid drop model and the droplet model. Mass-asymmetric and axially (..gamma..) asymmetric shapes may be studied by use of these codes.
This progress report studies of fluctuation processes in nuclear collisions discusses the following topics: quantal effects on growth of instabilities in nuclearmatter; collisional damping of giant resonances in a non-Markovian approach; and medium-modified interaction induced by fluctuations.
Modern concepts are presented about the processes of interaction of nuclear emissions with matter and features are examined of physical-mathematical modeling of the main problems of the methods of nuclear geophysics using these processes.
The dark matter content of the Universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the Universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freeze-out depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels). In these \\eta-parametrised asymmetric dark matter models (\\eta-ADM), the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of \\eta-dark matter asymmetry close to the baryon asymmetry \\eta_B. Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT and CRESST experiments. Here, we c...
The r-process, or the rapid neutron-capture process, of stellar nucleosynthesis is called for to explain the production of the stable (and some long-lived radioactive) neutron-rich nuclides heavier than iron that are observed in stars of various metallicities, as well as in the solar system. A very large amount of nuclear information is necessary in order to model the r-process. This concerns the static characteristics of a large variety of light to heavy nuclei between the valley of stability and the vicinity of the neutron-drip line, as well as their beta-decay branches or their reactivity. Fission probabilities of very neutron-rich actinides have also to be known in order to determine the most massive nuclei that have a chance to be involved in the r-process. Even the properties of asymmetricnuclearmatter may enter the problem. The enormously challenging experimental and theoretical task imposed by all these requirements is reviewed, and the state-of-the-art development in the field is presented. Nuclear-physics-based and astrophysics-free r-process models of different levels of sophistication have been constructed over the years. We review their merits and their shortcomings. The ultimate goal of r-process studies is clearly to identify realistic sites for the development of the r-process. Here too, the challenge is enormous, and the solution still eludes us. For long, the core collapse supernova of massive stars has been envisioned as the privileged r-process location. We present a brief summary of the one- or multidimensional spherical or non-spherical explosion simulations available to-date. Their predictions are confronted with the requirements imposed to obtain an r-process. The possibility of r-nuclide synthesis during the decompression of the matter of neutron stars following their merging is also discussed. Given the uncertainties remaining on the astrophysical r-process site and on the involved nuclear physics, any confrontation between predicted r-process yields and observed abundances is clearly risky. A comparison dealing with observed r-nuclide abundances in very metal-poor stars and in the solar system is attempted on grounds of r-process models based on parametrised astrophysics conditions. The virtues of the r-process product actinides for dating old stars or the solar system are also critically reviewed.
The fifth edition of the bi-annual 'Nuclear Physics in Astrophysics (NPA)' conference series was held in Eilat, Israel on April 3-8, 2011. This Conference is also designated as the 24th Nuclear Physics Divisional Conference of the EPS. The main purpose of this conference, as that of the four previous ones in this series, is to deal with those aspects of nuclear physics that are directly related to astrophysics. The concept of such a meeting was conceived by the Nuclear Physics Board of the European Physical Society in 1998. At that time, the idea of such a conference was quite new and it was decided that this meeting would be sponsored by the EPS. The first meeting, in January 2001, was planned and organized in Eilat, Israel. Due to international circumstances the conference was moved to Debrecen, Hungary. Subsequent conferences were held in Debrecen again, in Dresden, Germany, and in Frascati, Italy (moved from Gran Sasso due to the tragic earthquake that hit the L'Aquila region). After 10 years the conference finally returned to Eilat, the originally envisioned site. Eilat is a resort town located on the shore of the Gulf of Eilat, which connects Israel to the Red Sea and further south to the Indian Ocean. It commands spectacular views of the desert and mountains, offering unique touristic attractions. The local scientific backdrop of the conference is the fact that the Israeli scientific scene exhibits a wide variety of research activities in many areas of nuclear physics and astrophysics. A new accelerator, SARAF at Soreq Nuclear Research Center is presently undergoing final acceptance tests. SARAF will serve as a platform for production of radioactive ion beams and nuclear-astrophysics research in Israel. The meeting in Eilat was organized by four Israeli scientific institutions, Hebrew University, Soreq Nuclear Research Center, Tel Aviv University and the Weizmann Institute of Science. The welcome reception and lectures were held at the King Solomon hotel and the conference dinner banquet at the Dan hotel. An excursion to the 'Red Canyon' in the Eilat Mountains on Wednesday afternoon was one of the social highlights of the conference. A total number of 140 scientists attended NPA5 and about 30 accompanying persons; about 25% of these were young participants (less than 36 years old). 23 participants were from Israel, and 27 were from outside of Europe (including two from Africa). The subjects covered at the conference in Eilat concentrated mainly on the spirit of the original idea - to probe experimental and theoretical activity in nuclear structure and reactions that is directly related to the physics of the Universe. There were also sessions of general interest in astrophysics, as well as a poster session on Tuesday evening featuring 40 posters. The topics included: Nuclear Structure - Theory and Experiment Big-Bang Nucleosynthesis and Formation of First Stars Stellar Reactions and Solar Neutrinos Explosive Nucleosynthesis, Radioactive Beams and Exotic Nuclei-New Facilities and Future Possibilities for Astrophysics Neutrino Physics - the Low and High-Energy Frontiers Rare events, Dark Matter, Double beta-decay, Symmetries The conference started with an excellent exposé of the progress made in the discovery of super-heavy elements and the study of their properties. The progress in this field is enormous, and this subject should be communicated to more general audiences. The role of the nuclear equation of state and of the precise determination of nuclear masses in nucleosynthesis was emphasized in several talks. The role of neutrinos in astrophysics was discussed extensively in several sessions. One of the highlights of this was the presentation about the IceCube and DeepCore detectors operating deep in the Antarctic ice. These facilities are able to detect cosmogenic neutrinos in a wide energy range, from 10 GeV to 1010 GeV. The subject of solar neutrinos was discussed in a number of talks. Topics related to properties of neutrinos, such as double-beta decay and neutrino mixing were well represented at the conference. One of the central problems in modern cosmology and astrophysics is the search for dark matter. Several talks dealt with this subject and with methods to detect dark matter. Another intriguing and rather novel subject that was discussed at the meeting was time variation of fundamental physical constants. Two speakers have examined the sensitivity of Big-Bang Nucleosynthesis to the variation of the values of the fundamental constants. The role of some specific nuclei (such as Ni 56) in cosmology was pointed out. Many of the presentations at the conference described experimental studies of reactions relevant to nucleosynthesis at various stages of cosmic evolution. As reflected in the conference, these activities are widespread, encompassing many laboratories. Rare Isotope Beam (RIB) facilities are in the forefront of these studies. To understand the various processes of nucleosynthesis one has to have a good theory of nuclei far from the stability line. A number of presentations dealt with the description of such exotic nuclei. It is clear from the presentations that the future of experimental nuclear astrophysics looks promising as existing experimental facilities are being upgraded and new facilities are being built. X-Ray and Gamma-Ray Bursts and cosmic explosions were the subject of several talks. A discussion of various experiments attempting to measure time-reversal violation was the subject of one lecture. The solution of the puzzle as to why the universe is asymmetric with respect to matter-antimatter requires knowledge of the limit of time-reversal conservation. The late John Bahcall was a great astrophysicist and a supporter of the conference series 'Nuclear physics in Astrophysics'. On the last day of the conference, following a talk by Neta Bahcall from Princeton University on dark matter in the Universe, a short commemoration for John was held. Detailed information about the NPA5 conference and its scientific program can be found at: www.weizmann.ac.il/conferences/NPA5/ Naftali Auerbach Michael Hass Michael Paul Editors Conference photograph Conference photograph The PDF also contains lists of the committees and participants.
Using a self-consistent, Hartree description for both infinite nuclearmatter and finite nuclei based on a relativistic quark model (the quark-meson coupling model), we investigate the variation of the masses of the non-strange vector mesons, the hyperons and the nucleon in infinite nuclearmatter and in finite nuclei.
Quantum molecular dynamics is applied to study the ground state and excited state properties of nuclearmatter at subsaturation densities. The structure of nuclearmatter at subsaturation density shows some exotic shapes with variation of the density. However, the structure in our result is rather irregular compared to those of previous works due to the existence of local minimum configurations. (author)
By tuning several experimental observables, such as momentum and reaction plane, the PHENIX experiment has performed a systematic study of high $p_T$ parton energy loss in hot nuclearmatter, as well as jet induced medium modifications, such as the ridge and shoulder. Baseline d+Au measurements are also studied to provide the comparison as control of cold nuclearmatter effect.
The linear ? model (L?M) suggests that the nuclearmatter exhibits a phase transition to a pion-condensed ferromagnetic state at a few times the normal nuclearmatter density. Extending the naïve L?M so as to reproduce the known bulk properties of nuclearmatter around saturation, the equation of state of neutron star matter is constructed and used as an input for solving the Tolman-Oppenheimer-Volkoff equation. It is found that there exist gravitationally stable solutions to this equation. These solutions can model neutron stars with a maximal dipole magnetic field of O(1014 - 1015 G).
We calculate the symmetry energy of the nuclearmatter by using the bottom-up approach, so called hard wall model. To consider the nuclearmatter, we introduce the isospin for u- and d-quarks. We find that in the hard wall model, the symmetry energy of the nuclearmatter is proportional to the square of nucleon density. We also study the symmetry energy of the quark matter in the deconfining phase. Finally, we investigate the effect of the symmetry energy on the Hawking-Page transition and show that at the given quark density, the Hawking-Page transition temperature decreases due to the symmetry energy.
We use the flavor SU(2) NJL model to describe both nuclear and quark matter, and construct phase diagrams to illustrate the phase transitions to normal quark matter (NQM) and color superconducting quark matter (SQM). We calculate the corresponding charge neutral equations of state using the Gibbs conditions to generate the mixed phases.
We present a systematic study of the properties of pure hadronic and hybrid compact stars. The nuclear equation of state (EoS) for b-equilibrated neutron star matter was obtained using density dependent effective nucleon-nucleon interaction which satisfies the constraints from the observed flow data from heavy-ion collisions. The energy density of quark matter is lower than that of this nuclear EoS at higher densities implying the possibility of transition to quark matter inside the core. We solve the Einstein's equations for rotating stars using pure nuclearmatter and quark core. The b-equilibrated neutron star matter with a thin crust is able to describe highly massive compact stars but find that the nuclear to quark matter deconfinement transition inside neutron stars causes reduction ...
The core of neutron-star matter is supposed to be at a much higher density than the normal nuclearmatter density for which various possibilities have been suggested such as, for example, meson or hyperon condensation and/or deconfined quark or color-superconducting matter. In this work, we explore the implication on hadron physics of a dense compact object that has three "phases", nuclearmatter at the outer layer, kaon condensed nuclearmatter in the middle and strange quark matter at the core. Using a drastically simplified but not unreasonable model, we develop the scenario where the different phases are smoothly connected with the kaon condensed matter playing a role of "doorway" to a quark core, the equation of state (EoS) of which by fine-tuning parameters within the range allowed by nature could be made compatible with the mass vs. radius constraint given by the 2-solar mass object PSR J1614-2230 recently observed.
Pion condensation has not previously been investigated in a theory that accounts for the known bulk properties of nuclearmatter, its saturation energy and density and compressibility. We have formulated and solved self-consistently, in the mean field approximation, a relativistic field theory that possesses a condensate solution and reproduces the correct bulk properties of nuclearmatter, The theory is solved in its relativistically covariant form for a general class of space-time dependent pion condensates. Self-consistency and compatibility with bulk properties of nuclearmatter turn out to be very stringent conditions on the existence and energy of the condensate, but they do allow a weak condensate energy to develop. The spin-isospin density oscillations, on the other hand, can be large. It is encouraging, as concerns the possible existence of new phases of nuclearmatter, that this is so, unlike the Lee-Wick density isomer, that appears to be incompatible with nuclearmatter properties.
We study natural composite cold dark matter candidates which are pseudo Nambu-Goldstone bosons (pNGB) in models of dynamical electroweak symmetry breaking. Some of these can have a significant thermal relic abundance, while others must be mainly asymmetric dark matter. By considering the thermal abundance alone we find a lower bound of MW on the pNGB mass when the (composite) Higgs is heavier than 115 GeV. Being pNGBs, the dark matter candidates are in general light enough to be produced at the LHC.
We emphasize the central role played by the spectral function in the description of hadrons in matter and discuss the applicability of the quasiparticle concept to the propagation of hadrons in dense nuclearmatter. Theoretical and experimental results relevant for the in medium properties of vector mesons and kaons are briefly reviewed. We also present novel results for the {rho} and {omega} spectral functions in nuclearmatter, deduced from a coupled channel analysis of pion-nucleon scattering data. (orig.)
We construct the nuclear and quark matter equations of state at zero temperature in an effective quark theory (the Nambu-Jona-Lasinio model), and discuss the phase transition between them. The nuclearmatter equation of state is based on the quark-diquark description of the single nucleon, while the quark matter equation of state includes the effects of scalar diquark condensation (color superconductivity). The effect of diquark condensation on the phase transition is discussed in detail.
We develop a chiral SU(3) symmetric relativistic mean field (RMF) model with a logarithmic potential of scalar condensates. Experimental and empirical data of symmetric nuclearmatter saturation properties, bulk properties of normal nuclei, and separation energies of single- and double-$\\Lambda$ hypernuclei are well explained. The nuclearmatter equation of state (EOS) is found to be softened by $\\sigma\\zeta$ mixing which comes from determinant interaction. The neutron star matter EOS is further softened by $\\Lambda$ hyperons.
Subject matter includes structure of matter (what is matter, forces holding atoms together, visualizing the atom, the chemical elements, atomic symbols, isotopes, radiation from the atom), radioactivity (what holds the nucleus together, can one element change into another element, radiation from the nucleus, half-life, chart of the nuclides), and nuclear fission (nuclear energy release, the fission process, where does fission energy go, radiation and radioactivity resulting from fission).
Understanding the equation of state (EOS) of cold nuclearmatter, namely, the relation between the pressure and energy density, is a central goal of nuclear physics that cuts across a variety of disciplines. Indeed, the limits of nuclear existence, the collision of heavy ions, the structure of neutron stars, and the dynamics of core-collapse supernova, all depend critically on the equation of state of hadronic matter. In this contribution I will concentrate on the special role that nuclear physics plays in constraining the EOS of cold baryonic matter and its impact on the properties of neutron stars.
Recent analyses of several isospin effects in heavy-ion reactions have allowed us to constrain the density dependence of nuclear symmetry energy at sub-saturation densities within a narrow range. Combined with constraints on the Equation of State (EOS) of symmetric nuclearmatter obtained previously from analyzing the elliptic flow in relativistic heavy-ion collisions, the EOS of neutron-rich nuclearmatter is thus partially constrained. Here we report effects of the partially constrained EOS of neutron-rich nuclearmatter on the mass-radius correlation, moment of inertia, elliptical deformation and gravitational radiation of (rapidly) rotating neutron stars.
The symmetry energy contribution to the nuclear Equation of State (EoS) impacts various phenomena in nuclear astrophysics, nuclear structure, and nuclear reactions. Its determination is a key objective of contemporary nuclear physics with consequences for the understanding of dense matter within neutron stars. We examine the results of laboratory experiments that have provided initial constraints on the nuclear symmetry energy and its density dependence at and somewhat below normal nuclearmatter density. Some of these constraints have been derived from properties of nuclei. Others have been derived from the nuclear response to electroweak and hadronic probes. We also examine the most frequently used theoretical models that predict the symmetry energy and its slope. By comparing existing constraints on the symmetry pressure to theories, we demonstrate how the contribution of the three-body force, an essential ingredient in neutron matter models, can be determined.
The symmetry energy contribution to the nuclear equation of state impacts various phenomena in nuclear astrophysics, nuclear structure, and nuclear reactions. Its determination is a key objective of contemporary nuclear physics, with consequences for the understanding of dense matter within neutron stars. We examine the results of laboratory experiments that have provided initial constraints on the nuclear symmetry energy and on its density dependence at and somewhat below normal nuclearmatter density. Even though some of these constraints have been derived from properties of nuclei while others have been derived from the nuclear response to electroweak and hadronic probes, within experimental uncertainties-they are consistent with each other. We also examine the most frequently used theoretical models that predict the symmetry energy and its slope parameter. By comparing existing constraints on the symmetry pressure to theories, we demonstrate how contributions of three-body forces, which are essential ingredients in neutron matter models, can be determined.
Nuclear collisions at intermediate, relativistic, and ultra-relativistic energies offer unique opportunities to study in detail manifold fragmentation and clustering phenomena in dense nuclearmatter. At intermediate energies, the well known processes of nuclear multifragmentation -- the disintegration of bulk nuclearmatter in clusters of a wide range of sizes and masses -- allow the study of the critical point of the equation of state of nuclearmatter. At very high energies, ultra-relativistic heavy-ion collisions offer a glimpse at the substructure of hadronic matter by crossing the phase boundary to the quark-gluon plasma. The hadronization of the quark-gluon plasma created in the fireball of a ultra-relativistic heavy-ion collision can be considered, again, as a clustering process. We will present two models which allow the simulation of nuclear multifragmentation and the hadronization via the formation of clusters in an interacting gas of quarks, and will discuss the importance of clustering to our und...
The observational relation between the density of baryon and dark matter in the Universe, $\\Omega_{\\rm DM}/\\Omega_B\\simeq 5$, is one of the most difficult problems to solve in modern cosmology. We discuss a scenario that explains this relation by combining the asymmetric dark matter scenario and the spontaneous baryogenesis associated with the flat direction in the supersymmetric standard model. A part of baryon asymmetry is transferred to charge asymmetry $D$ that dark matter carries, if a symmetry violating interaction that works at high temperature breaks not only $B-L$ but also $D$ symmetries simultaneously. In this case, the present number density of baryon and dark matter can be same order if the symmetric part of dark matter annihilates sufficiently. Moreover, the baryon number density can be enhanced as compared to that of dark matter if another $B-L$ violating interaction is still in thermal equilibrium after the spontaneous genesis of dark matter, which accommodates a TeV scale asymmetric dark matte...
Coupled asymmetric double well ($a\\phi^2-b\\phi^3+c\\phi^4$) one-dimensional potentials arise in the context of first order phase transitions both in condensed matter physics and field theory. Here we provide an exhaustive set of exact periodic solutions of such a coupled asymmetric model in terms of elliptic functions (domain wall arrays) and obtain single domain wall solutions in specific limits. We also calculate the energy and interaction between solitons for various solutions. Both topological (kink-like at $T=T_c$) and nontopological (pulse-like for $T\
Considerable quantities of organic matter are associated with heavy metal minerals recovered from Suncor aqueous sludge. This organic matter is not extractable with common organic solvents. Attempts were made to concentrate this organic matter by dissolving the mineral matter in acids. Various soluble fractions were also obtained by extraction with methanol/benzene (1:4) after each dissolution step. All these fractions were analysed by elemental analysis, infrared, proton and /sup 13/C nuclear magnetic resonance spectroscopy. 56 references, 11 figures, 10 tables.
The guide sets forth requirements for safety of the population and the environment in nuclear power plant siting. It also sets out the general basis for procedures employed by other competent authorities when they issue regulations or grant licences. On request STUK (Radiation and Nuclear Safety Authority of Finland) issues case-specific statements about matters relating to planning and about other matters relating to land use in the environment of nuclear power plants.
Understanding the nature of the matter comprising the Solar System is crucial for understanding the mechanism that generates the Earth's geomagnetic field and the magnetic fields of other planets and satellites. The commonality in the Solar System of matter like that of the inside of the Earth, together with common nuclear reactor operating conditions,forms the basis for generalizing the author's concept of nuclear geomagnetic field generation to planetary magnetic field generation by natural planetocentric nuclear fission reactors.
For sufficiently wide resonances, nuclear resonance fluorescence behaves like elastic photo-nuclear scattering while retaining the large cross-section characteristic of resonant photo-nuclear absorption. We show that NRF may be used to characterize the signals produced by low-energy nuclear recoils by serving as a novel source of tagged low-energy nuclear recoils. Understanding these signals is important in determining the sensitivity of direct WIMP dark-matter and coherent neutrino-nucleus scattering searches.
We have developed a distorted-wave strong-potential Born approximation for charge transfer at large scattering angles in asymmetric ion-atom collisions, and applied it to the calculation of electron capture in resonant nuclear collisions. A strong variation of the capture probability across the resonance is predicted.
Multifragmentation is the dominant decay mode of heavy nuclear systems with excitation energies near their binding energies and is characterized by a multiple production of nuclear fragments with intermediate mass. At relativistic bombarding energies, multifragmentation may be observed in peripheral collisions of heavy symmetric systems or more central collisions of mass asymmetric systems. The decay properties indicate a high degree of equilibration and are well described by statistical multifragmentation models. Multifragmentation has been linked to the liquid-gas phase transition in finite nuclear systems. A caloric curve of nuclei has been obtained, and signatures of critical phenomena in finite nuclear systems are searched for in multifragmentation data.
The seven Joint Coordination Committee between R.O.K. and other countries, including U.S. and Canada are currently in operation for peaceful use of atomic energy. Among these, the most amicable and fruitful committees are the R.O.K-U.S.A joint standing committee on nuclear energy cooperation (JSCNEC) and R.O.K-Canada joint coordinated committee. Various matters encompassing 8 policy matters, 14 technological cooperation matters, 13 nuclear safety cooperation matters and 6 safeguards matters were discussed at the 19th R.O.K.-U.S.A. JSCNEC held June 22-26 in Seoul and Taejon. Among these, matters related to KAERI are the 13 technical cooperation and 2 nuclear safety cooperation concerns. (author). 10 refs., 5 tabs., 2 figs.
QMD (quantum molecular dynamics) has not been applied to supernova and neutron star matter. We begun to apply QMD, microscopic simulation of nuclear reaction, to the infinite system of nuclearmatter. The infinite system was simulated by N particles system under the periodic boundary condition. Pauli potential introduced repulsive force which the same kinds of particles could not approach at phase space, instead of antisymmetrization of the system. Supernova matter was appropriate to the symmetric nuclearmatter, the inhomogeneous structure was observed less than 0.8 {rho}{sub 0} of density, but homogeneous more than it. Each nucleus was seen to separate from others less than 0.2 {rho}{sub 0}. Neutron star matter attains {beta} equilibrium and not symmetric matter and the lowest energy was obtained at about 0.03-0.08 of proton content. (S.Y.)
We study nuclear fusion occurring according to conventional wisdom in the planet Jupiter. In particular, we consider if in a standard evolutionary model of Jupiter a significant part of Jupiter's luminosity has been due to nuclear fusion at any time during its evolution. Nuclear rate equations in dense matter allowing for screening and pressure effects have been integrated in time.
This document presents the 64 articles of the law n.2006-686 on the nuclear security. It concerns the regulation in matter of safety and transparency, the Authority of Nuclear Safety, the public information, the base nuclear installations and the radioactive substances transport, the risks prevention and the penalties. (A.L.B.)
We present predictions for nuclear modification factor in proton-lead collisions at LHC energy 5.5 TeV from Glauber-Gribov theory of nuclear shadowing. We have also made predictions for baseline cold-matternuclear effects in lead-lead collisions at the same energy.
This report reviews the following topics: nuclear and quark matter; correlated pairs from heavy ion collisions-search for new low mass resonances coupled to electron-positron collisions; proposed light ion research program; experimental nuclear astrophysics (explosive nucleosynthesis); search for rare decay modes and rare processes in nuclei; and nuclear spectroscopy at the extremes of spin, isospin, and temperature. (LSP).
We propose an alternative mechanism of baryogenesis in which a scalar baryon undergoes a percolating first-order phase transition in the early Universe. The potential barrier that divides the phases contains explicit B and CP violation and the corresponding instanton that mediates decay is therefore asymmetric. The nucleation and growth of these asymmetric bubbles dynamically generates baryons, which thermalize after percolation; bubble collision dynamics can also add to the asymmetry yield. We present an explicit toy model that undergoes bubble baryogenesis, and numerically study the evolution of the baryon asymmetry through bubble nucleation and growth, bubble collisions, and washout. We discuss more realistic constructions, in which the scalar baryon and its potential arise amongst the color-breaking minima of the MSSM, or in the supersymmetric neutrino seesaw mechanism. Phenomenological consequences, such as gravitational waves, and possible applications to asymmetric dark-matter generation are also discussed.
We propose an alternative mechanism of baryogenesis in which a scalar baryon undergoes a percolating first-order phase transition in the early Universe. The potential barrier that divides the phases contains explicit B and CP violation and the corresponding instanton that mediates decay is therefore asymmetric. The nucleation and growth of these asymmetric bubbles dynamically generates baryons, which thermalize after percolation; bubble collision dynamics can also add to the asymmetry yield. We present an explicit toy model that undergoes bubble baryogenesis, and numerically study the evolution of the baryon asymmetry through bubble nucleation and growth, bubble collisions, and washout. We discuss more realistic constructions, in which the scalar baryon and its potential arise amongst the color-breaking minima of the MSSM, or in the supersymmetric neutrino seesaw mechanism. Phenomenological consequences, such as gravitational waves, and possible applications to asymmetric dark-matter generation are also discu...
The understanding of the interaction of nucleons in nuclear and neutron-rich matter at non-zero temperature is important for a variety of applications ranging from heavy-ion collisions to nuclear astrophysics. In this paper we apply the Dirac-Brueckner-Hartree-Fock method along with the Bonn B nucleon-nucleon potential to predict single-particle properties in symmetric nuclearmatter and pure neutron matter at finite temperature. It is found that temperature effects are generally small but can be significant at low density and momentum.
We investigate the properties of isospin-symmetric nuclearmatter and neutron stars in a chiral model approach adopting the SU(2) parity-doublet formulation. This ansatz explicitly incorporates chiral symmetry restoration with the limit of degenerate masses of the nucleons and their parity partners. Instead of searching for an optimized parameter set we explore the general parameter dependence of nuclearmatter and star properties in the model. We are able to get a good description of ground-state nuclearmatter as well as large values of mass for neutron stars in agreement with observation.
The electromagnetic field has been studied in nuclearmatter and nuclei. Because the expectation of the electric charge density operator is not zero, different from that in vacuum, the U(1) local gauge symmetry of electric charge is spontaneously broken in nuclearmatter, then the photon acquires a mass through Higgs mechanism. Perturbative calculation of photon self-energy shows the photon effective mass is about $85.343MeV$ in the symmetric nuclearmatter at the saturation density $\\rho_0 = 0.16fm^{-3}$. It is concluded that these two methods are equivalent to each other in this problem. Meanwhile, our result implies that more superheavy elements beyond Z=114 may be synthesized.
Diagnosing corticobasal degeneration is often difficult on the basis of clinical symptoms and radiological images. We aimed to clarify the imaging findings of corticobasal degeneration syndrome (CBDS). Included in the study were 16 patients (8 men, 8 women, 46-75 years old) with clinically diagnosed CBDS. We evaluated the patients' symptoms and signs, and MR and single-photon emission CT (SPECT) imaging findings. All the patients had cerebral atrophy. Asymmetric cerebral atrophy was observed in 13 patients (81%) predominantly contralateral to the side clinically more affected. Atrophy in the cerebral peduncle was observed in seven patients. FLAIR images showed hyperintensity in the subcortical white matter in the frontoparietal lobes in the clinically more affected side in 14 patients, and in the rolandic region in 13 patients. Asymmetric hypoperfusion in the frontoparietal lobes on SPECT images was observed in all of the patients, and in the basal ganglia in 11 patients. CBDS might be unique in showing hyperintensity in the subcortical white matter in the rolandic region on FLAIR images with asymmetric atrophy predominantly contralateral to the side clinically more severely affected. Asymmetric atrophy in the cerebral peduncle without signal abnormalities was also characteristic of CBDS. Atrophy in the midbrain tegmentum was also seen in patients with CBDS. (orig.)
The sole gateway for molecular exchange between the cytoplasm and the nucleus is the nuclear pore complex (NPC). This large supramolecular assembly mediates transport of cargo into and out of the nucleus and fuse the inner and outer nuclear membranes to form an aqueous translocation channel. The NPC is composed of eight proteinaceous asymmetric units forming a pseudo-8-fold symmetric passage. Due to its shear size, complexity, and plastic nature, dissecting the high-resolution three-dimensional structure of the NPC in its hydrated state is a formidable challenge. Toward this goal, we applied cryo-electron tomography to spread nuclear envelopes from Xenopus oocytes. To compensate for perturbations of the 8-fold symmetry of individual NPCs, we performed symmetry-independent asymmetric unit a...
We report the unidirectional transport of ionic dyes by new soft matter ratchets, which are made of melamine foam with non-centrosymmetric triangular shapes and driven by an AC electric field. The time evolution of the distributions of the ions in the ratchet has been analyzed to reveal that the ratchets can transport the ions preferentially in one direction with an asymmetric transport ratio of more than 7.
Recent empirical research has documented asymmetric volatility and volatility clustering in stock markets. We conjecture that a limit of arbitrage due to a borrowing constraint and herding behavior by investors are related to these phenomena. This study conducts simulation analyses on a spin model where borrowing constrained agents imitate their nearest neighbors but switch their strategies to a different one intermittently. We show that herding matters for volatility clustering while a borrowing constraint intensifies the asymmetry of volatility through the herding effect.
Recent empirical research has documented asymmetric volatility and volatility clustering in stock markets. We conjecture that a limit of arbitrage due to a borrowing constraint and herding behavior by investors are related to these phenomena. This study conducts simulation analyses on a spin model where borrowing constrained agents imitate their nearest neighbors but switch their strategies to a different one intermittently. We show that herding matters for volatility clustering while a borrowing constraint intensifies the asymmetry of volatility through the herding effect.
