Nuclear matter with pseudo-particle model: static bulk and surface properties

International Nuclear Information System (INIS)

Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

1993-01-01

Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a Gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of Gaussian per nucleon and the Gaussian widths are critical parameters in that semi-classical model. (author) 13 refs.; 9 figs.; 2 tabs

Nuclear pasta in hot dense matter and its implications for neutrino scattering

Science.gov (United States)

Roggero, Alessandro; Margueron, Jérôme; Roberts, Luke F.; Reddy, Sanjay

2018-04-01

The abundance of large clusters of nucleons in neutron-rich matter at subnuclear density is found to be greatly reduced by finite-temperature effects when matter is close to β equilibrium, compared to the case where the electron fraction is fixed at Ye>0.1 , as often considered in the literature. Large nuclei and exotic nonspherical nuclear configurations called pasta, favored in the vicinity of the transition to uniform matter at T =0 , dissolve at a relatively low temperature Tu as protons leak out of nuclei and pasta. For matter at β equilibrium with a negligible neutrino chemical potential we find that Tuβ≃4 ±1 MeV for realistic equations of state. This is lower than the maximum temperature Tmaxβ≃9 ±1 MeV at which nuclei can coexist with a gas of nucleons and can be explained by a change in the nature of the transition to uniform matter called retrograde condensation. An important new finding is that coherent neutrino scattering from nuclei and pasta makes a modest contribution to the opacity under the conditions encountered in supernovas and neutron star mergers. This is because large nuclear clusters dissolve at most relevant temperatures, and at lower temperatures, when clusters are present, Coulomb correlations between them suppress coherent neutrino scattering off individual clusters. Implications for neutrino signals from galactic supernovas are briefly discussed.

Variational Calculation for the Equation of State of Hot Asymmetric Nuclear Matter

International Nuclear Information System (INIS)

Togashi, Hajime; Kanzawa, Hiroaki; Takano, Masatoshi

2010-01-01

We calculate the equation of state (EOS) of asymmetric nuclear matter at finite temperatures with the cluster variational method based on the realistic nuclear Hamiltonian composed of the AV18 and UIX nuclear potentials. The free energy is calculated with an extension of the variational method proposed by Schmidt and Pandharipande. The obtained thermodynamic quantities such as entropy, internal energy, pressure and chemical potential derived from the free energy are reasonable. It is also found that the present variational calculation is self-consistent. These thermodynamic quantities are essential ingredients in our project for constructing a new nuclear EOS applicable to supernova simulations.

Nuclear matter with a pseudo-particle model: static bulk and surface properties

International Nuclear Information System (INIS)

Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

1993-01-01

Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of gaussians per nucleon and the gaussian widths are critical parameters in that semi-classical model. (orig.)

Nuclear matter with a pseudo-particle model: static bulk and surface properties

Energy Technology Data Exchange (ETDEWEB)

Idier, D. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Benhassine, B. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Farine, M. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Remaud, B. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Sebille, F. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France))

1993-11-15

Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of gaussians per nucleon and the gaussian widths are critical parameters in that semi-classical model. (orig.)

Axions as hot and cold dark matter

International Nuclear Information System (INIS)

Jeong, Kwang Sik; Kawasaki, Masahiro; Tokyo Univ., Kashiwa; Takahashi, Fuminobu; Tokyo Univ., Kashiwa

2013-10-01

The presence of a hot dark matter component has been hinted at 3σ by a combination of the results from different cosmological observations. We examine a possibility that pseudo Nambu- Goldstone bosons account for both hot and cold dark matter components. We show that the QCD axions can do the job for the axion decay constant f a 10 ) GeV, if they are produced by the saxion decay and the domain wall annihilation. We also investigate the cases of thermal QCD axions, pseudo Nambu-Goldstone bosons coupled to the standard model sector through the Higgs portal, and axions produced by modulus decay.

Axions as hot and cold dark matter

Energy Technology Data Exchange (ETDEWEB)

Jeong, Kwang Sik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kawasaki, Masahiro [Tokyo Univ., Kashiwa (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Kashiwa (Japan). Kavli IPMU, TODIAS; Takahashi, Fuminobu [Tohoku Univ., Sendai (Japan). Dept. of Physics; Tokyo Univ., Kashiwa (Japan). Kavli IPMU, TODIAS

2013-10-15

The presence of a hot dark matter component has been hinted at 3{sigma} by a combination of the results from different cosmological observations. We examine a possibility that pseudo Nambu- Goldstone bosons account for both hot and cold dark matter components. We show that the QCD axions can do the job for the axion decay constant f{sub a}

Description of hot compressed hadronic matter based on an effective chiral Lagrangian

Energy Technology Data Exchange (ETDEWEB)

Florkowski, W. [Institute of Nuclear Physics, Cracow (Poland)

1996-11-01

In this report we give the review of the recent results obtained in the Nambu-Jona-Lasinio (NJL) model, describing the properties of hot compressed matter. The first large class problems concerns the behaviour of static meson correlation functions. In particular, this includes the investigation of the screening of meson fields at finite temperature or density. Another wide range of problems presented in our report concerns the formulation of the transport theory for the NJL model and its applications to the description of high energy nuclear collision. 86 refs, 35 figs.

Description of hot compressed hadronic matter based on an effective chiral Lagrangian

International Nuclear Information System (INIS)

Florkowski, W.

1996-11-01

In this report we give the review of the recent results obtained in the Nambu-Jona-Lasinio (NJL) model, describing the properties of hot compressed matter. The first large class problems concerns the behaviour of static meson correlation functions. In particular, this includes the investigation of the screening of meson fields at finite temperature or density. Another wide range of problems presented in our report concerns the formulation of the transport theory for the NJL model and its applications to the description of high energy nuclear collision. 86 refs, 35 figs

Nuclear matter revisited

International Nuclear Information System (INIS)

Negele, J.W.; Zabolitzky, J.G.

1978-01-01

It is stated that at the Workshop on Nuclear and Dense Matter held at the University of Illinois in May 1977 significant progress was reported that largely resolves many of the questions raised in this journal Vol. 6, p.149, 1976. These include perturbative versus variational methods as applied to nuclear matter, exact solutions for bosons, what is known as the fermion 'homework problem', and various other considerations regarding nuclear matter, including the use of variational methods as opposed to perturbation theory. (15 references) (U.K.)

Is it possible to tell the difference between fermionic and bosonic hot dark matter?

Energy Technology Data Exchange (ETDEWEB)

Hannestad, S.; Tu, H. [Aarhus Univ. (Denmark). Dept. of Physics and Astronomy; Ringwald, A.; Wong, Y.Y.Y. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2005-07-01

We study the difference between thermally produced fermionic and bosonic hot dark matter in detail. In the linear regime of structure formation, their distinct free-streaming behaviours can lead to pronounced differences in the matter power spectrum. While not detectable with current cosmological data, such differences will be clearly observable with upcoming large scale weak lensing surveys for particles as light as m{sub HDM} {proportional_to} 0.2 eV. In the nonlinear regime, bosonic hot dark matter is not subject to the same phase space constraints that severely limit the amount of fermionic hot dark matter infall into cold dark matter halos. Consequently, the overdensities in fermionic and bosonic hot dark matter of equal particle mass can differ by more than a factor of five in the central part of a halo. However, this unique manifestation of quantum statistics may prove very difficult to detect unless the mass of the hot dark matter particle and its decoupling temperature fall within a very narrow window, 1hot dark matter infall may have some observable consequences for the nonlinear power spectrum and hence the weak lensing convergence power spectrum at l {proportional_to} 10{sup 3} {yields} 10{sup 4} at the percent level. (orig.)

Hadrons in dense matter. Proceedings

International Nuclear Information System (INIS)

Buballa, M.; Noerenberg, W.; Schaefer, B.J.; Wambach, J.

2000-03-01

The following topics were dealt with: Elementary hadronic reactions, Delta dynamics in nuclei, in-medium s-wave ππ-correlations, strangeness in hot and dense matter, medium modifications of vector mesons and dilepton production, medium modifications of charmonium, thermal properties of hot and dense hadronic matter, nuclear matter, spectral functions and QCD sum rules

Transport properties of hot gluonic matter

CERN Document Server

Bluhm, Marcus

2012-01-01

We discuss the temperature dependence of the scaled jet quenching parameter of hot gluonic matter within a quasiparticle approach. A pronounced maximum in the vicinity of the transition temperature is observed, where the ratio of the scaled jet quenching parameter and the inverse specific shear viscosity increases above typical values for weakly coupled systems.

Hot neutron stars at birth and energy release

International Nuclear Information System (INIS)

Takatsuka, Tatsuyuki

1994-01-01

For the discussion of hot neutron stars at birth, it is necessary to calculate the equation of state for a so-called 'supernova matter' consisting of a neutron-rich nuclear matter and degenerated leptons. One of the aims of this paper is to obtain the realistic results for the equation of state. In 10-20s after the birth, new born hot neutron stars are cooled down by neutrino diffusion process, and gradually contract to usual cold neutron starts. It is another aim of this paper to determine how much energy is released during this cooling stage. The points to which attention was paid are explained. A three-nucleon interaction was introduced phenomenologically, as a two-nucleon interaction is insufficient to satisfy the empirical saturation property of symmetric nuclear matters. The separation of uncertain part from well-known part has the merit to clarify the dependence of the results on the present theoretical uncertainties. The validity of the simplified calculation as an approximation for the exact calculation is discussed. The results by both calculations were compared for the case of hot symmetric nuclear matters. The comparison of the density profiles for a hot neutron star and a cold neutron star is shown. The binding energy for hot and cold neutron stars was plotted. These results are examined. (K.I.)

Menopausal Hot Flashes and White Matter Hyperintensities

Science.gov (United States)

Thurston, Rebecca C.; Aizenstein, Howard J.; Derby, Carol A.; Sejdić, Ervin; Maki, Pauline M.

2015-01-01

Objective Hot flashes are the classic menopausal symptom. Emerging data links hot flashes to cardiovascular disease (CVD) risk, yet how hot flashes are related to brain health is poorly understood. We examined the relationship between hot flashes - measured via physiologic monitor and self-report - and white matter hyperintensities (WMH) among midlife women. Methods Twenty midlife women ages 40-60 without clinical CVD, with their uterus and both ovaries, and not taking hormone therapy were recruited. Women underwent 24 hours of ambulatory physiologic and diary hot flash monitoring to quantify hot flashes; magnetic resonance imaging to assess WMH burden; 72 hours of actigraphy and questionnaires to quantify sleep; and a blood draw, questionnaires, and physical measures to quantify demographics and CVD risk factors. Test of a priori hypotheses regarding relations between physiologically-monitored and self-reported wake and sleep hot flashes and WMH were conducted in linear regression models. Results More physiologically-monitored hot flashes during sleep were associated with greater WMH, controlling for age, race, and body mass index [beta(standard error)=.0002 (.0001), p=.03]. Findings persisted controlling for sleep characteristics and additional CVD risk factors. No relations were observed for self-reported hot flashes. Conclusions More physiologically-monitored hot flashes during sleep were associated with greater WMH burden among midlife women free of clinical CVD. Results suggest that relations between hot flashes and CVD risk observed in the periphery may extend to the brain. Future work should consider the unique role of sleep hot flashes in brain health. PMID:26057822

Effects of isospin and momentum dependent interactions on thermal properties of asymmetric nuclear matter

International Nuclear Information System (INIS)

Xu Jun; Ma Hongru; Chen Liewen; Li Baoan

2008-01-01

Thermal properties of asymmetric nuclear matter are studied within a self-consistent thermal model using an isospin and momentum-dependent interaction (MDI) constrained by the isospin diffusion data in heavy-ion collisions, a momentum-independent interaction (MID), and an isoscalar momentum-dependent interaction (eMDYI). In particular, we study the temperature dependence of the isospin-dependent bulk and single-particle properties, the mechanical and chemical instabilities, and liquid-gas phase transition in hot asymmetric nuclear matter. Our results indicate that the temperature dependence of the equation of state and the symmetry energy are not so sensitive to the momentum dependence of the interaction. The symmetry energy at fixed density is found to generally decrease with temperature and for the MDI interaction the decrement is essentially due to the potential part. It is further shown that only the low momentum part of the single-particle potential and the nucleon effective mass increases significantly with temperature for the momentum-dependent interactions. For the MDI interaction, the low momentum part of the symmetry potential is significantly reduced with increasing temperature. For the mechanical and chemical instabilities as well as the liquid-gas phase transition in hot asymmetric nuclear matter, our results indicate that the boundaries of these instabilities and the phase-coexistence region generally shrink with increasing temperature and are sensitive to the density dependence of the symmetry energy and the isospin and momentum dependence of the nuclear interaction, especially at higher temperatures

Hot interstellar matter in elliptical galaxies

CERN Document Server

Kim, Dong-Woo

2012-01-01

Based on a number of new discoveries resulting from 10 years of Chandra and XMM-Newton observations and corresponding theoretical works, this is the first book to address significant progress in the research of the Hot Interstellar Matter in Elliptical Galaxies. A fundamental understanding of the physical properties of the hot ISM in elliptical galaxies is critical, because they are directly related to the formation and evolution of elliptical galaxies via star formation episodes, environmental effects such as stripping, infall, and mergers, and the growth of super-massive black holes. Thanks to the outstanding spatial resolution of Chandra and the large collecting area of XMM-Newton, various fine structures of the hot gas have been imaged in detail and key physical quantities have been accurately measured, allowing theoretical interpretations/predictions to be compared and tested against observational results. This book will bring all readers up-to-date on this essential field of research.

Effects of energy conservation on equilibrium properties of hot asymmetric nuclear matter

Science.gov (United States)

Zhang, Zhen; Ko, Che Ming

2018-01-01

Based on the relativistic Vlasov-Uehling-Uhlenbeck transport model, which includes relativistic scalar and vector potentials on baryons, we consider an N -Δ -π system in a box with periodic boundary conditions to study the effects of energy conservation in particle production and absorption processes on the equilibrium properties of the system. The density and temperature of the matter in the box are taken to be similar to the hot dense matter formed in heavy ion collisions at intermediate energies. We find that to maintain the equilibrium numbers of N ,Δ , and π , which depend on the mean-field potentials of N and Δ , we must include these potentials in the energy conservation condition that determines the momenta of outgoing particles after a scattering or decay process. We further find that the baryon scalar potentials mainly affect the Δ and pion equilibrium numbers, while the baryon vector potentials have considerable effect on the effective charged pion ratio at equilibrium. Our results thus indicate that it is essential to include in the transport model the effect of potentials in the energy conservation of a scattering or decay process, which is ignored in most transport models, for studying pion production in heavy ion collisions.

Hot and dense matter in compact stars - from nuclei to quarks

International Nuclear Information System (INIS)

Hempel, Matthias

2010-01-01

This dissertation deals with the equation of state of hot and dense matter in compact stars, with special focus on first order phase transitions. A general classification of first order phase transitions is given and the properties of mixed phases are discussed. Aspects of nucleation and the role of local constraints are investigated. The derived theoretical concepts are applied to matter in neutron stars and supernovae, in the hadron-quark and the liquid-gas phase transition. For the detailed description of the liquid-gas phase transition a new nuclear statistical equilibrium model is developed. It is based on a thermodynamic consistent implementation of relativistic mean-field interactions and excluded volume effects. With this model different equation of state tables are calculated and the composition and thermodynamic properties of supernova matter are analyzed. As a first application numerical simulations of core-collapse supernovae are presented. For the hadron-quark phase transition two possible scenarios are studied in more detail. First the appearance of a new mixed phase in a proto neutron star and the implications on its evolution. In the second scenario the consequences of the hadron-quark transition in corecollapse supernovae are investigated. Simulations show that the appearance of quark matter has clear observable signatures and can even lead to the generation of an explosion. (orig.)

Hot and dense matter in compact stars - from nuclei to quarks

Energy Technology Data Exchange (ETDEWEB)

Hempel, Matthias

2010-10-19

This dissertation deals with the equation of state of hot and dense matter in compact stars, with special focus on first order phase transitions. A general classification of first order phase transitions is given and the properties of mixed phases are discussed. Aspects of nucleation and the role of local constraints are investigated. The derived theoretical concepts are applied to matter in neutron stars and supernovae, in the hadron-quark and the liquid-gas phase transition. For the detailed description of the liquid-gas phase transition a new nuclear statistical equilibrium model is developed. It is based on a thermodynamic consistent implementation of relativistic mean-field interactions and excluded volume effects. With this model different equation of state tables are calculated and the composition and thermodynamic properties of supernova matter are analyzed. As a first application numerical simulations of core-collapse supernovae are presented. For the hadron-quark phase transition two possible scenarios are studied in more detail. First the appearance of a new mixed phase in a proto neutron star and the implications on its evolution. In the second scenario the consequences of the hadron-quark transition in corecollapse supernovae are investigated. Simulations show that the appearance of quark matter has clear observable signatures and can even lead to the generation of an explosion. (orig.)

Transportation conformity particulate matter hot-spot air quality modeling.

Science.gov (United States)

2013-07-01

In light of the new development in particulate matter (PM) hot-spot regulations and Illinois Department : of Transportation (IDOT)s National Environmental Policy Act (NEPA) documentation requirements, : this project is intended to (1) perform and ...

Nuclear track radiography of 'hot' aerosol particles

International Nuclear Information System (INIS)

Boulyga, S.F.; Kievitskaja, A.I.; Kievets, M.K.; Lomonosova, E.M.; Zhuk, I.V.; Yaroshevich, O.I.; Perelygin, V.P.; Petrova, R.; Brandt, R.; Vater, P.

1999-01-01

Nuclear track radiography was applied to identify aerosol 'hot' particles which contain elements of nuclear fuel and fallout after Chernobyl NPP accident. For the determination of the content of transuranium elements in radioactive aerosols the measurement of the α-activity of 'hot' particles by SSNTD was used in this work, as well as radiography of fission fragments formed as a result of the reactions (n,f) and (γ,f) in the irradiation of aerosol filters by thermal neutrons and high energy gamma quanta. The technique allowed the sizes and alpha-activity of 'hot' particles to be determined without extracting them from the filter, as well as the determination of the uranium content and its enrichment by 235 U, 239 Pu and 241 Pu isotopes. Sensitivity of determination of alpha activity by fission method is 5x10 -6 Bq per particle. The software for the system of image analysis was created. It ensured the identification of track clusters on an optical image of the SSNTD surface obtained through a video camera and the determination of size and activity of 'hot' particles

Nuclear matter and electron scattering

Energy Technology Data Exchange (ETDEWEB)

Sick, I [Dept. fuer Physik und Astronomie, Univ. Basel (Switzerland)

1998-06-01

We show that inclusive electron scattering at large momentum transfer allows a measurement of short-range properties of nuclear matter. This provides a very valuable constraint in selecting the calculations appropriate for predicting nuclear matter properties at the densities of astrophysical interest. (orig.)

Chiral thermodynamics of nuclear matter

International Nuclear Information System (INIS)

Fiorilla, Salvatore

2012-01-01

The equation of state of nuclear matter is calculated at finite temperature in the framework of in-medium chiral perturbation theory up to three-loop order. The dependence of its thermodynamic properties on the isospin-asymmetry is investigated. The chiral quark condensate is evaluated for symmetric nuclear matter. Its behaviour as a function of density and temperature sets important nuclear physics constraints for the QCD phase diagram.

Chiral thermodynamics of nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Fiorilla, Salvatore

2012-10-23

The equation of state of nuclear matter is calculated at finite temperature in the framework of in-medium chiral perturbation theory up to three-loop order. The dependence of its thermodynamic properties on the isospin-asymmetry is investigated. The chiral quark condensate is evaluated for symmetric nuclear matter. Its behaviour as a function of density and temperature sets important nuclear physics constraints for the QCD phase diagram.

Future cosmological sensitivity for hot dark matter axions

CERN Document Server

Archidiacono, Maria; Hamann, Jan; Hannestad, Steen; Raffelt, Georg; Wong, Yvonne Y Y

2015-01-01

We study the potential of a future, large-volume photometric survey to constrain the axion mass $m_a$ in the hot dark matter limit. Future surveys such as Euclid will have significantly more constraining power than current observations for hot dark matter. Nonetheless, the lowest accessible axion masses are limited by the fact that axions lighter than $\\sim 0.15$ eV decouple before the QCD epoch, assumed here to occur at a temperature $T_{\\rm QCD} \\sim 170$ MeV; this leaves an axion population of such low density that its late-time cosmological impact is negligible. For larger axion masses, $m_a \\gtrsim 0.15$ eV, where axions remain in equilibrium until after the QCD phase transition, we find that a Euclid-like survey combined with Planck CMB data can detect $m_a$ at very high significance. Our conclusions are robust against assumptions about prior knowledge of the neutrino mass. Given that the proposed IAXO solar axion search is sensitive to $m_a\\lesssim 0.2$ eV, the axion mass range probed by cosmology is n...

Birth, life and death of hot nuclei

International Nuclear Information System (INIS)

Suraud, E.; Tamain, B.; Gregoire, C.

1989-01-01

Intermediate energy heavy-ions (10-100 MeV/u) are the most powerful tool to study hot nuclear matter properties. In this paper we give a review of experimental and theoretical works which support this statement. The first challenge is to achieve hot nuclei formation. The second one is to study their properties. The formation step is governed by the relative influence of nucleon-nucleon collisions and mean field effects. Fundamental quantities such as excited matter decay time, thermalization time, relaxation time for collective modes are of major importance and are compared with typical collision times. It appears that semi-classical theories are able to give a reasonable description of the collision and that they are a good guide for defining further experiments. We show how it has been possible to experimentally establish that very hot equilibrated nuclei are really formed. Their decay properties are not basically different from decay properties at lower bombarding energy. However specific channels are open: in that sense, we take stock of the multifragmentation process. Moreover, compression effects may be an important feature of this energy range. Future studies will involve heavier projectiles around 30-50 MeV/u. They will be the best probe for hot and compressed nuclear matter studies

Skin Dose Assessment by Hot Particles in Domestic Nuclear Power Plant

International Nuclear Information System (INIS)

Choi, Bo Yeol; Cho, Woon Kap; Lee, Jai Ki

2009-01-01

Since a contamination event by hot particles happened due to damaged nuclear fuel at a nuclear power plant (NPP) in the 1980's, skin exposure resulted from hot particles has gotten considerable attention from all the radiation workers in the nuclear industry. In particular, contamination incident caused by hot particles which happened at a NPP in Susquehanna proved that there existed hot particles with the radioactivity of 0.7 GBq, 0.78 GBq, and even 2.78 GBq at maximum. One of these particles was found on a worker's shoe and gave out a dose of 170 mSv. Although there has been no contamination event reported in domestic NPPs which are caused by hot particles, it is hard to conclude that there is no possibility of such contamination for radiation workers. The contaminated samples employed in this study were taken from local NPPs and supposes a case of a worker's skin contaminated by hot particles to evaluate the dose provided to the worker's skin

Cosmological N-body simulations with generic hot dark matter

DEFF Research Database (Denmark)

Brandbyge, Jacob; Hannestad, Steen

2017-01-01

We have calculated the non-linear effects of generic fermionic and bosonic hot dark matter components in cosmological N-body simulations. For sub-eV masses, the non-linear power spectrum suppression caused by thermal free-streaming resembles the one seen for massive neutrinos, whereas for masses...

Past and present of nuclear matter

International Nuclear Information System (INIS)

Ritter, H.G.

1994-05-01

The subject of nuclear matter 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 nuclear matter 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 nuclear matter 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 nuclear matter, and it lasts only for collision times of ∼ 10 -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 nuclear matter. 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 nuclear matter. 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

Nuclear viscosity of hot rotating 240Cf

International Nuclear Information System (INIS)

Shaw, N. P.; Dioszegi, I.; Mazumdar, I.; Buda, A.; Morton, C. R.; Velkovska, J.; Beene, J. R.; Stracener, D. W.; Varner, R. L.; Thoennessen, M.

2000-01-01

The absolute γ-ray/fission multiplicities from hot rotating 240 Cf, populated at seven bombarding energies using the reaction 32 S+ 208 Pb, are reported. Statistical model calculations including nuclear dissipation have been performed to extract the dependence of the nuclear viscosity on temperature and/or nuclear deformation. The extracted nuclear dissipation coefficient is found to be independent of temperature. Large dissipation during the saddle to scission path provides a good fit to the γ-ray spectra. (c) 2000 The American Physical Society

Confinement and deconfinement of quarks in nuclear matter

International Nuclear Information System (INIS)

Baym, G.

1982-01-01

Nuclear matter at high baryon density or excitation energy is expected to undergo a transition to deconfined quark matter, a new state of matter, whose production and detection would be an exciting and basic advance in nuclear physics. These lectures summarize current understanding of quark matter and the deconfinement transition. Beginning with a review of elementary models of confinement, the basic properties of quark matter are described, estimates of the transition from hadronic to quark matter are made, and various ways one might see quark matter experimentally by production in nuclear collisions or in the form of metastable exotic nuclear objects are discussed. (author)

Thermodynamics of neutron-rich nuclear matter

Energy Technology Data Exchange (ETDEWEB)

López, Jorge A., E-mail: jorgelopez@utep.edu [Department of Physics, University of Texas at El Paso, El Paso, Texas 79968, U.S.A (United States); Porras, Sergio Terrazas, E-mail: sterraza@uacj.mx; Gutiérrez, Araceli Rodríguez, E-mail: al104010@alumnos.uacj.mx [Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chihuahua, México (Mexico)

2016-07-07

This manuscript presents methods to obtain properties of neutron-rich nuclear matter from classical molecular dynamics. Some of these are bulk properties of infinite nuclear matter, phase information, the Maxwell construction, spinodal lines and symmetry energy.

Probing nuclear matter with dileptons

International Nuclear Information System (INIS)

Schroeder, L.S.

1986-06-01

Dileptons are shown to be of interest in helping probe extreme conditions of temperature and density in nuclear matter. The current state of experimental knowledge about dileptons is briefly described, and their use in upcoming experiments with light ions at CERN SPS are reviewed, including possible signatures of quark matter formation. Use of dileptons in an upcoming experiment with a new spectrometer at Berkeley is also discussed. This experiment will probe the nuclear matter equation of state at high temperature and density. 16 refs., 8 figs

Nuclear track radiography of 'hot' aerosol particles

CERN Document Server

Boulyga, S F; Kievets, M K; Lomonosova, E M; Zhuk, I V; Yaroshevich, O I; Perelygin, V P; Petrova, R I; Brandt, R; Vater, P

1999-01-01

Nuclear track radiography was applied to identify aerosol 'hot' particles which contain elements of nuclear fuel and fallout after Chernobyl NPP accident. For the determination of the content of transuranium elements in radioactive aerosols the measurement of the alpha-activity of 'hot' particles by SSNTD was used in this work, as well as radiography of fission fragments formed as a result of the reactions (n,f) and (gamma,f) in the irradiation of aerosol filters by thermal neutrons and high energy gamma quanta. The technique allowed the sizes and alpha-activity of 'hot' particles to be determined without extracting them from the filter, as well as the determination of the uranium content and its enrichment by sup 2 sup 3 sup 5 U, sup 2 sup 3 sup 9 Pu and sup 2 sup 4 sup 1 Pu isotopes. Sensitivity of determination of alpha activity by fission method is 5x10 sup - sup 6 Bq per particle. The software for the system of image analysis was created. It ensured the identification of track clusters on an optical imag...

Theoretical studies in nuclear reactions and nuclear structure

International Nuclear Information System (INIS)

Wallace, S.J.

1991-05-01

This report discusses topics in the following areas: Hadronic structure; hadrons in nuclei; hot hadronic matter; relativistic nuclear physics and NN interaction; leptonic emissions from high-Z heavy ion collisions; theoretical studies of heavy ion dynamics; nuclear pre-equilibrium reactions; classical chaotic dynamics and nuclear structure; and, theory of nuclear fission

Phase transition from nuclear matter to color superconducting quark matter

Energy Technology Data Exchange (ETDEWEB)

Bentz, W. E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Horikawa, T.; Ishii, N.; Thomas, A.W

2003-06-02

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 nuclear matter 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.