Abstract in english We investigate the emergence of time-dependent nonperturbative configurations during the evolution of nonlinear scalar field models with symmetric and asymmetric double-well potentials. Complex spatio-temporal behavior emerges as the system seeks to establish equipartition after a fast quench. We show that fast quenches may dramatically modify the decay rate of metastable states in first order phase transitions. We discuss possible applications in condensed matter systems and in inflationary cosmology.
Quarterly Reports on the operation of Finnish nuclear power plants describe nuclear and radiation safety related events and observations which the Finnish Centre for Radiation and Nuclear Safety (STUK) considers safety significant. Safety improvements at the plants and general matters relating to the use of nuclear energy are also reported. A summary of the radiation safety of plant personnel and of the environment, and tabulated data on the plants` production and load factors are also given. (4 figs., 4 tabs.).
After making a brief history on the nuclear law, the author shows that ethical aspects got involved in nuclearmatters at three levels: security of nuclear supplies, radioactive waste management, and potential human failures. Then a list of ``good conduct norms`` which should be the link between law and ethics is given. They correspond to different issues of nuclear development: technological quality, radiation protection, radioactive waste management, public information, international cooperation, non-proliferation. (TEC).
We examine jamming and ratchet effects for vortex matter in superconductors with asymmetric funnel geometries. We show that the vortex-vortex interactions can induce a clogging or jamming effect where it becomes increasingly difficult for the vortices to move through the system. We also find that commensurability effects can arise when certain vortex configurations form highly symmetrical structures in the funnel plaquettes. Due to the asymmetry, the critical currents are different for driving in different directions, leading to a diode effect. We also discuss other possible geometries that could be used to explore jamming in vortex matter.
In an unconventional realization of left-right symmetry, the particle corresponding to the left-handed neutrino ?L [with SU(2)L interactions] in the right-handed sector, call it nR [with SU(2)R interactions], is not its Dirac mass partner, but a different particle which may be a dark-matter candidate. In parallel to leptogenesis in the SU(2)L sector, asymmetric production of nR may occur in the SU(2)R sector. This mechanism is especially suited for nR mass of order 1 to 10 keV, i.e. warm dark matter, which is a possible new paradigm for explaining the structure of the Universe at all scales.
Some people have a concern for a fair distribution of incomes while others do not. Does such a concern matter for majority voting on redistribution? Fairness preferences are relevant for redistribution outcomes only if fair-minded voters are pivotal. Pivotality, in turn, depends on the structure of income classes. We experimentally study voting on redistribution between two income classes and show that the effect of inequality aversion is asymmetric. Inequality aversion is more likely to matter if the “rich” are in majority. With a “poor” majority, we find that redistribution outcomes look as if all voters were exclusively motivated by self-interest.
Some people have a concern for a fair distribution of incomes while others do not. Does such a concern matter for majority voting on redistribution? Fairness preferences are relevant for redistribution outcomes only if fair-minded voters are pivotal. Pivotality, in turn, depends on the structure of income classes. We experimentally study voting on redistribution between two income classes and show that the effect of inequality aversion is asymmetric. Inequality aversion is more likely to matter if the “rich” are in majority. With a “poor” majority, we find that redistribution outcomes look as if all voters were exclusively motivated by self-interest.
Strange stars (ReSS) calculated from a realistic equation of state (EOS), that incorporate chiral symmetry restoration as well as deconfinement at high density [Phys. Lett. B 438 (1998) 123; Phys. Lett. B 447 (1999) 352, Addendum; Phys. Lett. B 467 (1999) 303, Erratum; Indian J. Phys. B 73 (1999) 377] show compact objects in the mass radius curve. We compare our calculations of incompressibility for this EOS with that of nuclearmatter. One of the nuclearmatter EOS has a continuous transition to ud-matter at about five times normal density. Another nuclearmatter EOS incorporates density dependent coupling constants. From a look at the consequent velocity of sound, it is found that the transition to ud-matter seems necessary.
Strange stars (ReSS) calculated from a realistic equation of state (EOS), that incorporate chiral symmetry restoration as well as deconfinement at high density [Phys. Lett. B 438 (1998) 123; Phys. Lett. B 447 (1999) 352, Addendum; Phys. Lett. B 467 (1999) 303, Erratum; Indian J. Phys. B 73 (1999) 377] show compact objects in the mass radius curve. We compare our calculations of incompressibility for this EOS with that of nuclearmatter. One of the nuclearmatter EOS has a continuous transition to ud-matter at about five times normal density. Another nuclearmatter EOS incorporates density dependent coupling constants. From a look at the consequent velocity of sound, it is found that the transition to ud-matter seems necessary.
Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclearmatter can be described using a previously developed formalism of the quark compound bags (QCB). Partial-wave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of $P$-matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclearmatter and the G-matrix. The approach provides a link between high-density nuclearmatter with the MQS components and the cumulative effect observed in reactions on th...
Screening effects of electrons on inhomogeneous nuclearmatter, which includes spherical, slablike, and rodlike nuclei as well as spherical and rodlike nuclear bubbles, are investigated in view of possible application to cold neutron star matter and supernova matter at subnuclear densities. Using a compressible liquid-drop model incorporating uncertainties in the surface tension, we find that the energy change due to the screening effects broadens the density region in which bubbles and nonspherical nuclei appear in the phase diagram delineating the energetically favorable shape of inhomogeneous nuclearmatter. This conclusion is considered to be general since it stems from a model-independent feature that the electron screening acts to decrease the density at which spherical nuclei become unstable against fission and to increase the density at which uniform matter becomes unstable against proton clustering.
The possibility of using the optimized {delta} expansion for studying medium effects on hadronic properties in quark or nuclearmatter is investigated. The {delta} expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclearmatter. The results obtained with the {delta} expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the {delta} expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs.
The biggest particle accelerator in the world, at CERN, will undergo its first test in November at the fraco-swiss border. Researchers in nuclear Physics expect crucial informations about the origine of matter. (1/3 page)
These proceedings cover many aspects of the usefulness of spallation neutrons. Nine different areas are considered: surfaces and interfaces, engineering, materials science, polymers and complex fluids, chemistry, structural biology, nuclear engineering and radiation effects, condensed matter physics and fundamental physics.
Analytic expressions of the density and of the particle-hole polarization propagator are derived for a slab of noninteracting nuclearmatter. The nondiagonal behaviour of the polarization propagator in the momentum components perpendicular to the slab is explored.
The use of dilepton production in p-A and A-A collisions as a probe of nuclearmatter under extreme conditions is described. Recent results from the DLS collaboration at the Bevalac are presented. 10 refs., 2 figs.
This report discusses topics in the following areas: QCD transport theory; minijets in hadronic and nuclear collisions; lattice gauge theory; hadronic matter and other studies; and strong electromagnetic fields. (LSP)
This report discusses the following topics: Memory effect in Boltzmann-Langevin model; effect of memory time on agitation of unstable modes in nuclearmatter; and non-markovian approach to damping of giant monopole resonances in nuclei.
With the global color symmetry model (GCM) being extended to finite chemical potential, the density dependence of the bag constant, the total energy and the radius of a nucleon, as well as the quark condensate in nuclearmatter are investigated. A maximal nuclearmatter density for the existence of the bag with three quarks confined within is obtained. The calculated results indicate that, before the maximal density is reached, the bag constant, the total energy of a nucleon and the quark condensate decrease gradually, and the radius of a nucleon increases, with the increasing of the nuclearmatter density. Nevertheless no sudden change emerges. As the maximal nuclearmatter density is reached, a phase transition from nucleons to quarks takes place and the chiral symmetry is restored.
Within the self-consistent Green's functions formalism, we study the effects of three-body forces on the in-medium spectral function, self-energy and effective mass of the nuclearmatter constituents, analyzing the density and momentum dependence.
Typical examples of muon's application, such as for muon catalyzed fusion, nuclear physics, condensed matter physics, surface and nano-scale science, and radiography, are introduced. Also, the importance and the benefit of intense muon beams are stressed.
We study the octet baryon electromagnetic form factors in nuclearmatter using the covariant spectator quark model extended to the nuclearmatter regime. The parameters of the model in vacuum are fixed by the study of the octet baryon electromagnetic form factors. In nuclearmatter the changes in hadron properties are calculated by including the relevant hadron masses and the modification of the pion-baryon coupling constants calculated in the quark-meson coupling model. In nuclearmatter the magnetic form factors of the octet baryons are enhanced in the low $Q^2$ region, while the electric form factors show a more rapid variation with $Q^2$. The results are compared with the modification of the bound proton electromagnetic form factors observed at Jefferson Lab. In addition, the corresponding changes for the bound neutron are predicted.
This document is part of Subvolume D5 `Chemical Shifts and Coupling Constants for Carbon-13. Part 5: Organometallic Compounds' of Volume 35 `Nuclear Magnetic Resonance Data' of Landolt-Börnstein Group III: `Condensed Matter'.
This document is part of Subvolume D5 `Chemical Shifts and Coupling Constants for Carbon-13. Part 5: Organometallic Compounds' of Volume 35 `Nuclear Magnetic Resonance Data' of Landolt-Börnstein Group III: `Condensed Matter'.
This document is part of Part 1 `Aliphatic Compounds' of Subvolume D `Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 `Nuclear Magnetic Resonance Data', Group III `Condensed Matter'.
This document is part of Part 1 `Aliphatic Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.
This document is part of Part 1 `Aliphatic Compounds' of Subvolume D `Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 `Nuclear Magnetic Resonance Data', Group III `Condensed Matter'.
This document is part of Part 6 `Organic Metalloid Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.
This document is part of Subvolume D5 `Chemical Shifts and Coupling Constants for Carbon-13. Part 5: Organometallic Compounds' of Volume 35 `Nuclear Magnetic Resonance Data' of Landolt-Börnstein Group III: `Condensed Matter'.
This document is part of Part 6 `Organic Metalloid Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.
This document is part of Subvolume D5 `Chemical Shifts and Coupling Constants for Carbon-13. Part 5: Organometallic Compounds' of Volume 35 `Nuclear Magnetic Resonance Data' of Landolt-Börnstein Group III: `Condensed Matter'.
This document is part of Part 1 `Aliphatic Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.
This document is part of Part 6 `Organic Metalloid Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.
This document is part of Part 6 `Organic Metalloid Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.
This document is part of Part 1 `Aliphatic Compounds' of Subvolume D `Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 `Nuclear Magnetic Resonance Data', Group III `Condensed Matter'.
Geant4 is a toolkit for the simulation of the passage of particles through matter. Its application areas include high energy physics and nuclear experiments, medical, accelerator and space physics studies.
Nuclearmatter and charge distributions, and the radii of light exotic nuclei have been calculated with the Dynamic Correlation Model and compared with those extracted from proton and electron scattering experiments.
A brief review is provided of some straightforward K-nuclear and ..lambda..-hypernuclear systems. A discussion of less straightforward speculations on H-dibaryons and strange quark matter by many authors, is also given. 28 refs., 6 figs.
Strange baryon spectra and form factors are key probes to study excited nuclearmatter. The use of lattice QCD allows us to test the strength of the Standard Model by calculating strange baryon quantities from first principles.
I discuss three open problems in astrophysics where nuclear physics can make important contributions: the solar abundance problem, dark matter particle detection, and the origin of the r-process elements.
...License Nos (Redacted), EA (Redacted); NRC- 2010-0351] In the Matter of All Power Reactor Licensees and Research Reactor Licensees Who Transport Spent Nuclear Fuel; Order Modifying License (Effective Immediately) I. The...
...License Nos.: (Redacted), EA (Redacted); NRC- 2010-0351] In the Matter of All Power Reactor Licensees and Research Reactor Licensees Who Transport Spent Nuclear Fuel; Order Modifying License (Effective Immediately) I The licensees...
4 days ago ... 1998-2000, Research Associate, Nuclear Physics Laboratory, University ... "From Quantum to Cosmos: Fundamental Physics Research in Space," (2006). ... Results on the Strong Equivalence Principle, Dark Matter, and New ...
This document is part of Part 6 `Organic Metalloid Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.
A novel concept to produce a reasonable simulation of a fusion first wall/blanket test environment (except the 14 MeV neutron component) employing an existing nuclear facility is presented. Preliminary results show that an asymmetric, nuclear test environment with surface and volumetric heating rates similar to those expected in a fusion first wall/blanket or divertor chamber surface appears feasible. The proposed concept takes advantage of nuclear reactions within the annulus of a test space (15 cm in diameter and approximately 100 cm high) to provide an energy flux to the surface of a test module.
On the basis of a smooth crossover from the hadronic matter with hyperons to quark matter with strangeness, we show that the maximum mass of neutron stars with quark matter core can be larger than those without quark matter core. This is in contrast to the conventional softening of equation of state due to exotic components at high density. Essential conditions to reach our conclusion are (i) the crossover takes place at relatively low densities, i.e., (2 - 4) times the normal nuclear density, and (ii) the quark matter is strongly interacting in the crossover region. By these, the pressure of the system can be greater than that of purely hadronic matter in the crossover region and leads to the maximum mass greater than 2 solar mass. Several implications of this result to the nuclear incompressibility, the hyperon mixing, and the neutrino cooling are also remarked.
The masses of the scalar ($\\sigma$) and vector ($\\omega$) mesons and their widths in nuclearmatter are studied in detail using the quark-meson coupling (QMC) model. It is shown that above normal nuclearmatter density the effects of $\\sigma$-$\\omega$ mixing and the decay of the $\\sigma$ into $2\\pi$ change the scalar meson mass considerably, while the vector meson mass remains near its mean-field value. We compare the QMC results with those of other effective models.
We study here hot nuclearmatter in the quark meson coupling (QMC) model which incorporates explicitly quark degrees of freedom, with quarks coupled to scalar and vector mesons. The equation of state of nuclearmatter including the composite nature of the nucleons is calculated at finite temperatures. The calculations are done taking into account the medium-dependent bag constant. Nucleon properties at finite temperatures as calculated here are found to be appreciably different from the value at $T=0.$
The recent progress on the study of the collective excitation in relativistic nuclearmatter is reviewed. The collective excitation modes are derived by meson propagators in nuclearmatter. The mesons we study are $\\sigma, ømega, particle - hole, delta - hole excitations but also antiparticle excitations, such as particle - antiparticle, antidelta - particle, delta - antiparticle excitations. By calculating the dispersion relation and the spin - isospin dependent response function, the effects of all these excitation are studied.
We present results obtained for nuclei, nuclear and neutron star matter, and neutron star structure obtained with the recent Argonne v{sub 18} two- nucleon and Urbana IX three-nucleon interactions including relativistic boost corrections. These interactions predict that matter will undergo a transition to a spin layered phase with neutral pion condensation. We also consider the possibility of a transition to quark matter. (orig.)
It has been argued that compression of nuclearmatter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the ..cap alpha.. particle, composed of spin-zero pairs of each of the baryon octet (an ''octet'' particle).
We investigate the nucleation of strange quark matter inside hot, dense nuclearmatter. Applying Zel'dovich's kinetic theory of nucleation we find a lower limit of the temperature {ital T} for strange-matter bubbles to appear, which happens to be satisfied inside the Kelvin-Helmholtz cooling era of a compact star life but not much after it. Our bounds thus suggest that a prompt conversion could be achieved, giving support to earlier expectations for nonstandard type-II supernova scenarios.
The value of nuclear magnetic resonance imaging in the diagnosis and quantitation of the progression of multiple sclerosis is discussed. Magnetic resonance imaging generates images that reflect differential density and velocity of hydrogen nuclei between cerebral gray and white matter, as well as between white matter and pathological lesions of the disease.
Nuclear regulatory reform is divided into two parts. The first part contains all those matters for which new legislation is required. The second part concerns all those matters that are within the power of the Commission under existing statutes. Recommendations are presented.
Progress in the areas of pQCD radiative processes in dense matter, QCD transport theories to describe the evolution of nonequilibrium phenomena in dense matter, and the development and testing of phenomenological models of high-energy nuclear collisions is summarized. The evolution of the total energy density of quarks and gluons with minijet initial conditions at RHIC energy is shown for Au+Au.
The implications of nuclearmatter equation of state measurements for a quark matter phase transition are discussed. The possibility of detecting such a phase transition by looking for changes in the pattern of collective flow associated with heavy ion collisions is pointed out. 18 references, 8 figures, 3 tables.
The Landau parameters of nuclearmatter and neutron matter are extracted from the Brueckner theory including three-body forces. The dynamical response function to weak neutrino current is calculated in terms of the Landau parameters in the RPA limit. Then, the neutrino mean free path in neutron stars in calculated for different conditions of density and temperature.
Simulation of antiproton-proton, pion-nuclear and photo-nuclear reactions with CHIPS is published and implemented in GEANT4. In CHIPS the hadronic compounds (quasmons) are created by projectiles on nuclear clusters with subsequent hadronization of the quasmons in vacuum (quark fusion) or in nuclearmatter (quark exchange). The antiproton-nuclear reactions at rest are simulated in two steps: first, antinucleons annihilate with the peripheral nucleons which are relatively far from the dense nuclear surface, second, a part of the secondary mesons interact with the residual nucleus. The solid angle in which the secondary mesons are absorbed by nuclei is a parameter. The second step is the parallel hadronization of a set of quasmons, created by the absorbed mesons, inside the same nucleus. The multi- quasmon fragmentation algorithm of CHIPS is well tested now. The result of simulation is compared with experimental data. CHIPS can simulate yields of charged nuclear fragments, which are locally absorbed by matter an...
Properties of effective interactions in neutron-rich matter are reflected in the medium's equation of state (EOS), which is a relationship among several state variables. Spin and isospin asymmetries play an important role in the energy balance and could alter the stability conditions of the nuclear EOS. The EOS has far-reaching consequences for numerous nuclear processes in both the terrestrial laboratories and the cosmos. Presently the EOS, especially for neutron-rich matter, is still very uncertain. Heavy-ion reactions provide a unique means to constrain the EOS, particularly the density dependence of the nuclear symmetry energy. On the other hand, microscopic, self-consistent, and parameter-free approaches are ultimately needed for understanding nuclear properties in terms of the fundamental interactions among the basic constituents of nuclear systems. In this talk, after a brief review of our recent studies on spin-polarized neutron matter, we discuss constraining the changing rate of the gravitational co...
The properties and structure of neutron stars are determined by the equation of state (EOS) of neutron-rich stellar matter. While the collective flow and particle production in relativistic heavy-ion collisions have tightly constrained the EOS of symmetric nuclearmatter up to about 5 times the normal nuclearmatter density, more recent experimental data on isospin diffusion and isoscaling in heavy-ion collisions at intermediate energies have constrained considerably the density dependence of the nuclear symmetry energy at subsaturation densities. Although there are still many uncertainties and challenges to pin down completely the EOS of neutron-rich nuclearmatter, heavy-ion reaction experiments in terrestrial laboratories have limited the EOS of neutron-rich nuclearmatter to a range much narrower than that spanned by the various EOSs currently used in astrophysical studies in the literature. These nuclear physics constraints could thus provide more reliable information about the properties of neutron stars. Within well-established formalisms using the nuclear-constrained EOSs, we study the moments of inertia of neutron stars. We place special emphasis on component A of the extremely relativistic double neutron star system PSR J0737-3039. Its moment of inertia is found to be between 1.30×1045 and 1.63×1045 g cm2. Moreover, the transition density at the crust-core boundary is shown to lie in the narrow range ?t=0.091-0.093 fm-3.
Studies at the RIKEN RI beam factory / T. Motobayashi -- Dilute nuclear states / M. Freer -- Studies of exotic systems using transfer reactions at GANIL / D. Beaumel et al. -- First results from the Magnex large-acceptance spectrometer / A. Cunsolo et al. -- The ICHOR project and spin-isospin physics with unstable beams / H. Sakai -- Structure and low-lying states of the [symbol]He exotic nucleus via direct reactions on proton / V. Lapoux et al. -- Shell gap below [symbol]Sn based on the excited states in [symbol]Cd and [symbol]In / M. Górska -- Heavy neutron-rich nuclei produced in the fragmentation of a [symbol]Pb beam / Zs. Podolyák et al. -- Breakup and incomplete fusion in reactions of weakly-bound nuclei / D.J. Hinde et al. -- Excited states of [symbol]B and [symbol]He and their cluster aspect / Y. Kanada-En'yo et al. -- Nuclear reactions with weakly-bound systems: the treatment of the continuum / C. H. Dasso, A. Vitturi -- Dynamic evolution of three-body decaying resonances / A. S. Jensen et al. -- Prerainbow oscillations in [symbol]He scattering from the Hoyle state of [symbol]C and alpha particle condensation / S. Ohkubo, Y. Hirabayashi -- Angular dispersion behavior in heavy ion elastic scattering / Q. Wang et al. -- Microscopic optical potential in relativistic approach / Z.Yu. Ma et al. -- Exotic nuclei studied in direct reactions at low momentum transfer - recent results and future perspectives at fair / P. Egelhof -- Isotopic temperatures and symmetry energy in spectator fragmentation / M. De Napoli et al. -- Multi-channel algebraic scattering theory and the structure of exotic compound nuclei / K. Amos et al. -- Results for the first feasibility study for the EXL project at the experimental storage ring at GSI / N. Kalantar-Nayestanaki et al. -- Coulomb excitation of ISOLDE neutron-rich beams along the Z = 28 chain / P. Van Duppen -- The gamma decay of the pygmy resonance far from stability and the GDR at finite temperature / G. Benzoni et al. -- Thermal pairing in nuclei / N. D. Dang -- Molecular-orbital and di-nuclei states in Ne and F isotopes / M. Kimura -- Low-momentum interactions for nuclei / A. Schwenk -- Nonrelativistic nuclear energy functionals including the tensor force / G. Colo et al. -- New aspects on dynamics in nuclei described by covariant density functional theory / P. Ring, D. Pena -- Theoretical studies on ground-state properties of superheavy nuclei / Z. Z. Ren et al. -- New results in the study of superfluid nuclei: many-body effects, spectroscopic factors / P. F. Bortignon et al. -- New Effective nucleon-nucleon interaction for the mean-field approximation / V. K. Au et al. -- Linear response calculations with the time-dependent Skyrme density functional / T. Nakatsukasa et al. -- Dissipative dynamics with exotic beams / M. Di Toro et al. -- Exploring the symmetry energy of asymmetricnuclearmatter with heavy ion reactions / M. B. Tsang -- Invariant mass spectroscopy of halo nuclei / T. Nakamura et al. -- Core [symbol] structures in [symbol]C, [symbol]C and [symbol]C up to high excitation energies / H. G. Bohlen et al. -- Light neutron-rich nuclei studied by alpha-induced reactions / S. Shimoura -- Fusion and direct reactions around the Coulomb barrier for the system [symbol]He + [symbol]Zn / V. Scuderi et al. -- Analyzing power measurement for proton elastic scattering on [symbol]He / S. Sakaguchi et al. -- Knockout reaction spectroscopy of exotic nuclei / J. A. Tostevin -- Exotic nuclei, quantum phase transitions, and the evolution of structure / R. F. Casten -- Structure of exotic nuclei in the medium mass region / T. Otsuka -- Pairing correlations in halo nuclei / H. Sagawa, K. Hagino -- Experimental approach to high-temperature Stellar reactions with low-energy RI beams / S. Kubono et al. -- Transition to quark matter in neutron stars / G. X. Peng et al. -- Research at VATLY: main themes and recent results / P. N. Diep et al. -- Study of the astrophysical reaction [symbol]C([symbol], n)[symbol]O by the transfer reaction [symbol]C([symbol]Li, t)[symbol]O / F. Hammache et al.
At high temperatures and densities the nuclearmatter undergoes a phase transition to a new state of matter called quark gluon plasma (QGP). This new state of matter which existed in the universe after a few microsecond of the big bang can be created in the laboratory by colliding two nuclei at relativistic energies. In this presentation we will discuss how the the properties of QGP can be extracted by analyzing the spectra of photons, dileptons and heavy flavours produced in nuclear collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies.
We investigate the role of naturalness in effective field theory. We focus on dense hadronic matter using a generalized relativistic multi-baryon lagrangian density mean field approach which contains nonlinear self-couplings of the {sigma}, {delta} meson fields and the fundamental baryon octet. We adjust the model parameters to describe bulk static properties of ordinary nuclearmatter. Then, we show that our approach represents a natural modelling of nuclearmatter under the extreme conditions of density as the ones found in the interior of neutron stars.
The past fifty years have seen the emergence of a new field of research in physics, the study of matter at extreme temperatures and densities. The theory of strong interactions, quantum chromodynamics (QCD), predicts that in this limit, matter will become a plasma of deconfined quarks and gluons -- the medium which made up the early universe in the first 10 microseconds after the big bang. High energy nuclear collisions are expected to produce short-lived bubbles of such a medium in the laboratory. I survey the merger of statistical QCD and nuclear collision studies for the analysis of strongly interacting matter in theory and experiment.
The subject of nuclearmatter is interesting for many fields of physics ranging from condensed matter to lattice QCD. Knowing its properties is important for our understanding of neutron stars, supernovae and cosmology. Experimentally, we have the most precise information on ground state nuclearmatter from the mass formula and from the systematics of monopole vibrations. This gives us the ground state density, binding energy and the compression modulus k at ground state density. However, those methods can not be extended towards the regime we are most interested in, the regime of high density and high temperature. Additional information can be obtained from the observation of neutron stars and of supernova explosions. In both cases information is limited by the rare events that nature provides for us. High energy heavy ion collisions, on the other hand, allow us to perform controlled experiments in the laboratory. For a very short period in time we can create a system that lets us study nuclearmatter properties. Density and temperature of the system depend on the mass of the colliding nuclei, on their energy and on the impact parameter. The system created in nuclear collisions has at best about 200 constituents not even close to infinite nuclearmatter, and it lasts only for collision times of {approx} 10{sup {minus}22}sec, not an ideal condition for establishing any kind of equilibrium. Extended size and thermal and chemical equilibrium, however, axe a priori conditions of nuclearmatter. As a consequence we need realistic models that describe the collision dynamics and non-equilibrium effects in order to relate experimental observables to properties of nuclearmatter. The study of high energy nuclear collisions started at the Bevalac. I will try to summarize the results from the Bevalac studies, the highlights of the continuing program, and extension to higher energies without claiming to be complete.
The ISOLDE facility uses protons from CERN's accelerator complex to produce exotic nuclei of most of the elements. These radioactive nuclei are used for basic research in many areas of science: nuclear physics, nuclear astrophysics, atomic physics, condensed matter physics, radiobiology, and elementary particle physics.
The ISOLDE facility uses protons from CERN's accelerator complex to produce exotic nuclei of most of the elements. These radioactive nuclei are used for basic research in many areas of science: nuclear physics, nuclear astrophysics, atomic physics, condensed matter physics, radiobiology, and elementary particle physics.
More than two decades ago, the van der Waals behavior of the nucleon - nucleon force inspired the idea of a liquid-gas phase transition in nuclearmatter. Heavy-ion reactions at relativistic energies offer the unique possibility for studying this phase transition in a finite, hadronic system. A general overview of this subject is given emphasizing the most recent results on nuclear calorimetry. (orig.)
We show that the dynamical evolution of density waves in an expanding nuclear system differs markedly from their evolution in an expanded but static system. This leads, in particular, to the growth of instabilities in the stable region of the nuclearmatter phase diagram.
Two heavy ion interaction potentials have been computed using the same nuclear force. One has been obtained from symmetric semi-infinite nuclearmatter slabs and the other one from finite nuclei. After a proximity scaling, two rather different universal functions are obtained. We argue that this is ...
We show that nuclear physics is extremely important for accurate risk assessments for space missions. Due to paucity of experimental input radiation interaction information it is imperative to develop reliable accurate models for the interaction of radiation with matter. State-of-the-art nuclear cross sections models have been developed at the NASA Langley Research center and are discussed.
We calculate the equation of state of nuclearmatter in the self-consistent T-matrix scheme including three-body nuclear interactions. We study the effect of the three-body force on the self-energies and spectral functions of nucleons in medium.
We calculate the equation of state of nuclearmatter in the self-consistent T-matrix scheme including three-body nuclear interactions. We study the effect of the three-body force on the self-energies and spectral functions of nucleons in medium.
A brief introduction into some of the physics probed by heavy ion projectiles at low, intermediate and high energies is given. Emphasis is placed on nuclearmatter under extreme conditions in this discussion, which should provide a common area of interest to both particle and nuclear physics.
Research in progress and plans for future investigations are briefly summarized for the following areas: light-ion structure and reactions; nuclear structure; peripheral heavy-ion reactions at medium and high energy; medium-energy heavy-ion collisions and properties of highly excited nuclearmatter; and high-energy heavy-ion collisions and QCD plasma.
These lectures are a brief introduction to some of the basic concepts used in the nuclear many body problem: nuclearmatter viewed as a Fermi liquid quasiparticles, mean field approximation, correlations and effective interactions. Nucleons are treated as nonrelativistic particles. Problems relating to hard core are also discussed. (author) 14 refs., 6 figs.
"The war in Iraq has made the subject of nuclear research in countries of the third world a matter of current interest. Talk at this time is mostly about Iran, which has oil, and American experts believe, will in the next 3-4 years be perfectly capable of making a nuclear bomb" (1 page).
This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for C7H7Cl3OSi (Subst. No. 0995)
This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for C4H6D4OSi (Subst. No. 0691)
This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for (C4H10OSi)x (Subst. No. 1715)
This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for C2H5Cl3OSi (Subst. No. 0547)
The dipole response function of nuclearmatter at finite temperature is investigated by employing a linearized Landau–Vlasov equation with pairing correlations. We calculate the giant dipole resonance strength function with and without quasiparticle collisional effects. Calculations are carried out for nuclear dipole vibrations of finite nuclei by employing the Steinwedel–Jensen model, and their results are compared with experimental results for 120Sn.
"The largest particle physics centre in the world is located in Europe. It straddles the Franco-Swiss border, near Geneva. At CERN - the European Organisation for Nuclear Research , which is focused on the science of nuclearmatter rather than on the exploitation of atomic energy - there are over 6 500 scientists." (1 page)
At densities just below nuclear saturation density, there may be possible non-uniform spatial configurations of neutron rich matter. In this work we present a calculation using molecular dynamics techniques for a nuclear system interacting via a semiclassical potential depending on both positions and momenta and kept at fixed temperature by using the Nose-Hoover Thermostat.
There exist several effective interactions whose parameters are fitted to force mean field predictions to reproduce experimental findings of finite nuclei and calculated properties of infinite nuclearmatter. By exploiting this technique, one can give a good description of nuclear binding energies. ...
This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for C13H10Cl2 (Subst. No. 1401)
AbstractThis paper approaches the choice between the open and closed nuclear fuel cycles as a matter of intergenerational justice, by revealing the value conflicts in the production of nuclear energy. The closed fuel cycle improve sustainability in terms of the supply certainty of uranium and involv...
the following topics are dealt with: The FAIR project, nuclear structure studies, nuclear and quark matter experiments, search for superheavy elements, atomic, plasma, and solid-state physics with heavy ions, radiation research and biophysics with heavy ions, accelerator operations and developments, radiation detection, cancer therapy with ion beams. (HSI)
We explore in more detail the modified quark meson coupling (MQMC) model in nuclearmatter. Based on previous studies two different functional forms for the density dependence of the bag constant are discussed. For uniform matter distributions the MQMC model can be cast in a form identical to QHD by a redefinition of the sigma meson field. It is then clear that modifications similar to those introduced in QHD will permit the reproduction of all nuclearmatter properties including the compressibility. After calibrating the model parameters at equilibrium nuclearmatter density, the model and parameter dependence of the resulting equation of state is examined. Nucleon properties and scaling relations between the bag constant and the effective nucleon mass are discussed.
We present a covariant extension of the relativistic Fermi gas model which incorporates correlation effects in nuclei. Within this model, inspired by the BCS descriptions of systems of fermions, we obtain the nuclear spectral function and from it the superscaling function for use in treating high-energy quasielastic electroweak processes. Interestingly, this model has the capability to yield the asymmetric tail seen in the experimental scaling function.
Low-energy fission of neutron-deficient actinium, thorium, protactinium and uranium isotopes has been investigated using a new experimental technique. The isotopes were produced as secondary beams by projectile fragmentation from a 950 A MeV {sup 238}U primary beam. Their fission was induced by electromagnetic excitation and nuclear reactions in a lead and in a plastic target. The transition from symmetric to asymmetric fission is shown to take place around N = 138. (orig.)
Excited states of {sup 220}Ac have been investigated by means of the {sup 209}Bi({sup 14}C,3n) reaction and using the 'Chateau de Cristal' gamma ray facility. The observation of bands with alternating parity states reveals the reflection asymmetricnuclear shape of {sup 220}Ac. The extracted B(E1)/B(E2) ratios display a clear spin dependence. (orig.).
We obtained angular differential cross sections of {sup 9}Be-d nuclear reaction at low energy and the energy dependence of astrophysical S-factors. Angular distributions were asymmetric around 90 degree (back- or forward-peaking) and the values of S-factors for {sup 9}Be(d, p) and {sup 9}Be(d, {alpha}{sub 0}) were about 3 MeV barn and 9 MeV barn at E{sub lab} = 290 keV, respectively. (author)
The isospin fractionation in heavy-ion collisions is investigated using a static method and an isospin-dependent quantum molecular dynamics (IQMD) model. A static interpretation of the isospin fractionation is provided based on a phenomenological asymmetricnuclear equation of state. The effects of different dynamic ingredients on the isospin fractionation, i.e. symmetry potential. Coulomb potential and isospin dependence of N-N cross section, are discussed in the frame of IQMD model
The concept presented makes use of the fast spectrum in the Engineering Test Reactor (ETR) at the Idaho National Engineering Laboratory (INEL). Preliminary results show that an asymmetric, nuclear test environment with particle and radiant energy fluxes impinging on a first wall/blanket or divertor surface appears feasible in a neutron/gamma field not greatly different from that seen by a representative first wall/blanket module.
Theories have been developed to treat charge exchange in ion-atom collisions at large impact parameters that are based on asymptotic expressions for electron orbitals, JWKB treatment of orbital distortion and simple classical models for the nuclear motion. These methods, which can be applied without the use of a computer, have been remarkably successful for symmetric charge transfer. The basic elements of the asymptotic theories are reviewed and the problems associated with the application to asymmetric charge exchange are discussed.
A brief account of the presently ongoing studies of compressed hadronic matter formed in relativistic nucleus-nucleus interactions has been given. The observed radial expansion of the collision zone with average collective particle velocities of {approx} 0.3 . c is consistent with the formation of compressed hadronic matter at baryon densities of 2-3 times normal nuclearmatter density. The hadro-chemical composition of the compressed matter, i.e. the fraction of excited baryon resonances has been analyzed by systematic studies of meson production. (author) 12 refs.
The Dark Matter Time Projection Chamber (DMTPC) is a low pressure (75 Torr CF{sub 4}) 10 liter detector capable of measuring the vector direction of nuclear recoils with the goal of directional dark matter detection. In this Letter we present the first dark matter limit from DMTPC from a surface run at MIT. In an analysis window of 80-200 keV recoil energy, based on a 35.7 g-day exposure, we set a 90% C.L. upper limit on the spin-dependent WIMP-proton cross section of 2.0x10{sup -33} cm{sup 2} for 115 GeV/c{sup 2} dark matter particle mass.
The Dark Matter Time Projection Chamber (DMTPC) is a low pressure (75 Torr CF4) 10 liter detector capable of measuring the vector direction of nuclear recoils with the goal of directional dark matter detection. In this Letter we present the first dark matter limit from DMTPC from a surface run at MIT. In an analysis window of 80??????¢??¢â???š??¬??¢â??? ¬?????200 keV recoil energy, based on a 35.7 g-day exposure, we set a 90% C.L. upper limit on the spin-dependent WIMP-proton cross section of Formula Not Shown for 115 GeV/c2 dark matter particle mass.
The DMTPC directional dark matter detection experiment is a low-pressure CF4 gas time projection chamber, instrumented with charge and scintillation photon readout. This detector design strategy emphasizes reconstruction of WIMPinduced nuclear recoil tracks, in order to determine the direction of incident dark matter particles. Directional detection has the potential to make the definitive observation of dark matter using the unique angular signature of the dark matter wind, which is distinct from all known backgrounds. This talk will review the experimental technique and current status of DMTPC.
The Dark Matter Time Projection Chamber (DMTPC) is a low pressure (75 Torr CF4) 10 liter detector capable of measuring the vector direction of nuclear recoils with the goal of directional dark matter detection. In this paper we present the first dark matter limit from DMTPC. In an analysis window of 80-200 keV recoil energy, based on a 35.7 g-day exposure, we set a 90\\% C.L. upper limit on the spin-dependent WIMP-proton cross section of 2.0 x 10^{-33} cm^{2} for 115 GeV/c^2 dark matter particle mass.
The DMTPC directional dark matter detection experiment is a low-pressure CF4 gas time projection chamber, instrumented with charge and scintillation photon readout. This detector design strategy emphasizes reconstruction of WIMP-induced nuclear recoil tracks, in order to determine the direction of incident dark matter particles. Directional detection has the potential to make the definitive observation of dark matter using the unique angular signature of the dark matter wind, which is distinct from all known backgrounds. This talk will briefly review the experimental technique and current status of DMTPC.
A first order phase transition from nuclearmatter to antikaon condensed matter may proceed through thermal nucleation of a critical droplet of antikaon condensed matter during the early evolution of protoneutron stars (PNS). Droplets of new phase having radii larger than a critical radius would survive and grow, if the latent heat is transported from the droplet surface to the metastable phase. We investigate the effect of shear viscosity on the thermal nucleation time of the droplets of antikaon condensed matter. In this connection we particularly study the contribution of neutrinos in the shear viscosity and nucleation in PNS.
A first order phase transition from nuclearmatter to antikaon condensed matter may proceed through thermal nucleation of a critical droplet of antikaon condensed matter during the early evolution of proto neutron stars (PNS). Droplets of new phase having radii larger than a critical radius would survive and grow, if the latent heat is transported from the droplet surface to the metastable phase. We investigate the effect of shear viscosity on the thermal nucleation time of the droplets of antikaon condensed matter. In this connection we particularly study the contribution of neutrinos in the shear viscosity and nucleation in PNS.
Central nuclear collisions at energies far above 1 GeV/nucleon may provide for conditions, where the transition from highly excited hadronic matter into quark matter or quark-gluon plasma can be probed. We review current ideas about the nature of, and signals for, this transition, and we discuss the (hadronic) string model approach to the nuclear collisions dynamics. At even higher energies in the TeV/nucleon range peripheral nuclear collisions may become a laboratory for electroweak physics at the unification scale allowing, e.g., for Higgs boson production. 42 refs., 29 figs.,
Recent experimental studies of the synthesis and properties of deeply bound antikaon mediated nuclear systems are reviewed. Following a brief introduction in the basic properties of the antikaon-nucleon interaction which may lead to cold and dense antikaonic nuclear systems, we review the results of very first experiments which give indications of the existence of such exotic clusters of matter. Then ongoing efforts to substantiate the early findings are presented and future experimental approaches which will allow a very detailed study of the decay modes, the sizes and density distributions of these kaonic nuclear clusters are discussed including their relevance for possible phase transitions in cold dense matter.
Recent experimental studies of the synthesis and properties of deeply bound antikaon mediated nuclear systems are reviewed. Following a brief introduction in the basic properties of the antikaon-nucleon interaction which may lead to cold and dense antikaonic nuclear systems, we review the results of very first experiments which give indications of the existence of such exotic clusters of matter. Then ongoing efforts to substantiate the early findings are presented and future experimental approaches which will allow a very detailed study of the decay modes, the sizes and density distributions of these kaonic nuclear clusters are discussed including their relevance for possible phase transitions in cold dense matter.
Correlated basis function perturbation theory and the formalism of cluster expansions have been recently employed to obtain an effective interaction from a state-of-the-art nucleon nucleon potential model. The approach based on the effective interaction allows for a consistent description of the nuclearmatter ground state and nucleon-nucleon scattering in the nuclear medium. This paper reports the the results of numerical calculations of different properties of nuclear and neutron matter, including the equation of state and the shear viscosity and thermal conductivity transport coefficients, carried out using the effective interaction.
There is a well known anomaly between the value of the Fermi decay constant extracted from super-allowed Fermi beta-decay of nuclear isotriplets and that required by unitarity of the Cabibbo-Kobayashi-Maskawa matrix. This discrepancy remains at the level of a few tenths of a percent after the most rigorous investigation of conventional nuclear and radiative corrections. Within the framework of the quark-meson coupling model of nuclearmatter, which has been previously applied successfully to phenomena such as nuclear saturation and nuclear charge symmetry violation, we show that it is possible to understand a significant fraction of the observed anomaly.
Isotope thermometry, widely used to measure the temperature of a hot nuclear system formed in energetic nuclear collisions, is examined in the light of S-matrix approach to the nuclear equation of state of disassembled nuclearmatter. Scattering between produced light fragment pairs, hitherto neglected, is seen to have an important bearing on the extraction of system temperature and volume at freeze-out from isotope thermometry. Taking due care of the scattering effects and decay of the primary fragments, a more reliable way to extract the nuclear thermodynamic parameters is suggested by exploiting least-squares fit to the observed fragment multiplicities.
Significant progress has been made in recent years in constraining the density dependence of nuclear symmetry energy using terrestrial nuclear laboratory data. Around and below the nuclearmatter saturation density, the experimental constraints start to merge in a relatively narrow region. At supra-saturation densities, there are, however, still large uncertainties. After summarizing the latest experimental constraints on the density dependence of nuclear symmetry energy, we highlight a few recent studies examining imprints of nuclear symmetry energy on the binding energy, energy release during hadron-quark phase transitions as well as the $w$-mode frequency and damping time of gravitational wave emission of neutron stars.
Recent developments have shown that it is possible to detect functional magnetic resonance imaging (fMRI) activation in white matter (WM). Enhanced sensitivity to WM fMRI signals has been associated with the asymmetric spin echo (ASE) spiral sequence. The ASE spiral sequence produces three consecutive images that have equal blood-oxygen level-dependent (BOLD) contrast but increasing T2 contrast. The current study evaluated whether ASE spiral sensitivity differed between white and gray matter in the corpus callosum, superior parietal lobes, cingulate gyrus, and inferior frontal lobes. Contrast and noise were compared across the three images for each region. Results showed increasing gains in functional contrast in both white and gray matter as a function of T2 contrast. The third image, wit...
State-of-the-art hydrodynamical simulations show that gas inflow through the virial sphere of dark matter halos is focused (i.e. has a preferred inflow direction), consistent (i.e. its orientation is steady in time) and amplified (i.e. the amplitude of advected specific angular momentum increases with time). This is a consequence of the dynamics of the cosmic web within the neighbourhood of the halo, which produces steady, angular momentum rich, filamentary inflow of cold gas. On large scales, the dynamics within neighbouring patches drives matter out of the surrounding voids, into walls and filaments before it finally gets accreted onto virialised dark matter halos. As these walls/filaments constitute the boundaries of asymmetric voids, they naturally acquire a net transverse motion, which explains the angular momentum rich nature of the later infall which comes from further away (lever effect). We argue that this large-scale driven consistency explains why cold flows are so efficient at building up thin dis...
This report presents the results of the EDF nuclear park, during 2000, in matter of safety, environment and competitiveness. In 2000, the EDF nuclear installations safety still improved. Hopeful the nuclear energy part in its power production, EDF avoids the carbon dioxide diffusion in the atmosphere. EDF also commits itself to reduce the liquid effluents, the gaseous emissions and the solid wastes. At the same time EDF remained competitive with a decrease of the kWh price of 7%. (A.L.B.)
In this presentation the relationship between relativistic nucleus-nucleus collisions and the nuclear equation of state is discussed. The connection between observables measured in the experiments and thermodynamic variables used to describe the system is made. Through this connection a semi-empirical nuclear equation of state is extracted from the data. The resulting equation of state is discussed in terms of nuclearmatter calculations, neutron star stability and supernova collapse. 22 refs., 7 figs.
Nuclear reactions with radioactive beams provide unique means to constrain the equation of state (EOS) of neutron-rich matter, in particular its density dependence through the nuclear symmetry energy. The EOS is important for our understanding of numerous phenomena in both nuclear physics and astrophysics. In this talk we will present our most recent results on the properties of rotating neutron stars with a particular emphasis on rapid rotations.
The AMADEUS experiment will perform the first complete experimental study of the case of the so-called Deeply Bound Kaonic Nuclear States or simply Kaonic Clusters. Such a study has deep consequences in a still open sector of the strangeness hadronic/nuclear physics: how the hadron masses and hadron interactions change in the nuclear medium with consequences on the structure of cold dense hadronic matter. AMADEUS will perform exclusive - full acceptance - measurements, all particles in the formation and decay processes will be detected.
The concept of the quark is nowadays the basic one in the theory of strong interactions. The study of high-energy nuclear interactions makes it possible to obtain information about multiquark states and possibly about a new state of nuclearmatter, the quark-gluon plasma. An introduction of the basic concepts and variables of relativistic nuclear physics is given. The most essential experimental data on the interactions of relativistic nuclei and a brief discussion of perspectives are presented.
The modified quark-meson coupling model, which features a density dependent bag constant and bag radius in nuclearmatter, is checked against the EMC effect within the framework of dynamical rescaling. Our emphasis is on the change in the average bag radius in nuclei, as evaluated in a local density approximation, and its implication for the rescaling parameter. We find that when the bag constant in nuclearmatter is significantly reduced from its free-space value, the resulting rescaling parameter is in good agreement with that required to explain the observed depletion of the structure functions in the medium Bjorken $x$ region. Such a large reduction of the bag constant also implies large and canceling Lorentz scalar and vector potentials for the nucleon in nuclearmatter which are comparable to those suggested by the relativistic nuclear phenomenology and finite-density QCD sum rules.
We discuss the flavor of leading jet partons as a valuable probe of nuclearmatter. We point out that the coupling of jets to nuclearmatter naturally leads to an alteration of jet chemistry even at high transverse momentum $p_T$. In particular, QCD jets coupling to a chemically equilibrated quark gluon plasma in nuclear collisions, will lead to hadron ratios at high transverse momentum $p_T$ that can differ significantly from their counterparts in $p+p$ collisions. Flavor measurements could complement energy loss as a way to study interactions of hard QCD jets with nuclearmatter. Roughly speaking they probe the inverse mean free path $1/\\lambda$, while energy loss probes the average momentum transfer $\\mu^2/\\lambda$. We present some estimates for the rate of jet conversions in a consistent Fokker-Planck framework and their impact on future high-$p_T$ identified hadron measurements at RHIC and LHC. We also suggest some novel observables to test flavor effects.
Using a relativistic Dirac-Brueckner analysis the OPEP contribution to the ground state energy of nuclearmatter is studied. In the study the pion is derivative-coupled. The author finds that the role of the tensor force in the saturation mechanism is substantially reduced compared to its dominant role in a usual nonrelativistic treatment. He shows that the damping of derivative-coupled OPEP is actually due to the decrease of M{sup *}/M with increasing density. He points out that if derivative-coupled OPEP is the preferred form of nuclear effective lagrangian nonrelativistic treatment of nuclearmatter is in trouble. Lacking the notion of M{sup *} it cannot replicate the damping. He suggests an examination of the feasibility of using pseudoscalar coupled {pi}N interaction before reaching a final conclusion about nonrelativistic treatment of nuclearmatter.
We are continuing our work on the {Lambda} hyperon single-particle (s.p.) energies and their interpretation in terms of the basic {Lambda}-nuclear interactions. In particular we are interpreting the results obtained by S.C. Pieper, A. Usmani and Q.N. Usmani. We obtain about 30 MeV for the repulsive contribution of the three-body {Lambda}NN forces in nuclearmatter. We are able to exclude purely {open_quotes}dispersive{close_quotes} {Lambda}NN forces. We are investigating the mix of dispersive and two-pion-exchange {Lambda}NN forces which provide a fit to the s.p. data. For interactions, which provide a fit to the s.p. data, the {Lambda} binding energy as a function of the nuclearmatter density shows characteristic saturation features with a maximum at a density not very different from that of normal nuclearmatter. We obtain a more precise measure of the space-exchange part of the {Lambda}-nuclear force than was previously available, corresponding to an exchange parameter {approx_equal} 0.32. The space-exchange force is rather directly related to the effective mass of a {Lambda} in the nuclear medium and turns out to be about 70% of its free mass. As a result, we also obtain a much better value for the p-state {Lambda}-nucleus potential which is about 40% of the s-state potential. The A binding to nuclearmatter is determined to be {approx_equal} 28 MeV.
Using ideas from BCS descriptions of systems of fermions, a covariant extension of the relativistic Fermi gas model is presented as a way to incorporate correlation effects in nuclei. The model is developed for the BCS nuclear ground state and for final states consisting of a single plane-wave nucleon plus a BCS recoiling daughter nucleus. The nuclear spectral function is obtained and from it the superscaling function for use in treating high-energy quasielastic electroweak processes. Interestingly, this model has the capability to yield the asymmetric tail seen in the experimental scaling function.
Use of appropriate theoretical techniques allows the study of the moments of the nuclear charge distribution to be extended above the Coulomb barrier. The investigation of nuclear moments through analysis of differential cross sections is discussed with the aid of several examples: /sup 12/C(70.4 MeV) + /sup 144/ /sup 146/Nd, importance of multistep effects; /sup 20/Ne(131 MeV) + /sup 208/Pb, large hexadecapole deformation; /sup 12/C(78 MeV) + /sup 194/Pt, asymmetric rotor model; and /sup 22/Ne(93.5 MeV) + /sup 126/Te, mutual excitation. 13 figures, 1 table. (RWR)
We show here a general model of phase separation in isotropic condensed matter, namely, a viscoelastic model. We propose that the bulk mechanical relaxation modulus that has so far been ignored in previous theories plays an important role in viscoelastic phase separation in addition to the shear relaxation modulus. In polymer solutions, for example, attractive interactions between polymers under a poor-solvent condition likely cause the transient gellike behavior, which makes both bulk and shear modes active. Although such attractive interactions between molecules of the same component exist universally in the two-phase region of a mixture, the stress arising from attractive interactions is asymmetrically divided between the components only in dynamically asymmetric mixtures such as polymer solutions and colloidal suspensions. Thus, the interaction network between the slower components, which can store the elastic energy against its deformation through bulk and shear moduli, is formed. It is the bulk relaxati...
Except for 1H, 2H, 3He, 4He, and 7Li, originating from the Big Bang, all heavier elements are made in stellar evolution and stellar explosions. Nuclear physics, and in many cases nuclear structure far from stability, enters in a crucial way. Therefore, we examine in this review the role of nuclear physics in astrophysics in general and in particular how it affects stellar events and the resulting nucleosynthesis. Stellar modeling addresses four major aspects: 1. energy generation and nucleosynthesis, 2. energy transport via conduction, radiation or possibly convection, 3. hydrodynamics/hydrostatics, and finally 4. thermodynamic properties of the matter involved. Nuclear Physics enters via nuclear reaction cross sections and nuclear structure (affecting the composition changes and nuclear energy generation), neutrino-nucleon and neutrino-nucleus cross sections (affecting neutrino opacities and transport), and e.g. the equation of state at and beyond nuclear densities which creates a relation between the nuclea...
This paper presents an investigation into the pycnonuclear reaction rates in dense crustal matter of neutron stars contaminated with strange quark matter nuggets. The presence of such nuggets in the crustal matter of neutron stars would be a natural consequence if Witten's strange quark matter hypothesis is correct. The methodology presented in this paper is a recreation of a recent representation of nuclear force interactions embedded within pycnonuclear reaction processes. The study then extends the methodology to incorporate distinctive theoretical characteristics of strange quark matter nuggets, like their low charge-per-baryon ratio, and then assesses their effects on the pycnonuclear reaction rates. Particular emphasis is put on the impact of color superconductivity on the reaction rates. Depending on whether or not quark nuggets are in this novel state of matter, their electric charge properties vary drastically which turns out to have a dramatic effect on the pycnonuclear reaction rates. Future nuclea...
We discuss aidnogenesis, the generation of a dark matter asymmetry via new sphaleron processes associated to an extra non-abelian gauge symmetry common to both the visible and the dark sectors. Such a theory can naturally produce an abundance of asymmetric dark matter which is of the same size as the lepton and baryon asymmetries, as suggested by the similar sizes of the observed baryonic and dark matter energy content, and provide a definite prediction for the mass of the dark matter particle. We discuss in detail a minimal realization in which the Standard Model is only extended by dark matter fermions which form "dark baryons" through an SU(3) interaction, and a (broken) horizontal symmetry that induces the new sphalerons. The dark matter mass is predicted to be approximately 6 GeV, close to the region favored by DAMA and CoGeNT. Furthermore, a remnant of the horizontal symmetry should be broken at a lower scale and can also explain the Tevatron dimuon anomaly.
In this article we calculate the probabilty of having ?(1232) resonance in frozen and hot neutron, nuclear and ?-stable matter. We use the temperature dependence correlation functions that are generated through a lowest order constrained variational calculation with the ?-Reid potential. The N N ? N ? transition is built in through a two-pion exchange interaction. The electrons and muons are treated relativistically in the total Hamiltonian at given temperature and density, in order to make the fluid electrically neutral and stable with respect to ?-decay. We ignore the weak interaction. It is seen that the ? probability in neutron matter is much larger than in nuclear and ?-stable matter at a given temperature and density. As we increase the temperature, the ? probability decreases in nuclear and neutron matter. However, this decrease is not significant in case of ?-stable nuclearmatter. There is overall agreement between our ? probability calculation and the recent experiments performed on 3He up to 208Pb nuclei. It is concluded that the isobar degrees of freedom could make the equation of state of neutron star matter harder at finite temperature and suppress the numbers of protons and leptons in the proto-neutron stars.
The primary motivation for studying nucleus-nucleus collisions at relativistic and ultrarelativistic energies is to investigate matter at high energy densities ({var_epsilon} {much_gt} 1 GeV/fm{sup 3}). Early speculations of possible exotic states of matter focused on the astrophysical implications of abnormal states of dense nuclearmatter. Field theoretical calculations predicted abnormal nuclear states and excitation of the vacuum. This generated an initial interest among particle and nuclear physicists to transform the state of the vacuum by using relativistic nucleus-nucleus collisions. Extremely high temperatures, above the Hagedorn limiting temperature, were expected and a phase transition to a system of deconfined quarks and gluons, the Quark-Gluon Plasma (QGP), was predicted. Such a phase of matter would have implications for both early cosmology and stellar evolution. The understanding of the behavior of high temperature nuclearmatter is still in its early stages. However, the dynamics of the initial stages of these collisions, which involve hard parton-parton interactions, can be calculated using perturbative QCD. Various theoretical approaches have resulted in predictions that a high temperature (T {approximately} 500 MeV) gluon gas will be formed in the first instants (within 0.3 fm/c) of the collision. Furthermore, QCD lattice calculations exhibit a phase transition between a QGP and hadronic matter at a temperature near 250 MeV. Such phases of matter may have existed shortly after the Big Bang and may exist in the cores of dense stars. An important question is whether such states of matter can be created and studied in the laboratory. The Relativistic Heavy Ion Collider (RHIC) and a full complement of detector systems are being constructed at Brookhaven National Laboratory to investigate these new and fundamental properties of matter.
Quark and gluon condensates in nuclearmatter are studied. These in-medium condensates may be linked to a wide range of nuclear phenomena and are important inputs to QCD sum-rule calculations at finite density. The Hellmann-Feynman theorem yields a prediction of the quark condensate that is model independent to first order in the nucleon density. This linear density dependence, with slope determined by the nucleon {sigma} term, implies that the quark condensate is reduced considerably at nuclearmatter saturation density---it is roughly 25--50 % smaller than the vacuum value. The trace anomaly and the Hellmann-Feynman theorem lead to a prediction of the gluon condensate that is model independent to first order in the nucleon density. At nuclearmatter saturation density, the gluon condensate is about 5% smaller than the vacuum value. Contributions to the in-medium quark condensate that are of higher order in the nucleon density are estimated with mean-field quark-matter calculations using the Nambu--Jona-Lasinio and Gell-Mann--Levy models. Treatments of nuclearmatter based on hadronic degrees of freedom are also considered, and the uncertainties are discussed.
Twenty-first century security challenges are multi-polar and asymmetric. A few nations have substantial nuclear arsenals and active nuclear weapons programs that still threaten vital US national security directly or by supporting proliferation. Maintaining a credible US nuclear deterrent and containing further proliferation will continue to be critical to US national security. Overlaid against this security backdrop, the rising worldwide population and its effects on global climate, food, and energy resources are greatly complicating the degree and number of security challenges before policy makers.This new paradigm requires new ways to assure allies that the United States remains a trusted security partner and to deter potential adversaries from aggressive actions that threaten global stability. Every U.S. President since Truman has affirmed the role of nuclear weapons as a supreme deterrent and protector of last resort of U.S. national security interests. Recently, President Bush called for a nuclear deterrent consistent with the 'lowest number of nuclear weapons' that still protects U.S. interests. How can this be achieved? And how can we continue on a path of nuclear reductions while retaining the security benefits of nuclear deterrence? Science and engineering have a key role to play in a potential new paradigm for nuclear deterrence, a concept known as 'capability-based deterrence.'
The diabatic approach to collective nuclear motion is reformulated in the local-density approximation in order to treat the normal modes of a spherical nuclear droplet analytically. In a first application the adiabatic isoscalar modes are studied and results for the eigenvalues of compressional (bulk) and pure surface modes are presented as function of density and temperature inside the droplet, as well as for different mass numbers and for soft and stiff equations of state. We find that the region of bulk instabilities (spinodal regime) is substantially smaller for nuclear droplets than for infinite nuclearmatter. For small densities below 30% of normal nuclearmatter density and for temperatures below 5 MeV all relevant bulk modes become unstable with the same growth rates. The surface modes have a larger spinodal region, reaching out to densities and temperatures way beyond the spinodal line for bulk instabilities. Essential experimental features of multifragmentation, like fragmentation temperatures and ...
Measurements of kaon production at subthreshold energies in heavy-ion collisions point to a soft nuclear equation of state for densities up to two to three times nuclearmatter saturation density. We apply these results to study the implications on compact star properties, especially in the context of the recent measurement of the two solar mass pulsar PSR J1614-2230. The implications are twofold: First, the heavy-ion results constrain nuclearmatter at densities relevant to light neutron stars. Hence, a radius measurement could provide information about the density dependence of the symmetry energy which is a crucial quantity in nuclear physics. Second, the information on the nucleon potential obtained from the analysis of the heavy-ion data can be combined with restrictions from causality on the nuclear equation of state. From this we can derive a limit for the highest allowed compact star mass of three solar masses.