Spectral properties of nuclear matter

International Nuclear Information System (INIS)

Bozek, P

2006-01-01

We review self-consistent spectral methods for nuclear matter calculations. The in-medium T-matrix approach is conserving and thermodynamically consistent. It gives both the global and the single-particle properties the system. The T-matrix approximation allows to address the pairing phenomenon in cold nuclear matter. A generalization of nuclear matter calculations to the super.uid phase is discussed and numerical results are presented for this case. The linear response of a correlated system going beyond the Hartree-Fock+ Random-Phase-Approximation (RPA) scheme is studied. The polarization is obtained by solving a consistent Bethe-Salpeter (BS) equation for the coupling of dressed nucleons to an external field. We find that multipair contributions are important for the spin(isospin) response when the interaction is spin(isospin) dependent

Formation and decay of hot nuclei

International Nuclear Information System (INIS)

Tamain, B.

1992-09-01

The mechanisms involved in hot nuclei formation and decay and their eventual connexion with fundamental properties of nuclear matter are discussed, i.e. its equation of state is considered. After a brief review of the reactions in which hot nuclei can be formed, the variables which are used to describe them, the corresponding theoretical descriptions and their limits when extreme states are reached are discussed. Experimental evidences for hot nuclei formation are presented, with the corresponding decay properties used as signatures. (R.P.) 64 refs.; 25 figs.; 2 tabs

Multifragmentation of hot nuclei

International Nuclear Information System (INIS)

Tamain, B.

1990-10-01

It is difficult to deposit a large amount (∼ 1 Gev) of excitation energy into a nucleus. And if one wants to deposit large excitation energy values, the best way consists of shooting a given target nucleus with several nucleons, which can be achieved by using intermediate energy (10-100 MeV/nucleon) heavy ions. Such very excited objects were named hot nuclei. The study of hot nuclei has been undertaken only for 7 years because intermediate energy heavy ion facilities were not available before. The game is then to determine the decay properties of such nuclei, their limits of existence. Their study is connected with general properties of nuclear matter: namely its equation of state. Of special interest, is the onset of a new decay mechanism: multifragmentation, which is the non-sequential disassembly of a hot nucleus into several light nuclei (often called intermediate-mass fragments or IMF) or particles. This paper, shows how this mechanism can reflect fundamental properties of nuclear matter, but also how its experimental signature is difficult to establish. Multifragmentation has also been studied by using very energetic projectiles (protons and heavy ions) in the relativistic or ultra-relativistic region. The multifragmentation question of hot nuclei is far from being solved. One knows that IMF production increases when the excitation energy brought into a system is strongly increased, but very little is known about the mechanisms involved and a clear onset for multifragmentation is not established

Physics of hot hadronic matter and quark-gluon plasma

International Nuclear Information System (INIS)

Shuryak, E.V.

1990-07-01

This Introductory talk contains a brief review of the current status of theoretical and experimental activities related to physics of superdense matter. In particular, we discuss latest lattice results on the phase transition, recent progress in chiral symmetry physics based on the theory of interacting instantons, new in the theory of QGP and of hot hadronic matter, mean p t and collective flow, the shape of p t distribution, strangeness production, J/ψ suppression and φ enhancement, two puzzles connected with soft pion and soft photon enhancements, and some other ''ultrasoft'' phenomena. 56 refs., 6 figs

Properties of the cloudy bag in nuclear matter

International Nuclear Information System (INIS)

Bunatyan, G.G.

1986-01-01

Because of the pion mode softening, the pion field of the clody bag in the nuclear matter increases if the nuclear density increases. This causes in its turn the decreasing of the bag size and at a sufficiently large density of the nuclear matter lead to absolute instability of the cloudy bag-nucleon, which means the transition of the nuclear matter in another nonnucleon phase

Probing properties of hot and dense QCD matter with heavy flavor in the PHENIX experiment at RHIC

Directory of Open Access Journals (Sweden)

Nouicer Rachid

2015-01-01

Full Text Available Hadrons carrying heavy quarks, i.e. charm or bottom, are important probes of the hot and dense medium created in relativistic heavy ion collisions. Heavy quarkantiquark pairs are mainly produced in initial hard scattering processes of partons. While some of the produced pairs form bound quarkonia, the vast majority hadronize into particles carrying open heavy flavor. Heavy quark production has been studied by the PHENIX experiment at RHIC via measurements of single leptons from semi-leptonic decays in both the electron channel at mid-rapidity and in the muon channel at forward rapidity. A large suppression and azimuthal anisotropy of single electrons have been observed in Au + Au collisions at 200 GeV. These results suggest a large energy loss and flow of heavy quarks in the hot, dense matter. The PHENIX experiment has also measured J/ψ production at 200 GeV in p + p, d + Au, Cu + Cu and Au + Au collisions, both at mid- and forward-rapidities, and additionally Cu + Au and U + U at forward-rapidities. In the most energetic collisions, more suppression is observed at forward rapidity than at central rapidity. This can be interpreted either as a sign of quark recombination, or as a hint of additional cold nuclear matter effects. The centrality dependence of nuclear modification factor, RAA(pT, for J/ψ in U + U collisions at √sNN = 193 GeV shows a similar trend to the lighter systems, Au + Au and Cu + Cu, at similar energy 200 GeV.

Low mass dilepton production at the SPS probing hot and dense nuclear matter

CERN Document Server

Pérez de los Heros, C; Baur, R; Breskin, Amos; Chechik, R; Drees, A; Jacob, C; Faschingbauer, U; Fisher, P H; Fraenkel, Zeev; Fuchs, C; Gatti, E; Glässel, P; Günzel, T F; Hess, F; Irmscher, D; Lenkeit, B C; Olsen, L H; Panebratsev, Yu A; Pfeiffer, A; Ravinovich, I; Rehak, P; Schön, A; Schükraft, Jürgen; Sampietro, M; Shimansky, S S; Shor, A; Specht, H J; Steiner, V; Tapprogge, Stefan; Tel-Zur, G; Tserruya, Itzhak; Ullrich, T S; Wurm, J P; Yurevich, V I

1996-01-01

CERES and HELIOS-3 have detected a significant enhancement of low--mass dileptons in nuclear collisions at 200 GeV/nucleon with respect to the expected ``conventional'' sources. The onset of the excess, starting at a mass of $\\sim2m_{\\pi}$, and the possibility of a quadratic dependence on the event multiplicity suggest the opening of the $\\pi^+\\pi^-\\rightarrow e^+e^-(\\mu^+\\mu^-)$ annihilation channel. This would be the first observation of thermal radiation from dense hadronic matter. Possible interpretations of these results are presented, including the reduction of the $\\rho$ mass due to partial restoration of chiral symmetry in the dense fireball formed in the collision.

Proceedings of the specialists' meeting on 'nuclear spectroscopy and condensed matter physics using short-lived nuclei'

International Nuclear Information System (INIS)

Kobayashi, Yoshio; Shibata, Michihiro; Ohkubo, Yoshitaka

2016-02-01

The research reactor at Research Reactor Institute, Kyoto University is a very useful neutron generator, providing us neutron-rich unstable nuclei by bombarding nuclei with those neutrons. The produced unstable nuclei exhibit aspects distinct from those of stable ones. Nuclear structure studies on a variety of excited states reflecting dynamic nuclear properties are one of fascinating research subjects of physics. On the other hand, some radioactive nuclei can be used as useful probes for understanding interesting properties of condensed matters through studies of hyperfine interactions of static nuclear electromagnetic moments with extranuclear fields. Concerning these two research fields and related areas, the 2nd symposium under the title of 'Nuclear Spectroscopy and Condensed Matter Physics Using Short-lived Nuclei' was held at the Institute for two days on November 4 and 5 in 2015. We are pleased that many hot discussions were made. The talks were given on the followings: 1) Nuclear spectroscopic experiments, 2) TDPAC (time-differential perturbed angular correlation), 3) β-NMR (nuclear magnetic resonance), 4) Moessbauer spectroscopy, 5) muon, etc. This issue is the collection of 17 papers presented at the entitled meeting. The 6 of the presented papers are indexed individually. (J.P.N.)

Relativity damps OPEP in nuclear matter

International Nuclear Information System (INIS)

Banerjee, M.K.

1998-06-01

Using a relativistic Dirac-Brueckner analysis the OPEP contribution to the ground state energy of nuclear matter 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 * /M with increasing density. He points out that if derivative-coupled OPEP is the preferred form of nuclear effective lagrangian nonrelativistic treatment of nuclear matter is in trouble. Lacking the notion of M * it cannot replicate the damping. He suggests an examination of the feasibility of using pseudoscalar coupled πN interaction before reaching a final conclusion about nonrelativistic treatment of nuclear matter

Selected topics in nuclear- and astro-physics

International Nuclear Information System (INIS)

Sujkowski, Z.; Szeflinska, G.

1991-11-01

The subjects cover the properties of hot and dense matter created in laboratory (the dynamics of the nucleus-nucleus collisions, the structure of hot and spinning nuclei), the properties of hot and dense stellar matter, the nuclear reactions of astrophysical interest (including the latest developments of the tools such as e.g. the radioactive beams) and the nucleosynthesis (esp. R-processes). (author)

Nuclear matter theory

International Nuclear Information System (INIS)

Negele, J.W.

1977-01-01

Recent advances in variational and perturbative theories are surveyed which offer genuine promise that nuclear matter will soon become a viable tool for investigating nuclear interactions. The basic elements of the hypernetted chain expansion for Jastrow variational functions are briefly reviewed, and comparisons of variational and perturbative results for a series of increasingly complicated systems are presented. Prospects for investigating realistic forces are assessed and the unresolved, open problems are summarized

Nuclear matter in neutron star crust

International Nuclear Information System (INIS)

Kido, Toshihiko; Maruyama, Toshiki; Chiba, Satoshi; Niita, Koji

2000-01-01

Properties of nuclear matter below the nuclear saturation density is analyzed by numerical simulations with the periodic boundary condition. The equation of state at these densities is softened by the formation of cluster(s) internal density of which is nearly equal to the saturation density. The structure of nuclear matter shows some exotic shapes with variation of the density. Furthermore, it is found that the symmetry parameter a sym (ρ) is not a linear function of density at low density region. (author)

Nuclear matter physics at NICA

Energy Technology Data Exchange (ETDEWEB)

Senger, P. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

2016-08-15

The exploration of the QCD phase diagram is one of the most exciting and challenging projects of modern nuclear physics. In particular, the investigation of nuclear matter at high baryon densities offers the opportunity to find characteristic structures such as a first-order phase transition with a region of phase coexistence and a critical endpoint. The experimental discovery of these prominent landmarks of the QCD phase diagram would be a major breakthrough in our understanding of the properties of nuclear matter. Equally important is the quantitative experimental information on the properties of hadrons in dense matter which may shed light on chiral symmetry restoration and the origin of hadron masses. Worldwide, substantial efforts at the major heavy-ion accelerators are devoted to the clarification of these fundamental questions, and new dedicated experiments are planned at future facilities like CBM at FAIR in Darmstadt and MPD at NICA/JINR in Dubna. In this article the perspectives for MPD at NICA will be discussed. (orig.)

Quasiparticle pole strength in nuclear matter

International Nuclear Information System (INIS)

Poggioli, R.S.; Jackson, A.D.

1975-01-01

It is argued that single-particle-like behavior in nuclear matter is much less probable than Brueckner theory suggests. In particular, the quasiparticle pole strength is evaluated for nuclear matter and it is shown that, contrary to the spirit of Brueckner theory, low momentum states play a crucial role in determining the magnitude of z/sub k/sub F/. (auth)

Structure of the subsaturated nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Maruyama, Toshiki; Maruyama, Tomoyuki; Chiba, Satoshi; Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Niita, Koji; Oyamatsu, Kazuhiro

1998-07-01

Quantum molecular dynamics is applied to study the ground state and excited state properties of nuclear matter at subsaturation densities. The structure of nuclear matter 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)

Incompressibility of asymmetric nuclear matter

International Nuclear Information System (INIS)

Chen, Liewen; Cai, Baojun; Shen, Chun; Ko, Cheming; Xu, Jun; Li, Baoan

2010-01-01

Using an isospin- and momentum-dependent modified Gogny (MDI) interaction, the Skyrme-Hartree-Fock (SHF) approach, and a phenomenological modified Skyrme-like (MSL) model, we have studied the incompressibility K sat (δ) of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of K sat (δ) in powers of isospin asymmetry δ, i.e., K sat (δ) = K 0 + K sat,2 δ 2 + K sat,4 δ 4 + O(δ 6 ), the magnitude of the 4th-order K sat,4 parameter is generally small. The 2nd-order K sat,2 parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matter at saturation density. Furthermore, the K sat,2 can be expressed as K sat,2 = K sym – 6L – J 0 /K 0 L in terms of the slope parameter L and the curvature parameter K sym of the symmetry energy and the third-order derivative parameter J 0 of the energy of symmetric nuclear matter at saturation density, and we find the higher order J 0 contribution to K sat,2 generally cannot be neglected. Also, we have found a linear correlation between K sym and L as well as between J 0 /K 0 and K 0 . Using these correlations together with the empirical constraints on K 0 and L, the nuclear symmetry energy E sym (ρ0) at normal nuclear density, and the nucleon effective mass, we have obtained an estimated value of K sat,2 = -370 ± 120 MeV for the 2nd-order parameter in the isospin asymmetry expansion of the incompressibility of asymmetric nuclear matter at its saturation density. (author)

The role of hadron resonances in hot hadronic matter

Energy Technology Data Exchange (ETDEWEB)

Goity, Jose [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hampton Univ., Hampton, VA (United States)

2017-02-01

Hadron resonances can play a significant role in hot hadronic matter. Of particular interest for this workshop are the contributions of hyperon resonances. The question about how to quantify the effects of resonances is here addressed. In the framework of the hadron resonance gas, the chemically equilibrated case, relevant in the context of lattice QCD calculations, and the chemically frozen case relevant in heavy ion collisions are discussed.

Effective Field Theories for Hot and Dense Matter

Directory of Open Access Journals (Sweden)

Blaschke D.

2010-10-01

Full Text Available The lecture is divided in two parts. The first one deals with an introduction to the physics of hot, dense many-particle systems in quantum field theory [1, 2]. The basics of the path integral approach to the partition function are explained for the example of chiral quark models. The QCD phase diagram is discussed in the meanfield approximation while QCD bound states in the medium are treated in the rainbow-ladder approximation (Gaussian fluctuations. Special emphasis is devoted to the discussion of the Mott effect, i.e. the transition of bound states to unbound, but resonant scattering states in the continnum under the influence of compression and heating of the system. Three examples are given: (1 the QCD model phase diagram with chiral symmetry ¨ restoration and color superconductivity [3], (2 the Schrodinger equation for heavy-quarkonia [4], and (2 Pions [5] as well as Kaons and D-mesons in the finite-temperature Bethe-Salpeter equation [6]. We discuss recent applications of this quantum field theoretical approach to hot and dense quark matter for a description of anomalous J/ψ supression in heavy-ion collisions [7] and for the structure and cooling of compact stars with quark matter interiors [8]. The second part provides a detailed introduction to the Polyakov-loop Nambu–Jona-Lasinio model [9] for thermodynamics and mesonic correlations [10] in the phase diagram of quark matter. Important relationships of low-energy QCD like the Gell-Mann–Oakes–Renner relation are generalized to finite temperatures. The effect of including the coupling to the Polyakov-loop potential on the phase diagram and mesonic correlations is discussed. An outlook is given to effects of nonlocality of the interactions [11] and of mesonic correlations in the medium [12] which go beyond the meanfield description.

Nuclear track radiography of 'hot' aerosol particles

Energy Technology Data Exchange (ETDEWEB)

Boulyga, S.F.; Kievitskaja, A.I.; Kievets, M.K.; Lomonosova, E.M.; Zhuk, I.V.; Yaroshevich, O.I.; Perelygin, V.P.; Petrova, R.; Brandt, R.; Vater, P

1999-06-01

Nuclear track radiography was applied to identify aerosol 'hot' particles which contain elements of nuclear fuel and fallout after Chernobyl NPP accident. For the determination of the content of transuranium elements in radioactive aerosols the measurement of the {alpha}-activity of 'hot' particles by SSNTD was used in this work, as well as radiography of fission fragments formed as a result of the reactions (n,f) and ({gamma},f) in the irradiation of aerosol filters by thermal neutrons and high energy gamma quanta. The technique allowed the sizes and alpha-activity of 'hot' particles to be determined without extracting them from the filter, as well as the determination of the uranium content and its enrichment by {sup 235}U, {sup 239}Pu and {sup 241}Pu isotopes. Sensitivity of determination of alpha activity by fission method is 5x10{sup -6} Bq per particle. The software for the system of image analysis was created. It ensured the identification of track clusters on an optical image of the SSNTD surface obtained through a video camera and the determination of size and activity of 'hot' particles00.

A hydrodynamic approach to cosmology - Texture-seeded cold dark matter and hot dark matter cosmogonies

Science.gov (United States)

Cen, R. Y.; Ostriker, J. P.; Spergel, D. N.; Turok, N.

1991-01-01

Hydrodynamical simulations of galaxy formation in a texture-seeded cosmology are presented, with attention given to Omega = 1 galaxies dominated by both hot dark matter (HDM) and cold dark matter (CDM). The simulations include both gravitational and hydrodynamical physics with a detailed treatment of collisional and radiative thermal processes, and use a cooling criterion to estimate galaxy formation. Background radiation fields and Zel'dovich-Sunyaev fluctuations are explicitly computed. The derived galaxy mass function is well fitted by the observed Schechter luminosity function for a baryonic M/L of 3 and total M/L of 60 in galaxies. In both HDM and CDM texture scenarios, the 'galaxies' and 'clusters' are significantly more strongly correlated than the dark matter due to physical bias processes. The slope of the correlation function in both cases is consistent with observations. In contrast to Gaussian models, peaks in the dark matter density distributrion are less correlated than average.

Pion condensation in symmetric nuclear matter

Science.gov (United States)

Kabir, K.; Saha, S.; Nath, L. M.

1988-01-01

Using a model which is based essentially on the chiral SU(2)×SU(2) symmetry of the pion-nucleon interaction, we examine the possibility of pion condensation in symmetric nucleon matter. We find that the pion condensation is not likely to occur in symmetric nuclear matter for any finite value of the nuclear density. Consequently, no critical opalescence phenomenom is expected to be seen in the pion-nucleus interaction.

Isospin dependent properties of asymmetric nuclear matter

Science.gov (United States)

Chowdhury, P. Roy; Basu, D. N.; Samanta, C.

2009-07-01

The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and isovector components of the density dependent M3Y interaction. The incompressibility K∞ for the symmetric nuclear matter, the isospin dependent part Kasy of the isobaric incompressibility, and the slope L are all in excellent agreement with the constraints recently extracted from measured isotopic dependence of the giant monopole resonances in even-A Sn isotopes, from the neutron skin thickness of nuclei, and from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions. This work provides a fundamental basis for the understanding of nuclear matter under extreme conditions and validates the important empirical constraints obtained from recent experimental data.

Isospin dependent properties of asymmetric nuclear matter

OpenAIRE

Chowdhury, P. Roy; Basu, D. N.; Samanta, C.

2009-01-01

The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and the isovector components of density dependent M3Y interaction. The incompressibility $K_\\infty$ for the symmetric nuclear matter, the isospin dependent part $K_{asy}$ of the isobaric incompressibility and the slope $L$ are all in excellent agreement with the constraints recently extracted from measured isotopic de...

Nuclear matter as an MIT bag crystal

International Nuclear Information System (INIS)

Zhang, Q.; Derreth, C.; Schaefer, A.; Greiner, W.

1986-01-01

An MIT bag crystal model of nuclear matter is formulated. The energy bands of the quarks are calculated as a function of the overlap between adjacent bags. A clear indication of substantial overlap is found. Accordingly, infinite nuclear matter is more similar to a quark gas than to a nucleonic structure. (author)

Pion condensation in symmetric nuclear matter

International Nuclear Information System (INIS)

Kabir, K.; Saha, S.; Nath, L.M.

1987-09-01

Using a model which is based essentially on the chiral SU(2)xSU(2) symmetry of the pion-nucleon interaction, we examine the possibility of pion condensation in symmetric nucleon matter. We find that the pion condensation is not likely to occur in symmetric nuclear matter for any finite value of the nuclear density. Consequently, no critical opalescence phenomenon is expected to be seen in the pion-nucleus interaction. (author). 20 refs

Phase transitions in nuclear matter

International Nuclear Information System (INIS)

Glendenning, N.K.

1984-11-01

The rather general circumstances under which a phase transition in hadronic matter at finite temperature to an abnormal phase in which baryon effective masses become small and in which copious baryon-antibaryon pairs appear is emphasized. A preview is also given of a soliton model of dense matter, in which at a density of about seven times nuclear density, matter ceases to be a color insulator and becomes increasingly color conducting. 22 references

Strange hadrons and antiprotons as probes of hot and dense nuclear matter in relativistic heavy-ion collisions; Seltsame Hadronen und Antiprotonen als Proben heisser und dichter Kernmaterie in relativistischen Schwerionenkollisionen

Energy Technology Data Exchange (ETDEWEB)

Schade, Henry

2010-09-15

Strange particles play an important role as probes of relativistic heavy-ion collisions where hot and dense matter is studied. The focus of this thesis is on the production of strange particles within a transport model of Boltzmann-Uehling-Uhlenbeck (BUU) type. Current data of the HADES Collaboration concerning K{sup {+-}} and {phi} spectra provide the appropriate experimental framework. Moreover, the double-strange hyperon {xi}{sup -} is analyzed below the free NN production threshold. Hadron multiplicities, transversemomentum and rapidity spectra are compared with recent experimental data. Further important issues are in-medium mass shifts, the nuclear equation of state as well as the mean field of nucleons. Besides the study of AA collisions a comparison with recent ANKE data regarding the {phi} yield in pA collisions is done. Transparency ratios are determined and primarily investigated for absorption of {phi} mesons by means of the BUU transport code. Thereby, secondary {phi} production channels, isospin asymmetry and detector acceptance are important issues. A systematic analysis is presented for different system sizes. The momentum integrated Boltzmann equations describe dense nuclear matter on a hadronic level appearing in the Big Bang as well as in little bangs, in the context of kinetic off-equilibrium dynamics. This theory is applied to antiprotons and numerically calculated under consideration of various expansion models. Here, the evolution of proton- and antiproton densities till freeze-out is analyzed for ultra-relativistic heavy-ion collisions within a hadrochemic resonance gas model acting as a possible ansatz for solving the ''antiproton puzzle''. Furthermore, baryonic matter and antimatter is investigated in the early universe and the adiabatic path of cosmic matter is sketched in the QCD phase diagram. (orig.)

Monopole transitions in hot nuclei

Energy Technology Data Exchange (ETDEWEB)

Sujkowski, Z. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

1994-12-31

Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs.

Monopole transitions in hot nuclei

International Nuclear Information System (INIS)

Sujkowski, Z.

1994-01-01

Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs

Transition to Δ matter from hot, dense nuclear matter within a relativistic mean field formulation of the nonlinear σ and ω model

International Nuclear Information System (INIS)

Li, Z.; Zhuo, Y.; Li, Z.; Mao, G.; Zhuo, Y.; Mao, G.; Greiner, W.

1997-01-01

An investigation of the transition to Δ matter is performed based on a relativistic mean field formulation of the nonlinear σ and ω model. We demonstrate that in addition to the Δ-meson coupling, the occurrence of the baryon resonance isomer also depends on the nucleon-meson coupling. Our results show that for the favored phenomenological value of m * and K, the Δ isomer exists at baryon density ∼2 3ρ 0 if β=1.31 is adopted. For universal coupling of the nucleon and Δ, the Δ density at baryon density ∼2 3ρ 0 and temperature ∼0.4 0.5 fm -1 is about normal nuclear matter density, which is in accord with a recent experimental finding. copyright 1997 The American Physical Society

Neutrino interactions in hot and dense matter

International Nuclear Information System (INIS)

Reddy, S.; Prakash, M.; Lattimer, J.M.

1998-01-01

We study the charged and neutral current weak interaction rates relevant for the determination of neutrino opacities in dense matter found in supernovae and neutron stars. We establish an efficient formalism for calculating differential cross sections and mean free paths for interacting, asymmetric nuclear matter at arbitrary degeneracy. The formalism is valid for both charged and neutral current reactions. Strong interaction corrections are incorporated through the in-medium single particle energies at the relevant density and temperature. The effects of strong interactions on the weak interaction rates are investigated using both potential and effective field-theoretical models of matter. We investigate the relative importance of charged and neutral currents for different astrophysical situations, and also examine the influence of strangeness-bearing hyperons. Our findings show that the mean free paths are significantly altered by the effects of strong interactions and the multi-component nature of dense matter. The opacities are then discussed in the context of the evolution of the core of a protoneutron star. copyright 1998 The American Physical Society

A fermionic molecular dynamics technique to model nuclear matter

International Nuclear Information System (INIS)

Vantournhout, K.; Jachowicz, N.; Ryckebusch, J.

2009-01-01

Full text: At sub-nuclear densities of about 10 14 g/cm 3 , nuclear matter arranges itself in a variety of complex shapes. This can be the case in the crust of neutron stars and in core-collapse supernovae. These slab like and rod like structures, designated as nuclear pasta, have been modelled with classical molecular dynamics techniques. We present a technique, based on fermionic molecular dynamics, to model nuclear matter at sub-nuclear densities in a semi classical framework. The dynamical evolution of an antisymmetric ground state is described making the assumption of periodic boundary conditions. Adding the concepts of antisymmetry, spin and probability distributions to classical molecular dynamics, brings the dynamical description of nuclear matter to a quantum mechanical level. Applications of this model vary from investigation of macroscopic observables and the equation of state to the study of fundamental interactions on the microscopic structure of the matter. (author)

National Nuclear Physics Summer School

CERN Document Server

2016-01-01

The 2016 National Nuclear Physics Summer School (NNPSS) will be held from Monday July 18 through Friday July 29, 2016, at the Massachusetts Institute of Technology (MIT). The summer school is open to graduate students and postdocs within a few years of their PhD (on either side) with a strong interest in experimental and theoretical nuclear physics. The program will include the following speakers: Accelerators and Detectors - Elke-Caroline Aschenauer, Brookhaven National Laboratory Data Analysis - Michael Williams, MIT Double Beta Decay - Lindley Winslow, MIT Electron-Ion Collider - Abhay Deshpande, Stony Brook University Fundamental Symmetries - Vincenzo Cirigliano, Los Alamos National Laboratory Hadronic Spectroscopy - Matthew Shepherd, Indiana University Hadronic Structure - Jianwei Qiu, Brookhaven National Laboratory Hot Dense Nuclear Matter 1 - Jamie Nagle, Colorado University Hot Dense Nuclear Matter 2 - Wilke van der Schee, MIT Lattice QCD - Sinead Ryan, Trinity College Dublin Neutrino Theory - Cecil...

Colour deconfinement in hot and dense matter

CERN Document Server

Satz, Helmut

1996-01-01

We first introduce the conceptual basis of critical behaviour in strongly interacting matter, with colour deconfinement as QCD analog of the insulator-conductor transition and chiral symmetry restoration as special case of the associated shift in the mass of the constituents. Next we summarize quark-gluon plasma formation in finite temperature lattice QCD. We consider the underlying symmetries and their spontaneous breaking/restoration in the transition, as well as the resulting changes in thermodynamic behaviour. Finally, we turn to the experimental study of strongly interacting matter by high energy nuclear collisions, using charmonium production to probe the confinement status of the produced primordial medium. Recent results from Pb-Pb collisions at CERN may provide first evidence for colour deconfinement.

Hirschegg '95: Dynamical properties of hadrons in nuclear matter. Proceedings

International Nuclear Information System (INIS)

Feldmeier, H.; Noerenberg, W.

1995-01-01

The following topics were dealt with: Chiral symmetry, chiral condensates, in-medium effective chiral Lagrangians, Δ's in nuclei, nonperturbative QCD, electron scattering from nuclear matter, nuclear shadowing, QCD sum rules, deconfinement, ultrarelativistic heavy ion collisions, nuclear dimuon and electron pair production, photoproduction from nuclei, subthreshold K + production, kaon polarization in nuclear matter, charged pion production in relativistic heavy ion collisions, the Nambu-Jona-Lasinio model, the SU(3) L xSU(3) R sigma model, nonequilibrium dense nuclear matter, pion pair production at finite temperature. (HSI)

Search for cold and hot dark matter with the Heidelberg-Moscow experiment, HDMS, GENIUS and GENIUS-TF

International Nuclear Information System (INIS)

Klapdor-Kleingrothaus, H.V.; Dietz, A.; Krivosheina, I.V.

2003-01-01

The recent result from the Heidelberg-Moscow double beta experiment allows neutrinos still to play an important role as hot dark matter in the Universe. HDMS has started in 2001 its search for cold dark matter (WIMPS), with a HPGe crystal of enriched 73 Ge. Concerning hot dark matter, GENIUS will improve the present accuracy for the (effective) neutrino mass. At the same time GENIUS will extend the range of sensitivity in an unprecedented way to cover a wide range of the parameter space of SUSY parameters for neutralinos as cold dark matter. A GENIUS Test Facility in the Gran Sasso has been approved in 2001 and will come into operation by end of 2002. Finally some comments are given to some criticism of the result presented elsewhere

History of the nuclear matter safety and control law

International Nuclear Information System (INIS)

Dean, G.

1994-01-01

In this text we give the history of the law creation on the control and safety of nuclear matter. Initially based on the CEA regulation single owner of nuclear matter, the development of nuclear energy has conducted the French government to edict law in relation with IAEA and Euratom recommendations

Modified quark-meson coupling model for nuclear matter

International Nuclear Information System (INIS)

Jin, X.; Jennings, B.K.

1996-01-01

The quark-meson coupling model for nuclear matter, which describes nuclear matter as nonoverlapping MIT bags bound by the self-consistent exchange of scalar and vector mesons, is modified by introducing medium modification of the bag constant. We model the density dependence of the bag constant in two different ways: One invokes a direct coupling of the bag constant to the scalar meson field, and the other relates the bag constant to the in-medium nucleon mass. Both models feature a decreasing bag constant with increasing density. We find 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 nuclear matter emerge naturally. Such potentials are comparable to those suggested by relativistic nuclear phenomenology and finite-density QCD sum rules. This suggests that the reduction of bag constant in nuclear medium may play an important role in low- and medium-energy nuclear physics. copyright 1996 The American Physical Society

Development of a hot cell for post-irradiation analysis of nuclear fuels

Energy Technology Data Exchange (ETDEWEB)

Silva, Selma S.C.; Silva Junior, Silverio Ferreira da; Loureiro, Joao Roberto M. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: selmasallam@yahoo.com.br, e-mail: silvasf@cdtn.br, e-mail: jrmattos@cdtn.br

2009-07-01

Post irradiation examinations of nuclear fuels are performed in order to verify their in-service behavior. Examinations are conducted in compact structures called hot cells, designed to attend the different types of tests and analysis for fuel's characterization. The characterization of fuel microstructure is an activity performed in hot cells. Usually, hot cells for microstructural fuel analysis are designed to allow the metallographic and ceramographic samples preparation and after that, microscopical analysis of the fuel's microstructure. Due to the complexity of the foreseen operations, the severe limitations imposed by the available space into the hot cells, the capabilities of the remote manipulation devices, the procedures of radiological protection and the needs to obtain samples with an adequate surface quality for microscopic analysis, the design of a hot cell for fuel samples preparation presents a high level of complexity. In this paper, the methodology used to develop a hot cell facility for nuclear fuel's metallographic and ceramographic samples preparation is presented. Equipment, devices and systems used in conventional sample preparation processes were evaluated during bench tests. After the necessary adjustments and processes adaptations, they were assembled in a mock-up of the respective hot cell, where they were tested in conditions as realistic as possible, in order to improve the operations and processes to be performed at the real hot cells. (author)

Development of a hot cell for post-irradiation analysis of nuclear fuels

International Nuclear Information System (INIS)

Silva, Selma S.C.; Silva Junior, Silverio Ferreira da; Loureiro, Joao Roberto M.

2009-01-01

Post irradiation examinations of nuclear fuels are performed in order to verify their in-service behavior. Examinations are conducted in compact structures called hot cells, designed to attend the different types of tests and analysis for fuel's characterization. The characterization of fuel microstructure is an activity performed in hot cells. Usually, hot cells for microstructural fuel analysis are designed to allow the metallographic and ceramographic samples preparation and after that, microscopical analysis of the fuel's microstructure. Due to the complexity of the foreseen operations, the severe limitations imposed by the available space into the hot cells, the capabilities of the remote manipulation devices, the procedures of radiological protection and the needs to obtain samples with an adequate surface quality for microscopic analysis, the design of a hot cell for fuel samples preparation presents a high level of complexity. In this paper, the methodology used to develop a hot cell facility for nuclear fuel's metallographic and ceramographic samples preparation is presented. Equipment, devices and systems used in conventional sample preparation processes were evaluated during bench tests. After the necessary adjustments and processes adaptations, they were assembled in a mock-up of the respective hot cell, where they were tested in conditions as realistic as possible, in order to improve the operations and processes to be performed at the real hot cells. (author)

Hot wire TIG temper bead welding for nuclear repairs

International Nuclear Information System (INIS)

Lambert, J.A.; Gilston, P.F.

1989-08-01

A preliminary assessment has been carried out to determine the suitability of the hot wire tungsten inert gas (TIG) welding process for the repair of thick section, ferritic steel nuclear pressure vessels. The objective has been to identify a hot wire TIG temper bead procedure, suitable for repairs without post weld heat treatment. This procedure involves depositing two weld layers with carefully selected welding parameters such that overlapping thermal cycles produce a refined and tempered heat affected zone, HAZ, microstructure. (author)

Cosmological N -body simulations with generic hot dark matter

Energy Technology Data Exchange (ETDEWEB)

Brandbyge, Jacob; Hannestad, Steen, E-mail: jacobb@phys.au.dk, E-mail: sth@phys.au.dk [Department of Physics and Astronomy, University of Aarhus, Ny Munkegade 120, DK–8000 Aarhus C (Denmark)

2017-10-01

We have calculated the non-linear effects of generic fermionic and bosonic hot dark matter components in cosmological N -body simulations. For sub-eV masses, the non-linear power spectrum suppression caused by thermal free-streaming resembles the one seen for massive neutrinos, whereas for masses larger than 1 eV, the non-linear relative suppression of power is smaller than in linear theory. We furthermore find that in the non-linear regime, one can map fermionic to bosonic models by performing a simple transformation.

Clustering phenomena in nuclear matter below the saturation density

International Nuclear Information System (INIS)

Takemoto, Hiroki; Fukushima, Masahiro; Chiba, Satoshi; Horiuchi, Hisashi; Akaishi, Yoshinori; Tohsaki, Akihiro

2004-01-01

We investigate density-fluctuated states of nuclear matter as a result of clustering below the saturation density ρ 0 by description in terms of the Bloch function. The Bloch description has the advantage of a unified representation for a density-fluctuated state from an aggregate of uncorrelated clusters in extremely low-density regions to the plane-wave state of uniform matter in relatively high-density regions. We treat the density-fluctuated states due to α and 16 O clustering in symmetric nuclear matter and due to 10 He clustering in asymmetric nuclear matter. The density-fluctuated states develop as the density of matter decreases below each critical density around 0.2-0.4 ρ 0 which depends on what kind of effective force we use

Dibaryons and nuclear matter

International Nuclear Information System (INIS)

Besliu, C.; Popa, L.; Popa, V.

1992-01-01

We discuss some recent ideas concerning the structure and the properties of the dibaryonic resonances, with special emphasis on their behaviour when produced in dense nuclear matter. Some features of their de-excitation mechanism and consequent experimentally identifiable signatures are predicted. (Author)

On the thermal properties of polarized nuclear matter

International Nuclear Information System (INIS)

Hassan, M.Y.M.; Montasser, S.S.; Ramadan, S.

1979-08-01

The thermal properties of polarized nuclear matter are calculated using Skyrme III interaction modified by Dabrowski for polarized nuclear matter. The temperature dependence of the volume, isospin, spin and spin isospin pressure and energies are determined. The temperature, isospin, spin and spin isospin dependence of the equilibrium Fermi momentum is also discussed. (author)

$J/\\Psi$ mass shift in nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Gastao Krein, Anthony Thomas, Kazuo Tsushima

2011-02-01

The $J/\\Psi$ mass shift in cold nuclear matter is computed using an effective Lagrangian approach. The mass shift is computed by evaluating $D$ and $D^*$ meson loop contributions to the $J/\\Psi$ self-energy employing medium-modified meson masses. The modification of the $D$ and $D^*$ masses in nuclear matter is obtained using the quark-meson coupling model. The loop integrals are regularized with dipole form factors and the sensitivity of the results to the values of form-factor cutoff masses is investigated. The $J/\\Psi$ mass shift arising from the modification of the $D$ and $D^*$ loops at normal nuclear matter density is found to range from $-16$~MeV to $-24$~MeV under a wide variation of values of the cutoff masses. Experimental perspectives for the formation of a bound state of $J/\\Psi$ to a nucleus are investigated.

A three-dimensional hydrodynamic treatment of the hot dark matter cosmological scenario

Science.gov (United States)

Cen, Renyue; Ostriker, Jeremiah P.

1992-01-01

The study computes the evolution of the hot dark matter (HDM) model containing both baryonic matter and dark matter for a post recombination Friedmann-Robertson-Walker universe. A locally valid Newtonian approximation is used to model a representative piece of the universe with size much less than the horizon. For the HDM model with the present chosen normalization, the hard X-ray (1-10 keV) radiation intensity is less than that in the observations (Wu et al., 1991) by a factor of 30. In agreement with other work, it is found that baryonic matter is slightly antibiased over dark matter on the cell scale, 0.5/h Mpc = 667 kpc. The HDM model with the present chosen parameters does not overproduce X-ray-luminous clusters, and there is a negative evolution in the late epochs in the sense that the number density of X-ray clusters was higher at 0.5 redshift than at 0 redshift at the brightest end.

Detection of Hot Halo Gets Theory Out of Hot Water

Science.gov (United States)

2006-02-01

Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of

Can tonne-scale direct detection experiments discover nuclear dark matter?

Energy Technology Data Exchange (ETDEWEB)

Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M., E-mail: Alistair.Butcher.2010@live.rhul.ac.uk, E-mail: Russell.Kirk.2008@live.rhul.ac.uk, E-mail: Jocelyn.Monroe@rhul.ac.uk, E-mail: Stephen.West@rhul.ac.uk [Department of Physics, Royal Holloway University of London, Egham, Surrey, TW20 0EX (United Kingdom)

2017-10-01

Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .

Can tonne-scale direct detection experiments discover nuclear dark matter?

International Nuclear Information System (INIS)

Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M.

2017-01-01

Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .

Track theory and nuclear photographic emulsions for Dark Matter searches

International Nuclear Information System (INIS)

Ditlov, V.A.

2013-01-01

This work is devoted to the analysis of possibilities of nuclear emulsions for Dark Matter search, particles of which can produce slow recoil-nuclei. Tracks of such recoil-nuclei in developed nuclear emulsion consist from several emulsion grains. The analysis was carried out with Monte-Carlo calculations made on the basis of the Track Theory and the various factors influencing Dark Matter particles registration efficiency were investigated. Problems, which should be solved for optimal utilization of nuclear emulsions in Dark Matter search, were formulated. B ody - Highlights: ► Specific features of Dark Matter Search in nuclear photographic emulsions. ► Track theory for WIMP search in nuclear emulsions. ► Primary efficiency for single WIMP registration. ► Properties of primary WIMP registration efficiency. ► Primary registration efficiency of WIMP flow

Nuclear chemistry

International Nuclear Information System (INIS)

Vertes, A.; Kiss, I.

1987-01-01

This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors

Nuclear chemistry

International Nuclear Information System (INIS)

Vertes, A.; Kiss, I.

1987-01-01

This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors. (Auth.)

Soliton matter as a model of dense nuclear matter

International Nuclear Information System (INIS)

Glendenning, N.K.

1985-01-01

We employ the hybrid soliton model of the nucleon consisting of a topological meson field and deeply bound quarks to investigate the behavior of the quarks in soliton matter as a function of density. To organize the calculation, we place the solitons on a spatial lattice. The model suggests the transition of matter from a color insulator to a color conductor above a critical density of a few times normal nuclear density. 9 references, 5 figures

Accelerators and nuclear reactors as tools in hot atom chemistry

International Nuclear Information System (INIS)

Lindner, L.

1975-01-01

The characteristics of accelerators and of nuclear reactors - the latter to a lesser extent - are discussed in view of their present and future use in hot atom chemistry research and its applications. (author)

Decay of a hot zone in finite nuclei

International Nuclear Information System (INIS)

De, J.N.; Gregoire, C.

1987-01-01

Assuming that a hot zone is formed in nuclear collisions, we study its decay in the surrounding colder nuclear matter. Thermal equilibration resulting from energy transport is analyzed in terms of a classical model and within the Vlasov-Uehling-Uhlenbeck self-consistent approach. Convection is found to be the dominant energy propagation mode. Thermal equilibration time is found to be of the order of the damping of isoscalar quadrupole vibration, i.e. a few 10 -21 sec. This feature may not be fully consistent with recent available experimental data and casts doubt on the possibility of formation of a sharply localised thermally equilibrated hot zone as a likely intermediate state for excitation in finite nuclei in intermediate energy collisions. 16 refs

Simulations of cold nuclear matter at sub-saturation densities

Energy Technology Data Exchange (ETDEWEB)

Giménez Molinelli, P.A., E-mail: pagm@df.uba.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina); Nichols, J.I. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina); López, J.A. [Department of Physics, University of Texas at El Paso, El Paso, TX 79968 (United States); Dorso, C.O. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina)

2014-03-01

Ideal nuclear matter is expected to undergo a first order phase transition at the thermodynamic limit. At such phase transitions the size of density fluctuations (bubbles or droplets) scale with the size of the system. This means that simulations of nuclear matter at sub-saturation densities will inexorably suffer from what is vaguely referred to as “finite size effects”. It is usually thought that these finite size effects can be diminished by imposing periodic boundary conditions and making the system large enough, but as we show in this work, that is actually not the case at sub-saturation densities. In this paper we analyze the equilibrium configurations of molecular dynamics simulations of a classical model for symmetric ideal (uncharged) nuclear matter at sub-saturation densities and low temperatures, where phase coexistence is expected at the thermodynamic limit. We show that the most stable configurations in this density range are almost completely determined by artificial aspects of the simulations (i.e. boundary conditions) and can be predicted analytically by surface minimization. This result is very general and is shown to hold true for several well known semi-classical models of nuclear interaction and even for a simple Lennard-Jones potential. Also, in the limit of very large systems, when “small size” effects can be neglected, those equilibrium configurations seem to be restricted to a few structures reminiscent to the “Pasta Phases” expected in Neutron Star matter, but arising from a completely different origin: In Neutron Star matter, the non-homogeneous structures arise from a competition between nuclear and Coulomb interactions while for ideal nuclear matter they emerge from finite (yet not “small”) size effects. The role of periodic boundary conditions and finite size effects in Neutron Star matter simulations are reexamined.

Effects of delta degrees of freedom on quark condensate in hot and dense matter

International Nuclear Information System (INIS)

Li Lei; Ning Pingzhi

1996-01-01

The relativistic mean-field theory is applied to study the quark condensate systematically in nuclear matter at zero and finite temperature in terms of the relative importance of delta degrees of freedom. Calculations have included the high-order contributions to quark condensate in nuclear medium due to the baryon-baryon interactions. Numerical results are presented for the nuclear density up to five times larger than the normal density and temperature up to 120 MeV. It is found that the delta resonance in nuclear matter can cause substantial decreases to in-medium quark condensate

Role of isospin in nuclear-matter liquid-gas phase transition

International Nuclear Information System (INIS)

Ducoin, C.

2006-10-01

Nuclear matter presents a phase transition of the liquid-gas type. This well-known feature is due to the nuclear interaction profile (mean-range attractive, short-range repulsive). Symmetric-nuclear-matter thermodynamics is thus analogous to that of a Van der Waals fluid. The study shows up to be more complex in the case of asymmetric matter, composed of neutrons and protons in an arbitrary proportion. Isospin, which distinguishes both constituents, gives a measure of this proportion. Studying asymmetric matter, isospin is an additional degree of freedom, which means one more dimension to consider in the space of observables. The nuclear liquid-gas transition is associated with the multi-fragmentation phenomenon observed in heavy-ion collisions, and to compact-star physics: the involved systems are neutron rich, so they are affected by the isospin degree of freedom. The present work is a theoretical study of isospin effects which appear in the asymmetric nuclear matter liquid-gas phase transition. A mean-field approach is used, with a Skyrme nuclear effective interaction. We demonstrate the presence of a first-order phase transition for asymmetric matter, and study the isospin distillation phenomenon associated with this transition. The case of phase separation at thermodynamic equilibrium is compared to spinodal decomposition. Finite size effects are addressed, as well as the influence of the electron gas which is present in the astrophysical context. (author)

Empirical information on nuclear matter fourth-order symmetry energy from an extended nuclear mass formula

Directory of Open Access Journals (Sweden)

Rui Wang

2017-10-01

Full Text Available We establish a relation between the equation of state of nuclear matter and the fourth-order symmetry energy asym,4(A of finite nuclei in a semi-empirical nuclear mass formula by self-consistently considering the bulk, surface and Coulomb contributions to the nuclear mass. Such a relation allows us to extract information on nuclear matter fourth-order symmetry energy Esym,4(ρ0 at normal nuclear density ρ0 from analyzing nuclear mass data. Based on the recent precise extraction of asym,4(A via the double difference of the “experimental” symmetry energy extracted from nuclear masses, for the first time, we estimate a value of Esym,4(ρ0=20.0±4.6 MeV. Such a value of Esym,4(ρ0 is significantly larger than the predictions from mean-field models and thus suggests the importance of considering the effects of beyond the mean-field approximation in nuclear matter calculations.

Pion condensation and density isomerism in nuclear matter

International Nuclear Information System (INIS)

Hecking, P.; Weise, W.

1979-01-01

The possible existence of density isomers in nuclear matter, induced by pion condensation, is discussed; the nuclear equation of state is treated within the framework of the sigma model. Repulsive short-range baryon-baryon correlations, the admixture of Δ (1232) isobars and finite-range pion-baryon vertex form factors are taken into account. The strong dependence of density isomerism on the high density extrapolation of the equation of state for normal nuclear matter is also investigated. We find that, once finite range pion-baryon vertices are introduced, the appearance of density isomers becomes unlikely

The determination of nuclear matter temperature and density

International Nuclear Information System (INIS)

Wolf, K.L.

1981-01-01

The purpose of this paper is to review some of the things we have learned about nuclear matter under extreme conditions during the past few years in relativistic heavy ion studies. High energy heavy-ion collisions provide a unique mechanism for exploring the dependence of the nuclear potential energy epsilon(rho,T) on the degree of compression and excitation, and may even show the existence of new phases of matter. Thus the determination of the nuclear equation of state remains the ultimate goal of many researchers in this field. (orig.)

Pion condensation in a theory consistent with bulk properties of nuclear matter

International Nuclear Information System (INIS)

Glendenning, N.K.

1980-01-01

A relativistic field theory of nuclear matter is solved for the self-consistent field strengths inthe mean-field approximation. The theory is constrained to reproduce the bulk properties of nuclear matter. A weak pion condensate is compatible with this constraint. At least this is encouraging as concerns the possible existence of a new phase of nuclear matter. In contrast, the Lee-Wick density isomer is probably not compatible with the properties of nuclear matter. 3 figures

Nuclear matter in relativistic mean field theory with isovector scalar meson.

Energy Technology Data Exchange (ETDEWEB)

Kubis, S.; Kutschera, M. [Institute of Nuclear Physics, Cracow (Poland)

1996-12-01

Relativistic mean field (RMF) theory of nuclear matter 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 nuclear matter, it can influence properties of asymmetric nuclear matter 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.

Nuclear matter in relativistic mean field theory with isovector scalar meson

International Nuclear Information System (INIS)

Kubis, S.; Kutschera, M.

1996-12-01

Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the δ-meson [a 0 (980)] is studied. While the δ-meson field vanishes in symmetric nuclear matter, it can influence properties of asymmetric nuclear matter in neutron stars. The RMF contribution due to δ-field to the nuclear symmetry energy is negative. To fit the empirical value, E s ∼30 MeV, a stronger ρ-meson coupling is required than in absence of the δ-field. The energy per particle of neutron star matter is than larger at high densities than the one with no δ-field included. Also, the proton fraction of β-stable matter increases. Splitting of proton and neutron effective masses due to the δ-field can affect transport properties of neutron star matter. (author). 4 refs, 6 figs

Process considerations for hot pressing ceramic nuclear waste forms

International Nuclear Information System (INIS)

Wilson, C.N.; Brite, D.W.

1981-01-01

Spray calcined simulated ceramic nuclear waste powders were hot pressed in graphite, nickel-lined graphite and ZrO 2 -lined Al 2 O 3 dies. Densification, initial off-gas, waste element retention and pellet-die interactions were evaluated. Indicated process considerations and limitations are discussed. 15 figures

Nuclear applications for steam and hot water supply

International Nuclear Information System (INIS)

1991-07-01

An increase in the heat energy needs underlined by the potential increase in fossil fuel prices, particularly in oil supplies, and by the necessity for an improvement of the environment worldwide, as signalized by the IAEA Member States, prompted the decision to start a programme leading to this report. This document is intended to help to identify the experience of Member States where nuclear power plants or specialized nuclear heat plants are employed or envisaged to be used for distribution of steam or hot water to industrial or residential consumers, covering low and medium temperature ranges. 25 refs, 33 figs, 15 tabs

Covariant density functional theory for nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Badarch, U.

2007-07-01

The present thesis is organized as follows. In Chapter 2 we study the Nucleon-Nucleon (NN) interaction in Dirac-Brueckner (DB) approach. We start by considering the NN interaction in free-space in terms of the Bethe-Salpeter (BS) equation to the meson exchange potential model. Then we present the DB approach for nuclear matter by extending the BS equation for the in-medium NN interaction. From the solution of the three-dimensional in-medium BS equation, we derive the DB self-energies and total binding energy which are the main results of the DB approach, which we later incorporate in the field theoretical calculation of the nuclear equation of state. In Chapter 3, we introduce the basic concepts of density functional theory in the context of Quantum Hadrodynamics (QHD-I). We reach the main point of this work in Chapter 4 where we introduce the DDRH approach. In the DDRH theory, the medium dependence of the meson-nucleon vertices is expressed as functionals of the baryon field operators. Because of the complexities of the operator-valued functionals we decide to use the mean-field approximation. In Chapter 5, we contrast microscopic and phenomenological approaches to extracting density dependent meson-baryon vertices. Chapter 6 gives the results of our studies of the EOS of infinite nuclear matter in detail. Using formulas derived in Chapters 4 and 5 we calculate the properties of symmetric and asymmetric nuclear matter and pure neutron matter. (orig.)

Covariant density functional theory for nuclear matter

International Nuclear Information System (INIS)

Badarch, U.

2007-01-01

The present thesis is organized as follows. In Chapter 2 we study the Nucleon-Nucleon (NN) interaction in Dirac-Brueckner (DB) approach. We start by considering the NN interaction in free-space in terms of the Bethe-Salpeter (BS) equation to the meson exchange potential model. Then we present the DB approach for nuclear matter by extending the BS equation for the in-medium NN interaction. From the solution of the three-dimensional in-medium BS equation, we derive the DB self-energies and total binding energy which are the main results of the DB approach, which we later incorporate in the field theoretical calculation of the nuclear equation of state. In Chapter 3, we introduce the basic concepts of density functional theory in the context of Quantum Hadrodynamics (QHD-I). We reach the main point of this work in Chapter 4 where we introduce the DDRH approach. In the DDRH theory, the medium dependence of the meson-nucleon vertices is expressed as functionals of the baryon field operators. Because of the complexities of the operator-valued functionals we decide to use the mean-field approximation. In Chapter 5, we contrast microscopic and phenomenological approaches to extracting density dependent meson-baryon vertices. Chapter 6 gives the results of our studies of the EOS of infinite nuclear matter in detail. Using formulas derived in Chapters 4 and 5 we calculate the properties of symmetric and asymmetric nuclear matter and pure neutron matter. (orig.)

Equation of state and stability of hot asymmetric nuclear matter

International Nuclear Information System (INIS)

Samaddar, S.K.

1989-01-01

The nuclear incompressibility as obtained from different sources, from nuclei, high energy nuclear collisions, supernova and neutron stars are briefly reviewed. All these data in general favour a compression modulus, K α ∼ 300 Mev with a minimum uncertainty ∼ 50 MeV. Using a finite rang e density and momentum dependent two-body effective interaction, variation of nucl ear incompressibility with temperature, asymmetry and density is discussed in a non-relativistic mean field approach. The same formalism has also been used to study the limiting temperatures of infinite as well as finite nuclear systems in the astrophysical context as well as in high energy heavy ion collisions. (autho r). 16 refs., 6 figs., 1 tab

Non-Markovian effects on the dynamics of bubble growth in hot asymmetric nuclear matter

International Nuclear Information System (INIS)

Kolomietz, V.M.; Sanzhur, A.I.; Shlomo, S.

2003-01-01

We study the conditions for the generation and the dynamical evolution of embryonic overcritical vapor bubbles in an overheated asymmetric nuclear matter. We show that the Fermi-surface distortion and memory effects significantly hinder the growth of the bubbles. Moreover, the growth of the bubble is accompanied by characteristic oscillations of its radius R. The characteristic energy E, the damping parameter Γ, and the instability growth rate parameter ζ, depend on the relaxation time τ. The characteristic oscillations disappear in the short relaxation time limit τ→0. Our approach ignores the fluctuations of the particle numbers in the bubble region and the finite diffuse layer of the bubble. The minimum size of the critical radius R * for which our approach applies is determined by the condition a/R * <<1, where a=0.5-1 fm is the temperature-dependent surface thickness of the bubble

Vector manifestation and violation of vector dominance in hot matter

International Nuclear Information System (INIS)

Harada, Masayasu; Sasaki, Chihiro

2004-01-01

We show the details of the calculation of the hadronic thermal corrections to the two-point functions in the effective field theory of QCD for pions and vector mesons based on the hidden local symmetry (HLS) in hot matter using the background field gauge. We study the temperature dependence of the pion velocity in the low-temperature region determined from the hadronic thermal corrections, and show that, due to the presence of the dynamical vector meson, the pion velocity is smaller than the speed of the light already at one-loop level, in contrast to the result obtained in the ordinary chiral perturbation theory including only the pion at one-loop. Including the intrinsic temperature dependences of the parameters of the HLS Lagrangian determined from the underlying QCD through the Wilsonian matching, we show how the vector manifestation (VM), in which the massless vector meson becomes the chiral partner of pion, is realized at the critical temperature. We present a new prediction of the VM on the direct photon-π-π coupling which measures the validity of the vector dominance (VD) of the electromagnetic form factor of the pion: we find that the VD is largely violated at the critical temperature, which indicates that the assumption of the VD made in several analyses on the dilepton spectra in hot matter may need to be weakened for consistently including the effect of the dropping mass of the vector meson

Pseudo-Goldstone modes in isospin-asymmetric nuclear matter

International Nuclear Information System (INIS)

Cohen, T.D.; Broniowski, W.