The nuclear equation of state (EOS) is very basic information concerning the response of nuclearmatter to compression and excitation. One way of representing the EOS is to plot the energy per nucleon of nuclearmatter versus the density for a schematic description of the EOS corresponding to a stiff EOS (K=380 MeV) and a soft EOS (K=200 MeV) where K is the nuclear incompressibility. In the region of compression accessible using beams from the NSCL K1200 Superconducting Cyclotron, compressions of up to 1.5 normal nuclearmatter densities are predicted in transport theories such as BUU corresponding to energy differences of several MeV per nucleon. Another way of representing the EOS is to plot the pressure as a function of the density for several isotherms. In this representation, the critical point of nuclearmatter can be located and a critical temperature defined. In order to study the EOS, the system must be prepared with a known excitation and known number of participant nucleons. Here this is carried out by selecting central collisions of nearly symmetric systems. This method allow the specification of the number of participant nucleons and variation of the excitation energy of the system by varying the incident energy.
The Report covers the following issues in 6 sections (1) Introduction. (2) Procedures and methodology: selection of documents, qualitative pre-evaluation, quantitative analysis. (3) Results from the medical point of view: rush of patients in case of asymmetric threads; rush of casualties in case of natural disasters, medical care impairment in case of destroyed infrastructure; epidemics and pandemics; attacks or accidents in nuclear facilities; disturbance of the drinking water supply; CBRN (chemical, biological, radiation, nuclear) attacks. (4) Results from the point of view of environmental and engineering science: overview, asymmetric threat, climatic change, D (information and communication technologies) hazards; public supply in case of emergency. (5) Results from the point of view of social science: overview on the matrix; vulnerabilities, institutional challenges, self-protection, information and warning of the public. (6) Conclusions: dominance of asymmetric threat and need of systemic approaches in civil defense; supply of the public and critical infrastructures, transformation processes and challenges in civil defense; quality of documents and need of additional research on emergency protection.
Cell death and survival of neural progenitor (NP) cells are determined by signals that are largely unknown. We have analyzed pro-apoptotic signaling in individual NP cells that have been derived from mouse embryonic stem cells. NP formation was concomitant with elevated apoptosis and increased expression of ceramide and prostate apoptosis response 4 (PAR-4). Morpholino oligonucleotide-mediated antisense knockdown of PAR-4 or inhibition of ceramide biosynthesis reduced stem cell apoptosis, whereas PAR-4 overexpression and treatment with ceramide analogs elevated apoptosis. Apoptotic cells also stained for proliferating cell nuclear antigen (a nuclear mitosis marker protein), but not for nestin (a marker for NP cells). In mitotic cells, asymmetric distribution of PAR-4 and nestin resulted in one nestin(-)/PAR-4(+) daughter cell, in which ceramide elevation induced apoptosis. The other cell was nestin(+), but PAR-4(-), and was not apoptotic. Asymmetric distribution of PAR-4 and simultaneous elevation of endogenous ceramide provides a possible mechanism underlying asymmetric differentiation and apoptosis of neuronal stem cells in the developing brain. PMID:12885759
We investigate the influence of the asymmetric quark matter ({rho}{sub u}{ne}{rho}{sub d}{ne}{rho}{sub s}) on the mass of the quasiparticles and the phase diagram of the chiral quark model parametrized at the one-loop level of the renormalized theory, using the optimized perturbation theory for the resummation of the perturbative series. The effect of various chemical potentials introduced in the grand canonical ensemble is investigated with the method of relativistic many-body theory. The temperature dependence of the topological susceptibility is estimated with the help of the Witten-Veneziano mass formula.
We analyze the symmetry breaking of matter-wave solitons in a pair of cigar-shaped traps coupled by tunneling of atoms. The model is based on a system of linearly coupled nonpolynomial Schroedinger equations. Unlike the well-known spontaneous-symmetry-breaking (SSB) bifurcation in coupled cubic equations, in the present model the SSB competes with the onset of collapse in this system. Stability regions of symmetric and asymmetric solitons, as well as the collapse region, are identified in the system's parameter space.
We show that in asymmetric heavy-ion collisions, especially off-central Cu+Au collisions, a sizable strength of electric field directed from Au nucleus to Cu nucleus is generated in the overlapping region, because of the difference in the number of electric charges between the two nuclei. This electric field would induce an electric current in the matter created after the collision, which result in a dipole deformation of the charge distribution. The directed flow parameters $v_1^{\\pm}$ of charged particles turn out to be sensitive to the charge dipole and provide us with information about electric conductivity of the quark gluon plasma.
For several years now the physics and chemistry of condensed matter attracts a great deal of attention, while also occupying an extremely important position in the research activity worldwide. Liquid crystalline materials, in particular, present numerous applications in the fields of science and technology. Since the development of the liquid crystals display (LCD) technology, a significant concern was devoted to the development and characterization of these fascinating mesophases. In the present paper we perform several Monte Carlo simulations, by using the Lebwohl-Lasher model, for investigating the molecular director configuration in a nematic liquid crystal cell having varying boundary anchoring conditions in asymmetric circumstances. For this geometry, we analyze the molecular spatial...
We show that the Wheeler-DeWitt equation with a consistent boundary condition is only compatible with an arrow of time that formally reverses in a recollapsing universe. Consistency of these opposite arrows is facilitated by quantum effects in the region of the classical turning point. Since gravitational time dilation diverges at horizons, collapsing matter must then start re-expanding ``anticausally" (controlled by the reversed arrow) before horizons or singularities can form. We also discuss the meaning of the time-asymmetric expression used in the definition of ``consistent histories". We finally emphasize that there is no mass inflation nor any information loss paradox in this scenario.
We argue that current neutron star observations exclude asymmetric bosonic non-interacting dark matter in the range from 2 keV to 16 GeV, including the 5-15 GeV range favored by DAMA and CoGeNT. If bosonic WIMPs are composite of fermions, the same limits apply provided the compositeness scale is higher than ~10^12 GeV (for WIMP mass ~1 GeV). In case of repulsive self-interactions, we exclude large range of WIMP masses and interaction cross sections which complements the constraints imposed by observations of the Bullet Cluster.
This book describes basic atomic and nuclear structure, the physical processes that result in the emission of ionizing radiations, and external and internal radiation protection criteria, standards, and practices from the standpoint of their underlying physical and biological basis. The sources and properties of ionizing radiation-charged particles, photons, and neutrons-and their interactions with matter are discussed in detail. The underlying physical principles of radiation detection and systems for radiation dosimetry are presented. Topics considered include atomic physics and radiation; atomic structure and radiation; the nucleus and nuclear radiation; interaction of heavy charged particles with matter; interaction of beta particles with matter; phenomena associated with charged-particle tracks; interaction of photons with matter; neutrons, fission and criticality; methods of radiation detection; radiation dosimetry; chemical and biological effects of radiation; radiation protection criteria and standards; external radiation protection; and internal dosimetry and radiation protection.
Making use of the recently developed chiral power counting for the physics of nuclearmatter [1,2], we evaluate the in-medium chiral quark condensate up to next-to-leading order for both symmetric nuclearmatter and neutron matter. Our calculation includes the full in-medium iteration of the leading order local and one-pion exchange nucleon-nucleon interactions. Interestingly, we find a cancellation between the contributions stemming from the quark mass dependence of the nucleon mass appearing in the in-medium nucleon-nucleon interactions. Only the contributions originating from the explicit quark mass dependence of the pion mass survive. This cancellation is the reason of previous observations concerning the dominant role of the long-range pion contributions and the suppression of short-range nucleon-nucleon interactions. We find that the linear density contribution to the in-medium chiral quark condensate is only slightly modified for pure neutron matter by the nucleon-nucleon interactions. For symmetric nu...
The current experimental techniques may be inadequate to provide unambiguous positive signals as the limits on direct searches for dark matter improve. Thus, convincing evidence for dark matter particles may be possible only by detecting the direction of the incoming particles in the presence of background. We present in this article an experimental method to determine the direction and sense ('head-tail') of dark matter wind by measuring the direction of the elastic nuclear recoils in the scattering of dark matter particles with the detector material. We measure the direction and sense of the nuclear recoils created by the scattering of low-energy neutrons with CF4 in a low-pressure time-projection chamber as a demonstration. The decreasing stopping power along the recoil trajectory allows us to detect the sense and direction of the incoming neutrons, and proves that the 'head-tail' effect can be measured.
Recently, it has been recently shown that the linear response theory in symmetric nuclearmatter can be used as a tool to detect finite size instabilities for different Skyrme functionals. In particular it has been shown that there is a correlation between the density at which instabilities occur in infinite matter and the instabilities in finite nuclei. In this article we present a new fitting protocol that uses this correlation to add new additional constraint in Symmetric Infinite NuclearMatter in order to ensure the stability of finite nuclei against matter fluctuation in all spin and isospin channels. As an application, we give the parameters set for a new Skyrme functional which includes central and spin-orbit parts and which is free from instabilities by construction.
We study a possible transition between symmetric nuclearmatter and the diquark Bose-Einstein condensate (BEC) matter at zero temperature. We find that chiral restoration transition is first order and coincides with deconfinement. We investigate various possible coexistence patterns which may emerge from the first order deconfinement phase transition by assuming different values for the critical deconfinement chemical potential. If deconfinement takes place at higher chemical potential, there exists a mixed phase of nuclear and chirally restored diquark BEC matter. This coexistence region extends over a large density region for a bigger diquark BEC or a weaker diquark-diquark interaction. For model parameters with heavy diquark in vacuum, phase transition to diquark matter becomes of second-order. We also show that in the case of precocious deconfinement, droplets of nucleons and droplets of chirally restored Bose-Einstein condensed diquarks coexist surrounded by non-trivial vacuum. We show that a early decon...
The present report gives an account of results on a research work about 'the stakes of the dialogue around the follow up of nuclear and non nuclear industrial facilities' and on conclusions of a seminar, on the same subject that stood at Ville D' Avray from the 21. to 22. of January 2003. This seminar has gathered different actors (administration, experts, associations, industrial operators) concerned by the dialogue around these installations. The work has been directed by I.R.S.N. and had for object to give the knowledge of the French and International experience in matter of dialogue around nuclear and non nuclear industrial sites. (N.C.)
In-medium subthreshold Formula Not Shown scattering amplitudes calculated within a chirally motivated meson?baryon coupled-channel model are used self consistently to confront Formula Not Shown atom data across the periodic table. Substantially deeper Formula Not Shown nuclear potentials are obtained compared to the shallow potentials derived in some approaches from threshold Formula Not Shown amplitudes, with Formula Not Shown at nuclearmatter density. When Formula Not Shown contributions are incorporated phenomenologically, a very deep Formula Not Shown nuclear potential results, Formula Not Shown , in agreement with density dependent potentials obtained in purely phenomenological fits to the data. Self consistent dynamical calculations of Formula Not Shown ?nuclear quasibound states ge...
We formulate a statistical model for description of nuclear composition and equation of state of stellar matter at subnuclear densities and temperature up to 20 MeV, which are expected during the collapse and explosion of massive stars. The model includes nuclear, electromagnetic and weak interactions between all kinds of particles, under condition of statistical equilibrium. We emphasize importance of realistic description of the nuclear composition for understanding stellar dynamics and nucleosynthesis. It is demonstrated that the experience accumulated in studies of nuclear multifragmentation reactions can be used for better modelling properties of stellar medium.
: Nuclear reactions with radioactive beams provide unique means to constrain the equation of state (EOS) of neutron-rich matter, in particular its density dependence through the nuclear symmetry energy. The EOS is important for our understanding of numerous phenomena in both nuclear physics and astrophysics. In this talk we will present our most recent results on the properties of rotating neutron stars with a particular emphasis on rapid rotations. The available constraints on the nuclear symmetry energy around saturation density restrict the possible rotating neutron-star configurations.
The way of doing in the transfer of knowledge and liability in the fields of exploitation and maintenance of nuclear reactors of Daya Bay is described in this article. The relations in matter of nuclear safety are also detailed and are situated in the frame of an agreement of cooperation signed in 1995. The third part treats the transfer of technology in the area of engineering of nuclear blocks and how it was used for the conception of nuclear blocks of Qinshan phase II. (N.C.)
The AMADEUS experiment will perform the first complete experimental study of the case of the so-called deeply bound kaonic nuclear states. Such a study has deep consequences in a still open sector of the strangeness hadronic/nuclear physics: how the hadron masses and hadron interactions change in the nuclear medium with consequences on the structure of cold dense hadronic matter. AMADEUS will perform exclusive full acceptance measurements, all particles in the formation and decay processes of deeply bound nuclear clusters will be detected. Preliminary results from the analysis of KLOE experiment data in the search for the kaonic clusters will be presented as well.
This two-volume reference uses many equations to provide detailed information on atomic and nuclear decay phenomena in a clear and concise manner. Vol. I. Includes a brief description of classical physics, its extension to special relativity and quantum mechanics, and an introduction to basic atomic and nuclear concepts. A thorough discussion of atomic structure is also included with emphasis on the theory of the multielectron atom, characteristic X-rays, and the Auger effect. Vol. II. Covers the areas of nuclear structure, nuclear decay processes, the interaction of radiation with matter, and the mathematics of radioactive decay.
We calculate the equation of state of nuclearmatter for arbitrary isospin-asymmetry up to three loop order in the free energy density in the framework of in-medium chiral perturbation theory. In our approach 1p- and 2p-exchange dynamics with the inclusion of the D-isobar excitation as an explicit degree of freedom, corresponding to the long- and intermediate-range correlations, are treated explicitly. Few contact terms fixed to reproduce selected known properties of nuclearmatter encode the short-distance physics. Two-body as well as three-body forces are systematically included. We find a critical temperature of about 15 MeV for symmetric nuclearmatter. We investigate the dependence of the liquid-gas first-order phase transition on isospin-asymmetry. In the same chiral framework we cal...
We study cold nuclearmatter based on the holographic gauge theory, where baryons are introduced as the instantons in the probe D8/$\\bar{\\rm D8}$ branes according to the Sakai-Sugimoto model. Within a dilute gas approximation of instantons, we seek for the stable states via the variational method and fix the instanton size. We find the first order phase transition from the vacuum to the nuclearmatter phase as we increase the chemical potential. At the critical chemical potential, we could see a jump of the baryon density from zero to a finite definite value. While the size of the baryon in the nuclearmatter is rather small compared to the nucleus near the transition point, where the charge density is also small, it increases with the baryon density. Those behaviors obtained here are discussed by relating to the force between baryons.
We discuss the ít SU(2) chiral sigma model in the context of nuclearmatter using a mean field approach at high density. In this model we include a dynamically generated isoscalar vector field and higher-order terms in the scalar field. With the inclusion of these, we reproduce the empirical values of the nuclearmatter saturation density, binding energy, and nuclear incompressibility. The value of the incompressibility is chosen according to recently obtained heavy-ion collision data. We then apply the same dynamical model to neutron-rich matter in beta equilibrium, related to neutron star structure. The maximum mass and corresponding radius of stable non-rotating neutron stars are found to be in the observational limit.
We study the properties of the scalar charm resonances $D_{s0}(2317)$ and $D_0(2400)$, and the theoretical hidden charm state X(3700) in nuclearmatter. We find that for the $D_{s0}(2317)$ and X(3700) resonances, with negligible and small width at zero density, respectively, the width becomes about $100 {\\rm MeV}$ and $200 {\\rm MeV}$ at normal nuclearmatter density, accordingly. For $D_0(2400)$ the change in width is relatively less important. We discuss the origin of this new width and trace it to reactions occurring in the nucleus. We also propose a possible experimental test for those modifications in nuclearmatter, which will bring valuable information on the nature of those scalar resonances and the interaction of $D$ mesons with nucleons.
An extension of the generalized relativistic mean-field (gRMF) model with density dependent couplings is introduced in order to describe thermodynamical properties and the composition of dense nuclearmatter for astrophysical applications. Bound states of light nuclei and two-nucleon scattering correlations are considered as explicit degrees of freedom in the thermodynamical potential. They are represented by quasiparticles with medium-dependent properties. The model describes the correct low-density limit given by the virial equation of state (VEoS) and reproduces RMF results around nuclear saturation density where clusters are dissolved. A comparison between the fugacity expansions of the VEoS and the gRMF model provides consistency relations between the quasiparticles properties, the nucleon-nucleon scattering phase shifts and the meson-nucleon couplings of the gRMF model at zero density. Relativistic effects are found to be important at temperatures that are typical in astrophysical applications. Neutron matter and symmetric nuclearmatter are studied in detail.
The properties of the hot and dense nuclearmatter produced at RHIC can be investigated in multiple ways by heavy flavor production. The STAR experiment has capability to study both open heavy flavor and quarkonia. Heavy quarks are produced in early stage of the collision and the mechanisms of their interaction with nuclearmatter is not yet well understood. This can be studied by non-photonic electrons originating from semileptonic decays of heavy flavor mesons. For the interpretations of the experimental data contributions from charm and bottom mesons have to be separated. The heavy quarkonium production is expected to be sequentially suppressed depending on the temperature of the produced nuclearmatter. In this contribution we report recent results from STAR on non-photonic electrons, direct reconstruction of charm mesons, J/? as well ? in p+p, Cu+Cu and Au+Au collisions at ?sNN =200 GeV.
A broad coverage of radioactivity and nuclear phenomena fundamentals is presented, followed by discussions of applications in such fields as basic chemistry, biology, medicine, earth and space sciences. Following an introductory historical chapter, the basic fundamentals of nuclear properties, radioactive growth and decay, and nuclear reactions are covered in the first five chapters. Chapters 6-10 deal mainly with topics essential to the practicing radiochemist. They include discussion of interactions of radiation with matter, radiation detection and measurement, techniques in nuclear chemistry, statistics and radioactivity and nuclear models. Applications of these disciplines in the various fields noted above together with chapters on nuclear energy and sources of nuclear bombarding particles complete the 15 chapters of the book. (JMT)
The seven Joint Coordinating Committees between R.O.K. and other countries, including the U.S. are currently in operation. Among these, the most amicable and fruitful one is the R.O.K.-U.S.A. Joint Standing Committee on Nuclear Energy Cooperation(JSCNEC). It is a prerequisite to assess the current status of international joint research which is under way for the effective implementation of international cooperation. It is anticipated that this can be realized by devising continuous follow-up measures based on its assessment and smooth feedback. Various matters encompassing 8 policy matters, 14 technological cooperation matters, 13 nuclear safety cooperation matters and 6 safeguards matters were discussed at the 19th R.O.K.-U.S.A. JSCNEC held June 22-26 in Seoul and Taejon. Among these, matters related to KAERI are the 13 technical cooperation and 2 nuclear safety cooperation concerns. The background and current status of matters in the technical cooperation and nuclear safety cooperation areas as well as our position and discussion direction for each item, with a review of the summary record of the 18th R.O.K.-U.S.A. JSCNEC are presented in this report. At the same time, its publication is meaningful in that after this committee meeting, a status of nuclear technological and safety cooperation between R.O.K. and U.S., which are related to KAERI, has been complied and is clear at a glance. This will be a review of the discussion results from the 19th R.O.K.-U.S.A. JSCNEC. After its publication, we intend to implement a bilateral cooperation with the U.S. more effectively by devising follow-up measures for each issue. This will be achieved through a thorough management of its progress and systematic cooperation in work affairs between personnel of the government and KAERI responsible for bilateral cooperation with the U.S. (author)
A quantitative model, based on hadronic physics, is developed and applied to heavy ion collisions at BNL-AGS energies. This model is in excellent agreement with observed particle spectra in heavy ion collisions using Si beams, where baryon densities of three and four times the normal nuclearmatter density ({rho}{sub 0}) are reached. For Au on Au collisions, the authors predict the formation of matter at very high densities (up to 10 {rho}{sub 0}).
The impact of nuclear physics theories on cooling of isolated neutron stars is analyzed. Physical properties of neutron star matter important for cooling are reviewed such as composition, the equation of state, superfluidity of various baryon species, neutrino emission mechanisms. Theoretical results are compared with observations of thermal radiation from neutron stars. Current constraints on theoretical models of dense matter, derived from such a comparison, are formulated.
An attempt is made to review a small fraction of what has happened in Nuclear Physics after Rutherford, some milestones and the shifting focus of the field. In a hundred years enormous progress had been made, but there is still a great deal about the properties of hadronic matter that we do not understand, matter that makes up virtually all of the visible mass in our Universe.
The report is intended to identify the compelling research opportunities of high intellectual value in high energy density physics. The opportunities for discovery include the broad scope of this highly interdisciplinary field that spans a wide range of physics areas including plasma physics, laser and particle beam physics, nuclear physics, astrophysics, atomic and molecular physics, materials science and condensed matter physics, intense radiation-matter interaction physics, fluid dynamics, and magnetohydrodynamics
We study the phase diagram of the three flavor Polyakov-Nambu-Jona Lasinio (PNJL) model and in particular the interplay between chiral symmetry restoration and deconfinement crossover. We compute chiral condensates, quark densities and the Polyakov loop at several values of temperature and chemical potential. Moreover we investigate on the role of the Polyakov loop dynamics in the transition from nuclearmatter to quark matter.
"Physicists investigating heavy-particle collisions believe they are on the track of a universal form of matter, one common to very high energy particles ranging from protons to heavy nuclei such as uranium. Some think that this matter, called a color glass condensate, may explain new nuclear properties and the process of particle formation during collisions. Experimentalists have recently reported intriguing data that suggest a color glass condensate has actually formed in past work" (1 page)
We propose a model of asymmetric dark matter (DM) where dark sector is an identical copy of both forces and matter of the standard model (SM) as in the mirror universe models discussed in literature. In addition to being connected by gravity, the SM and DM sectors are also connected at high temperature by a common set of heavy right handed Majorana neutrinos via their Yukawa couplings to leptons and Higgs bosons. The lightest nucleon in the dark (mirror) sector is a candidate for dark matter. The out of equilibrium decay of right-handed neutrino produces equal lepton asymmetry in both the sectors via resonant leptogenesis which then get converted to baryonic and dark baryonic matter. The dark baryon asymmetry due to higher dark nucleon masses leads to higher dark matter density compared to familiar baryon density, that is observed. The standard model neutrinos in this case acquire masses from the inverse seesaw mechanism. A kinetic mixing between the U(1) gauge fields of the two sectors introduced to guarante...
Recent experiments on beta-delayed fission in the mercury-lead region and the discovery of asymmetric fission in $^{180}$Hg [1] have stimulated renewed interest in the mechanism of fission in heavy nuclei. Here we study fission modes and fusion valleys in $^{180}$Hg and $^{198}$Hg using the self-consistent nuclear density functional theory employing Skyrme and Gogny energy density functionals. We show that the observed transition from asymmetric fission in $^{180}$Hg towards more symmetric distribution of fission fragments in $^{198}$Hg can be explained in terms of competing fission modes of different geometries that are governed by shell effects in pre-scission configurations. The density distributions at scission configurations are studied and related to the experimentally observed mass splits.
In a nuclear reactor including at least one guide thimble and at least one control rod received in the guide thimble and supported for movement relative thereto, an improvement is described which comprises: an end plug having a central axis and an imperforate asymmetrical tip configuration attached to an end of the control rod, the asymmetrical tip configuration defining a lower terminal end on the end plug which is offset to one side of the central axis. It produces, in response to axial flow of coolant along the control rod and within its respective guide thimble, a non-symmetric coolant flow velocity pattern about the end plug and a lateral substantially steady state force on the control rod which presses the control rod end plug against a wall of the guide thimble so as to substantially prevent lateral vibration of the control rod due to the axial flow of the coolant.
The newly introduced title compounds were found to be efficient chiral auxiliaries for the asymmetric Simmons–Smith cyclopropanation of allylic alcohols and for asymmetric addition of diethylzinc to aldehydes. For example, Simmons-Smith cyclopropanation of cinnamyl alcohol in the presence of N,N,N?,N?-tetraethyl-2,2?-dihydroxy-1,1?-binaphthyl-3,3?-dicarboxamide (1b) proceeded with high enantioselectivity of 94% ee and addition of diethylzinc to benzaldehyde in the presence of N,N,N?,N?-tetraisopropyl-2,2?-dihydroxy-1,1?-binaphthyl-3,3?-dicarboxamide (1e) proceeded with enantioselectivity of 99% ee. Although the reaction mechanism of these reactions is still nuclear, a monomeric seven-membered 2,2?-dihydroxy-1,1? -binaphthyl-3,3?-dicarboxamide (1)–Zn complex is considered to be an active species which catalyzes the above reactions, on the basis of NMR experiments.
The dynamics of nuclear collective motion is investigated in the case of reflection-asymmetric shapes. The model is based on a new parameterization of the octupole and quadrupole degrees of freedom, valid for nuclei close to the axial symmetry. Amplitudes of oscillation in other degrees of freedom different from the axial ones are assumed to be small, but not frozen to zero. The case of nuclei which already possess a permanent quadrupole deformation is discussed in some more detail and a simple solution is obtained at the critical point of the phase transition between harmonic octupole oscillation and a permanent asymmetric shape. The results are compared with experimental data of the Thorium isotopic chain. The isotope Th-226 is found to be close to the critical point.
The barriers standing against the formation of superheavy elements and their consecutive $\\alpha$ decay have been determined in the quasimolecular shape path within a Generalized Liquid Drop Model including the proximity effects between nucleons in a neck, the mass and charge asymmetry, a precise nuclear radius and the shell effects given by the Droplet Model. For moderately asymmetric reactions double-hump potential barriers stand and fast fission of compact shapes in the outer well is possible. Very asymmetric reactions lead to one hump barriers which can be passed only with a high energy relatively to the superheavy element energy. Then, only the emission of several neutrons or an $\\alpha$ particle can allow to reach an eventual ground state. For almost symmetric heavy-ion reactions, there is no more external well and the inner barrier is higher than the outer one.
This report covers the activity developed in the Lyon Institute of Nuclear Physics in the years 1996-1997. The INP-Lyon is a mixed research unit, dependent on Lyon 1 Claude Bernard University, on one side, and on CNRS Institute of Nuclear and Particle Physics, on the other side. Its personnel of some 200 fellows is formed up of a half of researchers and undergraduate researchers, the other half being engineers, technicians and administration personnel. The principal activities in INP Lyon are the experimental research in sub-atomic physics as well as the training by research of the master and enrolled towards Ph D students. The main research problems concern the particle physics nuclearmatter and the particle astrophysics as well as the works in theoretical physics, radioactive product management and the interactions ions/clusters - matter. The report contains the following chapters: Physics at LEP, Experiment preparation for LHC, Hadronic and NuclearMatter, Astro-particles, Theoretical Physics, Ions/clusters - matter and physico-chemistry of the ion-matter interaction, Technical activities, Scientific life at INP -Lyon
We present spectral calculations of nuclearmatter properties including three-body forces. Within the in-medium T-matrix approach, implemented with the CD-Bonn and Nijmegen potentials plus the three-nucleon Urbana interaction, we compute the energy per particle in symmetric and neutron matter. The three-body forces are included via an effective density dependent two-body force in the in-medium T-matrix equations. After fine tuning the parameters of the three-body force to reproduce the phenomenological saturation point in symmetric nuclearmatter, we calculate the incompressibility and the energy per particle in neutron matter. We find a soft equation of state in symmetric nuclearmatter but a relatively large value of the symmetry energy. We study the the influence of the three-body forces on the single-particle properties. For symmetric matter the spectral function is broadened at all momenta and all densities, while an opposite effect is found for the case of neutrons only. Noticeable modification of the spectral functions are realized only for densities above the saturation density. The modifications of the self-energy and the effective mass are not very large and appear to be strongly suppressed above the Fermi momentum.
Minimal walking technicolor models can provide a nontrivial solution for cosmological dark matter, if the lightest technibaryon is doubly charged. Technibaryon asymmetry generated in the early Universe is related to baryon asymmetry and it is possible to create excess of techniparticles with charge (-2). These excessive techniparticles are all captured by $^4He$, creating \\emph{techni-O-helium} $tOHe$ ``atoms'', as soon as $^4He$ is formed in Big Bang Nucleosynthesis. The interaction of techni-O-helium with nuclei opens new paths to the creation of heavy nuclei in Big Bang Nucleosynthesis. Due to the large mass of technibaryons, the $tOHe$ ``atomic'' gas decouples from the baryonic matter and plays the role of dark matter in large scale structure formation, while structures in small scales are suppressed. Nuclear interactions with matter slow down cosmic techni-O-helium in Earth below the threshold of underground dark matter detectors, thus escaping severe CDMS constraints. On the other hand, these nuclear interactions are not sufficiently strong to exclude this form of Strongly Interactive Massive Particles by constraints from the XQC experiment. Experimental tests of this hypothesis are possible in search for $tOHe$ in balloon-borne experiments (or on the ground) and for its charged techniparticle constituents in cosmic rays and accelerators. The $tOHe$ ``atoms'' can cause cold nuclear transformations in matter and might form anomalous isotopes, offering possible ways to exclude (or prove?) their existence.
Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions [77Asb1, 81Bou1]. The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the RHIC and LHC injector chains for the heaviest ion species used to date. The RHIC pulsed sputter source (PSC) and Tandem electrostatic accelerator are being replaced by an Electron Beam Ion Source (EBIS), Radio Frequency Quadrupole (RFQ) and short linac [08Ale1]. With EBIS beams of any element can be prepared for RHIC including uranium and spin-polarized 3He. At CERN an ECR ion source is used, followed by an RFQ and Linac. The ions are then accumulated, electron cooled, and accelerated in LEIR. After transfer to and acceleration in the PS, ion beams are injected into the SPS.
Nuclearmatter density distributions of {sup 4}He and the neutron-rich nuclei {sup 6}He and {sup 8}He were studied via intermediate-energy proton nucleus scattering in inverse kinematics using the recoil detector IKAR. For these nuclei, differential cross sections for elastic scattering at low momentum transfer were measured with an accuracy of 2% on absolute normalization. The experimental method and the procedure of data analysis are described. Phenomenological and microscopically calculated nuclearmatter distributions were related to the measured cross sections with the aid of the Glauber multiple scattering theory. (orig.)