1995-01-01

The authors analyze the chiral limit in dense isospin-asymmetric nuclear matter. It is shown that the pseudo-Goldstone modes in this system are qualitatively different from the case of isospin-symmetric matter

Nucleation of strange matter in dense stellar cores

International Nuclear Information System (INIS)

Horvath, J.E.; Benvenuto, O.G.; Vucetich, H.

1992-01-01

We investigate the nucleation of strange quark matter inside hot, dense nuclear matter. Applying Zel'dovich's kinetic theory of nucleation we find a lower limit of the temperature 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

Charge symmetry breaking nuclear forces and the properties of nuclear matter

International Nuclear Information System (INIS)

Haensel, P.

1977-01-01

The charge symmetry breaking (CSB) component of the nuclear forces yields the charge asymmetric term Esub(a)(N-Z)/A in the nuclear binding energy of nuclear matter. Calculation performed with several models of the CSB nuclear forces, and accounting for the strong short-range two-body correlations, gives Esub(a) approximately -0.2 MeV at the normal nuclear density. The charge asymmetry of the effective nucleon-nucleon interaction is determined primarily by the CSB nuclear forces at the neutron excess, observed in finite nuclei. The exclusion principle and dispersion (self-consistency) effects of the nuclear medium decrease this charge asymmetry. (author)

Nuclear matter from effective quark-quark interaction.

Science.gov (United States)

Baldo, M; Fukukawa, K

2014-12-12

We study neutron matter and symmetric nuclear matter with the quark-meson model for the two-nucleon interaction. The Bethe-Bruckner-Goldstone many-body theory is used to describe the correlations up to the three hole-line approximation with no extra parameters. At variance with other nonrelativistic realistic interactions, the three hole-line contribution turns out to be non-negligible and to have a substantial saturation effect. The saturation point of nuclear matter, the compressibility, the symmetry energy, and its slope are within the phenomenological constraints. Since the interaction also reproduces fairly well the properties of the three-nucleon system, these results indicate that the explicit introduction of the quark degrees of freedom within the considered constituent quark model is expected to reduce the role of three-body forces.

Properties of Localized Protons in Neutron Star Matter at Finite Temperatures

Science.gov (United States)

Szmaglinski, A.; Kubis, S.; Wójcik, W.

2014-02-01

We study properties of the proton component of neutron star matter for realistic nuclear models. Vanishing of the nuclear symmetry energy implies proton-neutron separation in dense nuclear matter. Protons which form admixture tend to be localized in potential wells. Here, we extend the description of proton localization to finite temperatures. It appears that the protons are still localized at temperatures typical for hot neutron stars. That fact has important astrophysical consequences. Moreover, the temperature inclusion leads to unexpected results for the behavior of the proton localized state.

Photons in dense nuclear matter: Random-phase approximation

Science.gov (United States)

Stetina, Stephan; Rrapaj, Ermal; Reddy, Sanjay

2018-04-01

We present a comprehensive and pedagogic discussion of the properties of photons in cold and dense nuclear matter based on the resummed one-loop photon self-energy. Correlations among electrons, muons, protons, and neutrons in β equilibrium that arise as a result of electromagnetic and strong interactions are consistently taken into account within the random phase approximation. Screening effects, damping, and collective excitations are systematically studied in a fully relativistic setup. Our study is relevant to the linear response theory of dense nuclear matter, calculations of transport properties of cold dense matter, and investigations of the production and propagation of hypothetical vector bosons such as the dark photons.

Nuclear interactions and hadronic matter

International Nuclear Information System (INIS)

Petrovici, Mihai; Pop, Amalia; Stoicea, Gabriel; Berceanu, Ionela; Moisa, Dorin; Petris, Mariana; Simion, Victor; Aiftimiei, Cristina; Cruceru, Ilie; Ciobanu, Mircea; Catanescu, Vasile; Caragheorgheopol; Gheorghe

2002-01-01

The new generation of heavy ion accelerators and complex experimental devices, developed in the last two decades, give access to new information concerning the dynamics of nuclear collisions and allow to obtain and study in the laboratory the nuclear matter under extreme conditions of density and temperature. Of special interest is the intermediate energy region where the reactions are dominated by the competition between the mean field and nucleon-nucleon interaction. Fundamental aspects of nuclear reaction studies are probed at different instants of a nuclear collision. One can learn about the transport properties of nuclear matter in pure nucleonic regime and understand the modification of the nucleon-nucleon cross section due to various in-medium effects: density effects, effective mass, quantum effects, three-body interactions. With increasing energy, fast particle emission associated with direct nucleon-nucleon collisions in the first steps of the reaction come into play too. At higher energy, flow measurements are crucial tests of the influence of medium effects by probing the elastic part of the nucleon-nucleon collisions. On the other side, at higher incident energies, the characteristics of the nuclear equation of state (EoS) can be studied if local thermal and chemical equilibrium turns out to be established. Understanding of the properties of the nuclear matter in extreme conditions is a fundamental goal. The EoS is also an essential ingredient in the description of the massive stars leading to supernova explosion and neutron star formation. Experimental studies of such aspects needs experimental devices of high complexity which can detect and identify event by event all products coming out from heavy ion interactions at intermediate, relativistic and ultra-relativistic energies, having as complete as possible information on their mass, charge, velocity vector. CHIMERA and FOPI are such devices for intermediate and relativistic energy, respectively. Our

Research and systematization of 'hot' particles in the Semipalatinsk nuclear test site soils - methodology and first results

International Nuclear Information System (INIS)

Gorlachev, I.D.; Knyazev, B.B.; Kvochkina, T.N.; Lukashenko, S.N.

2005-01-01

Full text: Sources of soil activity in Semipalatinsk Nuclear Test Site (SNTS) could be both 'hot' particles dimensions from tens microns to units millimeters and sub-microns particles determining a matrix activity of soil samples. The fractionating of radionuclides and formation of 'hot' particles radionuclide composition arose from temperature changes and complicated nuclear-physical and thermodynamics processes occurring in a fire ball and cloud of nuclear explosion. Knowledge of 'hot' particles physical-chemical properties is needed for evaluation of radioactive products migration in the environment and danger level of the people external and internal exposure. Moreover, minute information about the structure and compound of 'radioactive' particles can be useful for specification of processes occurring in a fiery sphere when conducting explosions of different phylum and also for specification of radioactive fallout forming mechanism. The main polluted spots of SNTS could be divided into the four the species depending on nuclear explosion phylum. Species of radionuclide and their distribution for the different nuclear explosions are able to differ considerably. Therefore, several most typical areas for the each phylum test were selected and twenty soil samples were collected to reveal their radionuclide pollution peculiarities. Collected soil samples were separated into the five granulometric fractions: 1 mm - 2 mm, 0.5 mm - 1 mm. 0.28 mm-0.5 mm, 0.112 mm - 0.28 mm and 1 mm), 210 'hot' particles of second fraction (1>f>0.5 mm) and 154 'hot' particles of third fraction (0.5>f>0.28 mm) have been selection from the twelve SNTS soil samples by the compelled fission and visual identification methods. Main sources of soil samples and 'hot' particles activities are 239+240 Pu, 241 Am, 137 Cs and 152 Eu isotopes.In addition to the described works the special sampling of large 'hot' particles (dimension more than 2 mm) was carried out in areas of the ground and air tests

Simulation study for the nuclear matter below the saturation density

International Nuclear Information System (INIS)

Kido, Toshihiko; Maruyama, Toshiki; Chiba, Satoshi; Niita, Koji

1999-01-01

The infinite nuclear matter that consists of numerous protons and neutrons is described by using periodic boundary conditions. The motion of each nucleon in the fundamental cell is decided by a Molecular Dynamics. The ground states or the excited states of the nuclear matter are simulated. (author)

Symmetric nuclear matter with Skyrme interaction

International Nuclear Information System (INIS)

Manisa, K.; Bicer, A.; Atav, U.

2010-01-01

The equation of state (EOS) and some properties of symmetric nuclear matter, such as the saturation density, saturation energy and incompressibility, are obtained by using Skyrme's density-dependent effective nucleon-nucleon interaction.

Skyrmions, dense matter and nuclear forces

International Nuclear Information System (INIS)

Pethick, C.J.

1984-12-01

A simple introduction to a number of properties of Skyrme's chiral soliton model of baryons is given. Some implications of the model for dense matter and for nuclear interactions are discussed. (orig.)

Antiferromagnetism of nuclear matter in the model with effective Gogny interaction

International Nuclear Information System (INIS)

Isayev, A.A.; Yang, J.

2006-01-01

The possibility of ferromagnetic (FM) antiferromagnetic (AFM) phase transitions in symmetric nuclear matter is analyzed within the framework of a Fermi-liquid theory with the effective Gogny interaction. It is shown that at some critical density nuclear matter undergoes a phase transition to the AFM spin state. The self-consistent equations of spin-polarized nuclear matter have no solutions corresponding to FM spin ordering and, hence, the FM transition does not appear. The AFM spin state properties are investigated [ru

Hot Laboratories and Remote Handling

International Nuclear Information System (INIS)

Bart, G.; Blanc, J.Y.; Duwe, R.

2003-01-01

The European Working Group on ' Hot Laboratories and Remote Handling' is firmly established as the major contact forum for the nuclear R and D facilities at the European scale. The yearly plenary meetings intend to: - Exchange experience on analytical methods, their implementation in hot cells, the methodologies used and their application in nuclear research; - Share experience on common infrastructure exploitation matters such as remote handling techniques, safety features, QA-certification, waste handling; - Promote normalization and co-operation, e.g., by looking at mutual complementarities; - Prospect present and future demands from the nuclear industry and to draw strategic conclusions regarding further needs. The 41. plenary meeting was held in CEA Saclay from September 22 to 24, 2003 in the premises and with the technical support of the INSTN (National Institute for Nuclear Science and Technology). The Nuclear Energy Division of CEA sponsored it. The Saclay meeting was divided in three topical oral sessions covering: - Post irradiation examination: new analysis methods and methodologies, small specimen technology, programmes and results; - Hot laboratory infrastructure: decommissioning, refurbishment, waste, safety, nuclear transports; - Prospective research on materials for future applications: innovative fuels (Generation IV, HTR, transmutation, ADS), spallation source materials, and candidate materials for fusion reactor. A poster session was opened to transport companies and laboratory suppliers. The meeting addressed in three sessions the following items: Session 1 - Post Irradiation Examinations. Out of 12 papers (including 1 poster) 7 dealt with surface and solid state micro analysis, another one with an equally complex wet chemical instrumental analytical technique, while the other four papers (including the poster) presented new concepts for digital x-ray image analysis; Session 2 - Hot laboratory infrastructure (including waste theme) which was

Some topics on nuclear astrophysics and neutrino astronomy

International Nuclear Information System (INIS)

Nakazato, Ken'ichiro

2010-01-01

Massive stars make a gravitational collapse at the end of their lives emitting a large amount of neutrinos. In this process, the density and temperature of matter become high. Therefore neutrino detection of stellar collapse can teach us properties of hot and/or dense nuclear matter. In this article, some subjects on the nuclear astrophysics and/or neutrino astronomy, on which we are now working, are reported. (author)

Monotonous braking of high energy hadrons in nuclear matter

International Nuclear Information System (INIS)

Strugalski, Z.

1979-01-01

Propagation of high energy hadrons in nuclear matter is discussed. The possibility of the existence of the monotonous energy losses of hadrons in nuclear matter is considered. In favour of this hypothesis experimental facts such as pion-nucleus interactions (proton emission spectra, proton multiplicity distributions in these interactions) and other data are presented. The investigated phenomenon in the framework of the hypothesis is characterized in more detail

Proceedings of RIKEN BNL Research Center Workshop: P- and CP-odd Effects in Hot and Dense Matter

Energy Technology Data Exchange (ETDEWEB)

Deshpande, A.; Fukushima, K.; Kharzeev, D.; Warringa, H.; Voloshin, S.

2010-04-26

This volume contains the proceedings of the RBRC/CATHIE workshop on 'P- and CP-odd Effects in Hot and Dense Matter' held at the RIKEN-BNL Research Center on April 26-30, 2010. The workshop was triggered by the experimental observation of charge correlations in heavy ion collisions at RHIC, which were predicted to occur due to local parity violation (P- and CP-odd fluctuations) in hot and dense QCD matter. This experimental result excited a significant interest in the broad physics community, inspired a few alternative interpretations, and emphasized the need for a deeper understanding of the role of topology in QCD vacuum and in hot and dense quark-gluon matter. Topological effects in QCD are also closely related to a number of intriguing problems in condensed matter physics, cosmology and astrophysics. We therefore felt that a broad cross-disciplinary discussion of topological P- and CP-odd effects in various kinds of matter was urgently needed. Such a discussion became the subject of the workshop. Specific topics discussed at the workshop include the following: (1) The current experimental results on charge asymmetries at RHIC and the physical interpretations of the data; (2) Quantitative characterization of topological effects in QCD matter including both analytical (perturbative and non-perturbative using gauge/gravity duality) and numerical (lattice-QCD) calculations; (3) Topological effects in cosmology of the Early Universe (including baryogenesis and dark energy); (4) Topological effects in condensed matter physics (including graphene and superfiuids); and (5) Directions for the future experimental studies of P- and CP-odd effects at RHIC and elsewhere. We feel that the talks and intense discussions during the workshop were extremely useful, and resulted in new ideas in both theory and experiment. We hope that the workshop has contributed to the progress in understanding the role of topology in QCD and related fields. We thank all the speakers and

Proceedings of RIKEN BNL Research Center Workshop: P- and CP-odd Effects in Hot and Dense Matter

International Nuclear Information System (INIS)

Deshpande, A.; Fukushima, K.; Kharzeev, D.; Warringa, H.; Voloshin, S.

2010-01-01

This volume contains the proceedings of the RBRC/CATHIE workshop on 'P- and CP-odd Effects in Hot and Dense Matter' held at the RIKEN-BNL Research Center on April 26-30, 2010. The workshop was triggered by the experimental observation of charge correlations in heavy ion collisions at RHIC, which were predicted to occur due to local parity violation (P- and CP-odd fluctuations) in hot and dense QCD matter. This experimental result excited a significant interest in the broad physics community, inspired a few alternative interpretations, and emphasized the need for a deeper understanding of the role of topology in QCD vacuum and in hot and dense quark-gluon matter. Topological effects in QCD are also closely related to a number of intriguing problems in condensed matter physics, cosmology and astrophysics. We therefore felt that a broad cross-disciplinary discussion of topological P- and CP-odd effects in various kinds of matter was urgently needed. Such a discussion became the subject of the workshop. Specific topics discussed at the workshop include the following: (1) The current experimental results on charge asymmetries at RHIC and the physical interpretations of the data; (2) Quantitative characterization of topological effects in QCD matter including both analytical (perturbative and non-perturbative using gauge/gravity duality) and numerical (lattice-QCD) calculations; (3) Topological effects in cosmology of the Early Universe (including baryogenesis and dark energy); (4) Topological effects in condensed matter physics (including graphene and superfiuids); and (5) Directions for the future experimental studies of P- and CP-odd effects at RHIC and elsewhere. We feel that the talks and intense discussions during the workshop were extremely useful, and resulted in new ideas in both theory and experiment. We hope that the workshop has contributed to the progress in understanding the role of topology in QCD and related fields. We thank all the speakers and

Temperature dependence of single-particle properties in nuclear matter

International Nuclear Information System (INIS)

Zuo, W.; Lu, G.C.; Li, Z.H.; Lombardo, U.; Schulze, H.-J.

2006-01-01

The single-nucleon potential in hot nuclear matter is investigated in the framework of the Brueckner theory by adopting the realistic Argonne V 18 or Nijmegen 93 two-body nucleon-nucleon interaction supplemented by a microscopic three-body force. The rearrangement contribution to the single-particle potential induced by the ground state correlations is calculated in terms of the hole-line expansion of the mass operator and provides a significant repulsive contribution in the low-momentum region around and below the Fermi surface. Increasing temperature leads to a reduction of the effect, while increasing density makes it become stronger. The three-body force suppresses somewhat the ground state correlations due to its strong short-range repulsion, increasing with density. Inclusion of the three-body force contribution results in a quite different temperature dependence of the single-particle potential at high enough densities as compared to that adopting the pure two-body force. The effects of three-body force and ground state correlations on the nucleon effective mass are also discussed

From quantum to semiclassical kinetic equations: Nuclear matter estimates

International Nuclear Information System (INIS)

Galetti, D.; Mizrahi, S.S.; Nemes, M.C.; Toledo Piza, A.F.R. de

1985-01-01

Starting from the exact microscopic time evolution of the quantum one body density associated with a many fermion system semiclassical approximations are derived to it. In the limit where small momentum transfer two body collisions are dominant we get a Fokker-Planck equation and work out friction and diffusion tensors explicitly for nuclear matter. If arbitrary momentum transfers are considered a Boltzmann equation is derived and used to calculate the viscosity coefficient of nuclear matter. A derivation is given of the collision term used by Landau to describe the damping of zero sound waves at low temperature in Plasmas. Memory effects are essential for this. The damping of zero sound waves in nuclear matter is also calculated and the value so obtained associated with the bulk value of the damping of giant resonances in finite nuclei. The bulk value is estimated to be quite small indicating the importance of the nuclear surface for the damping. (Author) [pt

Fluctuation effects on bubble growth in hot nuclear matter

International Nuclear Information System (INIS)

Santiago, A.J.; Chung, K.C.

1991-01-01

The evolution of bubbles with arbitrary density in an infinite nuclear system is studied in a simplified treatment. Kinetic pressure fluctuations on the bubble surface are considered. The critical radius, evolution time and probability for bubble expansion are shown to depend significantly on the initial bubble density. (author)

Quark mobility in extended nuclear matter

International Nuclear Information System (INIS)

Sivers, D.

1988-01-01

The propagation of an energetic quark through extended nuclear matter is analyzed in terms of a simple model in which localization of color is imposed through chromoelectric flux tubes. A mobile quark in the nuclear medium creates a disturbance which affects neighboring nucleons. The model suggests that the spatial properties of the disturbance involve a competition among different dynamical mechanisms. Experimental measurements involving the target fragmentation region in deep-inelastic leptoproduction on large nuclei may help specify some of the important features of nuclear dynamics. copyright 1988 Academic Press, Inc

Equation of state of dense nuclear matter and neutron star structure from nuclear chiral interactions

Science.gov (United States)

Bombaci, Ignazio; Logoteta, Domenico

2018-02-01

Aims: We report a new microscopic equation of state (EOS) of dense symmetric nuclear matter, pure neutron matter, and asymmetric and β-stable nuclear matter at zero temperature using recent realistic two-body and three-body nuclear interactions derived in the framework of chiral perturbation theory (ChPT) and including the Δ(1232) isobar intermediate state. This EOS is provided in tabular form and in parametrized form ready for use in numerical general relativity simulations of binary neutron star merging. Here we use our new EOS for β-stable nuclear matter to compute various structural properties of non-rotating neutron stars. Methods: The EOS is derived using the Brueckner-Bethe-Goldstone quantum many-body theory in the Brueckner-Hartree-Fock approximation. Neutron star properties are next computed solving numerically the Tolman-Oppenheimer-Volkov structure equations. Results: Our EOS models are able to reproduce the empirical saturation point of symmetric nuclear matter, the symmetry energy Esym, and its slope parameter L at the empirical saturation density n0. In addition, our EOS models are compatible with experimental data from collisions between heavy nuclei at energies ranging from a few tens of MeV up to several hundreds of MeV per nucleon. These experiments provide a selective test for constraining the nuclear EOS up to 4n0. Our EOS models are consistent with present measured neutron star masses and particularly with the mass M = 2.01 ± 0.04 M⊙ of the neutron stars in PSR J0348+0432.

Description of a nucleon in nuclear matter

International Nuclear Information System (INIS)

Bunatian, G.G.

1992-01-01

The nonlinear cloudy bag model, CBM, is generalized to describe a nucleon in nuclear matter at various densities ρ and temperatures T. The influence of the nuclear medium on the bag-nucleon in the framework of CBM is due to the modification of the equation describing the CBM pion field π. These changes are accounted for in the CBM by including in the CBM lagrangian the pion polarization operator π(ρ,T). The free pion propagator D is replaced in a nuclear medium by D(ρ,T). The changing of the pion field π and propagator D leads via the CBM equations to the modification of the bag size R and quark momentum p, determined simultaneously from these equations, and then to modifications of other bag-nucleon characteristics: the total energy E, r.m.s. radii, magnetic moment μ, polarizability α and so on, which all are expressed as the expectation values of the corresponding operators in the bag-nucleon state. The quantity π(ρ,T) was studied in the works whose results are used in this investigation. The nucleon size R in the nuclear matter at normal density ρ o and zero temperature decreases by 5% and the quarks momentum p also decreases, however, insignificantly, by 1-2%. On the other hand, the values of the r.m.s. radii increases by 15% for a proton and by 100% for a neutron. The author has also found that the polarizability of a nucleon in nuclear matter is roughly two times as much as in free space

Asymmetric nuclear matter in a modified quark meson coupling model

International Nuclear Information System (INIS)

Mishra, R.N.; Sahoo, H.S.; Panda, P.K.; Barik, N.

2014-01-01

In an earlier attempt we have successfully used this model in developing the nuclear equation of state and analysed various other bulk properties of symmetric nuclear matter with the dependence of quark masses. In the present work we want to apply the model to analyze asymmetric nuclear matter with the variation of the asymmetry parameter y p as well as analyze the effects of symmetry energy and the slope of the symmetry energy L

Meson theory and nuclear matter

International Nuclear Information System (INIS)

Skyrme, T.H.R.

1994-01-01

An attempt is made to justify the use of the concept of a 'mesic fluid' in connection with the structure of nuclear matter. A transformation is made of the usual symmetric pseudo-scalar meson theory to bring into evidence certain saturation properties, which provide a natural basis for the use of a 'self-consistent' field in the discussion of nuclear structure. Fluctuations about this semi-classical saturated state will give rise to residual interparticle forces within the nucleus, and are also briefly considered in relation to electromagnetic interactions. (author). 5 refs

General problems specific to hot nuclear materials research facilities

International Nuclear Information System (INIS)

Bart, G.

1996-01-01

During the sixties, governments have installed hot nuclear materials research facilities to characterize highly radioactive materials, to describe their in-pile behaviour, to develop and test new reactor core components, and to provide the industry with radioisotopes. Since then, the attitude towards the nuclear option has drastically changed and resources have become very tight. Within the changed political environment, the national research centres have defined new objectives. Given budgetary constraints, nuclear facilities have to co-operate internationally and to look for third party research assignments. The paper discusses the problems and needs within experimental nuclear research facilities as well as industrial requirements. Special emphasis is on cultural topics (definition of the scope of nuclear research facilities, the search for competitive advantages, and operational requirements), social aspects (overageing of personnel, recruitment, and training of new staff), safety related administrative and technical issues, and research needs for expertise and state of the art analytical infrastructure

The role of meson dynamics in nuclear matter saturation

International Nuclear Information System (INIS)

Goncalves, E.

1988-01-01

The problem of the saturation of nuclea matter in the non-relativistic limit of the model proposed by J.D. Walecka is studied. In the original context nuclear matter saturation is obtained as a direct consequence of relativistic effects and both scalar and vector mesons are treated statically. In the present work we investigate the effect of the meson dynamics for the saturation using a Born-Oppenheimer approximation for the ground state. An upper limit for the saturation curve of nuclear matter and are able to decide now essential is the relativistic treatment of the nucleons for this problem, is obtained. (author) [pt

Quark condensates in nuclear matter in the global color symmetry model of QCD

International Nuclear Information System (INIS)

Liu Yuxin; Gao Dongfeng; Guo Hua

2003-01-01

With the global color symmetry model being extended to finite chemical potential, we study the density dependence of the local and nonlocal scalar quark condensates in nuclear matter. The calculated results indicate that the quark condensates increase smoothly with the increasing of nuclear matter density before the critical value (about 12ρ 0 ) is reached. It also manifests that the chiral symmetry is restored suddenly as the density of nuclear matter reaches its critical value. Meanwhile, the nonlocal quark condensate in nuclear matter changes nonmonotonously against the space-time distance among the quarks

Hot rolled composite billet for nuclear control rods

International Nuclear Information System (INIS)

Miller, G.E.

1976-01-01

This invention relates to a composite plate shaped billet, useful in the fabrication of nuclear control rods, which comprises a core of stainless steel containing about 2 percent boron 10, a thin coating of zirconia on the surfaces of said core, and said zirconia coating being completely encased in a jacket of mild steel, said composite having been hot rolled between about 1075 0 and about 1165 0 C. 1 claim, 8 figures

Quark distributions in nuclear matter and the EMC effect

Energy Technology Data Exchange (ETDEWEB)

Mineo, H.; Bentz, W. E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Ishii, N.; Thomas, A.W.; Yazaki, K

2004-05-03

Quark light cone momentum distributions in nuclear matter and the structure function of a bound nucleon are investigated in the framework of the Nambu-Jona-Lasinio model. This framework describes the nucleon as a relativistic quark-diquark state, and the nuclear matter equation of state by using the mean field approximation. The scalar and vector mean fields in the nuclear medium couple to the quarks in the nucleon and their effect on the spin independent nuclear structure function is investigated in detail. Special emphasis is placed on the important effect of the vector mean field and on a formulation which guarantees the validity of the number and momentum sum rules from the outset.

Review of the theory of infinite nuclear matter

International Nuclear Information System (INIS)

Llano, M. de; Tolmachev, V.V.

1975-01-01

Given a two-body force, there seems to be two distinct starting points in the many-body perturbation-theoretic problem of computing the energy per nucleon of infinite (as well as finite) nuclear matter: ordinary Hartree-Fock theory and the Brueckner theory. The former theory, treated almost exclusively with plane-wave solutions, has long-ago fallen into disuse, to yield to the latter, apparently more sophisticated, theory. After a brief outline of many-fermion diagramatic techniques, the Brueckner-Bethe-Goldstone series expansion in terms of the density is discussed as a low density, non-ideal Fermi gas theory, whose convergence is analyzed. A calculation based on particle-hole Green's function techniques shows that a nucleon gas condenses to the liquid phase at about 3% of the empirical nuclear matter saturation density. The analogy between the BBG expansion and the virial expansion for a classical or quantum gas is studied with special emphasis on the apparent impossibility of analytical-continuing the latter gas theory to densities in the liquid regime, as first elucidated by Lee and Yang. It is finally argued that ordinary HF theory may provide a good starting point for the eventual understanding of nuclear matter as it gives (in the finite nuclear problem, at any rate) not only the basic liquid properties of a definite density and a surface but also provides independent-particle aspects, avoiding at the same time the idea of n-body clusters appropriate only for dilute gases. This program has to date not been carried out for infinite nuclear matter, mainly because of insufficient knowledge regarding low-energy, non-plane-wave solutions of the HF equations, in the thermodynamic limit [pt

α particles and the ''pasta'' phase in nuclear matter

International Nuclear Information System (INIS)

Avancini, S. S.; Barros, C. C. Jr.; Menezes, D. P.; Providencia, C.

2010-01-01

The effects of the α particles in nuclear matter at low densities are investigated within three different parametrizations of relativistic models at finite temperature. Both homogeneous and inhomogeneous matter (pasta phase) are described for neutral nuclear matter with fixed proton fractions and stellar matter subject to β equilibrium and trapped neutrinos. In homogeneous matter, α particles are present only at densities below 0.02 fm -3 and their presence decreases with increase of the temperature and, for a fixed temperature, the α particle fraction decreases for smaller proton fractions. A repulsive interaction is important to mimic the dissolution of the clusters in homogeneous matter. The effect of the α particles on the pasta structure is very small except close to the critical temperatures and/or proton fractions, when it may still predict a pasta phase while no pasta phase would occur in the absence of light clusters. It is shown that for densities above 0.01 fm 3 the α-particle fraction in the pasta phase is much larger than that in homogeneous matter.