Starting from a complete operator product expansion up to mass dimension-6 twist-4 and up to first order in the coupling constants we investigate the splitting and mixing of $\\rho$ and $\\omega$ mesons in isospin symmetric nuclearmatter. Special attention is devoted to the impact of the scalar 4-quark condensates on both effects. In nuclearmatter the Landau damping governs the $\\rho - \\omega$ mass splitting while the scalar 4-quark condensates govern the strenght of individual mass shifts. A strong in-medium mass splitting causes the disappearance of the $\\rho - \\omega$ mixing.
The most basic theoretical challenge for understanding low-energy nuclear reaction (LENR) and transmutation reaction (LETR) in condensed matters is to find mechanisms by which the large Coulomb barrier between fusing nuclei can be overcome. A unifying theory of LENR and LETR has been developed to provide possible mechanisms for the LENR and LETR processes in matters based on high-density nano-scale and micro-scale quantum plasmas. It is shown that recently developed theoretical models based on Bose-Einstein Fusion (BEF) mechanism and Quantum Plasma Nuclear Fusion (QPNF) mechanism are applicable to the results of many different types of LENR and LETR experiments.
The field of relativistic heavy ion physics entered a new era with the start of the physics program at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory on Long Island, New York. This dedicated facility allows extensive studies of the nuclearmatter phase diagram at the highest temperatures so far available in the laboratory. The goal of the program is to conclusively establish the existence of the deconfined state of nuclearmatter predicted by QCD, the Quark Gluon Plasma (QGP), and study its properties.
This handbook gives a complete and concise description of the up-to-date knowledge of nuclear and radiochemsitry and applications in the various fields of science. I is based on teaching courses and on research for over 40 years. The book is addressed to any researcher whishing sound knowledge about the properties of matter, be it a chemist, a physicist, a medical doctor, a mineralogist or a biologist. They will all find it a valuable source of information about the principles and applications of nuclear and radiochemistry. Research in radiochemistry includes: Study of radioactice matter in na
Collective flow of nuclearmatter probes the dynamics of heavy-ion reactions and can provide information about the nuclear-matter equation of state. In particular, the incident energy dependences of collective flow may be a sensitive means to deduce the existence of a Quark Gluon Plasma phase in the equation of state. Collective flow measurements from 30 A MeV to 200 A GeV incident energies are briefly reviewed. Preliminary results on collective flow from the WA98 experiment at the CERN SPS are presented.
Some processes involving the interaction of medium energy quarks and gluons with nuclearmatter are described. Possible mechanisms for the A-dependence of the energy loss of leading protons produced in proton-nucleus collisions are given, and an experiment which may help to distinguish these mechanisms is described. A possible color transparency experiment at CEBAF is described. Experiments to measure energy loss of quarks in nuclearmatter and the formation time of hadrons are discussed along with the possibilities of measuring {sigma}{sub J}/{psi} and {sigma}{sub {psi}{prime}} at CEBAF.
Including the vacuum effects, the compressional properties of nuclearmatter are studied in the cutoff field theory. Under the Hartree approximation, the low-energy effective Lagrangian is derived in the framework of the renormalization group methods. The coefficients are determined in a way where the physical results hardly depend on the value of the cutoff which is conveniently introduced into the theory. It is shown that, to reproduce the empirical data of the nucleus incompressibility, the compressibility of the nuclearmatter is favorable to be 250$\\sim$350MeV.
Not a conference summary, these concluding remarks consider five major themes that were illuminated during the conference and the problems within them that need to be resolved in the future. The five topics considered and the following: new degrees of freedom (single-particle motion, giant resonances, nuclear molecular resonances, nuclearmatter, kaon-produced hypernuclei, implications of the bag model and quantum chromodynamics), new forms of matter, new reaction mechanisms (direct vs compound-nucleus reactions, heavy-ion reactions), new aspects of the weak interactions in nuclei (weak neutral currents, P invariance), and new symmetries. 4 figures. (RWR)
Range-energy relations for hadrons in nuclearmatter exist similarly to the range-energy relations for charged particles in materials. When hadrons of GeV kinetic energies collide with atomic nuclei massive enough, events occur in which incident hadron is stopped completely inside the target nucleus without causing particle production - without pion production in particular. The stoppings are always accompanied by intensive emission of nucleons with kinetic energy from about 20 up to about 400 MeV. It was shown experimentally that the mean number of the emitted nucleons is a measure of the mean path in nuclearmatter in nucleons on which the incident hadrons are stopped.
We investigate the possibility to describe nuclearmatter in an approach constrained by the proeminent features of quantum chromodynamics. We mapped the in-medium nucleon self-energies of a point coupling relativistic mean-field model on self-energies obtained in effective theories of QCD. More precisely, the contributions to the nucleon self-energy have been separated into the short range part, driven principally by the quark structure of the nucleon described in a quark-diquark picture, and the long range part, dictated by pion dynamics and determined with in-medium chiral perturbation theory. A realistic description of nuclearmatter saturation properties has been obtained with the inclusion of small phenomenological correction terms.
The relation between collective modes and the phase transition in low density nuclearmatter is examined. The dispersion relations for collective modes in a linear approach are evaluated within a Landau-Fermi liquid scheme by assuming coexisting phases in thermodynamical equilibrium. Temperature and isospin composition are taken as relevant parameters. The in-medium nuclear interaction is taken from a recently proposed density functional model. We found significative modifications in the energy spectrum, within certain range of temperatures and isospin asymmetry, due to the separation of matter into independent phases. We conclude that detailed calculations should not neglect this effect.
The Formula Not Shown meson in dense matter is analyzed by means of a unitary approach in coupled channels based on the local hidden gauge formalism. The Formula Not Shown self-energy and the corresponding Formula Not Shown spectral function in the nuclear medium are obtained. We observe that the Formula Not Shown develops a width in matter up to five times bigger than in free space. We also estimate the transparency ratio of the Formula Not Shown reaction. This ratio is an excellent tool to detect experimentally modifications of the Formula Not Shown meson in dense matter.
Dark matter interacting predominantly with leptons instead of nuclearmatter has received a lot of interest recently. In this talk, we investigate the signals expected from such 'leptophilic Dark Matter' in direct detection experiments and in experiments looking for Dark Matter annihilation into neutrinos in the Sun. In a model-independent framework, we calculate the expected interaction rates for different scattering processes, including elastic and inelastic scattering off atomic electron shells, as well as loop-induced scattering off atomic nuclei. In those cases where the last effect dominates, leptophilic Dark Matter cannot be distinguished from conventional WIMPs. On the other hand, if inelastic scattering off the electron shell dominates, the expected event spectrum in direct detection experiments is different and would provide a distinct signal. However, we find that the signals in DAMA and/or CoGeNT cannot be explained by invoking leptophilic DM because the predicted and observed energy spectra do no...
Multi-wavelength observations were performed in order to investigate various phases of interstellar matter in early type galaxies. The IRAS coadding procedure for a large sample of galaxies, the author found that about half of early type galaxies contain detectable amounts of cold interstellar dust. Selecting galaxies with strong far infrared fluxes, he undertook optical imaging and spectroscopy, HI {lambda}21 cm line observations and CO J = 1-0 line observations. He successfully detected cold dust, HI gas, ionized gas and molecular material; proving that the far infrared flux is indeed a good indicator for the presence of interstellar matter. The infrared emission mechanism and origin and fate of interstellar matter are discussed using the data obtained from various phases of interstellar matter. The interstellar matter is also used as a probe of dynamical structure, nuclear activity and star formation in early type galaxies.
Exotic dark matter and dark energy together seem to dominate in the Universe. %The nature of dark matter, however, can be unveiled only if is detected in the laboratory. Supersymmetry naturally provides a candidate for the dark matter constituents via the lightest supersymmetric particle (LSP). The most important process for directly detecting dark matter is the LSP-nucleus elastic scattering by measuring the energy of the recoiling nucleus. In the present work we explore a novel process, which has definite experimental advantages, that is the detection of the dark matter constituents by observing the low energy ionization electrons. These electrons, which are produced during the LSP-nucleus collision, may be observed separately or in coincidence with the recoiling nuclei. We develop the formalism and apply it in calculating the ratio of the ionization rate to the nuclear recoil rate in a variety of atoms including Ne-20, Ar-40, Ge-76, Kr-78 and Xe-132 employing realistic Hartree-Fock electron wave functions....
Direct photon productions in minimum bias d+Cu and d+Au and central Cu+Cu and Au+Au at center of mass energies {radical}s = 62.4 GeV and 200GeV at RHIC are investigated systematically by taking into account jet quenching effect, medium-induced photon bremsstrahlung and jet-photon conversion in the hot QGP as well as known cold nuclearmatter effects such as the isospin effect, the Cronin effect, shadowing effect, EMC effect and cold nuclearmatter energy loss. It is shown that at high p{sub T} the nuclear modification factor for direct photon R{sub AA}(p{sub T}) is suppressed and dominated by cold nuclearmatter effects, and there is no large enhancement due to medium-induced photon bremsstrahlung and jet-photon conversion in the hot QGP. Comparison of numerical simulations with experimental data rules out large Cronin enhancement and incoherent photon emission in medium, though large error bars in currently experimental data can not provide tight constraints on other nuclearmatter effects.
The three-flavor crystalline color-superconducting (CCS) phase of quantum chromodynamics (QCD) is a candidate phase for the ground state of cold matter at moderate densities above the density of the deconfinement phase transition. Apart from being a superfluid, the CCS phase has properties of a solid, such as a lattice structure and a shear modulus, and hence the ability to sustain multipolar deformations in gravitational equilibrium. We construct equilibrium configurations of hybrid stars composed of nuclearmatter at low, and CCS quark matter at high, densities. Phase equilibrium between these phases is possible only for rather stiff equations of state of nuclearmatter and large couplings in the effective Nambu--Jona-Lasinio Lagrangian describing the CCS state. We identify a new branch of stable CCS hybrid stars within a broad range of central densities which, depending on the details of the equations of state, either bifurcate from the nuclear sequence of stars when the central density exceeds that of the deconfinement phase transition or form a new family of configurations separated from the purely nuclear sequence by an instability region. The maximum masses of our nonrotating hybrid configurations are consistent with the presently available astronomical bounds. The sequences of hybrid configurations that rotate near the mass-shedding limit are found to be more compact and thus support substantially larger spins than their same mass nuclear counterparts.
We propose the hybrid gravity-gauge mediated supersymmetry breaking where the gravitino mass is about several GeV. The strong constraints on supersymmetry viable parameter space from the CMS and ATLAS experiments at the LHC can be relaxed due to the heavy colored supersymmetric particles, and it is consistent with null results in the dark matter (DM) direct search experiments such as XENON100. In particular, the possible maximal flavor and CP violations from the relatively small gravity mediation may naturally account for the recent LHCb anomaly. In addition, because the gravitino mass is around the asymmetric DM mass, we propose the asymmetric origin of the gravitino relic density and solve the cosmological coincident problem on the DM and baryon densities ?DM : ? B ? 5 : 1. The gravitino relic density arises from asymmetric metastable particle (AMP) late decay. However, we show that there is no AMP candidate in the minimal supersymmetric Standard Model (SM) due to the robust gaugino/Higgsino mediated wash-out effects. Interestingly, AMP can be realized in the well motivated supersymmetric SMs with vector-like particles or continuous U(1) R symmetry. Especially, the lightest CP-even Higgs boson mass can be lifted in the supersymmetric SMs with vector-like particles.
The existence of a shadow world (or mirror universe) with matter and forces identical to that of the visible world but interacting with the latter only via gravity can be motivated by superstring theories as well as by recent attempts to understand the nature of a sterile neutrino needed if all known neutrino data are to be consistent with each other. A simple way to reconcile the constraints of big bang nucleosynthesis in such a theory is to postulate that the reheating temperature after inflation in the mirror universe is lower than that in the visible one. We have constructed explicit models that realize this proposal and have shown that the asymmetric reheating can be related to a difference of the electroweak symmetry breaking scales in the two sectors, which is needed for a solution of the neutrino puzzles in this picture. Cosmological implications of the mirror matter are also discussed.
Experimental and numerical investigation of single beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to the appearance of a single peak of the probe beam amplification at the transition frequency. The greater probe intensity results in an asymmetrical transmission spectrum with amplification at the blue wing of the absorption line and attenuation at the red one. Under high medium density, a broad band of amplification appears. Theoretical model is based on the solution of the Maxwell-Bloch equations for a two-level system. Different types of probe transmission spectra obtained are attributed to complex dynamics of a coherent...
We show how one can, in principle, reconstruct the electron number density profile of the Earth by studying the Earth matter effect on oscillations of solar and supernova neutrinos. A direct inversion of the oscillation problem is possible due to the existence of a very simple analytic formula for the Earth matter effect on oscillations of solar and supernova neutrinos. From the point of view of the Earth tomography, these oscillations have a number of advantages over the oscillations of the accelerator or atmospheric neutrinos, which stem from the fact that solar and supernova neutrinos are coming to the Earth as mass eigenstates rather than flavour eigenstates. In particular, this allows reconstruction of density profiles even over relatively short neutrino path lengths in the Earth, and also of asymmetric profiles. We study the requirements that future experiments must meet to achieve a given accuracy of the tomography of the Earth.
The structure and composition of the inner crust of neutron stars, as well as global stellar properties such as radius and moment of inertia, have been shown to correlate with parameters characterizing the symmetry energy of nuclearmatter such as its magnitude J and density dependence L at saturation density. It is thus mutually beneficial to nuclear physicists and astrophysicists to examine the combined effects of such correlations on potential neutron star observables in the light of recent experimental and theoretical constraints on J, L, and relationships between them. We review some basic correlations between these nuclear and astrophysical observables, and illustrate the impact of recent progress in constraining the J-L parameter space on the composition of the inner crust, crust-core transition density and pressure, and extent of the hypothesized pasta region. We use a simple compressible liquid drop model in conjunction with a simple model of nuclearmatter which allows for independent, smooth, varia...
We present a survey of the phenomenological adjustment of the parameters of the Skyrme-Hartree-Fock (SHF) model for a self-consistent description of nuclear structure and low-energy excitations. A large sample of reliable input data from nuclear bulk properties (energy, radii, surface thickness) is selected guided by the criterion that ground-state correlations should remain small. Least squares fitting techniques are used to determine the SHF parameters which accommodate best the given input data. The question of the predictive value of the adjustment is scrutinized by performing systematic variations with respect to chosen nuclearmatter properties (incompressibility, effective mass, symmetry energy, and sum-rule enhancement factor). We find that the ground-state data, although representing a large sample, leave a broad range of choices, i.e. a broad range of nuclearmatter properties. Information from giant resonances is added to pin down more precisely the open features. We then apply the set of newly adj...
An excellent description of both spin-independent and spin-dependent quark distributions and structure functions has been obtained with a modified Nambu-Jona-Lasinio model, which is free of unphysical thresholds for nucleon decay into quarks--hence incorporating an important aspect of confinement. We utilize this model to investigate nuclear medium modifications to structure functions, and find that we are readily able to reproduce both nuclearmatter saturation and the experimental F{sub 2N}{sup A}/F{sub 2N} ratio, that is, the EMC effect. Applying this framework to determine g{sub 1p}{sup A}, we find that the ratio g{sub 1p}{sup A}/g{sub 1p} differs significantly from 1, with the quenching caused by the nuclear medium being about twice that of the spin-independent case. This represents an exciting result, which if confirmed experimentally, will reveal much about the quark structure of nuclearmatter.
This chapter examines current interpretations of the available data on the properties of dense, highly excited nuclearmatter. Discusses high-energy heavy-ion accelerators; the high-density-temperature nuclear domain; the experimental view; theoretical tools; quantal and classical aspects; classical tools; statistical models; hydrodynamics; intranuclear cascade; nonequilibrium quantum scattering; elements of the reaction mechanism; collision geometry; evidence for multiple collisions; inclusive proton spectra; composite formation; pion production; strange-particle production; Coulomb final-state interactions; forward and backward spectra; spectator physics; the physics of dense nuclearmatter; nuclei entropy; and novel states of nuclei. Demonstrates that the field of high-energy nuclear collisions is still in a state of rapid development and flux. Recognizes the vast body of experimental work that has clarified the basic reaction mechanism. Suggests that future research focus on the following areas: measurements of extremely small cross sections; y and lepton yields; neutron-rich isotopes; multibaryonic excited states; and higher and lower beam energies.
We study the effect of nuclear equation of state on the r-mode instability of a rotating neutron star. We consider the case where the crust of the neutron star is perfectly rigid and we employ the related theory introduced by Lindblom {\\it et al.} \\cite{Lidblom-2000}. The gravitational and the viscous time scales, the critical angular velocity and the critical temperature are evaluated by employing a phenomenological nuclear model for the neutron star matter. The predicted equations of state for the $\\beta$-stable nuclearmatter are parameterized by varying the slope $L$ of the symmetry energy at saturation density on the interval $50 \\ {\\rm MeV} \\leq L \\leq 110 \\ {\\rm MeV}$. The effects of the density dependence of the nuclear symmetry energy on r-mode instability properties are presented and analyzed. A comparison of theoretical predictions with observed neutron stars in low-mass x-ray binaries is also performed and analyzed.
We study the implications on compact star properties of a soft nuclear equation of state determined from kaon production at subthreshold energies in heavy-ion collisions. On one hand, we apply these results to study radii and moments of inertia of light neutron stars. Heavy-ion data provides constraints on nuclearmatter at densities relevant for those stars and, in particular, to the density dependence of the symmetry energy of nuclearmatter. On the other hand, we derive a limit for the highest allowed neutron star mass of three solar masses. For that purpose, we use the information on the nucleon potential obtained from the analysis of the heavy-ion data combined with causality on the nuclear equation of state.
The lecture printed in this brochure gives a complete roundup on radiation and hazards related thereto. It deals with different kinds and effects of radiation injuries as well as the relationship between dose and radiation hazard. It furthermore gives an account of today's radiation dose to inhabitants, and an evaluation of radiation hazards related thereto as compared to other hazards of modern life. This includes topical questions and problems that are also discussed in public, e.g. reviewing the data of Hiroshima and Nagasaki, radiation sensitivity of the thyroid gland, natural radiation exposure from structural materials of the building industry, and the risk of lung cancer due to inhalation of radioactive matter. The statistic survey of the Federal Home Secretary on radiation exposure from emissions of radioactive matter of nuclear facilities such as nuclear power plants, nuclear experimental plants and nuclear fuel fabrication plants in the Federal Republic of Germany gives figures on the actual radiation hazards in this country.
The most probable charges of secondary fragments, produced after neutron evaporation from primary fragments, have been evaluated using fractional cumulative and mass yields in the 12MeV proton-induced fission of {sup 232}Th. The nuclear-charge polarization of primary fragments at scission has been obtained by correcting the most probable charge of secondary fragments for neutron evaporation. The fragment mass dependence of the nuclear-charge polarization at scission shows good agreement with that for thermal neutron-induced fission of {sup 235}U, indicating that the nuclear-charge polarization is nearly insensitive to mass and excitation energy of the fissioning nucleus for asymmetric fission in the actinide region. (orig.)
We assessed population genetic subdivision among four colonies of Common Eiders (Somateria mollissima v-nigrum) breeding in the Yukon-Kuskokwim Delta (YKD), Alaska, using microsatellite genotypes and DNA sequences with differing modes of inheritance. Significant, albeit low, levels of genetic differentiation were observed between mainland populations and Kigigak Island for nuclear intron lamin A and mitochondrial DNA (mtDNA) control region. Intercolony variation in haplotypic frequencies also was observed at mtDNA. Positive growth signatures assayed from microsatellites, nuclear introns, and mtDNA indicate recent colonization of the YKD, and may explain the low levels of structuring observed. Gene flow estimates based on microsatellites, nuclear introns, and mtDNA suggest asymmetrical gene flow between mainland colonies and Kigigak Island, with more individuals on average dispersing from mainland populations to Kigigak Island than vice versa. The directionality of gene flow observed may be explained by the colonization of the YKD from northern glacial refugia or by YKD metapopulation dynamics. ?? The Cooper Ornithological Society 2007.
We discuss the prospects for observing the mass of {rho}- and {omega}-mesons around nuclearmatter density by studying their coherent photoproduction in nuclear targets and subsequent in-medium decay into e{sup +}e{sup -}pairs. The quantum interference of {rho} and {omega}-mesons in the e{sup +}e{sup -}channel and the interference between Bethe-Heitler pairs and dielectrons from vector meson decays are of particular interest. (author). 21 refs.
An effective low energy Lagrangian density is applied to nuclear K{sup -}-dynamics. The free parameters, local s-wave couplings and SU(3)-symmetry constrained range terms are adjusted to describe elastic and inelastic K{sup -}-nucleon scattering data. The propagation and decay of the {Lambda}(1405)-resonance and the {Lambda}(1405)-nucleon hole state is studied self consistently with respect to the K{sup -}-propagation in isospin symmetric nuclearmatter. (orig.)
The Thomas-Fermi model of average nuclear properties described in Parts 1 and 2 is applied to the calculation of fission barriers and charge distributions. Comparison with experimental data reveals a barriers vs. size discrepancy. The suggestion is made that an extension of the Thomas-Fermi method is called for in order to describe the presence in nuclei of the ``quantal halo,`` i.e. of the classically forbidden region around the nuclear surface where matter exists at negative kinetic energy.
The Thomas-Fermi model of average nuclear properties described in Parts 1 and 2 is applied to the calculation of fission barriers and charge distributions. Comparison with experimental data reveals a barriers vs. size discrepancy. The suggestion is made that an extension of the Thomas-Fermi method is called for in order to describe the presence in nuclei of the quantal halo,'' i.e. of the classically forbidden region around the nuclear surface where matter exists at negative kinetic energy.
Some of the recent theoretical developments in relativistic (0.5 to 2.0-GeV/nucleon) nuclear collisions are reviewed. The statistical model, hydrodynamic model, classical equation of motion calculations, billiard ball dynamics, and intranuclear cascade models are discussed in detail. Inclusive proton and pion spectra are analyzed for a variety of reactions. Particular attention is focused on how the complex interplay of the basic reaction mechanism hinders attempts to deduce the nuclearmatter equation of state from data. 102 references, 19 figures.
This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for O8V2Zn3 [Zn3(VO4)2] (Subst. No. 2487)
The multifaceted role of the density dependent nuclear symmetry energy in the nuclear astrophysics involving neutron stars is highlighted. Efforts toward a model independent determination of the dense matter equation state through a deconstruction of the neutron star structure equation utilizing the masses and radii of several individual neutron stars are described. The need for observational data of both measurements for the same star is stressed.
This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for C10CoD10Se6.665Sn3.332 [C10CoD10·10/3(Se2Sn)] (Subst. No. 1202)
We present a set of three unified equations of states (EoSs) based on the nuclear energy-density functional (EDF) theory.These EoSs are based on generalized Skyrme forces fitted to essentially all experimental atomic mass data and constrained to reproduce various properties of infinite nuclearmatter as obtained from many-body calculations using realistic two- and three-body interactions. The structure of cold isolated neutron stars is discussed in connection with some astrophysical observations.
This review article is focused on the tremendous progress realized during the last fifteen years in the understanding of multifragmentation and its relationship to the liquid-gas phase diagram of nuclei and nuclearmatter. The explosion of the whole nucleus, early predicted by Bohr [N. Bohr, Nature 137 (1936) 351], is a very complex and rich subject which continues to fascinate nuclear physicists as well as theoreticians who extend the thermodynamics of phase transitions to finite systems.
Reprocessing nuclear fuels after burnup is considered by many an essential component of nuclear energy production. Though hazard risks associated with reprocessing plants are minor compared to those of power plants themselves, there are still numerous safety aspects to be considered. This book is devoted to a discussion of such aspects. Its 24 contributions treat the chemical and technical matters concerned. Both reprocessing as well as the treatment and final deposition of radioactive material that cannot be recycled are covered.
EXFOR is an exchange format designed to allow transmission of nuclear reaction data between the members of the Nuclear Data Centers Network. This document has been written for use by the members of the Network and includes matters of procedure and protocol, as well as detailed rules for the compilation of data. Users may prefer to consult EXFOR Basics' for a brief description of the format.
p p-bar annihilation into two mesons in nuclearmatter is studied in the framework of a hadron-exchange model. The influence of the reduction of the nucleon mass in medium, predicted by relativistic models of nuclear structure, is analyzed. It is found that threshold effects can lead to strong suppression of the annihilation width, as the effective nucleon mass decreases from the free-space value. (author) 7 refs., 1 tab.
A mechanism for the origin and development of spiral arms is recalled to show that spiral structure in the nucleus of a galaxy can be produced by matter ejected from a rotating nucleus. The mechanism can account for the observations of outward and/or inward motions in the nuclear regions of spirals. In particular, the model shows satisfactory agreement with observations when applied to the tight nuclear spiral of NGC 4736. 23 references.
The nuclear park management is connected to the ability of the operating to anticipate and respect the safety requirements. Beyond the technical constraints, the industrial in nuclear have to take in part the point of view of their interlocutors: the public and its representatives, the associations, the regulations authorities. In matter of safety, several challenges are to be taken up. They are approached hereafter. (N.C.).
In high-energy nuclear collisions, heavy quark potential at finite temperature controls the quarkonium production. Including the relaxation of the medium induced by the relative velocity between quarkonia and the deconfined expanding matter, the Debye screening is reduced and the quarkonium dissociation takes place at a higher temperature. As a consequence of the velocity dependent dissociation temperature, the quarkonium suppression at high transverse momentum is significantly weakened in high energy nuclear collisions at RHIC and LHC.
Generalized Cherenkov-like effects based on four fundamental interactions are investigated and classified. Two general Cherenkov-like coherence conditions are found as two natural limiting extremes of the same spontaneous particle emission process in nuclear media. Nuclear pionic and nuclear kaonic Cherenkov-like radiation (NPICR and NKCR) produced by high-energy nucleons passing through a nuclear medium are systematically studied using a quantum theoretical approach. The pion and kaon refractive indices, the pion and kaon phase velocities as well as the NPICR and NKCR thresholds are calculated via the Foldy-Lax multiple scattering formalism having as input the experimental data for the elementary pion-nucleon and kaon-nucleon forward scattering amplitudes. The differential cross sections, the angle-energy correlations, as well as some other essential signatures of coherent pion and kaon production via Cherenkov mechanism with high-energy proton beams are presented. Compressed nuclear media with densities up to five times normal nuclearmatter density are taken into account.
Cell type and tissue architecture correlate with genome organization in higher eukaryotes, and structural nuclear landmarks are faithfully transmitted from one cell generation to the next. However, how nuclear components find their place in the nucleus after mitosis is still a matter of debate. As the major structural proteins within nuclei, the nuclear lamins are good candidates to re-establish nuclear compartments following mitosis. Human cells with reduced expression of the major B-type lamin protein, lamin B1, were generated using RNA interference. Mitotic and nuclear assembly phenotypes were then visualized in both fixed and living cells. Mitotic defects in lamin B1-depleted cells correlated with a general deterioration in nuclear compartmentalization and chromatin structure, frequent...
The material presented describes the research activities of the Henryk Niewodniczanski Institute of Nuclear Physics in 1993. The main directions of scientific investigation were: nuclear reaction, nuclear spectroscopy, physics of condensed matter applying nuclear methods, theoretical physics, high energy physics, environmental and radiation transport physics, radiation and environmental biology, nuclear radio spectroscopy,nuclear physical chemistry, health physic. Technical enterprises, such as the construction of particle accelerators, detectors and electronics for low, intermediate and high energy physics, ion implantation and development of computer networks for scientific purposes. The report consist of 11 sections, each of them describes the activity of one among INP laboratories. Additionally an information as lists of personnel, publications, contributions to conferences, reports, seminars is presented. An introduction written by General Director of INP professor A. Budzanowski is also given.
This paper discusses how corporate nuclear safety committees use the principles of self-assessment to enhance nuclear power plant safety performance. Corporate nuclear safety committees function to advise the senior nuclear power executive on matters affecting nuclear safety. These committees are required by the administrative controls section of the plant technical specifications which are part of the final safety analysis report and the operating license. Committee membership includes senior utility executives, executives from sister utilities, utility senior technical experts, and outside consultants. Current corporate nuclear safety committees often have a finely tuned intuitive feel for self-assessment that they use to probe the underlying opportunities for quality and safety enhancements. The questions prompted by the self-assessment orientation enable the utility line organization members to gain better perspectives on the characteristics of the organizational systems that they manage and work in.