Lectures notes on phase transformations in nuclear matter

CERN Document Server

López, Jorge A

2000-01-01

The atomic nucleus, despite of being one of the smallest objects found in nature, appears to be large enough to experience phase transitions. The book deals with the liquid and gaseous phases of nuclear matter, as well as with the experimental routes to achieve transformation between them.Theoretical models are introduced from the ground up and with increasing complexity to describe nuclear matter from a statistical and thermodynamical point of view. Modern critical phenomena, heavy ion collisions and computational techniques are presented while establishing a linkage to experimental data.The

Nuclear matter and its equation of state

International Nuclear Information System (INIS)

Stock, R.

1985-11-01

We can estimate the nuclear bulk compressibility from the excitation energy of the monopole vibration mode, which represents a density oscillation about rho 0 , of extremely small magnitude (a few percent) only. A description of the monopole excitation energy systematics has been obtained by assuming a parabolic shape about rho 0 for the energy-density relation of cold nuclear matter. This implies a linear pressure response to small density changes inside nuclear matter. It enables one to define a nuclear 'sound' mode and the sound velocity turns out to be vsub(s)proportional0.2 c. All of this could be known only for small excursions from rho 0 as long as we were unable to subject nuclei to extreme stresses. The study of head-on collisions of heavy nuclei at high energy has removed this limitation. In these reactions we are reproducing under laboratory conditions the extremely violent transformations of matter occuring in the cosmic and stellar evolution. From the quark-gluon stage of the Big Bang, prior to hadronic freeze-out, to the supernova these cosmic events require an understanding of matter bulk properties over an enormous range of density, from about 10 times rho 0 down to about 10 -3 rho 0 . We will approach them through the compression-expansion-freeze-out cycle of central nucleus-nucleus collisions in the energy range from 50 MeV per projectile nucleon, corresponding to the compression barrier, upwards to 225 GeV/A (the top energy of the CERN SPS), and further into the TeV/A range by observation of events induced by cosmic ray nuclei. In this article I describe some of the results recently obtained at the BEVALAC, i.e. in the GeV/A domain. (orig./HSI)

Self-consistent green function calculations for isospin asymmetric nuclear matter

International Nuclear Information System (INIS)

Mansour, Hesham; Gad, Khalaf; Hassaneen, Khaled S.A.

2010-01-01

The one-body potentials for protons and neutrons are obtained from the self-consistent Green-function calculations of asymmetric nuclear matter, in particular their dependence on the degree of proton/neutron asymmetry. Results of the binding energy per nucleon as a function of the density and asymmetry parameter are presented for the self-consistent Green function approach using the CD-Bonn potential. For the sake of comparison, the same calculations are performed using the Brueckner-Hartree-Fock approximation. The contribution of the hole-hole terms leads to a repulsive contribution to the energy per nucleon which increases with the nuclear density. The incompressibility for asymmetric nuclear matter has been also investigated in the framework of the self-consistent Green-function approach using the CD-Bonn potential. The behavior of the incompressibility is studied for different values of the nuclear density and the neutron excess parameter. The nuclear symmetry potential at fixed nuclear density is also calculated and its value decreases with increasing the nucleon energy. In particular, the nuclear symmetry potential at saturation density changes from positive to negative values at nucleon kinetic energy of about 200 MeV. For the sake of comparison, the same calculations are performed using the Brueckner-Hartree-Fock approximation. The proton/neutron effective mass splitting in neutron-rich matter has been studied. The predicted isospin splitting of the proton/neutron effective mass splitting in neutron-rich matter is such that m n * ≥ m p * . (author)

Nuclear matter as a nonlinear optical medium

International Nuclear Information System (INIS)

Hefter, E.F.; Papini, G.

1986-01-01

This paper is concerned with the question whether nuclear matter should be considered as a nonlinear optical medium. Taking, in a pragmatic way, quality and quantity of the results of well-established linear and nonlinear approaches as the main criterion, an affirmative answer is seen to be consistent with long-standing practices adhered to in nuclear physics

Determination of nuclear-matter temperature and density

International Nuclear Information System (INIS)

Wolf, K.L.

1980-01-01

Some of the things learned about nuclear matter under extreme conditions during the past few years in relativistic heavy ion studies are reviewed. Two developments are discussed. The completion of analyses and publication of results from the impact parameter selected, single-particle inclusive experiments have proven to be important. Preliminary results from the new generation of two-particle correlation and particle-exclusive measurements, especially those using streamer chambers, look even more definitive. Also the measurement of more exotic ejectiles with long mean free paths in nuclear matter promises to provide more basic information. Calculations are offering real guidance and are providing explanations of high energy collisions. The Monte Carlo and intranuclear cascade calculations discussed are especially informative

Strangeness in nuclear matter at DAΦNE

International Nuclear Information System (INIS)

Gianotti, P.

1998-01-01

The low energy kaons from the φ meson produced at DAΦNE offer a unique opportunity to study strangeness in nuclear matter. The interaction of kaons with hadronic matter can be investigated at DAΦNE using three main approaches: study of hypernuclei production and decay, kaons scattering on nucleons, kaonic atoms formation. These studies explore kaon-nucleon and hyperon-nucleon forces at very low energy, the nuclear shell model in presence of strangeness quantum number and eventual quarks deconfinement phenomena. The experiments devoted to study this physical program at DAΦNE are FINUDA and DEAR. The physics topics of both experiments are illustrated together with a detailed descriptions of the two detectors

Instability in relativistic nuclear matter

International Nuclear Information System (INIS)

Tezuka, Hirokazu.

1979-11-01

The stability of the Fermi gas state in the nuclear matter which satisfies the saturation property is considered relativistically. It is shown that the Fermi gas state is stable at very low density and at high density, but it is unstable for density fluctuation in the intermediate density region including the normal density. (author)

Skyrme interaction to second order in nuclear matter

Science.gov (United States)

Kaiser, N.

2015-09-01

Based on the phenomenological Skyrme interaction various density-dependent nuclear matter quantities are calculated up to second order in many-body perturbation theory. The spin-orbit term as well as two tensor terms contribute at second order to the energy per particle. The simultaneous calculation of the isotropic Fermi-liquid parameters provides a rigorous check through the validity of the Landau relations. It is found that published results for these second order contributions are incorrect in most cases. In particular, interference terms between s-wave and p-wave components of the interaction can contribute only to (isospin or spin) asymmetry energies. Even with nine adjustable parameters, one does not obtain a good description of the empirical nuclear matter saturation curve in the low density region 0\\lt ρ \\lt 2{ρ }0. The reason for this feature is the too strong density-dependence {ρ }8/3 of several second-order contributions. The inclusion of the density-dependent term \\frac{1}{6}{t}3{ρ }1/6 is therefore indispensable for a realistic description of nuclear matter in the Skyrme framework.

Bulk viscosity of hot dense Quark matter in the PNJL model

International Nuclear Information System (INIS)

Xiao Shisong; Guo Panpan; Zhang Le; Hou Defu

2014-01-01

Starting from the Kubo formula and the QCD low energy theorem, we study the the bulk viscosity of hot dense quark matter in the PNJL model from the equation of state. We show that the bulk viscosity has a sharp peak near the chiral phase transition, and that the ratio of bulk viscosity over entropy rises dramatically in the vicinity of the phase transition. These results agree with those from the lattice and other model calculations. In addition, we show that the increase of chemical potential raises the bulk viscosity. (authors)

QUANTUM TRANSPORT-THEORY OF NUCLEAR-MATTER

NARCIS (Netherlands)

BOTERMANS, W; MALFLIET, R

1990-01-01

Quantum kinetic equations are derived using the Keldysh Green's function formalism to describe non-equilibrium processes in nuclear matter and nucleus-nucleus collisions. A general transport equation is proposed which includes energy spreading effects. We discuss a number of specific kinetic

On the spin saturation and thermal properties of nuclear matter

International Nuclear Information System (INIS)

Hassan, M.Y.M.; Ramadan, S.

1983-12-01

The binding energy and the incompressibility of nuclear matter with degree of spin saturation D is calculated using the Skyrme interaction and two forms of a velocity dependent effective potential. The effect of the degree of spin saturation D on the thermal properties of nuclear matter is also discussed. It is found that generally the pressure decreases with increasing D. (author)

Non-Abelian behavior of α bosons in cold symmetric nuclear matter

International Nuclear Information System (INIS)

Zheng Hua; Bonasera, Aldo

2011-01-01

The ground-state energy of infinite symmetric nuclear matter is usually described by strongly interacting nucleons obeying the Pauli exclusion principle. We can imagine a unitary transformation which groups four nonidentical nucleons (i.e., with different spin and isospin) close in coordinate space. Those nucleons, being nonidentical, do not obey the Pauli principle, thus their relative momenta are negligibly small (just to fulfill the Heisenberg principle). Such a cluster can be identified with an α boson. But in dense nuclear matter, those α particles still obey the Pauli principle since are constituted of fermions. The ground state energy of nuclear matter α clusters is the same as for nucleons, thus it is degenerate. We could think of α particles as vortices which can now braid, for instance making 8 Be which leave the ground state energy unchanged. Further braiding to heavier clusters ( 12 C, 16 O,...) could give a different representation of the ground state at no energy cost. In contrast d-like clusters (i.e., N=Z odd-odd nuclei, where N and Z are the neutron and proton number, respectively) cannot describe the ground state of nuclear matter and can be formed at high excitation energies (or temperatures) only. We show that even-even, N=Z, clusters could be classified as non-Abelian states of matter. As a consequence an α condensate in nuclear matter might be hindered by the Fermi motion, while it could be possible a condensate of 8 Be or heavier clusters.

The Nuclear Installations (Excepted Matter) Regulations 1978 (Statutory Instrument No. 1779, 4 December 1978)

International Nuclear Information System (INIS)

1979-01-01

These Regulations prescribe, for the purposes of the definition of 'excepted matter' in the Nuclear Installations Act 1965, certain specified quantities and forms of nuclear matter, and supersede the Nuclear Installations (excepted Matter) Regulations 1965. They bring the definition of excepted matter in those Regulations into line with the decisions of 27 October 1977 of the OECD Nuclear Energy Agency's Steering Committee excluding certain kinds and quantities of nuclear substances from the scope of the Paris Convention on Third Party Liability in the Field of Nuclear Energy. Compared with the 1965 Regulations, the principal changes in relation to consignments are that activity limits and packing requirements now take account of the most recent IAEA Regulations. (NEA) [fr

Microscopic study of nuclear 'pasta' by quantum molecular dynamics

International Nuclear Information System (INIS)

Watanabe, Gentaro; Sato, Katsuhiko; Yasuoka, Kenji; Ebisuzaki, Toshikazu

2002-01-01

Structure of cold dense matter at subnuclear densities is investigated by quantum molecular dynamics (QMD) simulations. We succeeded in showing that the phases with slab-like and rod-like nuclei etc. and be formed dynamically from hot uniform nuclear matter without any assumptions on nuclear shape. We also observe intermediate phases, which has complicated nuclear shapes. Geometrical structures of matter are analyzed with Minkowski functionals, and it is found out that intermediate phases can be characterized as ones with negative Euler characteristic. Our result suggests the existence of these kinds of phases in addition to the simple 'pasta' phases in neutron star crusts. (author)

Condensed Matter Nuclear Science

Science.gov (United States)

Biberian, Jean-Paul

2006-02-01

1. General. A tribute to gene Mallove - the "Genie" reactor / K. Wallace and R. Stringham. An update of LENR for ICCF-11 (short course, 10/31/04) / E. Storms. New physical effects in metal deuterides / P. L. Hagelstein ... [et al.]. Reproducibility, controllability, and optimization of LENR experiments / D. J. Nagel -- 2. Experiments. Electrochemistry. Evidence of electromagnetic radiation from Ni-H systems / S. Focardi ... [et al.]. Superwave reality / I. Dardik. Excess heat in electrolysis experiments at energetics technologies / I. Dardik ... [et al.]. "Excess heat" during electrolysis in platinum/K[symbol]CO[symbol]/nickel light water system / J. Tian ... [et al.]. Innovative procedure for the, in situ, measurement of the resistive thermal coefficient of H(D)/Pd during electrolysis; cross-comparison of new elements detected in the Th-Hg-Pd-D(H) electrolytic cells / F. Celani ... [et al.]. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for superstoihiometric H/D sites / A. Lipson ... [et al.]. Plasma electrolysis. Calorimetry of energy-efficient glow discharge - apparatus design and calibration / T. B. Benson and T. O. Passell. Generation of heat and products during plasma electrolysis / T. Mizuno ... [et al.]. Glow discharge. Excess heat production in Pd/D during periodic pulse discharge current in various conditions / A. B. Karabut. Beam experiments. Accelerator experiments and theoretical models for the electron screening effect in metallic environments / A. Huke, K. Czerski, and P. Heide. Evidence for a target-material dependence of the neutron-proton branching ratio in d+d reactions for deuteron energies below 20keV / A. Huke ... [et al.]. Experiments on condensed matter nuclear events in Kobe University / T. Minari ... [et al.]. Electron screening constraints for the cold fusion / K. Czerski, P. Heide, and A. Huke. Cavitation. Low mass 1.6 MHz sonofusion reactor / R. Stringham. Particle detection. Research

Relativistic nuclear fluid dynamics and VUU kinetic theory

International Nuclear Information System (INIS)

Molitoris, J.J.; Hahn, D.; Alonso, C.; Collazo, I.; D'Alessandris, P.; McAbee, T.; Wilson, J.; Zingman, J.

1987-01-01

Relativistic kinetic theory may be used to understand hot dense hadronic matter. We address the questions of collective flow and pion production in a 3 D relativistic fluid dynamic model and in the VUU microscopic theory. The GSI/LBL collective flow and pion data point to a stiff equation of state. The effect of the nuclear equation of state on the thermodynamic parameters is discussed. The properties of dense hot hadronic matter are studied in Au + Au collisions from 0.1 to 10 GeV/nucleon. 22 refs., 5 figs

Variational method for infinite nuclear matter with noncentral forces

International Nuclear Information System (INIS)

Takano, M.; Yamada, M.

1998-01-01

Approximate energy expressions are proposed for infinite zero-temperature nuclear matter by taking into account noncentral forces. They are explicitly expressed as functionals of spin- (isospin-) dependent radial distribution functions, tensor distribution functions and spin-orbit distribution functions, and can be used conveniently in the variational method. A notable feature of these expressions is that they automatically guarantee the necessary conditions on the spin-isospin-dependent structure functions. The Euler-Lagrange equations are derived from these energy expressions and numerically solved for neutron matter and symmetric nuclear matter. The results show that the noncentral forces bring down the total energies too much with too dense saturation densities. Since the main reason for these undesirable results seems to be the long tails of the noncentral distribution functions, an effective theory is proposed by introducing a density-dependent damping function into the noncentral potentials to suppress the long tails of the non-central distribution functions. By adjusting the value of a parameter included in the damping function, we can reproduce the saturation point (both the energy and density) of symmetric nuclear matter with the Hamada-Johnston potential. (Copyright (1998) World Scientific Publishing Co. Pte. Ltd)

Neutrino propagation in neutron matter and the nuclear equation of state

CERN Document Server

Margueron, J; Nguyen Van Giai; Jiang, W

2001-01-01

We study the propagation of neutrinos inside dense matter under the conditions prevailing in a proto-neutron star. Equations of state obtained with different nuclear effective interactions (Skyrme type and Gogny type) are first discussed. It is found that for many interactions, spin and/or isospin instabilities occur at densities larger than the saturation density of nuclear matter. From this study we select two representative interactions, SLy230b and D1P. We calculate the response functions in pure neutron matter where nuclear correlations are described at the Hartree-Fock plus RPA level. These response functions allow us to evaluate neutrino mean free paths corresponding to neutral current processes.

The giant resonances in hot nuclei. Linear response calculations

International Nuclear Information System (INIS)

Braghin, F.L.; Vautherin, D.; Abada, A.

1995-01-01

The isovector response function of hot nuclear matter is calculated using various effective Skyrme interactions. For Skyrme forces with a small effective mass the strength distribution is found to be nearly independent of temperature, and shows little collective effects. In contrast effective forces with an effective mass close to unity produce at zero temperature sizeable collective effects which disappear at temperatures of a few MeV. The relevance of these results for the saturation of the multiplicity of photons emitted by the giant dipole resonance in hot nuclei observed in recent experiments beyond T = 3 MeV is discussed. (authors). 12 refs., 3 figs

Chiral symmetry, scalar field and confinement: from nucleon structure to nuclear matter

International Nuclear Information System (INIS)

Chanfray, Guy; Ericson, Magda

2010-01-01

We discuss the relevance of the scalar modes appearing in chiral theories with spontaneous symmetry breaking such as the NJL model for nuclear matter studies. We show that it depends on the relative role of chiral symmetry breaking and confinement in the nucleon mass origin. It is only in the case of a mixed origin that nuclear matter can be stable and reach saturation. We describe models of nucleon structure where this balance is achieved. We show how chiral constarints and confinement modify the QCD sum rules for the mass evolution in nuclear matter.

Condensed matter studies by nuclear methods

International Nuclear Information System (INIS)

Krolas, K.; Tomala, K.

1988-01-01

The separate abstract was prepared for 1 of the papers in this volume. The remaining 13 papers dealing with the use but not with advances in the use of nuclear methods in studies of condensed matter, were considered outside the subject scope of INIS. (M.F.W.)

Some comments on the behaviour of the excited nuclear matter formed in nuclear collisions at high energies

International Nuclear Information System (INIS)

Besliu, Calin; Jipa, Alexandru; Argintaru, Dan

2003-01-01

In the last years many experiments have been performed in different laboratories to investigate the behaviour of the nuclear matter formed in nuclear collisions at high energies. Therefore, many experimental results are available at present. For explaining these experimental results a lot of models have been proposed. A very large number of concepts have been used. Taking into account some own experimental results obtained in proton-nucleus and nucleus-nucleus collisions at energies between a few A GeV and a few hundred A GeV we comments in the frame a phenomenological geometric picture the main experimental results on charged particle multiplicities, participants, cross sections, momentum spectra, temperature slopes, nuclear matter flow, size and structure of the participant regions, antiparticle to particle ratios and chemical potential. Some jumps in the dependencies of some interesting physical quantities on the available energies in the centre of mass system can be reported. Trends to behaviours like-saturation of some physical quantities are observed, too. Therefore, some connections with the possible phase transitions in nuclear matter are included. A few specific signals of different phase transitions in nuclear matter are suggested. (authors)

Hadronic spectral functions in nuclear matter

International Nuclear Information System (INIS)

Post, M.; Leupold, S.; Mosel, U.

2004-01-01

We study the in-medium properties of mesons (π,η,ρ) and baryon resonances in cold nuclear matter within a coupled-channel analysis. The meson self energies are generated by particle-hole excitations. Thus multi-peak spectra are obtained for the mesonic spectral functions. In turn this leads to medium-modifications of the baryon resonances. Special care is taken to respect the analyticity of the spectral functions and to take into account effects from short-range correlations both for positive and negative parity states. Our model produces sensible results for pion and Δ dynamics in nuclear matter. We find a strong interplay of the ρ meson and the D 13 (1520), which moves spectral strength of the ρ spectrum to smaller invariant masses and leads to a broadening of the baryon resonance. The optical potential for the η meson resulting from our model is rather attractive whereas the in-medium properties modifications of the S 11 (1535) are found to be quite small

Energy-range relations for hadrons in nuclear matter

Science.gov (United States)

Strugalski, Z.

1985-01-01

Range-energy relations for hadrons in nuclear matter 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 nuclear matter in nucleons on which the incident hadrons are stopped.

Sound-like collective mode excitation with pion absorption in nuclear matter

International Nuclear Information System (INIS)

Qiu Xijiun; Shen Jianguo; Huang Lingfang

1985-01-01

The relativistic mean field theory consistent with bulk properties of nuclear matter is extended to study the excitations of the sound-like collective modes in nuclear matter. Corresponding relativistic mean field equations are solved numerically and self-consistently. The effective mass of nucleon, the speed of the sound and the amplitude of the sound-like solution are calculated. When the nuclear density is near or greater than the saturation density, the sound-like non-trivial solution could be found

Spin polarized states in strongly asymmetric nuclear matter

International Nuclear Information System (INIS)

Isayev, A.A.; Yang, J.

2004-01-01

The possibility of appearance of spin polarized states in strongly asymmetric nuclear matter is analyzed within the framework of a Fermi liquid theory with the Skyrme effective interaction. The zero temperature dependence of the neutron and proton spin polarization parameters as functions of density is found for SLy4 and SLy5 effective forces. It is shown that at some critical density strongly asymmetric nuclear matter undergoes a phase transition to the state with the oppositely directed spins of neutrons and protons while the state with the same direction of spins does not appear. In comparison with neutron matter, even small admixture of protons strongly decreases the threshold density of spin instability. It is clarified that protons become totally polarized within a very narrow density domain while the density profile of the neutron spin polarization parameter is characterized by the appearance of long tails near the transition density

Matter in extremis: Ultrarelativistic nuclear collisions at RHIC

Energy Technology Data Exchange (ETDEWEB)

Jacobs, Peter; Wang, Xin-Nian

2004-08-20

We review the physics of nuclear matter 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 nuclear matter, 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.

Matter in extremis: Ultrarelativistic nuclear collisions at RHIC

International Nuclear Information System (INIS)

Jacobs, Peter; Wang, Xin-Nian

2004-01-01

We review the physics of nuclear matter 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 √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 nuclear matter, 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

Phase transitions in nuclear matter and consequences for neutron stars

International Nuclear Information System (INIS)

Kaempfer, B.

1983-04-01

Estimates of the minimal bombarding energy necessary to reach the quark gluon phase in heavy ion collisions are presented within a hydrodynamical scenario. Further, the consequences of first-order phase transitions from nuclear/neutron matter to pion-condensed matter or quark matter are discussed for neutron stars. (author)

Antiferromagnetic spin phase transition in nuclear matter with effective Gogny interaction

International Nuclear Information System (INIS)

Isayev, A.A.; Yang, J.

2004-01-01

The possibility of ferromagnetic and antiferromagnetic phase transitions in symmetric nuclear matter is analyzed within the framework of a Fermi liquid theory with the effective Gogny interaction. It is shown that at some critical density nuclear matter with the D1S effective force undergoes a phase transition to the antiferromagnetic spin state (opposite directions of neutron and proton spins). The self-consistent equations of spin polarized nuclear matter with the D1S force have no solutions corresponding to ferromagnetic spin ordering (the same direction of neutron and proton spins) and, hence, the ferromagnetic transition does not appear. The dependence of the antiferromagnetic spin polarization parameter as a function of density is found at zero temperature

Charmonium formation and suppression in nuclear matter

International Nuclear Information System (INIS)

Xu Jiajun; Wang Jia; Zhuang Chao; Zhuang Pengfei

2005-01-01

The coupling Schroedinger equations describing the evolution of cc-bar states in nuclear matter are analytically and systematically solved via perturbation method, and the correlation between charmonium formation and nuclear absorption is investigated. After calculating J/Ψ and Ψ' suppression in nucleon-nucleus collisions and comparing with experiment data, it is found that the formation time effect plays an important rule in charmonium suppression, especially in Ψ' suppression. (authors)

Many-body theory of nuclear and neutron star matter

International Nuclear Information System (INIS)

Pandharipande, V.R.; Akmal, A.; Ravenhall, D.G.

1998-01-01

We present results obtained for nuclei, nuclear and neutron star matter, and neutron star structure obtained with the recent Argonne v 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.)

Many-body theory of nuclear and neutron star matter

Energy Technology Data Exchange (ETDEWEB)

Pandharipande, V R; Akmal, A; Ravenhall, D G [Dept. of Physics, Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States)

1998-06-01

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.)

QCD sum rule for nucleon in nuclear matter

International Nuclear Information System (INIS)

Mallik, S.; Sarkar, Sourav

2010-01-01

We consider the two-point function of nucleon current in nuclear matter and write a QCD sum rule to analyse the residue of the nucleon pole as a function of nuclear density. The nucleon self-energy needed for the sum rule is taken as input from calculations using phenomenological N N potential. Our result shows a decrease in the residue with increasing nuclear density, as is known to be the case with similar quantities. (orig.)

Energy-weighted sum rules for mesons in hot and dense matter

NARCIS (Netherlands)

Cabrera, D.; Polls, A.; Ramos, A.; Tolos Rigueiro, Laura

2009-01-01

We study energy-weighted sum rules of the pion and kaon propagator in nuclear matter at finite temperature. The sum rules are obtained from matching the Dyson form of the meson propagator with its spectral Lehmann representation at low and high energies. We calculate the sum rules for specific

Heavy-flavour hadrons as probes of strongly-interacting matter: highlights from ALICE

CERN Multimedia

CERN. Geneva

2014-01-01

In Pb-Pb collisions the heavy-flavour nuclear modification factor together with the elliptic-flow measurements allow one to study the heavy-quark transport properties in the hot and dense medium. The production of heavy quarks in heavy-ion collisions is furthermore also affected by the presence of cold nuclear matter in the initial state. The study of p-Pb collisions is instrument...

The rule on granting subsidies for survey of hot drainage influences

International Nuclear Information System (INIS)

1977-01-01

The rule is based on the prescriptions of the Law Concerning Proper Budget Enforcement on Subsidies and its Enforcement Order. These rules apply to the granting subsidies provided for by the Enforcement Order for the Special Account Law for Measures Promoting Power Source Development. Terms are defined, such as nuclear power generating facilities; arrangement work for equipments for surveying hot drainage influences; work of preliminary survey of hot drainage; work of surveying hot drainage influences; establishments, etc. The Minister of International Trade and Industry delivers the subsidies for all or a part of the expenses necessary for arrangement work of equipments for surveying hot drainage influences, work of preliminary survey of hot drainage and work of surveying hot drainage influences to the prefectures where nuclear power generating facilities have been or are to be set up, or their neighboring prefectures. Terms of delivery concerning an establishment vary from two years to four years according to the kinds of such subsidies. Limits of the subsidies concerning an establishment range from 10 million yen to 2.5 million yen. The applicant prefecture files the application to the Minister of International Trade and Industry. The Minister examines such applications, and notifies his decision to the applicants. Conditions on delivery, reports submitted by receivers of the subsidies and other matters related are specified. (Okada, K.)

Infinite nuclear matter based for mass of atomic nuclei

International Nuclear Information System (INIS)

Satpathy, L.

1987-01-01

The ground-state energy of an atomic nucleus with asymmetry β is considered to be equivalent to the energy of a perfect sphere made up of infinite nuclear matter of the same asymmetry plus a residual energy eta, called the local energy. Eta represents the energy due to shell, deformation, diffuseness and exchange Coulomb effects, etc. Using this picture and the generalised Hugenholtz-Van Hove theorem of many-body theory, the previously proposed mass relation is derived in a transport way in which eta drops away in a very natural manner. The validity of this mass relation is studied globally using the latest mass table. The model is suitable for the extraction of the saturation properties of nuclear matter. The binding energy per nucleon and the saturation Fermi momentum of nuclear matter obtained through this model are 18.33 MeV and 1.48 fm -1 respectively. It is shown in several representative cases in the Periodic Table that the masses of nuclei in the far unknown region can be reliably predicted. (author)

Nuclear matter saturation in a U(1) circle-times chiral model

International Nuclear Information System (INIS)

Lin, Wei

1989-01-01

The mean-field approximation in the U(1) circle-times chiral model for nuclear matter maturation is reviewed. Results show that it cannot be the correct saturation mechanism. It is argued that in this chiral model, other than the fact the ω mass can depend on the density of nuclear matter, saturation is still quite like the Walecka picture. 16 refs., 3 figs

Sigma-omega meson coupling and properties of nuclei and nuclear matter

International Nuclear Information System (INIS)

Haidari, Maryam M.; Sharma, Madan M.

2008-01-01

We have constructed a Lagrangian model with a coupling of σ and ω mesons in the relativistic mean-field theory. Properties of finite nuclei and nuclear matter are explored with the new Lagrangian model SIG-OM. The study shows that an excellent description of binding energies and charge radii of nuclei over a large range of isospin is achieved with SIG-OM. With an incompressibility of nuclear matter K=265 MeV, it is also able to describe the breathing-mode isoscalar giant monopole resonance energies appropriately. It is shown that the high-density behaviour of the equation of state of nuclear and neutron matter with the σ-ω coupling is much softer than that of the non-linear scalar coupling model

Nonlinear mean field theory for nuclear matter and surface properties

International Nuclear Information System (INIS)

Boguta, J.; Moszkowski, S.A.

1983-01-01

Nuclear matter properties are studied in a nonlinear relativistic mean field theory. We determine the parameters of the model from bulk properties of symmetric nuclear matter and a reasonable value of the effective mass. In this work, we stress the nonrelativistic limit of the theory which is essentially equivalent to a Skyrme hamiltonian, and we show that most of the results can be obtained, to a good approximation, analytically. The strength of the required parameters is determined from the binding energy and density of nuclear matter and the effective nucleon mass. For realistic values of the parameters, the nonrelativistic approximation turns out to be quite satisfactory. Using reasonable values of the parameters, we can account for other key properties of nuclei, such as the spin-orbit coupling, surface energy, and diffuseness of the nuclear surface. Also the energy dependence of the nucleon-nucleus optical model is accounted for reasonably well except near the Fermi surface. It is found, in agreement with empirical results, that the Landau parameter F 0 is quite small in normal nuclear matter. Both density dependence and momentum dependence of the NN interaction, but especially the former, are important for nuclear saturation. The required scalar and vector coupling constants agree fairly well with those obtained from analyses of NN scattering phase shifts with one-boson-exchange models. The mean field theory provides a semiquantitative justification for the weak Skyrme interaction in odd states. The strength of the required nonlinear term is roughly consistent with that derived using a new version of the chiral mean field theory in which the vector mass as well as the nucleon mass is generated by the sigma-field. (orig.)

Nuclear physics: the core of matter, the fuel of stars

International Nuclear Information System (INIS)

Schiffer, J.P.

1999-01-01

Dramatic progress has been made in all branches of physics since the National Research Council's 1986 decadal survey of the field. The Physics in a New Era series explores these advances and looks ahead to future goals. The series includes assessments of the major subfields and reports on several smaller subfields, and preparation has begun on an overview volume on the unity of physics, its relationships to other fields, and its contributions to national needs. Nuclear Physics is the latest volume of the series. The book describes current activity in understanding nuclear structure and symmetries, the behavior of matter at extreme densities, the role of nuclear physics in astrophysics and cosmology, and the instrumentation and facilities used by the field. It makes recommendations on the resources needed for experimental and theoretical advances in the coming decade. Nuclear physics addresses the nature of matter making up 99.9 percent of the mass of our everyday world. It explores the nuclear reactions that fuel the stars, including our Sun, which provides the energy for all life on Earth. The field of nuclear physics encompasses some 3,000 experimental and theoretical researchers who work at universities and national laboratories across the United States, as well as the experimental facilities and infrastructure that allow these researchers to address the outstanding scientific questions facing us. This report provides an overview of the frontiers of nuclear physics as we enter the next millennium, with special attention to the state of the science in the United States.The current frontiers of nuclear physics involve fundamental and rapidly evolving issues. One is understanding the structure and behavior of strongly interacting matter in terms of its basic constituents, quarks and gluons, over a wide range of conditions - from normal nuclear matter to the dense cores of neutron stars, and to the Big Bang that was the birth of the universe. Another is to describe

A calculation of baryon diffusion constant in hot and dense hadronic matter based on an event generator URASiMA

International Nuclear Information System (INIS)

Sasaki, N.; Miyamura, O.; Nonaka, C.; Muroya, S.

2000-01-01

We evaluate thermodynamical quantities and transport coefficient of a dense and hot hadronic matter based on an event generator URASiMA (Ultra-Relativistic AA collision Simulator based on Multiple Scattering Algorithm). The statistical ensembles in equilibrium with fixed temperature and chemical potential are generated by imposing periodic boundary condition to the simulation of URASiMA, where energy density and baryon number density is conserved. Achievement of the thermal equilibrium and the chemical equilibrium are confirmed by the common value of slope parameter in the energy distributions and the saturation of the numbers of contained particles, respectively. By using the generated ensembles, we investigate the temperature dependence and the chemical potential dependence of the baryon diffusion constant of a dense and hot hadronic matter. (author)

Magnetic properties of strongly asymmetric nuclear matter

International Nuclear Information System (INIS)

Kutschera, M.; Wojcik, W.

1988-01-01

We investigate stability of neutron matter containing a small proton admixture with respect to spin fluctuations. We establish conditions under which strongly asymmetric nuclear matter could acquire a permanent magnetization. It is shown that if the protons are localized, the system becomes unstable to spin fluctuations for arbitrarily weak proton-neutron spin interactions. For non-localized protons there exists a threshold value of the spin interaction above which the system can develop a spontaneous polarization. 12 refs., 2 figs. (author)

Too hot to handle? Analytic solutions for massive neutrino or warm dark matter cosmologies

Science.gov (United States)

Slepian, Zachary; Portillo, Stephen K. N.

2018-05-01

We obtain novel closed-form solutions to the Friedmann equation for cosmological models containing a component whose equation of state is that of radiation (w = 1/3) at early times and that of cold pressureless matter (w = 0) at late times. The equation of state smoothly transitions from the early to late-time behavior and exactly describes the evolution of a species with a Dirac Delta function distribution in momentum magnitudes |p_0| (i.e. all particles have the same |p_0|). Such a component, here termed "hot matter", is an approximate model for both neutrinos and warm dark matter. We consider it alone and in combination with cold matter and with radiation, also obtaining closed-form solutions for the growth of super-horizon perturbations in each case. The idealized model recovers t(a) to better than 1.5% accuracy for all a relative to a Fermi-Dirac distribution (as describes neutrinos). We conclude by adding the second moment of the distribution to our exact solution and then generalizing to include all moments of an arbitrary momentum distribution in a closed-form solution.

Hyperons in nuclear matter from SU(3) chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Petschauer, S.; Kaiser, N. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Haidenbauer, J. [Institut fuer Kernphysik, Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany); Meissner, Ulf G. [Institut fuer Kernphysik, Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Weise, W. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Villa Tambosi, ECT, Villazzano (Trento) (Italy)

2016-01-15

Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Λ and Σ hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Σ-nuclear potential and a weak Λ-nuclear spin-orbit force. (orig.)

Tensor quasiparticle interaction and spin-isospin sound in nuclear matter

International Nuclear Information System (INIS)

Haensel, P.

1979-01-01

The effect of the tensor components of the quasiparticle interaction in nuclear matter on the spin-isospin sound type excitations is studied. Numerical results are obtained using a simplified model of the quasiparticle interaction in nuclear matter. The quasiparticle distribution matrix corresponding to the spin-isospin sound is found to be qualitatively different from that obtained for purely central quasiparticle interaction. The macroscopic effects, however, are restricted to a small change in the phase velocity of the spin-isospin sound. (Auth.)

Activities report 1991-1992: Nuclear Research Center of Strasbourg

International Nuclear Information System (INIS)

1993-01-01

This activities report of the Nuclear Research Centre of Strasbourg for the years 1991 and 1992, presents nine research axis: theoretical physics, mechanisms of reactions and nuclear structure, extreme forms of nuclei, exotic nuclei, hot and dense nuclear matter, ultra-relativistic heavy ions, physics of LEP (European Large Electron-Positron storage ring) at 'DELPHI', chemistry and physics of radiations, physics and applications of semi-conductors

Nuclear safety and radiation protection report of the Tricastin operational hot base nuclear facilities - 2013

International Nuclear Information System (INIS)

2014-01-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the Tricastin operational hot base facility (INB no. 157, Bollene, Vaucluse (FR)), a nuclear workshop for storage and maintenance and qualification operations on some EdF equipments. Then, the nuclear safety and radiation protection measures taken regarding the facility are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2013, if some, are reported as well as the effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facility is presented and sorted by type of waste, quantities and type of conditioning. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions

High Momentum Probes of Nuclear Matter

Energy Technology Data Exchange (ETDEWEB)

Fries, R.

2009-07-24

We discuss how the chemical composition of QCD jets is altered by final state interactions in surrounding nuclear matter. 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{sub 2} is suppressed.

Interacting hot dark matter

International Nuclear Information System (INIS)

Atrio-Barandela, F.; Davidson, S.

1997-01-01

We discuss the viability of a light particle (∼30eV neutrino) with strong self-interactions as a dark matter candidate. The interaction prevents the neutrinos from free-streaming during the radiation-dominated regime so galaxy-sized density perturbations can survive. Smaller scale perturbations are damped due to neutrino diffusion. We calculate the power spectrum in the imperfect fluid approximation, and show that it is damped at the length scale one would estimate due to neutrino diffusion. The strength of the neutrino-neutrino coupling is only weakly constrained by observations, and could be chosen by fitting the power spectrum to the observed amplitude of matter density perturbations. The main shortcoming of our model is that interacting neutrinos cannot provide the dark matter in dwarf galaxies. copyright 1997 The American Physical Society

Asymmetric nuclear matter and neutron star properties

International Nuclear Information System (INIS)

Engvik, L.; Hjorth-Jensen, M.; Osnes, E.; Bao, G.; Oestgaard, E.

1994-06-01

Properties of neutron stars such as mass and radius, using a relativistic Dirac-Brueckner-Hartree-Fock approach, are calculated. Modern meson-exchange potential models are used to evaluate the G-matrix for asymmetric nuclear matter. For pure neutron matter the maximum mass is found to be M max ∼ 2.4M for a radius R ∼ 12 km. With a proton fraction of 30% the result is M max ∼ 2.1M for a radius R ∼ 10.5 km, close to the experimental values. The implications are discussed. 20 refs., 3 figs

HOTLAB: European hot laboratories research capacities and needs. Plenary meeting 2004

International Nuclear Information System (INIS)

Oberlaender, B.C.; Jenssen, H.K.

2005-01-01

The report presents proceedings from the 2004 annual HOTLAB plenary meeting at Halden and Kjeller, Norway. The goal of the yearly plenary meeting was to: Exchange experience on analytical methods, their implementation in hot cells, the methodologies used and their application in nuclear research. Share experience on common infrastructure exploitation matters such as remote handling techniques, safety features, QA-certification, waste handling, etc. Promote normalisation and co-operation, e.g. by looking at mutual complementarities. Prospect present and future demands from the nuclear industry and to draw strategic conclusions regarding further needs. The main themes of the five topical oral sessions of the Halden plenary meeting cover: Work package leaders report and specific papers, presentation of PIE facility databases, i.e. one worldwide (IAEA) and one inside the European communities. Reports from present and future needs and on nuclear transports. Refabrication and instrumentation: Available equipment, technical characteristics such as fabrication procedures, hot-cell compatibility, and practical experiences. Post irradiation examination: Updated and new remote techniques and methodologies, new materials such as inert matrix fuels, spallation sources and neutron absorber materials. Refurbishment and decommissioning: reports on refurbishment and decommissioning of PIE facilities. Waste and transport: Hot laboratory waste characteristics and handling, spent fuel research. Several posters are presented

Some Recent Progress on Quark Pairings in Dense Quark and Nuclear Matter

International Nuclear Information System (INIS)

Pang Jinyi; Wang Jincheng; Wang Qun

2012-01-01

In this review article we give a brief overview on some recent progress in quark pairings in dense quark/nuclear matter mostly developed in the past five years. We focus on following aspects in particular: the BCS-BEC crossover in the CSC phase, the baryon formation and dissociation in dense quark/nuclear matter, the Ginzburg-Landau theory for three-flavor dense matter with U A (1) anomaly, and the collective and Nambu-Goldstone modes for the spin-one CSC. (physics of elementary particles and fields)

Comparative study of three-nucleon potentials in nuclear matter

Science.gov (United States)

Lovato, Alessandro; Benhar, Omar; Fantoni, Stefano; Schmidt, Kevin E.

2012-02-01

A new generation of local three-body potentials providing an excellent description of the properties of light nuclei, as well as of the neutron-deuteron doublet scattering length, has been recently derived. We have performed a comparative analysis of the equations of state of both pure neutron matter (PNM) and symmetric nuclear matter (SNM) at zero temperature obtained using these models of three-nucleon forces. In particular, we have carried out both variational and auxiliary field diffusion Monte Carlo calculations of the equation of state of PNM, while in the case of SNM we have only the variational approach has been considered. None of the considered potentials simultaneously explains the empirical equilibrium density and binding energy of symmetric nuclear matter. However, two of them provide reasonable values of the saturation density. The ambiguity concerning the treatment of the contact term of the chiral inspired potentials is discussed.

Isospin-dependent properties of asymmetric nuclear matter in relativistic mean field models

Science.gov (United States)

Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An

2007-11-01

Using various relativistic mean-field models, including nonlinear ones with meson field self-interactions, models with density-dependent meson-nucleon couplings, and point-coupling models without meson fields, we have studied the isospin-dependent bulk and single-particle properties of asymmetric nuclear matter. In particular, we have determined the density dependence of nuclear symmetry energy from these different relativistic mean-field models and compared the results with the constraints recently extracted from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions as well as from measured isotopic dependence of the giant monopole resonances in even-A Sn isotopes. Among the 23 parameter sets in the relativistic mean-field model that are commonly used for nuclear structure studies, only a few are found to give symmetry energies that are consistent with the empirical constraints. We have also studied the nuclear symmetry potential and the isospin splitting of the nucleon effective mass in isospin asymmetric nuclear matter. We find that both the momentum dependence of the nuclear symmetry potential at fixed baryon density and the isospin splitting of the nucleon effective mass in neutron-rich nuclear matter depend not only on the nuclear interactions but also on the definition of the nucleon optical potential.

Compression modes and the nuclear matter incompressibility ...

Indian Academy of Sciences (India)

We review the current status of the nuclear matter ( = and no Coulomb interaction) incompressibility coefficient, , and describe the theoretical and the experimental methods used to determine from properties of compression modes in nuclei. In particular we consider the long standing problem of the conflicting ...

Relativistic nuclear matter with alternative derivative coupling models

International Nuclear Information System (INIS)

Delfino, A.; Coelho, C.T.; Malheiro, M.

1994-01-01

Effective Lagrangians involving nucleons coupled to scalar and vector fields are investigated within the framework of relativistic mean-field theory. The study presents the traditional Walecka model and different kinds of scalar derivative coupling suggested by Zimanyi and Moszkowski. The incompressibility (presented in an analytical form), scalar potential, and vector potential at the saturation point of nuclear matter are compared for these models. The real optical potential for the models are calculated and one of the models fits well the experimental curve from-50 to 400 MeV while also gives a soft equation of state. By varying the coupling constants and keeping the saturation point of nuclear matter approximately fixed, only the Walecka model presents a first order phase transition of finite temperature at zero density. (author)

Pure Neutron Matter Constraints and Nuclear Symmetry Energy

International Nuclear Information System (INIS)

Fattoyev, F J; Newton, W G; Xu, Jun; Li, Bao-An

2013-01-01

In this review, we will discuss the results of our recent work [1] to study the general optimization of the pure isovector parameters of the popular relativistic mean-field (RMF) and Skyrme-Hartree-Fock (SHF) nuclear energy-density functionals (EDFs), using constraints on the pure neutron matter (PNM) equation of state (EoS) from recent ab initio calculations. By using RMF and SHF parameterizations that give equivalent predictions for ground-state properties of doubly magic nuclei and properties of symmetric nuclear matter (SNM) and PNM, we found that such optimization leads to broadly consistent symmetry energy J and its slope parameter L at saturation density within a tight range of α(J) sym , (b) the symmetry energy at supra-saturation densities, and (c) the radius of neutron stars.

Strange mesons in dense nuclear matter

International Nuclear Information System (INIS)

Senger, P.

2000-10-01

Experimental data on the production of kaons and antikaons in heavy ion collisions at relativistic energies are reviewed with respect to in-medium effects. The K - /K + ratios measured in nucleus-nucleus collisions are 1-2 orders of magnitude larger than in proton-proton collisions. The azimuthal angle distributions of K + mesons indicate a repulsive kaon-nucleon potential. Microscopic transport calculations consistently explain both the yields and the emission patterns of kaons and antikaons when assuming that their properties are modified in dense nuclear matter. The K + production excitation functions measured in light and heavy collision systems provide evidence for a soft nuclear equation-of-state. (orig.)

The 132Sn giant dipole resonance as a constraint on nuclear matter properties

Science.gov (United States)

Roach, Brandon; Bonasera, Giacomo; Shlomo, Shalom

2015-10-01

Nuclear giant resonances provide a sensitive method for constraining the properties of nuclear matter (NM) - many of which have large uncertainties - and thereby improve the nuclear energy-density functional. In this work, self-consistent Hartree-Fock random-phase approximation (HF-RPA) theory was employed to calculate the strength function and energy of the isovector giant dipole resonance (IVGDR) in the doubly-magic 132Sn nucleus. Several (17) commonly-used Skyrme-type interactions were employed. The correlations between the IVGDR centroid energy and each nuclear matter property were explored, as were correlations between the nuclear matter properties and the 132Sn neutron skin thickness rn -rp . Experimental data for the IVGDR centroid energy was used to constrain the symmetry energy density, the symmetry energy, and its first and second derivatives, respectively, of NM. Further investigation, particularly of nuclides far from stability, will be needed to extend the nuclear energy-density functional to the extremes of density and neutron abundance found in neutron stars and astrophysical nucleosynthesis environments.

Derivation of the Euler equations in Thomas-Fermi theories of a hot nuclear system

International Nuclear Information System (INIS)

Wang, C.

1992-01-01

The variational extreme condition with respect to statistical distribution of nucleons in momentum space is applied to derive the Euler equation of the nuclear density profile. The resultant Euler equation of the nuclear density profile is proven to be identical with that obtained in the usual Thomas-Fermi theories of a hot nuclear system where the variation is made with respect to the nuclear density profile. A Fermi-Dirac-type distribution appears as a result of variation in the present approach, while it is used as a given expression in obtaining the variation of the nuclear density profile in the usual Thomas-Fermi theories

Three-dimensional calculation of inhomogeneous nuclear matter

International Nuclear Information System (INIS)

Okamoto, Minoru; Maruyama, Toshiki; Yabana, Kazuhiro; Tatsumi, Toshitaka

2012-01-01

We numerically explore the pasta structures and properties of low-density symmetric nuclear matter without any assumption on the geometry. We observe conventional pasta structures, while a mixture of the pasta appears as a meta-stable state at some transient densities. We also analyze the lattice structure of droplets.

Three-dimensional calculation of inhomogeneous nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Okamoto, Minoru; Maruyama, Toshiki; Yabana, Kazuhiro; Tatsumi, Toshitaka [Graduate School of Pure and Applied Science, University of Tsukuba (Japan); Advanced Science Research Center, Japan Atomic Energy Agency (Japan); Graduate School of Pure and Applied Science, University of Tsukuba (Japan); Department of Physics, Kyoto University (Japan)

2012-11-12

We numerically explore the pasta structures and properties of low-density symmetric nuclear matter without any assumption on the geometry. We observe conventional pasta structures, while a mixture of the pasta appears as a meta-stable state at some transient densities. We also analyze the lattice structure of droplets.

Properties of the ρ meson in dense nuclear matter

International Nuclear Information System (INIS)

Herrmann, M.

1992-05-01

In order to reach a description of the ρ meson, which is in accordance with the principles of the gauge invariance of the electromagnetic interaction, the vector-dominance hypothesis, and the unitarity a model for the ρ meson in the vacuum is developed. Thereafter follows the calculation of the properties of the ρ meson in nuclear matter. First the connection between the spectral function of the ρ meson and the dilepton production rate for an equilibrium state is derived. Then the model for the pion in nuclear matter is described. Following approximations are applied: The description of the pion-baryon interaction pursues non-relativistically and both the width of the delta resonance and the short-range repulsive delta-nucleon interaction is neglected. The self-energy of the ρ meson in nuclear matter following from this description is formally derived from the requirement to couple the ρ meson to a conserved current. The corrections for the 3-point and 4-point vertex resulting from this are calculated and discussed. Thereafter the physical consequences of the changed self-energy of the ρ meson in nuclear matter are considered. By means of the spectral function it is shown that up to the two-fold of the ground-state density the position of the resonance is nearly not changed. At still higher densities the resonances is a little shifted to higher energies. In the range of an invariant mass of about 400 meV a strong increasement concentrated on a small range results. This is caused by coupling to a naked delta-hole state and a pion. Finally the possibilities are discussed to apply the results of this thesis to the prediction of experimental data. Thereby it is proved to be necessary to base on a simulation of the heavy ion reaction. (orig./HSI) [de

75 FR 10833 - In the Matter of Entergy Nuclear Operations; Vermont Yankee Nuclear Power Station; Demand for...

Science.gov (United States)

2010-03-09

... NUCLEAR REGULATORY COMMISSION [Docket No. 05000271; License No. DPR-28; EA-10-034; NRC-2010-0089] In the Matter of Entergy Nuclear Operations; Vermont Yankee Nuclear Power Station; Demand for... this Demand for Information, the following information, in writing, and under oath or affirmation: 1...

Ceramic nuclear waste forms. II. A ceramic-waste composite prepared by hot pressing. Progress report and preprint

International Nuclear Information System (INIS)

McCarthy, G.J.

1975-01-01

A feasibility study was conducted to determine whether nuclear waste calcine and a crystalline ceramic matrix can be fabricated by hot pressing into a composite waste form with suitable leaching resistance and thermal stability. It was found that a hard, dense composite could be formed using the typical commercial waste formulation PW-4b and a matrix of α-quartz with a small amount of a lead borosilicate glass added as a consolidation aide. Its density, waste loading, and leaching resistance are comparable to the glasses currently being considered for fixation of nuclear wastes. The hot pressed composite offers a closer approach to thermodynamic stability and improved thermal stability (in monolithic form) compared to glass waste forms. Recommendations for further optimization of the hot pressed waste form are given. (U.S.)

Nuclear matter descriptions including quark structure of the hadrons

International Nuclear Information System (INIS)

Huguet, R.

2008-07-01

It is nowadays well established that nucleons are composite objects made of quarks and gluons, whose interactions are described by Quantum chromodynamics (QCD). However, because of the non-perturbative character of QCD at the energies of nuclear physics, a description of atomic nuclei starting from quarks and gluons is still not available. A possible alternative is to construct effective field theories based on hadronic degrees of freedom, in which the interaction is constrained by QCD. In this framework, we have constructed descriptions of infinite nuclear matter in relativistic mean field theories taking into account the quark structure of hadrons. In a first approach, the in medium modifications of mesons properties is dynamically obtained in a Nambu-Jona-Lasinio (NJL) quark model. This modification is taken into account in a relativistic mean field theory based on a meson exchange interaction between nucleons. The in-medium modification of mesons masses and the properties of infinite nuclear matter have been studied. In a second approach, the long and short range contributions to the in-medium modification of the nucleon are determined. The short range part is obtained in a NJL quark model of the nucleon. The long range part, related to pions exchanges between nucleons, has been determined in the framework of Chiral Perturbation theory. These modifications have been used to constrain the couplings of a point coupling relativistic mean field model. A realistic description of the saturation properties of nuclear matter is obtained. (author)

Particle production in hot and dense nuclear matter

International Nuclear Information System (INIS)

Eklund, A.

1992-08-01

The charged particle production in heavy ion reactions at 200 A GeV has been studied for projectiles of 16 O and 32 S on targets of Al, Cu, Ag and Au. Up to 700 charged particles are measured in the pseudorapidity region -1.7 32 S+Au. The measured particle density is used to estimate the energy density attained in central collisions and gives a values of ≅2 GeV/fm 3 . This is close to the energy density predicted for the phase transition from hadronic matter to a quark-gluon plasma. To measure the large number of charged particle produced, finely granulated detector systems are employed. Streamer tube detectors with pad readout and large area, multi-step avalanche chambers with optical readout have been developed for the measurements. The widths of the pseudorapidity distributions of charged particles increase with decreasing centrality of the collision as well as with increasing mass of the target nucleus. This behaviour is assumed to be due to the target fragmentation. The Monte-Carlo model for nucleus-nucleus collisions, VENUS 3.11, which includes rescattering, is in reasonable agreement with the data. The yield of charged particles for central collisions of the heavy targets with 33 S is found to be proportional to the target mass, A, at target rapidity. At midrapidity it is approximately proportional to A 0.3 . At midrapidity the charged particle measurements are supplemented by measurements of the transverse energy. The dimensionless, normalized variances of the multiplicity and transverse energy distributions are, to a large extent, governed by the collision geometry. The change in the normalized variance when studying the charged particle distribution in a narrow angular region is explained as being of statistical nature. (au)

Extension of Hartree-Fock theory including tensor correlation in nuclear matter

Science.gov (United States)

Hu, Jinniu; Toki, Hiroshi; Ogawa, Yoko

2013-10-01

We study the properties of nuclear matter in the extension of Hartree-Fock theory including tensor correlation using a realistic nucleon-nucleon (NN) interaction. The nuclear wave function consists of the Hartree-Fock and two-particle-two-hole (2p-2h) states, following the concept of the tensor-optimized shell model (TOSM) for light nuclei. The short range repulsion and strong tensor force of realistic NN interaction provide high momentum components, which are taken into account in a many-body framework by introducing 2p-2h states. Single particle states are determined by the variational principle of the total energy with respect to 2p-2h amplitudes and Hartree-Fock (HF) single-particle states. The resulting differential equation is almost identical with that of Brueckner-Hartree-Fock (BHF) theory by taking two-body scattering terms only. We calculate the equation of state (EOS) of nuclear matter in this framework with the Bonn potential as a realistic NN interaction. We found similar results to BHF theory with slightly repulsive effects in the total energy. The relativistic effect is discussed for the EOSs of nuclear matter in both non-relativistic and relativistic frameworks. The momentum distribution has large components at high momenta due to 2p-2h excitations. We also obtain the EOSs of pure neutron matter, where the tensor effect is small in the iso-vector channel.

Properties of nuclear matter from macroscopic–microscopic mass formulas

Directory of Open Access Journals (Sweden)

Ning Wang

2015-12-01

Full Text Available Based on the standard Skyrme energy density functionals together with the extended Thomas–Fermi approach, the properties of symmetric and asymmetric nuclear matter represented in two macroscopic–microscopic mass formulas: Lublin–Strasbourg nuclear drop energy (LSD formula and Weizsäcker–Skyrme (WS* formula, are extracted through matching the energy per particle of finite nuclei. For LSD and WS*, the obtained incompressibility coefficients of symmetric nuclear matter are K∞=230±11 MeV and 235±11 MeV, respectively. The slope parameter of symmetry energy at saturation density is L=41.6±7.6 MeV for LSD and 51.5±9.6 MeV for WS*, respectively, which is compatible with the liquid-drop analysis of Lattimer and Lim [4]. The density dependence of the mean-field isoscalar and isovector effective mass, and the neutron–proton effective masses splitting for neutron matter are simultaneously investigated. The results are generally consistent with those from the Skyrme Hartree–Fock–Bogoliubov calculations and nucleon optical potentials, and the standard deviations are large and increase rapidly with density. A better constraint for the effective mass is helpful to reduce uncertainties of the depth of the mean-field potential.