Aims: We present a study of the envelope morphology of the carbon Mira R For with VLTI/MIDI. This object is one of the few asymptotic giant branch (AGB) stars that underwent a dust-obscuration event. The cause of such events is still a matter of discussion. Several symmetric and asymmetric scenarios have been suggested in the literature. Methods: Mid-infrared interferometric observations were obtained separated by two years. The observations probe different depths of the atmosphere and cover different pulsation phases. The visibilities and the differential phases were interpreted using GEM-FIND, a tool for fitting spectrally dispersed interferometric observations with the help of wavelength-dependent geometric models. Results: We report the detection of an asymmetric structure revealed through the MIDI differential phase. This asymmetry is observed at the same baseline and position angle two years later. The observations are best simulated with a model that includes a uniform-disc plus a Gaussian envelope plus a point-source. The geometric model can reproduce both the visibilities and the differential phase signatures. Conclusions: Our MIDI data favour explanations of the R For obscuration event that are based on an asymmetric geometry. We clearly detect a photocentre shift between the star and the strongly resolved dust component. This might be caused by a dust clump or a substellar companion. However, the available observations do not allow us to distinguish between the two options. The finding has strong implications for future studies of the geometry of the envelope of AGB stars: if this is a binary, are all AGB stars that show an obscuration event binaries as well? Or are we looking at asymmetric mass-loss processes (i.e. dusty clumps) in the inner part of a carbon-rich Mira? Based on observations made with ESO telescopes at La Silla Paranal Observatory under program IDs 080.D-0231 and 084.D0361.Tables 1-3 and Figs. 1, 3 are only available in electronic form at http://www.aanda.org
BackgroundTo describe visual field (VF) outcome in three adolescents with damage to the optic radiation and to focus on mechanisms that may compensate the practical functional limitations of VF defects.DesignDescriptive, prospective multi-case study in a hospital setting.ParticipantsThree teenagers with cerebral visual dysfunction because of damage to the retro-geniculate visual pathways.MethodsBest-corrected visual acuity and eye alignment were assessed. Visual field function was tested with Goldmann perimetry, and with Rarebit, Humphrey Visual Field Analyzer and Esterman computerized techniques. Fixation was registered with video oculography during Rarebit examination. Magnetic resonance imaging of the brain illustrated brain damage and its relation to the posterior visual system.ResultsOne of the three subjects had bilateral asymmetric white matter damage of immaturity, early-onset exotropia, and a relative homonymous VF defect, but normal binocular VF. The second subject also had bilateral asymmetric white matter damage of immaturity and showed an inferior right quadrantanopia, confirmed by the binocular field. Registration of fixation revealed automatic scanning during perimetry. The third subject had an almost total left homonymous hemianopia after resection of a brain tumour in the right temporal lobe. The hemianopia could be compensated for by fast voluntary scanning.ConclusionCongenital and later-acquired homonymous VF defects may, at least in young subjects, be compensated for by scanning. Exotropia may compensate VF defects and, therefore, the VF should be tested before strabismus surgery. PMID:22995940
It is proposed that the dissipative process necessary for rapid accretion disk evolution is driven by hydraulic jump waves on the surface of the disk. These waves are excited by the asymmetric nature of the central rotator (e.g., neutron star magnetosphere) and spiral out into the disk to form a pattern corotating with the central object. Disk matter in turn is slowed slightly at each encounter with the jump and spirals inward. In this process, the disk is heated by true turbulence produced in the jumps. Additional effects, such as a systematic misalignment of the magnetic moment of the neutron star until it is nearly orthogonal, and systematic distortion of the magnetosphere in such a way as to form an even more asymmetric central 'paddle wheel', may enhance the interaction with inflowing matter. The application to X-ray sources corresponds to the 'slow' solutions of Ghosh and Lamb, and therefore to rms magnetic fields of about 4 x 10 to the 10th gauss. Analogous phenomena have been proposed to act in the formation of galactic spiral structure.
We propose that the dissipative process necessary for rapid accretion disk evolution is driven by hydraulic jump waves on the surface of the disk. These waves are excited by the asymmetric nature of the central rotator (e.g., neutron star magnetosphere) and spiral out into the disk to form a pattern corotating with the central object. Disk matter in turn is slowed slightly at each encounter with the jump and spirals inward. In this process, the disk is heated by true turbulence produced in the jumps. Additional effects, such as a systematic misalignment of the magnetic moment of the neutron star until it is nearly orthogonal, and systematic distortion of the magnetosphere in such a way as to form an even more asymmetric central ''paddle wheel'' may enhance the interaction with inflowing matter. The application to X-ray sources corresponds to the ''slow'' solutions of Ghosh and Lamb, and therefore to rms magnetic fields of about 4 x 10/sup 10/ gauss. Analogous phenomena have been proposed to act in the formation of galactic spiral structure.
Dynamic susceptibility contrast MRI has been performed using the gradient echo sequence on conventional MR imagers. On echo planar imaging (EPI) devices, not only gradient-echo EPI but also spin-echo EPI allow for the monitoring of contrast agent-induced changes in susceptibility. The purpose of this study was to evaluate the contribution of each EPI pulse sequence to susceptibility-induced {Delta}R2({sup *}) through the first pass of a bolus of Gd-DTPA. Thirty healthy volunteers were examined with a 1.0 T superconducting MRI unit (IMPACT, Siemens) using EPI. For dynamic susceptibility contrast MRI, we used gradient echo EPI (TE=60), spin echo EPI (TE=60) and asymmetric spin echo EPI (TE=88). Regional relative CBV (rrCBV) maps were generated. On the rrCBV map generated with gradient echo EPI, the high-intensity area of the brain surface was more conspicuous than that generated with spin echo EPI. The rrCBV map generated with asymmetric spin echo EPI represented the contrast between those generated with spin echo EPI and gradient echo EPI. The rrCBV rate between gray matter and white matter with gradient echo EPI was significantly higher than that with spin echo EPI. We suggest that the rrCBV map calculated with spin echo EPI tends to reflect capillary blood volume and the rrCBV map calculated with gradient echo EPI tends to reflect total blood volume. (author)
This report presents the activity of Experimental Research Division of the Orsay Institute of Nuclear Physics on 1996 - 1997. The following 10 sections are represented through summary reports or short communications: 1. Nuclear structure far from stability (with the topics: 1.1. Exotic nuclei -Secondary beams of radioactive ions; 1.2. On-line spectroscopy; 1.3. Discrete high-spin states); 2. High excitation energy nuclear states; 3. Nuclearmatter and nucleus-nucleus collisions (which includes 3.1. Evolution of reaction mechanisms from 10 to 150 MeV/u; 3.2. Hot nuclei; 3.3. Ultra-relativistic collisions); 4. Hadronic physics (with the topics: 4.1 Meson production; 4.2. Spin modes in nuclei; 4.3. Hadronic physics with electromagnetic probes); 5. Radiochemistry (with the sub-divisions: 5.1. Studies related to radioactive waste management; 5.2. Optical spectroscopy of actinide and lanthanide ions in solid media); 6. Inter-disciplinary research (with the topics: 6.1. Heavy ion and cluster interactions with matter and surfaces; 6.2. Medical imaging); 8. Teaching; 9. Publications - Conferences - Seminars; 10 Internal reports - Lectures - Theses - Patents. The scientific staff of the following groups is also presented: 1. Group of Nuclear Structure by Reactions; 2. Group of Heavy Ion Nuclear Physics; 3. Intermediary Energy Group; 4. Hadron Physics Group; 5. Nuclei-Ions-Matter Group; 6. Radiochemistry Group; 7. Group of Exotic Deformed Nuclei; 8. Group of Physics-Biology Interface
Research activity of the Department of the Theoretical Physics spans a wide variety of problems in theoretical high-energy and elementary particle physics, theoretical nuclear physics, theory of the nuclearmatter, quark gluon plasma and relativistic heavy-ion collisions, theoretical astrophysics, as well as general physics. Theoretical research in high energy and elementary particle physics is concentrated on the theory of deep inelastic lepton scattering in the region of low x and its phenomenological implication for the ep collider HERA at DESY, on the theory of nonleptonic decays of hadrons, and on low energy {pi}{pi} and K-anti-K interactions and scalar meson spectroscopy. The activity in the theory of relativistic heavy-ion collisions is focused on the study of quark condensate fluctuations, on the analysis of critical scattering near the chiral phase transition, and on Bose-Einstein correlation in heavy-ion collisions. Theoretical studies in nuclear physics and in theory of nuclearmatter concern analysis of models, with dynamical symmetry based on group S{sub p}(6,R) for the description of collective modes of atomic nuclei, analysis of the Goldstone bosons in nuclearmatter and analysis of saturation properties of nuclearmatter. Research in theoretical astrophysics is mainly devoted to the analysis of magnetic properties of hadronic matter in neutron stars with proton admixture. Studies in general physics concern problem related to the Galilean covariance of classical and quantum mechanics. The detailed results obtained in various fields are summarised in presented abstracts as well as information about employed personnel, publications, contribution to conferences, reports, workshops and seminars.
Asymmetrical introgression is an expected genetic consequence of hybridization when parental taxa differ in abundance; however, evidence for such effects in small populations is scarce. To test this prediction, we estimated the magnitude and direction of hybridization between red mulberry (Morus rubra L.), an endangered species in Canada, and the introduced and more abundant white mulberry (Morus alba L.) using nuclear (randomly amplified polymorphic DNA) and cytoplasmic (chloroplast DNA sequence) markers. Parentage of 184 trees (n = 42 using cpDNA) from four sympatric populations was estimated using a hybrid index and related to six morphological characters and population frequencies of the parental classes. Overall, the frequency of nuclear hybrids was 53.7% (n = 99) and ranged from 43% to 67% among populations. The parental and hybrid taxa differed with respect to all of the morphological traits. Sixty-seven percent of all hybrids contained more nuclear markers from M. alba than M. rubra (hybrid index x = 0.46); among populations, the degree of M. alba bias was correlated with the frequency of M. alba. In addition, the majority of hybrids (68%) contained the chloroplast genome of white mulberry. These results suggest that introgression is bidirectional but asymmetrical and is related, in part, to the relative frequency of parental taxa. PMID:16156816
Reviewed is a book whose chapters are: ''Introduction'', ''Atomic Nuclei'', ''Radioactive Decay Processes'', ''Nuclear Reactions'', ''Equations of Radioactive Decay and Growth'', ''Interaction of Radiations with Matter'', ''Radiation Detection and Measurement'', ''Techniques in Nuclear Chemistry'', Statistical Considerations in Radioactivity Measurements'', ''Nuclear Models'', ''Radiochemical Applications'', ''Nuclear Processes as Chemical Probes'', ''Nuclear Processes in Geology and Astrophysics'', ''Nuclear Energy'', and ''Sources of Nuclear Bombarding Particles.'' Shortcomings are too much emphasis on theory and nuclear chemistry; the only nuclear activation analysis discussed involves thermal neutrons; neutron radiography is not discussed; autoradiography and isotope dilution analysis methods are only treated briefly; and there is no specific mention of cadmium ratios or resonance integrals. It is recommended as an outstanding textbook for advanced courses in this field, also as an essential, frequently consulted reference work for those engaged in nuclear chemistry, radiochemistry, and the applications of nuclear methods in many fields.
The present compilation gives an overview of experimental results obtained with the GANIL facility during the period 1996-1997. It includes nuclear physics activities as well as interdisciplinary research. The scientific domain presented here extends well beyond the traditional nuclear physics and includes atomic physics, condensed matter physics, nuclear astrophysics, radiation chemistry, radiobiology as well as applied physics. In the nuclear physics field, many new results have been obtained concerning nuclear structure as well as the dynamics of nuclear collisions and nuclear disassembly of complex systems. Results presented deal in particular with the problem of energy equilibration, timescales and the origin of multifragmentation. Nuclear structure studies using both stable and radioactive beams deal with halo systems, study of shell closures far from stability, the existence of nuclear molecules as well as measurements of fundamental data s half lives, nuclear masses, nuclear radii, quadrupole and magnetic moments. In addition to traditional fields of atomic and solid state physics, new themes such as radiation chemistry and radiobiology are progressively being tackled. (K.A.)
Light WIMP dark matter and hidden sector dark matter have been proposed to explain the DAMA, CoGeNT and CRESST-II data. Both of these approaches feature spin independent elastic scattering of dark matter particles on nuclei. Light WIMP dark matter invokes a single particle species which interacts with ordinary matter via contact interactions. By contrast hidden sector dark matter is typically multi-component and is assumed to interact via the exchange of a massless mediator. Such hidden sector dark matter thereby predicts a sharply rising nuclear recoil spectrum, $dR/dE_R \\sim 1/E_R^2$ due to this dynamics, while WIMP dark matter predicts a spectrum which depends sensitively on the WIMP mass, $m_\\chi$. We compare and contrast these two very different possible origins of the CoGeNT low energy excess. In the relevant energy range, the recoil spectra predicted by these two theories approximately agree provided $m_\\chi \\simeq 8.5$ GeV - close to the value favoured from fits to the CoGeNT and CDMS low energy data....
We discuss the physics of matter that is relevant to the structure of compact stars. This includes nuclear, neutron star matter and quark matter and phase transitions between them. Many aspects of neutron star structure and its dependance on a number of physical assumptions about nuclearmatter properties and hyperon couplings are investigated. We also discuss the prospects for obtaining constraints on the equation of state from astrophysical sources. Neuron star masses although few are known at present, provide a very direct constraint in as much as the connection to the equation of state involves only the assumption that Einstein's general of theory of relativity is correct at the macroscopic scale. Supernovae simulations involve such a plethora of physical processes including those involved in the evolution of the precollapse configuration, not all of them known or understood, that they provide no constraint at the present time. Indeed the prompt explosion, from which a constraint had been thought to follow, is now believed not to be mechanism by which most, if any stars, explode. In any case the nuclear equation of state is but one of a multitude on uncertain factors, and possibly one of the least important. The rapid rotation of pulsars is also discussed. It is shown that for periods below a certain limit it becomes increasingly difficult to reconcile them with neutron stars. Strange stars are possible if strange matter is the absolute ground state. We discuss such stars and their compatibility with observation. 112 refs., 37 figs., 6 tabs.
Positive results of dark matter searches in experiments DAMA/NaI and DAMA/LIBRA confronted with results of other groups can imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2, bound with primordial helium in O-helium "atoms" (OHe), represent a specific nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground Dark matter detection using its nuclear recoil. However, low energy binding of OHe with sodium nuclei can lead to annual variations of energy release from OHe radiative capture in the interval of energy 2-4 keV in DAMA/NaI and DAMA/LIBRA experiments. At nuclear parameters, reproducing DAMA results, the energy release predicted for detectors with chemical content other than NaI differ in the most cases from the one in DAMA detector. Moreover there is no bound systems of OHe with light and heavy nuclei, so that there is no radiative capture of OHe in detectors with xenon or helium c...
Positive results of dark matter searches in DAMA/NaI and DAMA/LIBRA experiments, being put together with negative results of other groups, can imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2 bind with primordial helium in O-helium "atoms" (OHe), representing a specific Warmer than Cold nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground Dark matter detection like those used in CDMS experiment, but its reactions with nuclei can lead to annual variations of energy release in the interval of energy 2-6 keV in DAMA/NaI and DAMA/LIBRA experiments. Schrodinger equation for system of nucleus and OHe is solved for spherically symmetrical potential well, formed by the Yukawa tail of nuclear scalar isoscalar attraction potential, acting on He beyond the nucleus, and dipole Coulomb repulsion between the nucleus and OHe at distances from the nuclear surface, smaller than the size of OHe. ...
Positive results of dark matter searches in experiments DAMA/NaI and DAMA/LIBRA taken together with negative results of other groups can imply nontrivial particle physics solutions for cosmological dark matter. Stable particles with charge -2 bind with primordial helium in O-helium "atoms" (OHe), representing a specific Warmer than Cold nuclear-interacting form of dark matter. Slowed down in the terrestrial matter, OHe is elusive for direct methods of underground Dark matter detection like those used in CDMS experiment, but its low energy binding with nuclei can lead to annual variations of energy release in the interval of energy 2-6 keV in DAMA/NaI and DAMA/LIBRA experiments. Schrodinger equation for system of nucleus and OHe is solved for a spherically symmetrical potential, formed by the Yukawa tail of nuclear scalar isoscalar attraction potential, acting on He beyond the nucleus, and dipole Coulomb repulsion between the nucleus and OHe at distances from the nuclear surface, smaller than the size of OHe. ...
We report the results of semiclassical calculations of the asymmetric molecular-frame photoelectron angular distributions for C 1s ionization of CO{sub 2} measured with respect to the CO{sup +} and O{sup +} ions produced by subsequent Auger decay, and show how the decay event can be used to probe ultrafast molecular dynamics of the transient cation. The fixed-nuclei photoionization amplitudes were constructed using variationally obtained electron-molecular ion scattering wave functions. The amplitudes are then used in a semiclassical manner to investigate their dependence on the nuclear dynamics of the cation. The method introduced here can be used to study other core-level ionization events.
This paper presents reaction cross section predictions. These predictions are the result of a continuous pipeline which originates from a microscopic nuclear interaction. Density parameters and effective nucleon-nucleon cross sections (both involved in the reaction calculations) are by-products of the same equation of state. First, we perform tests of sensitivity to medium effects using reactions involving 208-Pb, a stable but weakly isospin-asymmetric nucleus. We also show predictions for collisions of some neutron-rich isotopes of Calcium and Argon. We observe significant sensitivity of the reaction cross section to medium effects but very weak sensitivity to inclusion of isospin asymmetry in the effective nucleon-nucleon cross sections.
It is now almost 15 years since the first detection of rotationally modulated emission from X-ray bursting neutron stars, "burst oscillations," This phenomenon enables us to see neutron stars spin, as the X-ray burst flux asymmetrically lights up the surface. It has enabled a new way to probe the neutron star spin frequency distribution, as well as to elucidate the multidimensional nature of nuclear burning on neutron stars. I will review our current observational understanding of the phenomenon, with an eye toward highlighting some of the interesting remaining puzzles, of which there is no shortage.
The symmetric and asymmetric fission path for 240Pu, 232Th, and 226Ra is investigated within the relativistic mean field model. Standard parametrizations which are well fitted to nuclear ground state properties are found to deliver reasonable qualitative and quantitative features of fission, comparable to similar nonrelativstic calculations. Furthermore, stable octupole deformations in the ground states of Radium isotopes are investigated. They are found in a series of isotopes, qualitatively in agreement with nonrelativistic models. But the quantitative details differ amongst the models and between the various relativsitic parametrizations.
Asymmetric intergeneric hybrid plants were obtained through protoplast fusion between Orychophragmus violaceus (L.) O.E. Schulz and Lesquerella fendleri (Gray) Wats. The latter carried chloroplasts transformed with the fused aadA16gfp gene construct, conferring streptomycin?spectinomycin resistance and UV-induced green fluorescence. The somatic hybrids were selected using the properties of spectinomycin-induced plastid defects in ?albino? O. violaceus plants (chloroplast recipient) combined with the ?-irradiation-induced inactivation of nuclei in plastid donor L. fendleri. The morphology and esterase isozyme pattern of the hybrid plant as well as the results of the PCR analysis of internal transcribed spacer of nuclear ribosomal DNA proved that the regenerated hybrids carried O. violaceus ...
An efficient full-configuration-interaction nuclear orbital treatment has been recently developed as a benchmark quantum-chemistry-like method to calculate ground and excited ``solvent'' energies and wave functions in small doped ?Eest clusters (Nbelt'' around the dopant, executing a sort of asymmetric umbrella motion. This pairing is a compromise between maximizing the 3He-3He and the He-dopant attractions, and suppressing at the same time the ``hard-core'' repulsion. Although the He-He attractive interaction is rather weak, its contribution to the total energy is found to scale as a power of three and it thus increasingly affects the pair density distributions as the cluster grows in size.
Many of the most exotic neutron-proton asymmetric nuclei are produced in relatively small numbers in high-energy fragmentation reactions. They are produced as fast secondary beams with energies of 100 MeV per nucleon or more. Developments made and recent results that both exploit and assess fast one- and two-nucleon removal reactions from such secondary beams are reviewed. This includes very recent work that interfaces the sudden, eikonal reaction models used with more ab-initio nuclear structure inputs. The potential use of neutron pick-up reactions to study particle-like states in exotic nuclei is also outlined.
Can atomic nuclei be unstable with respect to deformations that break intrinsic parity On the theoretical side calculations indicate the existence of stable octupole deformations. There is also vast supporting experimental evidence for the presence of very collective low-energy dipole and octupole modes. In this contribution, recent advances in the physics of nuclear reflection-asymmetric shapes are discussed in terms of underlying shell effects. Particular attention is given to the recently predicted octupole excitations at superdeformed shapes. 74 refs., 7 figs., 1 tab.
The nuclear transport factor 2-like (NTF2-like) domain of human G3BP1 was subcloned, overexpressed in Escherichia coli and purified. Crystals were obtained using the hanging-drop vapour-diffusion method. Diffraction data were collected to 3.6 Å resolution using synchrotron radiation. The crystals belonged to the hexagonal space group P6(3)22, with unit-cell parameters a=b=89.84, c=70.02 Å. The crystals contained one molecule per asymmetric unit, with an estimated solvent content of 56%. Initial phases were obtained by molecular replacement.
Violent collision of two independent many-particle systems, victims, are discussed in the atomic sphere. The asymmetric region where the charge of the projectile Z/sub p/ is less than the target nuclear charge Z/sub n/ is now well understood though interesting details still need to be worked out. Negatively charged projectiles offer a new illustration of Fadeev re-arrangement collisions. Multi-electron coherence effects illustrate the richness of the field but a symmetric (Z/sub p/ approx. Z/sub n/) collision treatment is needed. A new one and a half center expansion method promises a solution to this problem. Future areas of interest are discussed.
In this paper the current theoretical models for the description of electron transfer in adiabatic, intermediate and high-energy collisions are reviewed. Particular emphasis is laid on the recent development of atomic theories studied for fast or asymmetric ion-atom encounters. The comparison with other theories and with experimental data on total as well as differential capture cross sections is used to determine the applicability of a specific model. The selected examples concern capture to bound states, to continuum states, radiative transfer as well as capture in the presence of an isolated nuclear resonance.
The class Pedinophyceae was established for asymmetric uniflagellate green algae, and was originally considered as an ancestral lineage of viridiplants. However, analyses of 71 concatenated plastid proteins [Turmel et al. (2009): Mol. Biol. Evol. 26: 2317-2331] recovered Pedinomonas within the Chlorellales (Trebouxiophyceae), thereby questioning the Pedinophyceae as an independent class. For the present study, complete nuclear and plastid-encoded rRNA operon sequences have been determined for 37 taxa of green algae including 6 members of the Pedinophyceae, providing 9272 aligned nucleotide positions. Phylogenies using both rRNA operons consistently rejected any relationship between Pedinophyceae and the Chlorellales. Instead, the Pedinophyceae were significantly resolved as sister of all p...
We study the nuclear symmetry energy S(?) and related quantities of nuclear physics and nuclear astrophysics predicted generically by relativistic mean-field (RMF) and Skyrme-Hartree-Fock (SHF) models. We establish a simple prescription for preparing equivalent RMF and SHF parametrizations starting from a minimal set of empirical constraints on symmetric nuclearmatter, nuclear binding energy, and charge radii, enforcing equivalence of their Lorenz effective masses, and then using the pure neutron matter (PNM) equation of state obtained from ab initio calculations to optimize the pure isovector parameters in the RMF and SHF models. We find that the resulting RMF and SHF parametrizations give broadly consistent predictions of the symmetry energy J and its slope parameter L at saturation density within a tight range of ?2 and ?6 MeV, respectively, but that clear model dependence shows up in the predictions of higher-order symmetry energy parameters, leading to important differences in (a) the slope of the correlation between J and L from the confidence ellipse, (b) the isospin-dependent part of the incompressibility of nuclearmatter K?, (c) the symmetry energy at suprasaturation densities, and (d) the predicted neutron star radii. The model dependence can lead to about 1-2 km difference in predictions of the neutron star radius given identical predicted values of J and L and symmetric nuclearmatter (SNM) saturation properties. Allowing the full freedom in the effective masses in both models leads to constraints of 30?J?31.5 MeV, 35?L?60 MeV, and -330?K??-216 MeV for the RMF model as a whole and 30?J?33 MeV, 28?L?65 MeV, and -420?K??-325 MeV for the SHF model as a whole. Notably, given PNM constraints, these results place RMF and SHF models as a whole at odds with some constraints on K? inferred from giant monopole resonance and neutron skin experimental results.
A microscopic folding approach based upon the effective M3Y nucleon-nucleon interaction and the nuclearmatter densities of the interacting nuclei has been carried out to explain recently measured experimental data of the {sup 6}He+{sup 120}Sn elastic scattering reaction at four different laboratory energies near the Coulomb barrier. The corresponding reaction cross sections are also considered.
The gamma nuclear resonance or Moessbauer spectrometry uses the possibility to observe in solids, the resonant absorption without return of gamma photons. Since its discovery in 1958, its development was very rapid. It can be applied in physics and chemistry of condensed matter; we can quote solid physics, magnetism, physical metallurgy, catalysis, mineralogy, biology, archaeology and art.
The Meetings of Gamma and X 93 Spectrometry were held on 12-14 October 1993. The symposium was organized into six sessions: Instrumentation development, Nuclearmatter measurement, Method and calibration, Medical applications, Environment survey (radioactive traces measurement), other applications (spent fuels analysis, various techniques). Separate abstracts were prepared for all the papers in this volume. (TEC).
This interdisciplinary laboratory in the College of Engineering support research in areas of condensed matter physics, solid state chemistry, and materials science. These research programs are developed with the assistance of faculty, students, and research associates in the departments of Physics, Materials Science and Engineering, chemistry, Chemical Engineering, Electrical Engineering, Mechanical Engineering, and Nuclear Engineering.
We discuss how the chemical composition of QCD jets is altered by final state interactions in surrounding nuclearmatter. We describe this process through conversions of leading jet particles. We find that conversions lead to an enhancement of kaons at high transverse momentum in Au+Au collisions at RHIC, while their azimuthal asymmetry v_2 is suppressed.
It's something else that the seven mysterious and enigmatic disciples who populate the best seller written by Dan Brown, Angels and Devils! The real secrets of the European Center for Nuclear Research are named Atlas, Alice, the Large Hadron Collider Grid, the Web of the future... Hypertechnological devices that will reveal soon the mysteries of the matter and of the Universe (2 pages)
The goal of heavy ion physics is to study nuclearmatter under conditions of extreme temperature and density. Anisotropic flow, which measures the particle azimuthal correlations with respect to the reaction plane, provides the information on the early stages of the created system and are sensitive ...
The transfer of nucleons in hot-fusion reactions occurs within 0.17 yoctosecond, in a new state of nuclearmatter. We suggest that the same state should show itself in an early stage of the phenomena occurring in nucleus-nucleus collisions realized at relativistic energies.
Generalized beta equilibrium involving nucleons, hyperons, and isobars is examined for neutron star matter. The hyperons produce a considerable softening of the equation of state. It is shown that the observed masses of neutron stars can be used to settle a recent controversy concerning the nuclear compressibility. Compressibilities less than 200 MeV are incompatible with observed masses. 7 refs., 9 figs.
"The world's most ambitious particle collider - which scientists hope could reveal what matter is made of - might not be fully functional until next year, months after its scheduled startup date, officiels at the European Organization for Nuclear Reserach said Thursday." (1 page)
We treat the three-particle problem in nuclearmatter for the special class of two-body potentials for which the two-body interaction energy vanishes. We compare the results obtained using the variational method, the Bethe-Faddeev method, and a slightly modified version of the latter in which certain fourth-order diagrams, which can lead to divergences, are eliminated.
I give an overview of the processes determining the shape of energy spectra of hadrons emitted in relativistic nuclear collisions, and discuss how one can extract from them information on the presence of collective transverse flow and on the transition to quark-gluon matter in such collisions. 6 refs., 3 figs.
High pT hadrons produced in ultra-relativistic heavy-ion collisions at RHIC probe nuclearmatter at extreme conditions of high energy density. Experimental measurements in Au+Au collisions at sqrt sNN=130, 200 GeV establish the existence of strong medium effects on hadron production well into the perturbative regime.
The response function to an external prove is evaluated using the ring approximation in nuclearmatter. Contrary to what it is usually assumed, it is shown that the summation of the ring series and the solution of the Dyson's equation are two different approaches. The numerical results exhibit a perceptible difference between both approximations.
We study the non-central heavy-ion collisions at a SPS energy within a relativistic hydrodynamic model. We analyze the second Fourier coefficient v{sub 2} of the pion azimuthal distribution and show the effects of the resonance decays on the azimuthal anisotropy. We also discuss the possibility of creating the unusual distribution of hot and dense nuclearmatter at the SPS energy. (author)
The EDELWEISS Collaboration has performed a direct search for WIMP dark matter using a 320 g heat-and-ionization cryogenic Ge detector operated in a low-background environment in the Laboratoire Souterrain de Modane. No nuclear recoils are observed in the fiducial volume in the 30–200 keV energy ran...
In this paper are found technical and scientific papers on the main works of the Department of Astrophysics, Particles physic, Nuclear physic and Associated Instrumentation (DAPNIA) of the CEA. The presented fields are: the research programs; positron and electron collisions; proton-proton and proton-antiproton collisions; electron-proton collisions; CP invariance; neutrino and black matter. (A.L.B.)
In the framework of the new EPR European Pressurized Reactor implementation in France, the public asked the first Ministry on the protection of nuclearmatters, transports and installations against the terrorism and the spiteful actions. This document provides information on the subject and shows the safety of the new reactor. (A.L.B.)
The smallest atomic positive ion is the one of hydrogen, known as proton. ... the neutrons have a small majority, a fact important in releasing energy by nuclear fission. ... to study the structure of matter and produce a variety of "new" particles. Another "cleaner" mode of studying them is to cause a head-on collision between a ...
First, current attempts to deduce the nuclearmatter equation of state from inclusive data are discussed. Next, some puzzling projectile fragment properties found in emulsions are discussed. Finally, a new test of pion condensation is proposed, and current pion data are reviewed. 11 figures.
Nuclearmatter calculations based on low-momentum interactions derived from chiral nucleon-nucleon and three-nucleon effective field theory interactions and fit only to few-body data predict realistic saturation properties with controlled uncertainties. This is promising for a unified description of nuclei and to develop a universal density functional based on low-momentum interactions.