A new model for nuclear matter

International Nuclear Information System (INIS)

Skyrme, T.H.R.

1994-01-01

The different values obtained for nuclear radii from electromagnetic interactions as compared with specifically nuclear interactions suggested a model of nuclear matter in which the meson field is supposed to condense into an incompressible fluid and the nucleonic sources are confined to its interior by a strong interaction between the sources and the fluid as a whole. The sources are also coupled to spin and charge fluctuations in the fluid, whose exchange leads to further internucleonic forces. It is necessary to postulate that the fluid have a comparatively low density; as a result rotational levels of the fluid are high, leading to a small probability of exchange of angular momentum (and charge coupled to it) with the sources. The values of the anomalous electrical interactions of nucleons deduced are in rough agreement with the facts. The nuclear structure indicated is a shell model embedded in the mesic fluid whose oscillations, strongly coupled to the nucleons, give rise to the collective features of nuclear structure as in the theory of Bohr and Mottelson. It is suggested that this picture of the mesic field may indicate where to look for solutions of the meson field equations. (author). 9 refs

Description of a nucleon in nuclear matter using the chiral bag model

International Nuclear Information System (INIS)

Bunatyan, G.G.

1990-01-01

The chiral bag (cloudy bag) model, which contains an essentially nonlinear interaction of quarks with both the classical and quantum pion field, is extended for description of a nucleon in nuclear matter. The dependence on the density and temperature of the medium is studied. The pion field in nuclear matter differs considerably from the free field, and this leads to a modification of the nucleon bag. Increase of the density ρ and temperature T causes strengthening of the pion field and growth of its thermodynamic fluctuations. At sufficiently high densities ρ approx-gt ρ CB and temperatures T≥T cr this leads to instability of the three-quark nucleon bag. Under such conditions nuclear matter cannot be composed only of nucleons, and one should expect the appearance of a different, non-nucleon, phase. Estimates of the critical density and temperature are obtained: ρ CB ∼ (1.5-2)ρ 0 and T cr ∼ 200 MeV (where ρ 0 is the conventional nuclear density)

Kaons in nuclear matter

International Nuclear Information System (INIS)

Kolomeitsev, E.E.

1997-02-01

The subject of the doctoral thesis is examination of the properties of kaons in nuclear matter. A specific method is explained that has been developed for the scientific objectives of the thesis and permits description of the kaon-nucleon interactions and kaon-nucleon scattering in a vacuum. The main challenge involved was to find approaches that would enable application of the derived relations out of the kaon mass shell, connected with the second objective, namely to possibly find methods which are independent of models. The way chosen to achieve this goal relied on application of reduction formulas as well as current algebra relations and the PCAC hypothesis. (orig./CB) [de

Thermal properties of nuclear matter under the periodic boundary condition

International Nuclear Information System (INIS)

Otuka, Naohiko; Ohnishi, Akira

1999-01-01

We present the thermal properties of nuclear matter under the periodic boundary condition by the use of our hadronic nucleus-nucleus cascade model (HANDEL) which is developed to treat relativistic heavy-ion collisions from BNL-AGS to CERN-SPS. We first show some results of p-p scattering calculation in our new version which is improved in order to treat isospin ratio and multiplicity more accurately. We then display the results of calculation of nuclear matter with baryon density ρ b = 0.77 fm 3 at some energy densities. Time evolution of particle abundance and temperature are shown. (author)

HOTLAB: European hot laboratories research and capacities and needs. Plenary meeting 2004

Energy Technology Data Exchange (ETDEWEB)

Oberlaender, B.C.; Jenssen, H.K. (ed.)

2005-01-01

The report presents proceedings from the 2004 annual HOTLAB plenary meeting at Halden and Kjeller, Norway. The goal of the yearly plenary meeting was to: Exchange experience on analytical methods, their implementation in hot cells, the methodologies used and their application in nuclear research. Share experience on common infrastructure exploitation matters such as remote handling techniques, safety features, QA-certification, waste handling, etc. Promote normalisation and co-operation, e.g. by looking at mutual complementarities. Prospect present and future demands from the nuclear industry and to draw strategic conclusions regarding further needs. The main themes of the five topical oral sessions of the Halden plenary meeting cover: Work package leaders report and specific papers, presentation of PIE facility databases, i.e. one worldwide (IAEA) and one inside the European communities. Reports from present and future needs and on nuclear transports. Refabrication and instrumentation: Available equipment, technical characteristics such as fabrication procedures, hot-cell compatibility, and practical experiences. Post irradiation examination: Updated and new remote techniques and methodologies, new materials such as inert matrix fuels, spallation sources and neutron absorber materials. Refurbishment and decommissioning: reports on refurbishment and decommissioning of PIE facilities. Waste and transport: Hot laboratory waste characteristics and handling, spent fuel research. Several posters are presented.

Quantum hadrodynamic and nuclear matter

International Nuclear Information System (INIS)

Serot, B.D.

1984-01-01

The properties of infinite nuclear matter are studied in the model relativistic quantum field theory of Walecka. Neutral scalar and vector meson exchange reproduces the basic Lorentz structure of the observed nucleon-nucleon interaction, and the consequences of this structure are studied in detail. In the mean-field approximation, nuclear saturation involves a cancellation between large attractive and repulsive components in the average potential energy. The attractive scalar field decreases the nucleon mass significantly, and the strong vector repulsion implies a stiff high-density equation of state. Corrections to the mean-field approach arising from vacuum fluctuations, self-consistent nucleon exchange, and two-nucleon correlations are examined. These have a small effect on the condensed meson fields but may produce significant changes in the binding energy. Corrections to the mean-field equation of state are small at high density

Quasiparticle interaction in nuclear matter

International Nuclear Information System (INIS)

Poggioli, R.S.; Jackson, A.D.

1975-07-01

A microscopic calculation of the quasiparticle interaction in nuclear matter is detailed. In order to take especial care of the contributions from the low momentum states, a model space is introduced. Excluded from the model space, the high momentum states are absorbed into the model interaction. Brueckner theory suggests the choice of a truncated G-matrix as a good approximation for this model interaction. A simple perturbative approach is attempted within the model space. The calculated quasiparticle interaction is consistent with experimental results. (11 tables, 14 figures)

The hot and cold interstellar matter of early type galaxies and their radio emission

International Nuclear Information System (INIS)

Kim, Dongwoo; Fabbiano, G.

1990-01-01

Over the last few years, the knowledge of the interstellar matter (ISM) of early type galaxies has increased dramatically. Many early type galaxies are now known to have ISM in three different phases: cold (neutral hydrogen (HI), dust and molecular material), warm (ionized) and hot (S-ray emitting) gas. Early type galaxies have smaller masses of cold ISM (10 to the 7th power - 10 to the 8th power solar mass; Jura et al. 1987) than later type spiral galaxies, while they have far more hot gas (10 to the 9th power - 10 to the tenth power solar mass; Forman et al. 1985, Canizares et al. 1987). In order to understand the relationship between the different phases of the ISM and the role of the ISM in fueling radio continuum sources and star formation, researchers compared observational data from a wide range of wavelengths

Investigation of nuclear matter properties by means of high energy nucleus-nucleus collisions

International Nuclear Information System (INIS)

Stock, R.

1985-09-01

We review recent advances towards an understanding of high density nuclear matter, as created in central collisions of nuclei at high energy. In particular, information obtained for the nuclear matter equation of state will be discussed. The lectures focus on the Bevalac energy domain of 0.4 to 2 GeV per projectile nucleon. (orig.)

Nuclear ``pasta'' structures in low-density nuclear matter and properties of the neutron-star crust

Science.gov (United States)

Okamoto, Minoru; Maruyama, Toshiki; Yabana, Kazuhiro; Tatsumi, Toshitaka

2013-08-01

In the neutron-star crust, nonuniform structure of nuclear matter—called the “pasta” structure—is expected. From recent studies of giant flares in magnetars, these structures might be related to some observables and physical quantities of the neutron-star crust. To investigate the above quantities, we numerically explore the pasta structure with a fully three-dimensional geometry and study the properties of low-density nuclear matter, based on the relativistic mean-field model and the Thomas-Fermi approximation. We observe typical pasta structures for fixed proton number fraction and two of them for cold catalyzed matter. We also discuss the crystalline configuration of “pasta.”

Hot conditioning equipment conceptual design report

International Nuclear Information System (INIS)

Bradshaw, F.W.

1996-01-01

This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage

Hot conditioning equipment conceptual design report

Energy Technology Data Exchange (ETDEWEB)

Bradshaw, F.W., Westinghouse Hanford

1996-08-06

This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

Nuclear matter from chiral effective field theory

International Nuclear Information System (INIS)

Drischler, Christian

2017-01-01

Nuclear matter is an ideal theoretical system that provides key insights into the physics of different length scales. While recent ab initio calculations of medium-mass to heavy nuclei have demonstrated that realistic saturation properties in infinite matter are crucial for reproducing experimental binding energies and charge radii, the nuclear-matter equation of state allows tight constraints on key quantities of neutron stars. In the present thesis we take advantage of both aspects. Chiral effective field theory (EFT) with pion and nucleon degrees of freedom has become the modern low-energy approach to nuclear forces based on the symmetries of quantum chromodynamics, the fundamental theory of strong interactions. The systematic chiral expansion enables improvable calculations associated with theoretical uncertainty estimates. In recent years, chiral many-body forces were derived up to high orders, allowing consistent calculations including all many-body contributions at next-to-next-to-next-to-leading order (N 3 LO). Many further advances have driven the construction of novel chiral potentials with different regularization schemes. Here, we develop advanced methods for microscopic calculations of the equation of state of homogeneous nuclear matter with arbitrary proton-to-neutron ratio at zero temperature. Specifically, we push the limits of many-body perturbation theory (MBPT) considerations to high orders in the chiral and in the many-body expansion. To address the challenging inclusion of three-body forces, we introduce a new partial-wave method for normal ordering that generalizes the treatment of these contributions. We show improved predictions for the neutron-matter equation of state with consistent N 3 LO nucleon-nucleon (NN) plus three-nucleon (3N) potentials using MBPT up to third order and self-consistent Green's function theory. The latter also provides nonperturbative benchmarks for the many-body convergence. In addition, we extend the normal

Nuclear matter from chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Drischler, Christian

2017-11-15

Nuclear matter is an ideal theoretical system that provides key insights into the physics of different length scales. While recent ab initio calculations of medium-mass to heavy nuclei have demonstrated that realistic saturation properties in infinite matter are crucial for reproducing experimental binding energies and charge radii, the nuclear-matter equation of state allows tight constraints on key quantities of neutron stars. In the present thesis we take advantage of both aspects. Chiral effective field theory (EFT) with pion and nucleon degrees of freedom has become the modern low-energy approach to nuclear forces based on the symmetries of quantum chromodynamics, the fundamental theory of strong interactions. The systematic chiral expansion enables improvable calculations associated with theoretical uncertainty estimates. In recent years, chiral many-body forces were derived up to high orders, allowing consistent calculations including all many-body contributions at next-to-next-to-next-to-leading order (N{sup 3}LO). Many further advances have driven the construction of novel chiral potentials with different regularization schemes. Here, we develop advanced methods for microscopic calculations of the equation of state of homogeneous nuclear matter with arbitrary proton-to-neutron ratio at zero temperature. Specifically, we push the limits of many-body perturbation theory (MBPT) considerations to high orders in the chiral and in the many-body expansion. To address the challenging inclusion of three-body forces, we introduce a new partial-wave method for normal ordering that generalizes the treatment of these contributions. We show improved predictions for the neutron-matter equation of state with consistent N{sup 3}LO nucleon-nucleon (NN) plus three-nucleon (3N) potentials using MBPT up to third order and self-consistent Green's function theory. The latter also provides nonperturbative benchmarks for the many-body convergence. In addition, we extend the

Nuclear facilities of EdF's operational hot base of Tricastin. 2009 annual report

International Nuclear Information System (INIS)

2010-01-01

This annual report is established on account of article 21 of the 2006-686 French law from June 13, 2006, relative to the transparency and safety in the nuclear domain. It describes, first, the nuclear facilities of the EdF operational hot base of Tricastin, then, the measures taken to ensure their safety (personnel radioprotection, actions implemented for nuclear safety improvement, organisation in crisis situation, external and internal controls, technical assessment of the facilities), and finally the procedures of management of radioactive wastes. A glossary and the viewpoint of the Committee of Hygiene, safety and working conditions about the content of the document conclude the report. (J.S.)

Hyperons in nuclear matter from SU(3) chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Petschauer, Stefan; Kaiser, Norbert [Technische Universitaet Muenchen (Germany); Haidenbauer, Johann [Forschungszentrum Juelich (Germany); Meissner, Ulf G. [Forschungszentrum Juelich (Germany); Universitaet Bonn (Germany); Weise, Wolfram [Technische Universitaet Muenchen (Germany); ECT, Trento (Italy)

2016-07-01

Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Λ and Σ hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Σ-nuclear potential and a weak Λ-nuclear spin-orbit force. The splittings among the Σ{sup +}, Σ{sup 0} and Σ{sup -} potentials have a non-linear dependence on the isospin asymmetry which goes beyond the usual parametrization in terms of an isovector Lane potential.

Nuclear prehistory influence on transfer velocity of 54Mn impurity 'hot' atoms in irradiated metallic iron

International Nuclear Information System (INIS)

Alekseev, I.E.

2007-01-01

Influence of nuclear prehistory on transfer velocity of 54 Mn impurity 'hot'-atoms - got by different nuclear channels: 56 Fe(d, α), 54 Fe(n,p) in irradiated metallic iron - is studied. Irradiation of targets were carried out in U-120 accelerator (energy range 7.3/5.3 MeV, deuteron beam current makes up 5 μA). Mean density of thermal neutron (WWR-M reactor) makes up 8.6·10 13 neutron·cm -2 ·s -1 . It is shown, that transfer velocity of 54 Mn 'hot' atoms is defining by rate of radiation damage of targets in the irradiation process at that a key importance has a bombarding particles type applied for radioactive label getting

Nuclear and quark matter at high temperature

Energy Technology Data Exchange (ETDEWEB)

Biro, Tamas S. [H.A.S. Wigner Research Centre for Physics, Budapest (Hungary); Jakovac, Antal [Roland Eotvos University, Budapest (Hungary); Schram, Zsolt [University of Debrecen, Institute for Theoretical Physics, Debrecen (Hungary)

2017-03-15

We review important ideas on nuclear and quark matter description on the basis of high-temperature field theory concepts, like resummation, dimensional reduction, interaction scale separation and spectral function modification in media. Statistical and thermodynamical concepts are spotted in the light of these methods concentrating on the -partially still open- problems of the hadronization process. (orig.)

Shock waves in relativistic nuclear matter, I

International Nuclear Information System (INIS)

Gleeson, A.M.; Raha, S.

1979-02-01

The relativistic Rankine-Hugoniot relations are developed for a 3-dimensional plane shock and a 3-dimensional oblique shock. Using these discontinuity relations together with various equations of state for nuclear matter, the temperatures and the compressibilities attainable by shock compression for a wide range of laboratory kinetic energy of the projectile are calculated. 12 references

Vector Mesons in Cold Nuclear Matter

International Nuclear Information System (INIS)

Rodrigues, Tulio E; Arruda-Neto, Joāo Dias de Toledo

2013-01-01

The attenuation of vector mesons in cold nuclear matter is studied through the mechanism of incoherent photoproduction off complex nuclei. The latter is described via the time-dependent multi-collisional Monte Carlo (MCMC) intranuclear cascade model. The results for the transparency ratios of ω mesons reproduce previous measurements of CB-ELSA/TAPS with an inelastic ωN cross section around 40 mb for ρ ω ∼ 1.1 GeV/c. The corresponding in-medium width (nuclear rest frame) is extracted dinamically from the algorithm and depends on the average nuclear density p N and target nucleus: ∼ 49.2 MeV/c 2 for carbon (p N ≈ 0.114 far −3 ) and ∼ 77.3 MeV/c 2 for lead (p N ≈ 0.137 far −−3 ). The calculations fail to reproduce the huge absorption observed at JLab assuming the same inelastic cross section and the discrepancy between the two experiments remains a challenge.

Wanted! Nuclear Data for Dark Matter Astrophysics

International Nuclear Information System (INIS)

Gondolo, P.

2014-01-01

Astronomical observations from small galaxies to the largest scales in the universe can be consistently explained by the simple idea of dark matter. The nature of dark matter is however still unknown. Empirically it cannot be any of the known particles, and many theories postulate it as a new elementary particle. Searches for dark matter particles are under way: production at high-energy accelerators, direct detection through dark matter-nucleus scattering, indirect detection through cosmic rays, gamma rays, or effects on stars. Particle dark matter searches rely on observing an excess of events above background, and a lot of controversies have arisen over the origin of observed excesses. With the new high-quality cosmic ray measurements from the AMS-02 experiment, the major uncertainty in modeling cosmic ray fluxes is in the nuclear physics cross sections for spallation and fragmentation of cosmic rays off interstellar hydrogen and helium. The understanding of direct detection backgrounds is limited by poor knowledge of cosmic ray activation in detector materials, with order of magnitude differences between simulation codes. A scarcity of data on nucleon spin densities blurs the connection between dark matter theory and experiments. What is needed, ideally, are more and better measurements of spallation cross sections relevant to cosmic rays and cosmogenic activation, and data on the nucleon spin densities in nuclei

Influence of flow constraints on the properties of the critical endpoint of symmetric nuclear matter

Science.gov (United States)

Ivanytskyi, A. I.; Bugaev, K. A.; Sagun, V. V.; Bravina, L. V.; Zabrodin, E. E.

2018-06-01

We propose a novel family of equations of state for symmetric nuclear matter based on the induced surface tension concept for the hard-core repulsion. It is shown that having only four adjustable parameters the suggested equations of state can, simultaneously, reproduce not only the main properties of the nuclear matter ground state, but the proton flow constraint up its maximal particle number densities. Varying the model parameters we carefully examine the range of values of incompressibility constant of normal nuclear matter and its critical temperature, which are consistent with the proton flow constraint. This analysis allows us to show that the physically most justified value of nuclear matter critical temperature is 15.5-18 MeV, the incompressibility constant is 270-315 MeV and the hard-core radius of nucleons is less than 0.4 fm.

Nuclear safety and radiation protection report of EdF's Tricastin operational hot base nuclear facilities (BCOT) - 2010

International Nuclear Information System (INIS)

2011-06-01

This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the Tricastin operational hot base facility (INB no. 157, Bollene, Vaucluse (FR)), a nuclear workshop for storage and maintenance and qualification operations on some EdF equipments. Then, the nuclear safety and radiation protection measures taken regarding the facility are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, if some, are reported as well as the effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facility is presented and sorted by type of waste, quantities and type of conditioning. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

Preliminary design analysis of hot gas ducts and a intermediate heat exchanger for the nuclear hydrogen reactor

International Nuclear Information System (INIS)

Song, K. N.; Kim, Y. W.

2008-01-01

Korea Atomic Energy Research Institute (KAERI) is in the process of carrying out a nuclear hydrogen system by considering the indirect cycle gas cooled reactors that produce heat at temperatures in the order of 950 .deg. C. Primary and secondary hot gas ducts with coaxial double tubes and are key components connecting a reactor pressure vessel and a intermediate heat exchanger for the nuclear hydrogen system. In this study, preliminary design analyses on the hot gas ducts and the intermediate heat exchanger were carried out. These preliminary design activities include a preliminary design on the geometric dimensions, a preliminary strength evaluation, thermal sizing, and an appropriate material selection

Microcanonical simulation of nuclear disassembly

International Nuclear Information System (INIS)

Koonin, S.E.; Randrup, J.

1986-01-01

There is considerable interest in the disassembly of the hot nuclear matter produced in high-energy nuclear collisions. A particular stimulus has been the prospect of observing a nuclear liquid-gas phase transition. On rather general grounds, such a transition is expected to occur in nuclear matter at subsaturation densities with temperatures of 10-20 MeV. However, virtually all previous discussions of this phenomenon have been based on thermodynamical considerations valid for infinite, non-interacting systems and the qualitative validity of the results has not been ascertained for the relatively small, finite, interacting systems of practical relevance. Nor is it clear how the occurrence of the phase transition will manifest itself in the asymptotically observed fragment distribution. To progress in these matters, the authors have formulated a microcanonical simulation of the disassembly process, including interfragment interactions. It is a natural refinement of the grand canonical model first presented in [1] and further developed in [2] and is also a exact version of the model developed in [3] for the generation of complete multifragment events in medium-energy collisions. In this contribution, the authors give a brief description of the key ingredients in the model and its numerical implementation

Topology of large-scale structure in seeded hot dark matter models

Science.gov (United States)

Beaky, Matthew M.; Scherrer, Robert J.; Villumsen, Jens V.

1992-01-01

The topology of the isodensity surfaces in seeded hot dark matter models, in which static seed masses provide the density perturbations in a universe dominated by massive neutrinos is examined. When smoothed with a Gaussian window, the linear initial conditions in these models show no trace of non-Gaussian behavior for r0 equal to or greater than 5 Mpc (h = 1/2), except for very low seed densities, which show a shift toward isolated peaks. An approximate analytic expression is given for the genus curve expected in linear density fields from randomly distributed seed masses. The evolved models have a Gaussian topology for r0 = 10 Mpc, but show a shift toward a cellular topology with r0 = 5 Mpc; Gaussian models with an identical power spectrum show the same behavior.

Chiral approach to nuclear matter: Role of explicit short-range NN-terms

International Nuclear Information System (INIS)

Fritsch, S.; Kaiser, N.

2004-01-01

We extend a recent chiral approach to nuclear matter by including the most general (momentum-independent) NN-contact interaction. Iterating this two-parameter contact vertex with itself and with one-pion exchange the emerging energy per particle exhausts all terms possible up to and including fourth order in the small momentum expansion. Two (isospin-dependent) cut-offs Λ 0,1 are introduced to regularize the (linear) divergences of some three-loop in-medium diagrams. The equation of state of pure neutron matter, anti E n (k n ), can be reproduced very well up to quite high neutron densities of ρ n =0.5 fm -3 by adjusting the strength of a repulsive nn-contact interaction. Binding and saturation of isospin-symmetric nuclear matter is a generic feature of our perturbative calculation. Fixing the maximum binding energy per particle to - anti E(k f0 )=15.3 MeV we find that any possible equilibrium density ρ 0 lies below ρ 0 max =0.191 fm -3 . The additional constraint from the neutron matter equation of state leads however to a somewhat too low saturation density of ρ 0 =0.134 fm -3 . We also investigate the effects of the NN-contact interaction on the complex single-particle potential U(p,k f )+iW(p,k f ). We find that the effective nucleon mass at the Fermi surface is bounded from below by M * (k f0 ) ≥1.4 M. This property keeps the critical temperature of the liquid-gas phase transition at somewhat too high values T c ≥21 MeV. The downward bending of the asymmetry energy A(k f ) above nuclear-matter saturation density is a generic feature of the approximation to fourth order. We furthermore investigate the effects of the NN-contact interaction on the (vector-∇ρ) 2 -term in the nuclear energy density functional E[ρ,τ]. Altogether, there is within this complete fourth-order calculation no ''magic'' set of adjustable short-range parameters with which one could reproduce simultaneously and accurately all semi-empirical properties of nuclear matter. In

The single-particle potential of nuclear matter in the LOCV framework

Energy Technology Data Exchange (ETDEWEB)

Modarres, M., E-mail: mmodares@ut.ac.ir [Physics Department, University of Tehran, North-Kargar Ave., 1439955961 Tehran (Iran, Islamic Republic of); Rajabi, A. [Physics Department, Shahid Rajaei Teacher Training University, Lavizan, 16788 Tehran (Iran, Islamic Republic of)

2011-10-01

The density and momentum dependence of single-particle potential (SPP) and effective mass of symmetric nuclear matter are studied in the framework of lowest order constrained variational (LOCV) method. The Reid68, the Reid68-{Delta} and the Av{sub 18} interactions are considered as the input nucleon-nucleon potentials. It is shown that the SPP of nuclear matter, at fixed density, is an increasing function of nucleon momentum, and it has different behavior for the Reid type potentials with respect to Av{sub 18} interaction. We find good agreements between our LOCV SPP and those coming from others many-body techniques such as the (Dirac-)Brueckner-Hartree-Foch ((D)BHF), the fermion hypernetted chain (FHNC), mean field (MF), etc. On the other hand SPP dramatically depends on the density at low and high nucleon momentums. While the effective mass of nuclear matter increases as we increase the nucleon momentum, it decreases at the Fermi surface. Again, good agreements are observed between our calculated effective mass and those coming from the methods mentioned above.

Effective interactions and mean field theory: from nuclear matter to nuclei

International Nuclear Information System (INIS)

Cochet, B.

2005-07-01

The Skyrme force is a zero-range force that allows the construction of the mean field inside the nucleus in a simple way. Skyrme forces are reasonably predictive but some features of the infinite nuclear matter or the mass of heavy nuclei are not well computed. The aim of this work is to propose an expanded parametrization of the Skyrme force in order to improve its predictive power. The first part is dedicated to the construction of the expansion of the parametrization. We recall how the effective forces are linked to the nucleon-nucleon interaction then we show the limits of the standard Skyrme forces and we propose a relatively natural improvements based on the integration of spin and isospin instabilities. The second part deals with the validation of the model, first by describing infinite nuclear matter then by studying β-balanced nuclear matter which has enabled us to reproduce some features of neutron stars like mass and radius. The computation of properties of nuclei like binding energy, mass, radii depends strongly on the adjustment procedure. (A.C.)

Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts

International Nuclear Information System (INIS)

Krivoruchenko, M. I.; Nadyozhin, D. K.; Rasinkova, T. L.; Simonov, Yu. A.; Trusov, M. A.; Yudin, A. V.

2011-01-01

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 nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partialwave 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 nuclear matter and the G matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determines the natural scale of the density for a possible phase transition into theMQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernovamodels. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.

Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts

Energy Technology Data Exchange (ETDEWEB)

Krivoruchenko, M. I.; Nadyozhin, D. K.; Rasinkova, T. L.; Simonov, Yu. A.; Trusov, M. A., E-mail: trusov@itep.ru; Yudin, A. V. [Institute for Theoretical and Experimental Physics (Russian Federation)

2011-03-15

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 nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partialwave 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 nuclear matter and the G matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determines the natural scale of the density for a possible phase transition into theMQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernovamodels. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.

Inhomogeneous condensates in dilute nuclear matter and BCS-BEC crossovers

International Nuclear Information System (INIS)

Stein, Martin; Sedrakian, Armen; Huang, Xu-Guang; Clark, John W; Röpke, Gerd

2014-01-01

We report on recent progress in understanding pairing phenomena in low-density nuclear matter at small and moderate isospin asymmetry. A rich phase diagram has been found comprising various superfluid phases that include a homogeneous and phase-separated BEC phase of deuterons at low density and a homogeneous BCS phase, an inhomogeneous LOFF phase, and a phase-separated BCS phase at higher densities. The transition from the BEC phases to the BCS phases is characterized in terms of the evolution, from strong to weak coupling, of the condensate wavefunction and the second moment of its density distribution in r-space. We briefly discuss approaches to higher-order clustering in low-density nuclear matter.

Two-loop corrections for nuclear matter in the Walecka model

International Nuclear Information System (INIS)

Furnstahl, R.J.; Perry, R.J.; Serot, B.D.; Department of Physics, The Ohio State University, Columbus, Ohio 43210; Physics Department and Nuclear Theory Center, Indiana University, Bloomington, Indiana 47405)

1989-01-01

Two-loop corrections for nuclear matter, including vacuum polarization, are calculated in the Walecka model to study the loop expansion as an approximation scheme for quantum hadrodynamics. Criteria for useful approximation schemes are discussed, and the concepts of strong and weak convergence are introduced. The two-loop corrections are evaluated first with one-loop parameters and mean fields and then by minimizing the total energy density with respect to the scalar field and refitting parameters to empirical nuclear matter saturation properties. The size and nature of the corrections indicate that the loop expansion is not convergent at two-loop order in either the strong or weak sense. Prospects for alternative approximation schemes are discussed

Possibility of combining nuclear level pumping in plasma with lasing in solid

International Nuclear Information System (INIS)

Karamyan, S.A.; Carroll, J.J.