The strength distributions of the isoscalar giant monopole resonance have been calculated in $^{16}$O, $^{40}$Ca, $^{90}$Zr, $^{112-124}$Sn, $^{144}$Sm, and $^{208}$Pb nuclei within the self-consistent random phase approximation and its extensions which include pairing correlations and quasiparticle-phonon coupling. The results are compared with the available experimental data. The problem of the nuclearmatter incompressibility is discussed.
Heavy quarkonium is a sensitive probe of QCD matter - this is why strong 'anomalous' J/psi suppression observed recently by the NA50 Collaboration at CERN has attracted considerable attention. Is it an unambiguous signal of the quark-gluon plasma, or just a peculiar combination of mundane nuclear effects? This talk is a mini-review of the existing theoretical explanations.
Thermo Field Dynamics for inhomogeneous systems is generalized to quantum fields with a continuous single-particle mass spectrum. The modification of the hamiltonian in states with a local thermal Bogoliubov symmetry is used to calculate thermal conductivity and diffusion coefficient of pions interacting with hot, compressed nuclearmatter.
A brief review of the topical problems related to dynamics of vector meson is given. In particular, in-medium modification of the vector meson properties in hot and nuclearmatter, photoproduction of the phi-mesons as a probe for hidden strangeness in a nucleon phi-, omega-production and OZI-rule violation, omega-production as a tool for studying the baryon resonance properties are discussed
Nucleus-hydrogen scattering can be predicted using optical potentials formed by full folding effective two-nucleon interactions with detailed nuclear structure. Results when compared with measured cross sections (integral and angular) for energies in the range 25A to 250A MeV are excellent and such data analyses reveal attributes of the separate nucleon matter distributions of the nucleus involved.
While nucleons exist in highly excited nuclearmatter ready for emission, they have to be formed as three-quark colour singlets which may be emitted from a quark-gluon plasma (QGP). This is the basis for a new QGP test which is applied on some p-nucleus reactions at 5 and 5.5 GeV.
To find the secret of matter, the European Center for Nuclear Research (Cern) is building, on the Swiss border, LHC, a particle accelerator able to re-create the origines of the Universe. Price: 2,3 billions of Euros. And 800 millions for the experiments... (1 page)
A model interaction is used which is determined by a given nuclearmatter saturation curve. This interaction is used in a Hartree-Fock calculation of 40Ca to study the density, the single particle energies and the shell-model potential for various compressibility coefficients derived from the nuclea...
A simple theory of the interaction potential between heavy ions V, based on the local density approach and the frozen density model, is presented for nuclei with neutron excess. The energy density needed for calculating V is expressed in a simple way through the known properties of nuclearmatter.
We calculate for finite nuclei the imaginary part of the nucleus-nucleon optical potential on and off shell by using the local Fermi gas approximation and a finite range two-body exchange force. Results are compared with those obtained by infinite nuclearmatter calculations as well as using the loc...
The lowest order constrained variational method is applied to calculate the polarized symmetrical nuclearmatter properties with the modern $AV_{18}$ potential performing microscopic calculations. Results based on the consideration of magnetic properties show no sign of phase transition to a ferromagnetic phase.
A new variational method is proposed with its application to infinite zero-temperature nuclearmatter. In this variational method, approximate energy expressions expressed explicitly with variational functions are constructed, and the Euler-Lagrange equations are derived analytically from them. This variational method has also been applied to liquid {sup 3}He giving fairly good results. In the case of nuclearmatter, however, calculated energies are much lower than the experimental value, mainly caused by undesirable long tails of noncentral distribution functions. Thus, an effective theory is proposed by adding a density-dependent correction term to the energy expressions to suppress their long tails. This effective theory includes one adjustable parameter whose value is determined so as to reproduce the experimental saturation point of symmetric nuclearmatter. The EOS's of nuclearmatter calculated by the effective theory with the Hamada-Johnston potential and Paris potential are rather soft, but the study of neutron stars with use of these EOS's gives reasonable results. (author)
The energy weighted sum rule of single-particle spectral functions in nuclearmatter is studied. The spectral functions include the influence of short-range correlations as generated by the Reid potential in the framework of the self-consistent Greens function method. For the range of momenta studie...
The antikaon optical potential in hot and dense nuclearmatter is studied within the framework of a coupled-channel self-consistent calculation taking, as bare meson-baryon interaction, the meson-exchange potential of the Jlich group. Typical conditions found in heavy-ion collisions at GSI are explo...
The Cornwall-Jackiw-Tomboulis (CJT) effective action approach is applied to study the phase transition of nuclearmatter modeled by the four-nucleon interaction. It is shown that in the Hartree-Fock approximation (HFA) a first-order phase transition takes place at low temperature, whereas the phase transition is of second order at higher temperature.
Binding energies and widths of pions bound in the 1s state of heavy and superheavy atoms are evaluated. The repulsive strong interaction lowers the Coulomb binding energy by up to 50%. The energy width of the strongest bound state investigated becomes comparable with the binding energy. No drastic consequence for pion propagation in nuclearmatter is expected.
Accurate assessment of the value of the incompressibility coefficient, K-infinity of symmetric nuclearmatter, which is directly related to the curvature of the equation of state (EOS), is needed to extend our knowledge of the EOS in the vicinity of the saturation point. We review the current status...
We present a unified treatment of equilibrium and non-equilibrium phenoma in nuclearmatter based on the Dirac-Brueckner approach. The resulting quantum kinetic equation contains in a selfconsistent manner a mean field and a collision term. Differences with VUU are discussed.
The quark cluster model studies concerning the H dibaryon are reviewed. The covered topics are the H dibaryon itself, the interaction between a nucleon and an H dibaryon, and the one between two H dibaryons. A related study on the H dibaryon in nuclearmatter is also reviewed and its implication to double hypernuclei is discussed.
This document aims to specify the organization dispositions which have to bee taken by the interim job enterprises proposing personnel of A or B category to work in nuclear facilities. These dispositions should allow to respect the demands of the CEFRI in matter of formation, medical control and personnel dosimetry. (A.L.B.)
The measurement of event-by-event fluctuations and charge-dependent particle correlations are used to study properties of nuclearmatter at high temperatures as produced in ultrarelativistic heavy-ion collisions. We present results for event-by-event net-charge fluctuations and charge balance functions in \\Delta\\eta\\ and \\Delta\\phi\\ in Pb-Pb collisions at sqrt(s_NN)= 2.76$ TeV.
We study the effect of time-odd components of the Skyrme energy density functionals on the ground state of finite nuclei and in nuclearmatter. The spin-density dependent terms, which have been recently proposed as an extension of the standard Skyrme interaction, are shown to change the total bindin...
The recently developed variational Wigner-Kirkwood approach is extended to the relativistic mean field theory for finite nuclei. A numerical application to the calculation of the surface energy coefficient in semi-infinite nuclearmatter is presented. The new method is contrasted with the standard d...
In this contribution to the Quark Matter 2012 conference, we study whether energy loss models established for RHIC energies to describe the quenching of heavy quarks can be applied at LHC with the same success. We also benefit from the larger $p_T$-range accessible at this accelerator to test the impact of gluon damping on observables such as the nuclear modification factor.
We review the theoretical arguments indicating that hadronic matter dissolves into a quark gluon plasma at energy densities only one order of magnitude above the energy density in nuclei and point out that such energy densities can be achieved in nuclear collisions at 10 to 1000 AGeV. 17 references.
After an introduction to jet phenomenology and tests of AdS/CFT at LHC we derive the heavy quark drag of a string dangling in a shock metric of AdS space, thus generalizing the AdS/CFT drag calculations in strongly coupled thermal media to momentum loss in both hot and cold nuclearmatter.
In this article we present an alternative explanation of the phenomenon of wire fragmentation under high transient currents based on classical electromagnetism. We also explain how this phenomenon can be utilized as a primitive example of low energy-high power disruptive phenomena that can affect even nuclearmatter.
In this article we present an alternative explanation of the phenomenon of wire fragmentation under high transient currents based on classical electromagnetism. We also explain how this phenomenon can be utilized as a primitive example of low energy-high power disruptive phenomena that can affect even nuclearmatter.
Cross-section and analyzing-power angular distributions for elastic scattering of 400-MeV protons by Pb-208 have been measured between 3 and 51 deg. Results have been compared to second-order Kerman-McManus-Thaler (1959) calculations of the optical potential. There is evidence that free nucleon-nucleon scattering amplitudes do not adequately describe nucleon propagation in nuclearmatter at this energy.
Transverse energy has been used to estimate energy density in ultra-relativistic heavy ion collisions and to discriminate between competing models of hadronic interactions. Furthermore, fluctuations in transverse energy might signal the presence of a critical point in the phase diagram of nuclearmatter. The PHENIX Muon Piston Calorimeter (MPC) has acceptance in the range 3.1MPC at RHIC will be reported.
The dynamics of embryonic bubbles in overheated, viscous and non-Markovian nuclearmatter is studied. We show that the memory and the Fermi surface distortions significantly affect the hinderance of bubble collapse and determine a characteristic oscillations of the bubble radius. These oscillations occur due to the additional elastic force induced by the memory integral.
The transcription factors Tcf3 and Nanog regulate many genes in embryonic stem cells, but according to two reports in this issue of Cell Stem Cell (Festuccia et al., 2012, Martello et al., 2012), only one, Esrrb, encoding an orphan nuclear hormone receptor, truly matters in the maintenance of self-renewal.
Some of the basic concepts in Lie Algebra and superalgebra theory are reviewed, and then an elementary summary of each of the areas in which supersymmetry has already been applied is given. These areas include nuclear physics, condensed matter and statistical physics, and particle physics and supergravity. (WHK).
Background: Recent experiments on ?-delayed fission in the mercury-lead region and the discovery of asymmetric fission in 180Hg [A. N. Andreyev , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.105.252502 105, 252502 (2010)] have stimulated theoretical interest in the mechanism of fission in heavy nuclei.Purpose: We study fission modes and fusion valleys in 180Hg and 198Hg to reveal the role of shell effects in the prescission region and explain the experimentally observed fragment mass asymmetry and its variation with A.Methods: We use the self-consistent nuclear density functional theory employing Skyrme and Gogny energy density functionals.Results: The potential energy surfaces in multidimensional space of collective coordinates, including elongation, triaxiality, reflection-asymmetry, and necking, are calculated for 180Hg and 198Hg. The asymmetric fission valleys—well separated from fusion valleys associated with nearly spherical fragments—are found in both cases. The density distributions at scission configurations are studied and related to the experimentally observed mass splits.Conclusions: The energy density functionals SkM* and D1S give a very consistent description of the fission process in 180Hg and 198Hg. We predict a transition from asymmetric fission in 180Hg toward a more symmetric distribution of fission fragments in 198Hg. For 180Hg, both models yield 100Ru/80Kr as the most probable split. For 198Hg, the most likely split is 108Ru/90Kr in HFB-D1S and 110Ru/88Kr in HFB-SkM*.
I opened this book full of expectation. Frank Close is an interesting and exciting lecturer and I felt sure that Lucifer's Legacy would have a great hold on me. Of course, I did not know what the title meant but the subtitle The Meaning of Asymmetry seemed to hold promise of a topic close to my heart. It turns out that the main title refers to the fact that a statue of Lucifer in the Tuileries Gardens had lost its head, unlike its twin on the other side of the garden, and this accident had broken the garden's symmetry. Reading the inside cover told me that I would be taken on a sweeping tour of asymmetry in the world around me, from the development of human embryos to the mysterious Higgs boson. Certainly the start of the book describes what is meant by symmetry, the geometric type with which I am mainly familiar, and it talks about mirror images, asymmetric molecules and the non-symmetric nature of the brain. About a third of the way in, we get to x-rays, beta rays and alpha rays and our tour has turned into an exploration of the fundamental nature of matter and the four fundamental forces. It seems that at the Big Bang a perfectly symmetric universe was created but, as the universe cooled, so asymmetries emerged. By starting at the macroscopic level and working down, Frank Close takes us through the atom, the nucleus and the fundamental particles, including quarks and even higher energy particles. But somehow I got lost on the way. Maybe it was the large number of anecdotes inserted at random intervals or that the story here was an historical account of how atomic and nuclear physics progressed and how the particles were discovered. Maybe it was because I am too close to geometrical symmetry and failed to absorb the full flavour of the asymmetry of the universe. To me the book lacks a clear structure (strange when it is all about structure) and jumps disconcertingly around as ideas come into the author's head. So what audience is the book intended for? Not, I think, the non-scientist as it contains many very sophisticated ideas. Nor is it presumably intended for someone seeking out the physics of the development of the universe or the nature of matter; all the anecdotal stories and asides get in the way of this. Although Frank Close refers to the books of three other writers within the text, there is no bibliography, so presumably the intention is not to set the reader on a deeper search of the subject. Certain chapters with their historical discussion remind me of Longitude by Dava Sobel but without the same precise clarity. Perhaps this is a book with which one can curl up in front of the fire to enjoy the large number of unpredictable snippets of information as they emerge. The title Lucifer's Legacy might imply this; possibly I took the sub-title, The Meaning of Asymmetry, just that bit too seriously.
In a previous article, the 4D half-skyrmion (or 5D dyonic salt) structure of dense baryonic matter described in crystalline configuration in the large $N_c$ limit was shown to impact nontrivially on how anti-kaons behave in compressed nuclearmatter with a possible implication on an ``ice-9" phenomenon of deeply bound kaonic matter and condensed kaons in compact stars. We extend the analysis to make a further prediction on the scaling properties of hadrons that have a surprising effect on the nuclear tensor forces, the symmetry energy and hence on the phase structure at high density. We treat this problem relying on certain topological structure of chiral solitons. Combined with what can be deduced from hidden local symmetry for hadrons in dense medium and the ``soft" dilatonic degree of freedom associated with the trace anomaly of QCD, we uncover a novel structure of chiral symmetry in the ``supersoft" symmetry energy that can influence the structure of neutron stars.
A dramatic rise in the heat capacity eT4 of high-temperature nuclear/QGP matter has been a long-standing prediction in high-energy heavy-ion physics, but is difficult to verify directly. Initial-state energy densities, measured through calorimetery, and limits on initial-state temperature, inferred through measurement of high-PT direct photons, can be combined to provide a nearly model-independent lower limit on the beat capacity of initial-state matter in A+A collisions at the CERN-SPS. This is the most direct evidence to date for the rise in the heat capacity, and the implied new degrees of freedon, in high-temperature nuclearmatter.
The evolution of the nuclearmatter density distribution with excitation energy is studied within the framework of a finite-range interacting Fermi gas model and microcanonical thermodynamics in Thomas-Fermi approximation. It is found that with increasing excitation energy, both infinite and finite systems become unstable against infinitesimal matter density fluctuations, albeit in different ways. In modeling, this instability reveals itself via an apparent negative heat capacity of the system and is seen to result in the volume boiling in the case of infinite matter and surface boiling in the case of finite systems. The latter phenomenon of surface boiling is unique to small systems and it appears to provide a natural explanation for the observed saturation-like patterns in what is commonly termed caloric curves and what represents functional dependence of nuclear temperature on the excitation energy.
We review the physics of nuclearmatter at high energy density and the experimental search for the Quark-Gluon Plasma at the Relativistic Heavy Ion Collider (RHIC). The data obtained in the first three years of the RHIC physics program provide several lines of evidence that a novel state of matter has been created in the most violent, head-on collisions of Au nuclei at {radical}s = 200 GeV. Jet quenching and global measurements show that the initial energy density of the strongly interacting medium generated in the collision is about two orders of magnitude larger than that of cold nuclearmatter, well above the critical density for the deconfinement phase transition predicted by lattice QCD. The observed collective flow patterns imply that the system thermalizes early in its evolution, with the dynamics of its expansion consistent with ideal hydrodynamic flow based on a Quark-Gluon Plasma equation of state.
We discuss the thermalisation process of the neutron stars crust described by solving the heat transport equation with a microscopic input for the specific heat of baryonic matter. The heat equation is solved with initial conditions specific to a rapid cooling of the core. To calculate the specific heat of inner crust baryonic matter, i.e., nuclear clusters and unbound neutrons, we use the quasiparticle spectrum provided by the Hartree-Fock-Bogoliubov approach at finite temperature. In this framework we analyse the dependence of the crust thermalisation on pairing properties and on cluster structure of inner crust matter. It is shown that the pairing correlations reduce the crust thermalisation time by a very large fraction. The calculations show also that the nuclear clusters have a non-negligible influence on the time evolution of the surface temperature of the neutron star.
The energy per nucleon for infinite nuclearmatter with the parametrized Paris potential is calculated using the variational method recently proposed by Takano and Yamada. Approximate energy expressions playing an important role in this variational method are refined for the Paris potential, and in particular for the quadratic momentum parts in it. Since this variational method without any constraints gives extreme overbinding, an effective theory also proposed in conjunction with the above-mentioned variational method is applied, in a modified manner, to the calculations for symmetric nuclearmatter and neutron matter with the Paris potential, as well as the Hamada-Johnston and AV14 potentials. The obtained equation of state (EOS) for the Paris potential is, unlike the unrealistically soft EOS for the AV14 potential, capable of describing neutron stars with a reasonable maximum mass of 1.65 M\\odot.
We construct the equation of state (EOS) of nuclearmatter at finite temperature and density with various proton fractions within the relativistic mean field (RMF) theory for use in supernova simulations. The properties of nuclearmatter with both uniform and non-uniform distributions are studied consistently. We tabulate the outcome in terms of the pressure, free energy, entropy, etc. at a sufficiently large number of mesh points in the density range {rho}{sub B} = 10{sup 5.1} {approx} 10{sup 15.4}g/cm{sup 3}, the temperature range T 0 {approx} 100 MeV and the proton fraction range Y{sub p} = 0 {approx} 0.56 to be used for supernova simulations. We also discuss the EOS of neutron star matter at zero temperature in a wide density range including hyperons.
We test the extended Zimanyi-Moszkowski model of relativistic nuclearmatter for reproducing the density dependence of the symmetry energy, the direct URCA constraint M_{G}^{DU} \\geq 1.5M_{\\odot} on the gravitational mass of neutron star (NS), the large radii of NSs in RX J1856.5-3754 and qLMXB X7, the massive NSs in PSR J0751+1807 and 4U1700-37, and the baryonic mass of J0737-3039B. The two sets of NN\\rho coupling constant are considered. The first (EZM1) is the same as the Bonn A potential. The second (EZM2) is chosen so as to reproduce the symmetry energy E_s=32MeV of nuclearmatter. The EZM1 can pass 6 tests among 7, while the EZM2 passes 5 tests. We can therefore conclude that the EZM model has unique and excellent features and is the most prospective one for studying the dense baryonic matter.
The advances of space technology ushered in a new era in the development of man's ideas about the solar system. The flights of space vehicles to the moon, Venus, Mars and other planets made it possible to obtain quite new information on the composition, structure and properties of matter in the solar system. In these studies a prominent role is played by remote and contact nuclear physics methods of analyzing extraterrestrial matter - gamma spectrometry, X-ray spectrometry, alpha spectrometry and neutron spectrometry. At present practically any space vehicle bound for planets carries scientific instrumentation based on nuclear physics methods of analysis. The use of gamma and X-ray spectroscopy for obtaining information about composition, structure and properties of the matter of the moon and planets is reviewed.
This document is the March 1996 listing of NRC issuances. Included are: (1) NRC orders granting Cleveland Electric Illuminating Company`s petition for review of the ASLB order LBP-95-17, (2) NRC orders relating to the potential disqualification of two commissioners in the matter of the decommissioning of Yankee Nuclear Power Station, (3) ASLB orders pertaining to the Oncology Services Corporation, (4) ASLB orders pertaining to the Radiation Oncology Center, (5) ASLB orders pertaining to the Yankee Nuclear Power Station, and (6) Director`s decision pertaining to the Yankee Nuclear Power Station.
This program began in January 1993. Its primary goals are studies of highly excited matter and its production in nuclear collisions at very high energies. After a general orientation on the project, abstracts describing the contents of completed papers and providing some details of current projects are given. Principal topics of interest are the following: the dynamics of nuclear collisions at very high energies (RHIC and LHC), the dynamics of nuclear collisions at AGS energies, high-temperature QCD and the physics of the quark-gluon plasma, and the production of strangelets and other rare objects.
This program began in January 1993. Its primary goals are studies of highly excited matter and its production in nuclear collisions at very high energies. After a general orientation on the project, abstracts describing the contents of completed papers and providing some details of current projects are given. Principal topics of interest are the following: the dynamics of nuclear collisions at very high energies (RHIC and LHC), the dynamics of nuclear collisions at AGS energies, high-temperature QCD and the physics of the quark-gluon plasma, and the production of strangelets and other rare objects.
Supplement No. 14 to the Safety Evaluation Report for the application filed by the Tennessee Valley Authority for license to operate Watts Bar Nuclear Plant, Units 1 and 2, Docket Nos. 50-390 and 50-391, located in Rhea County, Tennessee, has been prepared by the Office of Nuclear Reactor Regulation of the Nuclear Regulatory Commission. The purpose of this supplement is to update the Safety Evaluation with additional information submitted by the applicant since Supplement No. 13 was issued, and matters that the staff had under review when Supplement No. 13 was issued.
Reactions of nuclear multifragmentation of excited finite nuclei can be interpreted as manifestation of the nuclear liquid-gas phase transition. During this process the matter at subnuclear density clusterizes into hot primary fragments, which are located in the vicinity of other nuclear species. In recent experiments there were found evidences that the symmetry and surface energies of primary fragments change considerably as compared to isolated cold or low-excited nuclei. The new modified properties of primary fragments should be taken into account during their secondary de-excitation.
One of the more controversial recent issues in Hadronic Physics is the possible existence of the so-called Kaonic Nuclear Clusters (KNC), often referred to also as Deeply Bound Kaon States (DBKS). They are strange (S = -1, -2) systems composed by nucleons strongly bound to one or two [image omitted]. This topic is connected with the possible existence of unusual nucleon bound states like pp or ppp, with the possibility that a high-density nuclear medium will be created around the K, that could be a seed for the understanding of the dense nuclearmatter in the neutron stars.
The licensing process for the power increase of a nuclear power station is presented, this includes the description of the effective normative framework, the attributions of the one Mexican regulator organism in nuclearmatter, the definition and importance of the power level of a nuclear reactor for the safety studies. Also, the types of power increase according to its magnitude, and the regulator process that it includes the scope and the detail of the required information that it should be evaluated by the one regulator organism are discussed. Finally it offers a summary of the experience that one has in Mexico for this type of processes. (Author)
We present the results of a test done with a Liquid Xenon (LXe) detector for 'Dark Matter' search, exposed to a neutron beam to produce nuclear recoil events simulating those which would be generated by WIMP's elastic scattering. The aim of the experiment was to measure directly the scintillation efficiency of nuclear recoil. The nuclear recoil considered in the test was in the tens of keV range. The ratio of measured visible energy over the true recoil energy was evaluated to be about 20%, in good agreement with the theoretical predictions.
We present the results of a test done with a Liquid Xenon (LXe) detector for 'Dark Matter' search, exposed to a neutron beam to produce nuclear recoil events simulating those which would be generated by WIMP's elastic scattering. The aim of the experiment was to measure directly the scintillation efficiency of nuclear recoil. The nuclear recoil considered in the test was in the tens of keV range. The ratio of measured visible energy over the true recoil energy was evaluated to be about 20%, in good agreement with the theoretical predictions.
We show for the first time that the quenching of electronic excitation from nuclear recoils in liquid xenon is well-described by Lindhard theory, if the nuclear recoil energy is reconstructed using the combined (scintillation and ionization) energy scale proposed by Shutt et al.. We argue for the adoption of this perspective in favor of the existing preference for reconstructing nuclear recoil energy solely from primary scintillation. We show that signal partitioning into scintillation and ionization is well-described by the Thomas-Imel box model. We discuss the implications for liquid xenon detectors aimed at the direct detection of dark matter.
In part 1 the effect of nuclear core dynamics on the binding energies of {Lambda} hypernuclei is discussed in the framework of variational correlated wave functions. In particular, the authors discuss a new rearrangement energy contribution and its effect on the core polarization. In part 2 they consider the interpretation of the {Lambda} single-particle energy in terms of basic {Lambda}-nuclear interactions using a local density approximation based on a Fermi hypernetted chain calculation of the A binding to nuclearmatter. To account for the data strongly repulsive 3-body {Lambda}NN forces are required. Also in this framework they discuss core polarization for medium and heavier hypernuclei.
The first symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on March 11 and 12, 1999. The symposium was devoted for discussions and presentations of research results in wide variety of fields such as observation of X-ray pulsars, theoretical studies of nuclearmatter, nuclear structure, low- and high-energy nuclear reactions and QCD. Thirty seven papers on these topics presented at the symposium are indexed individually. (J.P.N.)
The current status of heavy ion physics from medium energies to the quark gluon plasma is discussed in the light of several theoretical approaches. Relativistic mean field theory is discussed. The nuclear equation of state at high density and temperature is investigated in a nuclear fluid dynamic model: nuclearmatter is considered as a relativistic interacting Bose and Fermi gas of ? and ? mesons, photons, and nucleonic resonances. At the microscopic level, the approach to local kinetic equilibrium in relativistic heavy ion collisions is studied by following the time evolution of the Wigner function in configuration and momentum space using the Vlasov-Uehling-Uhlenbeck theory. This theoretical approach includes the nuclear mean field, two body collisions, particle production, relativistic kinematics, and the Pauli principle. A Newtonian Force Model, TDHF, the Vlasov equation, the IntraNuclear Cascade model, macroscopic Nuclear Fluid Dynamics, and a simple shock model are studied as reference cases. In the VUU theory, rapid equilibration of the participant region is observed within time spans on the order of 10 fm/c. Total stopping of the projectile occurs at small impact parameters: a sidesplash of nuclearmatter is predicted due to the interplay of the nuclear compressional energy and collisions. These theoretical approaches are compared to the experimental data. The pion yields, single particle spectra, and kinetic energy flow angular distributions are found to be sensitive to the nuclear compressibility and the Pauli principle: preliminary evidence for a surprisingly stiff nuclear equation of state is presented. Nuclear fragmentation or complex particle production is studied in a quantum statistical model that includes the isotopes up to Ne and also by applying a six dimensional coalescence model to the VUU final state. Permanent address: Institut for Theoretische Physik, Johann Wolfgang Goethe Unlversitgt, D-6000 Frankfurt am Main, Germany
Fundamental Chinese attitudes related to nuclear disarmament and proliferation, civil defense against nuclear attack, and the likely repercussions of nuclear war were set during the Korean War. Chinese viewpoints were heavily influenced by Western writings on nuclearmatters from 1945-1950 and were characterized by an integrated military, political, and psychological realism. Previous studies, failing to make use of relevant Chinese-language materials, have neglected this crucial formative period. Both the Truman and Eisenhower administrations considered using nuclear weapons in Korea and China and attempted to shape the political settlement of the war through nuclear threats. The Chinese reaction was notable for its efforts to counteract the effects of fear among its population. They acknowledged the unprecedented destructiveness, not the military decisiveness, of the weapons, but they adamantly denied that nuclear threats would cow them. Chinese propaganda stressed the Soviet deterrent and skillfully appealed to worldwide opposition to nuclear weapons, often utilizing Western spokesmen and playing upon the theme of US misuse of science. The Chinese considered a nuclear attack relatively unlikely but were prepared to absorb an attack and fight a war of long duration. In Korea both the terrain and the extensive tunneling by Chinese troops afforded significant protection from nuclear weapons.
Cell type and tissue architecture correlate with genome organization in higher eukaryotes, and structural nuclear landmarks are faithfully transmitted from one cell generation to the next. However, how nuclear components find their place in the nucleus after mitosis is still a matter of debate. As the major structural proteins within nuclei, the nuclear lamins are good candidates to re-establish nuclear compartments following mitosis. Human cells with reduced expression of the major B-type lamin protein, lamin B1, were generated using RNA interference. Mitotic and nuclear assembly phenotypes were then visualized in both fixed and living cells. Mitotic defects in lamin B1-depleted cells correlated with a general deterioration in nuclear compartmentalization and chromatin structure, frequent failure of chromosome segregation, and profound disorganization of centromeres. Examination of cells with normal lamin B1 expression indicated that small lamin B1 foci remain associated with major nuclear compartments--chromatin, nucleoli, and nuclear speckles--during an unperturbed mitosis. Our experiments show that normal lamin B1 expression is required for successful cell division and provide preliminary evidence that lamin B1-containing remnants of the interphase nucleoskeleton persist throughout mitosis. We suggest that these residual structures provide landmarks that are targeted during nuclear reassembly to allow key features of nuclear organization to be inherited from one cell cycle to the next. PMID:20568006
There has been considerable recent interest in the nuclear equation of state and how it may be determined in relativistic nucleus-nucleus collisions. In these collisions extremely high temperatures are reached and compression to densities several times that of normal nuclearmatter are predicted. This affords us the unique opportunity to study, in a somewhat controlled manner, the behavior of nuclearmatter under these extreme conditions. If the observables that are measured in experiments can be related in a quantitative way to state variables of the system then the equation of state can be extracted. This relation plays a very important role in understanding the formation and collapse of supernovae and the stability and structure of neutron stars. Furthermore, it can be used to test and constrain field theoretical approaches to nuclearmatter and to help to better understand the dynamics of high energy nucleus-nucleus collisions. In this presentation the relationship between the nuclear equation of state and relativistic nucleus-nucleus collisions will be discussed with an emphasis on how to extract the former. That a high density state of the collision should exist will be shown. One observable, namely the pion multiplicity, will be shown to survive the succeeding stages of the collision process to provide information on the equation of state at high densities. The resulting equation of state will be presented and discussed in the light of recent theoretical development. 34 refs., 12 figs.
At very high densities, electrons react with protons to form neutron rich matter. This material is central to many fundamental questions in nuclear physics and astrophysics. Moreover, neutron rich matter is being studied with an extraordinary variety of new tools such as the Facility for Rare Isotope Beams (FRIB) and the Laser Interferometer Gravitational Wave Observatory (LIGO). We describe the Lead Radius Experiment (PREX) that uses parity violating electron scattering to measure the neutron radius in $^{208}$Pb. This has important implications for neutron stars and their crusts. We discuss X-ray observations of neutron star radii. These also have important implications for neutron rich matter. Gravitational waves (GW) open a new window on neutron rich matter. They come from sources such as neutron star mergers, rotating neutron star mountains, and collective r-mode oscillations. Using large scale molecular dynamics simulations, we find neutron star crust to be very strong. It can support mountains on rotat...
From sixth Texas symposium on relativistic astrophysics; New York, New York, USA (18 Dec 1972). Results of calculations of the ground-state energies of liquid and crystalline neutron matter are presented. It is found that neutron matter will crystallize at a density near normal nuclear density. This results indicates that a large fraction of the interior of a neutron star consists of crystalline neutron matter. An intuitive physical discussion is given to illuminate this result. Furthermore, it is suggested that, contrary to the usual point of view, low-density matter should be regarded as a quantum liquid'' which is almost'' a quantum crystal''. (2 figures, 1 table) (auth)
In the context of supersymmetric models in which small Dirac neutrino masses are generated by supersymmetry breaking, a mainly right-handed (RH) mixed sneutrino can be an excellent cold dark matter (DM) candidate. We perform a global analysis of the Minimal Supersymmetric Standard Model (MSSM)+RH neutrino parameter space by means of Markov Chain Monte Carlo scans. We include all relevant constraints from collider and dark matter searches, paying particular attention to nuclear and astrophysical uncertainties. Two distinct cases can satisfy all constraints: heavy sneutrino DM with mass of order 100 GeV, as well as light sneutrino DM with mass of about 3-6 GeV. We discuss the implications for direct and indirect dark matter searches, as well as for SUSY and Higgs searches at the LHC for both, the light and the heavy sneutrino dark matter case. The light sneutrino case will in fact be excluded by a confirmation of the 125 GeV Higgs excess.
Inelastic dark matter reconciles the DAMA anomaly with other null direct detection experiments and points to a non-minimal structure in the dark matter sector. In addition to the dominant inelastic interaction, dark matter scattering may have a subdominant elastic component. If these elastic interactions are suppressed at low momentum transfer, they will have similar nuclear recoil spectra to inelastic scattering events. While upcoming direct detection experiments will see strong signals from such models, they may not be able to unambiguously determine the presence of the subdominant elastic scattering from the recoil spectra alone. We show that directional detection experiments can separate elastic and inelastic scattering events and discover the underlying dynamics of dark matter models.
Inelastic dark matter reconciles the DAMA anomaly with other null direct detection experiments and points to a non-minimal structure in the dark matter sector. In addition to the dominant inelastic interaction, dark matter scattering may have a subdominant elastic component. If these elastic interactions are suppressed at low momentum transfer, they will have similar nuclear recoil spectra to inelastic scattering events. While upcoming direct detection experiments will see strong signals from such models, they may not be able to unambiguously determine the presence of the subdominant elastic scattering from the recoil spectra alone. We show that directional detection experiments can separate elastic and inelastic scattering events and discover the underlying dynamics of dark matter models.
In part one of this paper the authors review the present status of neutron star matter calculations, and introduce a representative collection of realistic nuclear equations of state which are derived for different assumptions about the physical behavior of dense matter (baryon populations, pion condensation, possible transition of baryon matter to quark matter). Part two deals with the theoretical determination of the minimum possible rotational periods of neutron stars, performed in the framework of general relativity, whose knowledge serves to distinguish between pulsars that can be understood as rotating neutron stars and those that cannot. Likely candidates for the latter are hypothetical strange stars. Their properties are discussed in the third part of this contribution.
The properties of ?-cluster matter is studied within a microscopic framework, which takes full account of an effective inter-nucleon force and the Pauli exclusion principle. The ?-cluster matter plays an essential role in any ?-cluster model as its infinite limit. This is because the ?-cluster matter used in an ?-cluster model is under the same situation as is ordinary nuclearmatter for an independent particle model. In this study, all the ?-clusters are arranged in the generator coordinate space, which can be an equivalent model to the resonating group method. Every ?-cluster is in the same situation if the infinite system has an ordered configuration like a crystal structure. In this article, simple lattice configuration is mainly considered from various aspects. In particular, distorted ?-clusters are taken into account in order to see the properties of ?-cluster in the infinite systems.
We review some important results from the PHENIX experiment at RHIC. They were obtained in a unique environment for studying QCD bulk matter at temperatures and densities that sur- pass the limits where hadrons exist as individual entities, so raising to prominence the quark- gluon degrees of freedom. We present measurements of nuclear modification factors for neutral pions, light favors (strange hadrons), direct-photons and non-photonic electrons from decays of particles carrying charm or beauty quarks. We interpret the large suppression of hadron produc- tion at high transverse momenta as resulting from a large energy loss by the precursor parton on its path through the dense matter, primarily driven by gluon radiation. This dense QCD matter responds to energy loss in a pattern consistent with that expected from a hydrodynamic fluid. Further, its elliptic flow measurements suggest that the hadronization of bulk partonic matter exhibits collectivity with effective partonic degrees of freedom. The results are...
We emphasize that the composite structure of the nucleon may play quite an important role in nuclear physics. It is shown that the momentum-dependent repulsive force of second order in the scalar field, which plays an important role in Dirac phenomenology, can be found in the quark-meson coupling (QMC) model, and that the properties of nuclearmatter are well described through the quark-scalar density in a nucleon and a self-consistency condition for the scalar field. The difference between theories of point-like nucleons and composite ones may be seen in the change of the \\omega-meson mass in nuclearmatter if the composite nature of the nucleon suppresses contributions from nucleon-antinucleon pair creation.
The charmonium yields are expected to be considerably suppressed if a deconfined medium is formed in high-energy heavy-ion collisions. In addition, the bottomonium states, with the possible exception of the Upsilon(1S) state, are also expected to be suppressed in heavy-ion collisions. However, in proton-nucleus collisions the quarkonium production cross sections, even those of the Upsilon(1S), are also suppressed. These "cold nuclearmatter" effects need to be accounted for before signals of the high density QCD medium can be identified in the measurements made in nucleus-nucleus collisions. We identify two cold nuclearmatter effects important for midrapidity quarkonium production: "nuclear absorption", typically characterized as a final-state effect on the produced quarkonium state and shadowing, the modification of the parton densities in nuclei relative to the nucleon, an initial-state effect. We characterize these effects and study the energy, rapidity, and impact-parameter dependence of initial-state sh...
Using a nucleon-nucleon force of the type M3Y-Reid and an additional repulsive interaction which simulates the incompressibility effects of the nuclearmatter, we have examined the effects of the repulsive core modeling on the interaction potentials and complete fusion cross-sections for 9Be + 124Sn and 9Be + 89Y systems. The adjusted parameters of this repulsive force have been chosen in such a way that fully explains the properties of the nuclearmatter in the region where the nuclear densities of the interacting nuclei completely overlap. The results of our studies reveal that accounting for this correction in the calculations of the total potentials leads to improvement of calculated cross-sections and affects on the complete fusion suppression at above barrier energies.
We investigate the average sizes of the $n$ largest fragments in nuclear multifragmentation events near the critical point of the nuclearmatter phase diagram. We perform analytic calculations employing Poisson statistics as well as Monte Carlo simulations of the percolation type. We find that previous claims of manifestations of Zipf's Law in the rank-ordered fragment size distributions are not born out in our result, neither in finite nor infinite systems. Instead, we find that Zipf-Mandelbrot distributions are needed to describe the results, and we show how one can derive them in the infinite size limit. However, we agree with previous authors that the investigation of rank-ordered fragment size distributions is an alternative way to look for the critical point in the nuclearmatter diagram.
The strong nuclear force is described by Quantum Chromodynamics (QCD), the parallel field theory to Quantum Electrodynamics (QED) that describes the electromagnetic force. It is propagated by gluons analogously to photons in the electromagnetic force, but unlike photons, which do not carry electric charge, gluons carry color, and they can self-interact. However, as individual quarks have never been observed in nature, it is postulated that the color charge itself is confined, and hence all baryons and mesons must be colorless objects. To study nuclearmatter under extreme conditions, it is necessary to create hot and dense nuclearmatter in the laboratory. In such conditions the confinement between quarks and gluons is cancelled (deconfinement). This state is characterized with a qusi-free behavior of quarks and gluons. The strange (s) and anti-strange (anti-s) quarks are not contained in the colliding nuclei, but are newly produced and show up in the strange hadrons in the final state. It was suggested that ...
There are recent interests with CsI(Tl) scintillating crystals for Dark Matter experiments. The scattering signatures by neutrons on a CsI(Tl) detector were studied using a neutron beam generated by a 13 MV Tandem accelerator. The energy spectra of nuclear recoils from 7 keV to 132 keV were measured, and their quenching factors for scintillating light yield were derived. The data confirms the Optical Model predictions on neutron elastic scatterings with a direct measurement of the nuclear recoils on heavy nuclei. The pulse shape discrimination techniques to differentiate nuclear recoils from $\\gamma$-background were studied. Internal consistencies were obtained among the different methods of light yield measurements. The projected capabilities for Cold Dark Matter searches with CsI(Tl) crystals are presented.
The microscopic many-body theory of the Nuclear Equation of State is discussed in the framework of the Bethe-Brueckner-Goldstone method. The expansion is extended up to the three hole-line diagrams contribution. Within the same scheme, the hole spectral function is calculated in nuclearmatter to assess the relevance of nucleon-nucleon short-range correlations. The calculation is carried out by using several nucleon-nucleon realistic interactions. Results are compared with other approaches based on variational methods and transport theory. Discrepancies appear in the high-energy region, which is sensitive to short-range correlations, and are due to the different many-body treatment more than to the specific NN interaction used. Both nuclearmatter Equation of State and spectral function appear to be dominated by two-body correlations. (orig.)
The attitude structure toward nuclear power plant is analyzed with the attitudes toward relevant matters, for example image for nuclear power, knowledge of nuclear power, attitudes toward energy and environment, anxiety about various matters, cognition of risk, social and political attitudes and Japanese national character. Six types are revealed, that is to say, indifference group (13%), strongly favorable group (11%), strongly unfavorable group (9%), fairly favorable group (12%), fairly unfavorable group (5%), and intermediate group (50%). Strongly favorable and unfavorable groups are similar in some points and different in other points, for they are both rational whereas the former is optimistic in the attitude toward science and technology and less interested in environmental problems, and the latter is pessimistic in the attitude toward science and technology and extremely sensitive to environmental problems. The intermediate group has so-called Japanese-like characteristics. It is shown that the emotional persuasion and that based on fact presentation are particularly desirable for this group. (author)
We present results and predictions for the nuclear modification of the differential cross sections for inclusive light hadron and prompt photon production in minimum bias d+Au collisions at Formula Not Shown and minimum bias p+Pb collisions at Formula Not Shown at RHIC and LHC, respectively. Our calculations combine the leading order perturbative QCD formalism with cold nuclearmatter effects that arise from the elastic, inelastic and coherent multiple scattering of partons in large nuclei. We find that a theoretical approach that includes the isospin effect, Cronin effect, cold nuclearmatter energy loss and dynamical shadowing can describe the RHIC d+Au data rather well. The LHC p+Pb predictions will soon be confronted by new experimental results to help clarify the magnitude and origin ...
A density dependent, effective nucleon-nucleon force of the Skyrme type is derived from the quark-meson coupling model--a self-consistent, relativistic quark level description of nuclearmatter. This new formulation requires no assumption that the mean scalar field is small and hence constitutes a significant advance over earlier work. The similarity of the effective interaction to the widely used SkM* force encourages us to apply it to a wide range of nuclear problems, beginning with the binding energies and charge distributions of doubly magic nuclei. Finding impressive results in this conventional arena, we apply the same effective interaction, within the Hartree-Fock-Bogoliubov approach, to the properties of nuclei far from stability. The resulting two neutron drip lines and shell quenching are quite satisfactory. Finally, we apply the relativistic formulation to the properties of dense nuclearmatter in anticipation of future application to the properties of neutron stars.
We have derived a relationship in terms of the relativistic mean-field theory between the isovector optical model potential for nucleon-nucleus interactions and the possibility of Direct Urca process in neutron star matters which leads to an anomalously fast cooling of neutron stars. It became obvious that the possibility for the Direct Urca to occur in neutron stars, i.e., whether or not the proton mixing ratio exceeds the threshold value of 1/9, is highly connected with the symmetry energy coefficient of high-density nuclearmatter and the energy dependence of the isovector optical potential at the medium energy region. We hope such data would be measured in near future because they would be also important for understanding the nuclear reaction mechanisms and generating the medium-energy nuclear data. (author)
STUK is the independent nuclear supervisory agency in Finland with administrative powers; its staff has the technical and scientific competence required for safety assessments and for supervision. STUK operates under the supervision of the Ministry for Social Affairs and Health which, to demonstrate its independence, has no duties in the energy sector and, in addition, supervises STUK in administrative matters, not in scientific and technical decisions. Internal rules of STUK ensure neutrality also of its staff in matters of energy policy. The activities of STUK as a supervisory and licensing authority in Finland are described in detail for the management of spent nuclear fuel and the new Olkiluoto 3 nuclear power plant currently under construction. (orig./GL)
The low-momentum interaction $V_{\\text{low-k}}$ derived from realistic models of the nucleon-nucleon interaction is presented in a separable form. This separable force is supported by a contact interaction in order to achieve the saturation properties of symmetric nuclearmatter. Bulk properties of nuclearmatter and finite nuclei are investigated for the separable form of $V_{\\text{low-k}}$ and two different parameterizations of the contact term. The accuracy of the separable force in Hartree-Fock calculations with respect to the original interaction $V_{\\text{low-k}}$ is discussed. For a cutoff parameter $\\Lambda$ of 2 fm$^{-1}$ a representation by a rank 2 separable force yields a sufficient accuracy, while higher ranks are required for larger cut-off parameters. The resulting separable force is parameterized in a simple way to allow for an easy application in other nuclear structure calculations.
The past three decades of investigation on nuclear physics and pulsar astrophysics have seen gradual recognition that elastodynamic approach to the continuum mechanics of nuclearmatter provides proper account of macroscopic motions of degenerate Fermi-matter constituting interior of the nuclear material objects, the densest of all known today. This paper focuses on one theoretical issue of this development which is concerned with oscillatory behavior of a viscoelastic solid globe in the regime of quasistatic, force-free, non-compressional oscillations less investigated in the literature compared to oscillations in the regime of standing shear waves. We show that in this case the problem of computing frequency and lifetime of spheroidal and torsional modes of non-radial shear vibrations damped by viscosity can be unambiguously resolved by working from the energy balance equation and taking advantage of the Rayleigh's variational method. The efficiency of this method is demonstrated by solid globe models of nu...
Within the generalized statistics developed by Tsallis, we study nuclearmatter at high densities in the framework of an effective many-body field theory at finite temperature. Thermodynamics properties of nuclearmatter are studied considering the Sommerfeld approximation. We perform the calculations by using by using the nonlinear Boguta and Bodmer model, extended by the inclusion of the fundamental baryon octet and leptonic degrees of freedom. Through the integration of the Tolman-Oppenheimer-Volkoff equations we obtain, beyond the standard relations for the masses of protoneutron stars as functions of the central density, new results for these quantities as a function of temperature. The above formalism, which so far was not yet discussed in the study of many-body dense nuclear systems, predicts substantial differences from calculations based on standard statistics. (author)
An impressive array of astrophysical observations suggest that 83% of the matter in the universe is in a form of non-luminous, cold, collisionless, non-baryonic dark matter. Several extensions of the Standard Model of particle physics aimed at solving the hierarchy problem predict stable weakly interacting massive particles (WIMPs) that could naturally have the right cosmological relic abundance today to compose most of the dark matter if their interactions with normal matter are on the order of a weak scale cross section. These candidates also have the added benefit that their properties and interaction rates can be computed in a well defined particle physics model. A considerable experimental effort is currently under way to uncover the nature of dark matter. One method of detecting WIMP dark matter is to look for its interactions in terrestrial detectors where it is expected to scatter off nuclei. In 2007, the XENON10 experiment took the lead over the most sensitive direct detection dark matter search in operation, the CDMS II experiment, by probing spin-independent WIMP-nucleon interaction cross sections down to sigmachi N ˜ 5 x 10-44 cm 2 at 30 GeV/c2. Liquefied noble gas detectors are now among the technologies at the forefront of direct detection experiments. Liquid xenon (LXe), in particular, is a well suited target for WIMP direct detection. It is easily scalable to larger target masses, allows discrimination between nuclear recoils and electronic recoils, and has an excellent stopping power to shield against external backgrounds. A particle losing energy in LXe creates both ionization electrons and scintillation light. In a dual-phase LXe time projection chamber (TPC) the ionization electrons are drifted and extracted into the gas phase where they are accelerated to amplify the charge signal into a proportional scintillation signal. These two signals allow the three-dimensional localization of events with millimeter precision and the ability to fiducialize the target volume, yielding an inner core with a very low background. Additionally, the ratio of ionization and scintillation can be used to discriminate between nuclear recoils, from neutrons or WIMPs, and electronic recoils, from gamma or beta backgrounds. In these detectors, the energy scale is based on the scintillation signal of nuclear recoils and consequently the precise knowledge of the scintillation efficiency of nuclear recoils in LXe is of prime importance. Inspired by the success of the XENON10 experiment, the XENON collaboration designed and built a new, ten times larger, with a one hundred times lower background, LXe TPC to search for dark matter. It is currently the most sensitive direct detection experiment in operation. In order to shed light on the response of LXe to low energy nuclear recoils a new single phase detector designed specifically for the measurement of the scintillation efficiency of nuclear recoils was also built. In 2011, the XENON100 dark matter results from 100 live days set the most stringent limit on the spin-independent WIMP-nucleon interaction cross section over a wide range of masses, down to sigma chi N ˜ 7 x 10-45 cm2 at 50 GeV/c2, almost an order of magnitude improvement over XENON10 in less than four years. This thesis describes the research conducted in the context of the XENON100 dark matter search experiment. I describe the initial simulation results and ideas that influenced the design of the XENON100 detector, the construction and assembly steps that lead into its concrete realization, the detector and its subsystems, a subset of the calibration results of the detector, and finally dark matter exclusion limits. I also describe in detail the new improved measurement of the important quantity for the interpretation of results from LXe dark matter searches, the scintillation efficiency of low-energy nuclear recoils in LXe.
The National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) is primarily devoted to the study of exotic nuclei. The Laboratory is funded by the United States National Science Foundation (NSF) to operate two coupled superconducting cyclotrons (the K500 and the K1200) and a diverse array of experimental devices. This paper describes this facility, some of the planned research and its future directions. The planned program will cover three main areas; nuclear structure, nuclear astrophysics, and the equation of state of compressed nuclearmatter. In nuclear structure, one of the major goals will be to study the structure of very neutron and very proton rich nuclei with mass A<100. The tools for these studies are presented. Nuclear astrophysics studies will cover the full range of stellar evolution from main sequence burning to exploration of the properties of neutron stars.
The III Mexican School of Nuclear Physics which is directed to those post graduate in Sciences and those of last semesters students of the Physics career or some adjacent career was organized by the Nuclear Physics Division of the Mexican Physics Society, carrying out at November 18-29, 2002 in the installations of the Institute of Physics and the Institute of Nuclear Sciences both in the UNAM, and the National Institute of Nuclear Research (ININ). In this as well as the last version its were offered 17 courses, 9 of them including laboratory practices and the rest were of theoretical character only. This book treats about the following themes: Nuclear physics, Electrostatic accelerators, Cyclotrons, Thermonuclear reactions, Surface barrier detectors, Radiation detection, Neutron detection, Bonner sphere spectrometers, Radiation protection, Biological radiation effects, Particle kinematics, Nucleosynthesis, Plastics, Muons, Quadrupoles, Harmonic oscillators, Quantum mechanics among many other matters. (Author)
The planned upgrade of DA?NE at LNF with a peak luminosity in the order of L = 1033cm-2s-1 will be the ideal machine to search for and prove the existence of antikaon-mediated deeply bound nuclear cluster. Antikaon-mediated deeply bound nuclear clusters will allow the study of most important problems in hadron physics today, namely, how the hadron masses and hadron interactions change in the nuclear medium and what is the structure of cold dense hadronic matter. AMADEUS will use the KLOE detector with an additional dedicated target and detector system around the interaction zone to perform exclusive measurements - all particles in the formation and decay processes of deeply bound nuclear clusters will be detected. These measurements will prove beyond doubt the anticipated formation production of antikaon-mediated deeply bound nuclear clusters.
This research develops and tests a new concept in the valuation of nuclear waste transportation by using two simultaneous but complimentary approaches: (1) a contingent valuation method (CVM) and (2) an experimental inference procedure (EIP) that has direct monetary incentives for the respondents to accurately reveal preferences. Each approach is constructed to compensate for limitations of the other. Respondents of the survey indicated some willingness to negotiate for compensation on matters of nuclear waste transportation, but a majority of individuals tended to take an extreme position either for or against nuclear waste. Comparison of the inference game to CVM valuation of nuclear waste indicates that the CVM must be further calibrated by the inference game to accurately measure values towards nuclear waste valuation. (author) 4 tabs., 16 refs.
Using a single-phase liquid argon detector with a signal yield of 4.85 photoelectrons per keV of electronic-equivalent recoil energy (keVee), we measure the scintillation time dependence of both electronic and nuclear recoils in liquid argon down to 5 keVee. We develop two methods of pulse shape discrimination to distinguish between electronic and nuclear recoils. Using one of these methods, we measure a background and statistics-limited level of electronic recoil contamination to be $7.6\\times10^{-7}$ between 60 and 128 keV of nuclear recoil energy (keVr) for a nuclear recoil acceptance of 50% with no nuclear recoil-like events above 72 keVr. Finally, we develop a maximum likelihood method of pulse shape discrimination using the measured scintillation time dependence and predict the sensitivity to WIMP-nucleon scattering in three configurations of a liquid argon dark matter detector.
Nuclearmatter is considered to be inhomogeneous at sub-nuclear densities realized, e.g., in supernova cores and neutron star crusts and change structures from sphere to cylinder, slab, cylindrical hole and spherical hole as the density increases. In this letter, we discuss other possibilities, that is, gyroid and double-diamond morphologies, which are periodic bicontinuous structures discovered in a block copolymer. Utilizing the compressible liquid drop model, we evaluate their surface and Coulomb energies and show that there is a chance of gyroid appearance near the transition point from cylinder to slab. This interesting analogy between the nuclear and polymer systems is not just qualitative. The volume fraction at the phase transition is also quite similar for the two systems. Although the five shapes listed initially have been long thought to be the only major constituents of the so-called nuclear pasta at sub-nuclear densities, our findings imply that this may not be the case and suggest that more deta...
A brief account of an improbable career in the field of genetic toxicology is given, extending from my early years in Malta through a life-changing decision to study in Australia (Down Under). I describe the circumstances that led to the discovery of the cytokinesis-block micronucleus (CBMN) assay and its evolution into a cytome assay of chromosome breakage and loss (micronuclei), asymmetrical chromosome rearrangements or telomere end fusions (nucleoplasmic bridges), gene amplification (nuclear buds), cell death (necrosis, apoptosis) and cytostasis (nuclear division index). This paper also describes the role of my laboratory in the beginning of the HUMN project, its achievements, and the applications of CBMN cytome assays in the fields of radiation biology, genetic toxicology, epidemiology...
Four different critical core configurations of the IRR1 [Bettan, M., Hirshfeld H., Levine, S.H., 2002. Method to determine the burnup of the IRR1 fuel assemblies. In: Proceedings of the 21st Conference of the Nuclear Societies in Israel, p. 38-41], Cores 1, 2, 3, and 4, have been used to determine experimentally the reactivity changes caused by interchanging different fuel assemblies (FAs) in the same core position [Bettan, M., Hirshfeld H., Levine, S.H., 2002. Method to determine the burnup of the IRR1 fuel assemblies. In: Proceedings of the 21st Conference of the Nuclear Societies in Israel, p. 38-41; Levine, S.H., Kim, S.S., 1985. Development of an asymmetric multiple-position neutron source (AMPNS) method to monitor the criticality of a degraded reactor core. Ann. Nucl. Energy 12, 517;...
We investigated the ground state of a highly one-dimensional conductor, TPP[Co(Pc)(CN)2]2 (TPP = tetraphenylphosphonium and Pc = phthalocyanine), by the measurement of the X-ray diffraction, electron spin resonance, nuclear quadrupole resonance, and magnetoresistance. An increase of the magnetic fluctuations was observed below 20 K, where no structural deformation was detected. In the 59Co nuclear quadrupole resonance, we found an asymmetric broadening of the spectra owing to the intrinsic inhomogeneity of the molecular charge. We propose that the ground state is characterized by a weak charge disproportionation with antiferromagnetic fluctuations due to the high one dimensionality. A large magnetoresistance was observed under a high magnetic field. Spin effects are dominant at low fields. The anisotropic magnetoresistance suggests a change in the ground-state nature above 10 T.
The BCS-BEC crossover and phase diagram for asymmetricnuclear superfluid with pairings in isospin I = 0 and I = 1 channels are investigated at mean field level, by using a density dependent nucleon-nucleon potential. Induced by the in-medium nucleon mass and density dependent coupling constants, neutron-proton Cooper pairs could be in BEC state at sufficiently low density, but there is no chance for the BEC formation of neutron-neutron and proton-proton pairs at any density and asymmetry. We calculate the phase diagram in asymmetry-temperature plane for weakly interacting nuclear superfluid, and find that including the I = 1 channel changes significantly the phase structure at low temperature. There appears a new phase with both I = 0 and I = 1 pairings at low temperature and low asymmetry, and the gapless state in any phase with I = 1 pairing is washed out and all excited nucleons are fully gapped.
Electrocardiography (ECG), echocardiography, nuclear method, cardiac catheterization, left ventriculography and endomyocardial biopsy (biopsy) were performed in 40 cases of cardiomyopathy (CM), 9 of endocardial fibroelastosis and 19 of specific heart muscle disease, and the usefulness and limitation of each method was comparatively estimated. In CM, various methods including biopsy were performed. The 40 patients were classified into 3 groups, i.e., hypertrophic (17), dilated (20) and non-hypertrophic non-dilated (3) on the basis of left ventricular ejection fraction and hypertrophy of the ventricular wall. The hypertrophic group was divided into 4 subgroups: 9 septal, 4 apical, 2 posterior and 2 anterior. The nuclear study is useful in assessing the site of the abnormal ventricular thickening, perfusion defect and ventricular function. Echocardiography is most useful in detecting asymmetric septal hypertrophy. The biopsy gives the sole diagnostic clue, especially in non-hypertrophic non-dilated cardiomyopathy. ECG is useful in all cases but correlation with the site of disproportional hypertrophy was not obtained.
Recombination activity plays an important role in the heteroplasmic and stoichiometric variation of plant mitochondrial genomes. Recent studies show that the nuclear gene MSH1 functions to suppress asymmetric recombination at 47 repeat pairs within the Arabidopsis mitochondrial genome. Two additional nuclear genes, RECA3 and OSB1, have also been shown to participate in the control of mitochondrial DNA exchange in Arabidopsis. Here, we demonstrate that repeat-mediated de novo recombination is enhanced in Arabidopsis and tobacco mitochondrial genomes following passage through tissue culture, which conditions the MSH1 and RECA3 suppressions. The mitochondrial DNA changes arising through in vitro culture in tobacco were reversible by plant regeneration, with correspondingly restored MSH1 trans...
We propose two cosmological models in order to explain the universal baryon density parameter ?b h2 inferred from different observational data: One is from the Big-Bang nucleosynthesis, and the other is from the cosmic microwave background fluctuations. Our proposed theoretical models are the lepton asymmetric Universe model and the baryon inhomogeneous Big-Bang nucleosynthesis model. In these cosmological models the nuclear processes are similar to those in the r-process nucleosynthesis in gravitational core-collapse supernova explosion. Massive stars ? 10 M\\odot culminate their evolution by supernova explosions which are presumed to be the most viable candidate site for the r-process nucleosynthesis. Even in the nucleosynthesis of heavy elements, entropy and density in the hot bubble of core-collapse Type II supernovae are so high that nuclear statistical equilibrium favors production of abundant light nuclei. In such explosive circumstances many radioactive light-to-intermediate mass nuclei as well as heavy mass nuclei play the significant roles.
First high-resolution infrared absorption spectra in the fundamental symmetric/asymmetric CH stretching region of isotopically substituted methyl radical, CH2D, are reported and analyzed. These studies become feasible in the difference frequency spectrometer due to (i) high density radical generation via dissociative electron attachment to CH2DI in a discharge, (ii) low rotational temperatures (23 K) from supersonic cooling in a slit expansion, (iii) long absorption path length (64 cm) along the slit axes, and (iv) near shot noise limited absorption sensitivity (5 × 10-7/Hz). The spectra are fully rovibrationally resolved and fit to an asymmetric top rotational Hamiltonian to yield rotational/centrifugal constants and vibrational band origins. In addition, the slit expansion collisionally quenches the transverse velocity distribution along the laser probe direction, yielding sub-Doppler resolution of spin-rotation structure and even partial resolution of nuclear hyperfine structure for each rovibrational line. Global least-squ