2002-01-01

Nuclear isomers can be used for the storage and release of 'clean' nuclear energy, and the visible schemes are discussed. Resonance between the atomic and nuclear transitions may be manifested in a form of the hybridization of atomic-nuclear excitation at the appropriate case. The nuclear levels - candidates for triggering via atomic transitions are described. A variety of the ionization states and atomic-shell configurations arises in hot plasma generated by the short powerful pulse of laser light. The nonradiative conversion of the ionization energy within atom can be suppressed in the hot-plasma surroundings. Time-scales of different processes in nuclear, atomic and condensed-matter subsystems are compared. The processes of fast ionization in solid, X-ray radiance in plasma, sample melting and recrystallisation may precede nuclear fluorescence. Time-scale shorter 0.1 ns makes this sequence promising for the group excitation of short-lived modes in nuclear subsystem

Three-dimensional structure of low-density nuclear matter

International Nuclear Information System (INIS)

Okamoto, Minoru; Maruyama, Toshiki; Yabana, Kazuhiro; Tatsumi, Toshitaka

2012-01-01

We numerically explore the pasta structures and properties of low-density nuclear matter without any assumption on the geometry. We observe conventional pasta structures, while a mixture of the pasta structures appears as a metastable state at some transient densities. We also discuss the lattice structure of droplets.

Three-dimensional structure of low-density nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Okamoto, Minoru, E-mail: okamoto@nucl.ph.tsukuba.ac.jp [Graduate School of Pure and Applied Science, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan); Maruyama, Toshiki, E-mail: maruyama.toshiki@jaea.go.jp [Advanced Science Research Center, Japan Atomic Energy Agency, Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan); Graduate School of Pure and Applied Science, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan); Yabana, Kazuhiro, E-mail: yabana@nucl.ph.tsukuba.ac.jp [Graduate School of Pure and Applied Science, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan); Center of Computational Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan); Tatsumi, Toshitaka, E-mail: tatsumi@ruby.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)

2012-07-09

We numerically explore the pasta structures and properties of low-density nuclear matter without any assumption on the geometry. We observe conventional pasta structures, while a mixture of the pasta structures appears as a metastable state at some transient densities. We also discuss the lattice structure of droplets.

Radiative muon capture and induced pseudoscalar coupling constant in nuclear matter

International Nuclear Information System (INIS)

Cheoun, Myung Ki; Kim, K S; Choi, T K

2003-01-01

Radiative muon capture is studied to investigate the induced pseudoscalar coupling constant g P in nuclear matter. According to the recent TRIUMF experiment for μ - p → nν μ γ, the g P was surprisingly larger than the value obtained from μ - p → nν μ experiment by as much as 44%. The result may affect seriously theoretical interpretations of the experimental results for the radiative muon captures in finite nuclei. In view of the recent TRIUMF result, the radiative muon capture in nuclear matter is revisited in a framework of the relativistic mean field theory

Tensor Fermi liquid parameters in nuclear matter from chiral effective field theory

Science.gov (United States)

Holt, J. W.; Kaiser, N.; Whitehead, T. R.

2018-05-01

We compute from chiral two- and three-body forces the complete quasiparticle interaction in symmetric nuclear matter up to twice nuclear matter saturation density. Second-order perturbative contributions that account for Pauli blocking and medium polarization are included, allowing for an exploration of the full set of central and noncentral operator structures permitted by symmetries and the long-wavelength limit. At the Hartree-Fock level, the next-to-next-to-leading order three-nucleon force contributes to all noncentral interactions, and their strengths grow approximately linearly with the nucleon density up to that of saturated nuclear matter. Three-body forces are shown to enhance the already strong proton-neutron effective tensor interaction, while the corresponding like-particle tensor force remains small. We also find a large isovector cross-vector interaction but small center-of-mass tensor interactions in the isoscalar and isovector channels. The convergence of the expansion of the noncentral quasiparticle interaction in Landau parameters and Legendre polynomials is studied in detail.

Quark-Meson-Coupling (QMC) model for finite nuclei, nuclear matter and beyond

Science.gov (United States)

Guichon, P. A. M.; Stone, J. R.; Thomas, A. W.

2018-05-01

The Quark-Meson-Coupling model, which self-consistently relates the dynamics of the internal quark structure of a hadron to the relativistic mean fields arising in nuclear matter, provides a natural explanation to many open questions in low energy nuclear physics, including the origin of many-body nuclear forces and their saturation, the spin-orbit interaction and properties of hadronic matter at a wide range of densities up to those occurring in the cores of neutron stars. Here we focus on four aspects of the model (i) a full comprehensive survey of the theory, including the latest developments, (ii) extensive application of the model to ground state properties of finite nuclei and hypernuclei, with a discussion of similarities and differences between the QMC and Skyrme energy density functionals, (iii) equilibrium conditions and composition of hadronic matter in cold and warm neutron stars and their comparison with the outcome of relativistic mean-field theories and, (iv) tests of the fundamental idea that hadron structure changes in-medium.

Equation of state of nuclear matter of nucleons and dibaryons

International Nuclear Information System (INIS)

Mrowczynski, St.

1985-01-01

The nuclear matter is considered consisting of nucleons and dibaryons, i.e. elementary particles of double baryon charge. The equation of state of such matter at zero temperature is found. The ideal gas approximation is considered and then the role of interaction is discussed which is included by means of delta-like potential. The peculiarities and possible phisical consequences of the equation of state are considered

Softness of Nuclear Matter and the Production of Strange Particles in Neutron Stars

Institute of Scientific and Technical Information of China (English)

陈伟; 文德华; 刘良钢

2003-01-01

In the various models, we study the influences of the softness of nuclear matter, the vacuum fluctuation ofnucleons and σ mesons on the production of strange particles in neutron stars. Wefind that the stiffer the nuclear matter is, the more easily the strange particles is produced in neutron stars. The vacuum fluctuation of nucleons has large effect on strange particle production while that of σ meson has little effect on it.

D mesons in asymmetric nuclear matter

International Nuclear Information System (INIS)

Mishra, Amruta; Mazumdar, Arindam

2009-01-01

We calculate the in-medium D and D meson masses in isospin-asymmetric nuclear matter in an effective chiral model. The D and D mass modifications arising from their interactions with the nucleons and the scalar mesons in the effective hadronic model are seen to be appreciable at high densities and have a strong isospin dependence. These mass modifications can open the channels of the decay of the charmonium states (Ψ ' ,χ c ,J/Ψ) to DD pairs in dense hadronic matter. The isospin asymmetry in the doublet D=(D 0 ,D + ) is seen to be particularly appreciable at high densities and should show in observables such as their production and flow in asymmetric heavy-ion collisions in the compressed baryonic matter experiments in the future facility of FAIR, GSI. The results of the present work are compared to calculations of the D(D) in-medium masses in the literature using the QCD sum rule approach, quark meson coupling model, and coupled channel approach as well as to those from studies of quarkonium dissociation using heavy-quark potentials from lattice QCD at finite temperatures

Pion condensation in symmetric nuclear matter

International Nuclear Information System (INIS)

Shamsunnahar, T.; Saha, S.; Kabir, K.; Nath, L.M.

1991-01-01

We have investigated the possibility of pion condensation in symmetric nuclear matter using a model of pion-nucleon interaction based essentially on chiral SU(2) x SU(2) symmetry. We have found that pion condensation is not possible for any finite value of the density. Consequently, no critical opalescence phenomenon is likely to be seen in pion-nucleus scattering nor is it likely to be possible to explain the EMC effect in terms of an increased number of pions in the nucleus. (author)

Functional study of hot pepper 26S proteasome subunit RPN7 induced by Tobacco mosaic virus from nuclear proteome analysis

International Nuclear Information System (INIS)

Lee, Boo-Ja; Kwon, Sun Jae; Kim, Sung-Kyu; Kim, Ki-Jeong; Park, Chang-Jin; Kim, Young-Jin; Park, Ohkmae K.; Paek, Kyung-Hee

2006-01-01

Two-dimensional gel electrophoresis (2-DE) was applied for the screening of Tobacco mosaic virus (TMV)-induced hot pepper (Capsicum annuum cv. Bugang) nuclear proteins. From differentially expressed protein spots, we acquired the matched peptide mass fingerprint (PMF) data, analyzed by MALDI-TOF MS, from the non-redundant hot pepper EST protein FASTA database using the VEMS 2.0 software. Among six identified nuclear proteins, the hot pepper 26S proteasome subunit RPN7 (CaRPN7) was subjected to further study. The level of CaRPN7 mRNA was specifically increased during incompatible TMV-P 0 interaction, but not during compatible TMV-P 1.2 interaction. When CaRPN7::GFP fusion protein was targeted in onion cells, the nuclei had been broken into pieces. In the hot pepper leaves, cell death was exacerbated and genomic DNA laddering was induced by Agrobacterium-mediated transient overexpression of CaPRN7. Thus, this report presents that the TMV-induced CaRPN7 may be involved in programmed cell death (PCD) in the hot pepper plant

Neutrino reactions in hot and dense matter

Energy Technology Data Exchange (ETDEWEB)

Lohs, Andreas

2015-04-13

In this thesis, neutrino reactions in hot and dense matter are studied. In particular, this work is concerned with neutrino-matter interactions that are relevant for neutrino transport in core-collapse supernovae (CCSNe). The majority of the energy from a CCSN is released in the form of neutrinos. Accurate understanding and computation of these interactions is most relevant to achieve sufficiently reliable predictions for the evolution of CCSNe and other related question such as the production of heavy elements or neutrino oscillations. For this purpose this work follows the combined approach of searching for new important neutrino reactions and improving the computation of those reactions that are already implemented. First we estimate the relevance of charged-current weak interactions that include muon-neutrinos or muons, as well as the role of neutron decay for neutrino transport in CCSNe. All of these reactions were previously neglected in CCSN-simulations. We derive and compute the matrix element and subsequent semi-analytic expressions for transport properties like the inverse mean free path of the new reactions. It is found that these reactions are important for muon neutrinos and low energy electron antineutrinos at very high densities in the protoneutron star surface. Consequently their implementation might lead to several changes in the prediction of CCSNe signatures such as the nucleosynthesis yields. Second we improve the precision in the computation of well known neutrino-nucleon reactions like neutrino absorption on neutrons. We derive semi-analytic expressions for transport properties that use less restrictive approximations while keeping the computational demand constant. Therefore we consider the full relativistic kinematics of all participating particles i.e. allowing for relativistic nucleons and finite lepton masses. Also the weak magnetism terms of the matrix elements are explicitly included to all orders. From our results we suggest that the

Neutrino reactions in hot and dense matter

International Nuclear Information System (INIS)

Lohs, Andreas

2015-01-01

In this thesis, neutrino reactions in hot and dense matter are studied. In particular, this work is concerned with neutrino-matter interactions that are relevant for neutrino transport in core-collapse supernovae (CCSNe). The majority of the energy from a CCSN is released in the form of neutrinos. Accurate understanding and computation of these interactions is most relevant to achieve sufficiently reliable predictions for the evolution of CCSNe and other related question such as the production of heavy elements or neutrino oscillations. For this purpose this work follows the combined approach of searching for new important neutrino reactions and improving the computation of those reactions that are already implemented. First we estimate the relevance of charged-current weak interactions that include muon-neutrinos or muons, as well as the role of neutron decay for neutrino transport in CCSNe. All of these reactions were previously neglected in CCSN-simulations. We derive and compute the matrix element and subsequent semi-analytic expressions for transport properties like the inverse mean free path of the new reactions. It is found that these reactions are important for muon neutrinos and low energy electron antineutrinos at very high densities in the protoneutron star surface. Consequently their implementation might lead to several changes in the prediction of CCSNe signatures such as the nucleosynthesis yields. Second we improve the precision in the computation of well known neutrino-nucleon reactions like neutrino absorption on neutrons. We derive semi-analytic expressions for transport properties that use less restrictive approximations while keeping the computational demand constant. Therefore we consider the full relativistic kinematics of all participating particles i.e. allowing for relativistic nucleons and finite lepton masses. Also the weak magnetism terms of the matrix elements are explicitly included to all orders. From our results we suggest that the

Technical feasibility and economics of retrofitting an existing nuclear power plant to cogeneration for hot water district heating

International Nuclear Information System (INIS)

Kolb, J.O.; Bauman, H.F.; Jones, P.D.

1984-04-01

This report gives the results of a study of the hypothetical conversion of the Prairie Island Nuclear Plant of the Northern States Power Company to cogeneration operation to supply a future hot water district heating system load in the Twin Cities of Minneapolis-St. Paul. The conceptual design of the nuclear turbine retrofitted for cogeneration and of a hot water transmission system has been performed, and the capital investment and annual owning and operating costs have been estimated for thermal energy capacities of 600 and 1200 MW(t). Unit costs of thermal energy (in mid-1982 dollars/million Btu) have been estimated for cogenerated hot water at the plant gate and also for the most economic transmission system from Prairie Island to the Twin Cities. The economic results from the analysis of the Prairie Island plant and transmission route have been generalized for other transmission distances in other locations

Instability in relativistic mean-field theories of nuclear matter

International Nuclear Information System (INIS)

Friman, B.L.; Henning, P.A.

1988-01-01

We investigate the stability of the nuclear matter ground state with respect to small-perturbations of the meson fields in relativistic mean-field theories. The popular σ-ω model is shown to have an instability at about twice the nuclear density, which gives rise to a new ground state with periodic spin alignment. Taking into account the contributions of the Dirac sea properly, this instability vanishes. Consequences for relativistic heavy-ion-collisions are discussed briefly. (orig.)

Instability in relativistic mean-field theories of nuclear matter

International Nuclear Information System (INIS)

Friman, B.L.; Henning, P.A.

1988-01-01

We investigate the stability of the nuclear matter ground state with respect to small perturbations of the meson fields in relativistic mean-field theories. The popular σ-ω model is shown to have an instability at about twice the nuclear density, which gives rise to a new ground state with periodic spin alignment. Taking into account the contributions of the Dirac sea properly, this instability vanishes. Consequences for relativistic heavy-ion collisions are discussed briefly. (orig.)

The stability of nuclear matter in the Nambu-Jona-Lasinio model

Energy Technology Data Exchange (ETDEWEB)

Bentz, W. E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Thomas, A.W. E-mail: athomas@physics.adelaide.edu.au

2001-12-17

Using the Nambu-Jona-Lasinio model to describe the nucleon as a quark-diquark state, we discuss the stability of nuclear matter in a hybrid model for the ground state at finite nucleon density. It is shown that a simple extension of the model to simulate the effects of confinement leads to a scalar polarizability of the nucleon. This, in turn, leads to a less attractive effective interaction between the nucleons, helping to achieve saturation of the nuclear matter ground state. It is also pointed out that that the same effect naturally leads to a suppression of 'Z-graph' contributions with increasing scalar potential.

Infinite nuclear matter model and mass formulae for nuclei

International Nuclear Information System (INIS)

Satpathy, L.

2016-01-01

The matter composed of the nucleus is a quantum-mechanical interacting many-fermionic system. However, the shell and classical liquid drop have been taken as the two main features of nuclear dynamics, which have guided the evolution of nuclear physics. These two features can be considered as the macroscopic manifestation of the microscopic dynamics of the nucleons at fundamental level. Various mass formulae have been developed based on either of these features over the years, resulting in many ambiguities and uncertainties posing many challenges in this field. Keeping this in view, Infinite Nuclear Matter (INM) model has been developed during last couple of decades with a many-body theoretical foundation employing the celebrated Hugenholtz-Van Hove theorem, quite appropriate for the interacting quantum-mechanical nuclear system. A mass formula called INM mass formula based on this model yields rms deviation of 342 keV being the lowest in literature. Some of the highlights of its result includes its determination of INM density in agreement with the electron scattering data leading to the resolution of the long standing 'r 0 -paradox' it predicts new magic numbers giving rise to new island of stability in the drip-line regions. This is the manifestation of a new phenomenon where shell-effect over comes the repulsive component of nucleon-nucleon force resulting in the broadening of the stability peninsula. Shell quenching in N= 82,and N= 126 shells, and several islands of inversion have been predicted. The model determines the empirical value of the nuclear compression modulus, using high precission 4500 data comprising nuclear masses, neutron and proton separation energies. The talk will give a critical review of the field of mass formula and our understanding of nuclear dynamics as a whole

Covariant description of dynamical processes in relativistic nuclear matter

International Nuclear Information System (INIS)

Celenza, L.S.; Pantziris, A.; Shakin, C.M.

1992-01-01

We report results of covariant calculations of density-dependent polarization processes in relativistic nuclear matter. We consider the polarization induced by those mesons that play an important role in the boson-exchange model of nuclear forces (σ,π,ρ,ω). After obtaining the polarization operators, we construct the propagators for these mesons. The covariant nature of the calculation greatly clarifies the structure of the polarization operators and associated Green's functions. (In addition to the meson momentum, these quantities depend upon another four-vector, η μ , that describes the uniform motion of the medium.) In the case of the pion, we show that the same results are obtained for pseudovector or pseudoscalar coupling to the nucleon, if the associated Lagrangians are related by chiral transformations. Of particular interest are the extremely large values found for the polarization operators of the omega and sigma mesons. It is also found that the coupling of the sigma and omega fields through the polarization process is also extremely large. (Because of these results one cannot usefully consider the sigma and omega fields as independent degrees of freedom in nuclear matter.) We describe methods for reorganizing the calculation of ring diagrams in which we group those diagrams that exhibit strong cancellations. We also comment on the implication of our results for nuclear structure studies

Formation and decay of hot nuclei: the experimental situation

International Nuclear Information System (INIS)

Guerreau, D.

1989-01-01

With the achievement of new facilities in the 80's providing us heavy ion beams well above the Coulomb barrier, a unique opportunity was offered to the experimentalists to produce and study nuclear matter under extreme conditions. Effectively, in the energy range 20-100 MeV/u, on which we will concentrate in these lectures, it appeared very rapidly that excited nuclei could be formed at rather high temperatures. These lectures are intended to give an overview of the experimental status in this ''hot'' domain. Other lectures are more focused on the theoretical point of view. This paper will be arranged as follows: In a first part, the conceptual problems one might have to face will be introduced. A long chapter will be then devoted to the different experimental methods used so far in order to characterize the hot nucleus. We shall then discuss what can be learned from the study of deexcitation of nuclei at high T. The fourth part will be focused on the experimental evidences for the existence of limiting temperatures. Finally, a brief discussion will follow related to possible clues for the onset of nuclear instabilities at this critical temperature

Nuclear-Recoil Energy Scale in CDMS II Silicon Dark-Matter Detectors

Energy Technology Data Exchange (ETDEWEB)

Agnese, R.; et al.

2018-03-07

The Cryogenic Dark Matter Search (CDMS II) experiment aims to detect dark matter particles that elastically scatter from nuclei in semiconductor detectors. The resulting nuclear-recoil energy depositions are detected by ionization and phonon sensors. Neutrons produce a similar spectrum of low-energy nuclear recoils in such detectors, while most other backgrounds produce electron recoils. The absolute energy scale for nuclear recoils is necessary to interpret results correctly. The energy scale can be determined in CDMS II silicon detectors using neutrons incident from a broad-spectrum $^{252}$Cf source, taking advantage of a prominent resonance in the neutron elastic scattering cross section of silicon at a recoil (neutron) energy near 20 (182) keV. Results indicate that the phonon collection efficiency for nuclear recoils is $4.8^{+0.7}_{-0.9}$% lower than for electron recoils of the same energy. Comparisons of the ionization signals for nuclear recoils to those measured previously by other groups at higher electric fields indicate that the ionization collection efficiency for CDMS II silicon detectors operated at $\\sim$4 V/cm is consistent with 100% for nuclear recoils below 20 keV and gradually decreases for larger energies to $\\sim$75% at 100 keV. The impact of these measurements on previously published CDMS II silicon results is small.

Multifragment disintegrations of expanding nuclear systems

International Nuclear Information System (INIS)

Gelbke, K.

1993-01-01

Two phase transitions are expected to exist in bulk nuclear matter: a liquid-gas phase transition and a deconfinement transition to a quark-gluon plasma. In studies of nucleus-nucleus collisions, conditions similar to those pertaining to phase transitions in infinite systems can be created, but the fundamental problem yet to be solved is the identification of remnant signatures uniquely related to either of these phase transitions. Nuclear systems at densities and temperatures corresponding to the liquid-gas coexistence region can be produced in intermediate energy nucleus-nucleus collisions; they are expected to decay into many intermediate mass fragments (IMF's: Z=3-20). Recent investigations with low-threshold electronic 4π detector arrays have firmly established the occurrence of multifragment disintegrations of hot nuclear systems and allowed to challenge various theoretical approaches. In this talk, an overview of pertinent experimental results on multifragmentation will be presented and discussed. it will be shown that current microscopic transport theories designed to treat the growth of density fluctuations predict fragment multiplicities much smaller than observed experimentally. Measurements of the time scales of fragment formation are consistent with statistical model calculations for expanding hot nuclear system which indicate that fragments may form during a rather narrow time interval after the system has cooled and expanded to a density below that of normal nuclear matter. The expansion rate (and hence the fragment multiplicity) is sensitive to the equation of state (EOS). However, a number of recent results provide increasing evidence that current theoretical treatments need to be refined to allow an experimental determination of the EOS

The effective action approach applied to nuclear matter (1)

International Nuclear Information System (INIS)

Tran Huu Phat; Nguyen Tuan Anh.

1996-11-01

Within the framework of the Walecka model (QHD-I) the application of the Cornwall-Jackiw-Tomboulis (CJT) effective action to nuclear matter is presented. The main feature is the treating of the meson condensates for the system of finite nuclear density. The system of couple Schwinger-Dyson (SD) equations is derived. It is shown that SD equations for sigma-omega mixings are absent in this formalism. Instead, the energy density of the nuclear ground state does explicitly contain the contributions from the ring diagrams, amongst others. In the bare-vertex approximation, the expression for energy density is written down for numerical computation in the next paper. (author). 14 refs, 3 figs

Equation of state of asymmetric nuclear matter using re-projected nucleon–nucleon potentials

Science.gov (United States)

Asadi Aghbolaghi, Z.; Bigdeli, M.

2018-06-01

In this paper, we have calculated the equation of state of asymmetric nuclear matter using the lowest order constrained variational approach and Argonne family potentials with and without three-nucleon interaction (TNI) contribution. In particular, we have used the AV18 potential and the re-projected potentials, AV8‧, and AV6‧. We have also calculated the saturation properties of symmetric nuclear matter, and the nuclear symmetry energy using AV18+TNI, AV8‧+TNI and AV6‧+TNI potentials. The inclusion of TNI has modified the agreement with experiment. We have also made a comparison between our results and those of other many-body calculations.

Fundamentals of nuclear chemistry

International Nuclear Information System (INIS)

Majer, V.

1982-01-01

The author of the book has had 25 years of experience at the Nuclear Chemistry of Prague Technical University. In consequence, the book is intended as a basic textbook for students of this field. Its main objectives are an easily understandable presentation of the complex subject and in spite of the uncertainty which still characterizes the definition and subjects of nuclear chemistry - a systematic classification and logical structure. Contents: 1. Introduction (history and definition); 2. General nuclear chemistry (physical fundamentals, hot atom chemistry, interaction of nuclear radiation with matter, radioactive elements, isotope effects, isotope exchange, chemistry of radioactive trace elements); 3. Methods of nuclear chemistry of nuclear chemistry (radiochemical methods, activation, separation and enrichment chemistry); 4. Preparative nuclear chemistry (isotope production, labelled compounds); 5. Analytival nuclear chemistry; 6. Applied nuclear chemistry (isotope applications in general physical and analytical chemistry). The book is supplemented by an annex with tables, a name catalogue and a subject index which will facilitate access to important information. (RB) [de

{pi}{pi}-correlations in hot and dense matter; {pi}{pi}-Korrelationen in heisser und dichter Materie

Energy Technology Data Exchange (ETDEWEB)

Isselhorst, C.

2006-07-01

Properties of the {pi}{pi}-interactions in hot and dense matter are studied within a nonperturbative and symmetry conserving approach. The pion and its chiral partner, the {sigma}-meson, are described within the linear {sigma} model and special attention is given to the conservation of the underlying chiral symmetry. The first part deals with the properties of pion and {sigma} in the vacuum, the further being the ''Goldstone''-boson of the theory, while the latter is a broad resonance. The results in the vacuum are tested against experimental results like {pi}{pi}-phase shifts as well as the mass and the width of the {sigma}-meson. Besides the propagator of the {sigma}-meson, the preservation of the chiral symmetry is explicitly examined and chiral Ward identities for the n-point functions of the theory are fulfilled. Furthermore the {pi}{pi}-scattering matrix is calculated and shown to be consistent with predictions from chiral perturbation theory. In the second part of this work the model is extended to finite temperature with special emphasis on the chiral phase transition. The transition temperature and the critical exponent {beta} are determined, and the influence of the temperature on the propagator of the s-meson as well as on the {pi}{pi}-scattering matrix is examined. The third part deals with the properties of pion and {sigma} in dense matter. Additional couplings like the ones to particle-hole excitations and short range repulsion have to be included to ensure stability at nuclear matter density. At zero three momentum one observes a strong downward shift of the {sigma}-mass accompanied by an accumulation of strength near the two-pion threshhold in the spectral function. Taking into account a finite three momentum for the {pi}{pi}-pair, respectively the {sigma}-meson, one observes a weakening of the aforementioned effect. Having thus developed a model for the {pi}{pi}-interaction at finite temperature and density, we try to describe

J/psi production in proton-nucleus collisions at ALICE: cold nuclear matter really matters

CERN Multimedia

CERN. Geneva

2013-01-01

Heavy quarkonia are expected to be sensitive to the properties of strongly interacting matter, at both low and high temperatures. In nucleus-nucleus collisions, a phase transition to a deconfined state of quarks and gluons (Quark-Gluon Plasma) is thought to take place once the temperature of the system exceeds a critical temperature of the order of 150-200 MeV. The deconfined state can induce a suppression of charmonium (due to color screening, dominant at SPS and RHIC energies), which can be overturned at LHC energy by the (re)combination of the large number of free c and cbar quarks, taking place when the system cools down below the critical temperature. Cold nuclear matter also has an influence on heavy quarkonia. Such effects can be studied in proton-nucleus collisions, where no deconfined state is expected to be created. At LHC energy, they mainly include nuclear shadowing, gluon saturation, break-up of the quarkonium states, and parton energy loss in the initial and final state. The study of these eff...

Boiling Patterns of Iso-asymmetric Nuclear Matter

International Nuclear Information System (INIS)

Tõke, Jan

2013-01-01

Limits of thermodynamic metastability of self-bound neutron-rich nuclear matter are explored within the framework of microcanonical thermodynamics of interacting Fermi Gas model in Thomas-Fermi approximation. It is found that as the excitation energy per nucleon of the system is increased beyond a certain limiting value, the system loses metastability and becomes unstable with respect to joint fluctuations in excitation energy per nucleon and in isospin per nucleon. As a result, part of the system is forced to boil off in a form of iso-rich non-equilibrated vapors. Left behind in such a process, identifiable with distillation, is a more iso-symmetric metastable residue at a temperature characteristic of its residual isospin content. With a progressing increase in the initial excitation energy per nucleon, more neutron-rich matter is boiled off and a more iso-symmetric residue is left behind with progressively increasing characteristic temperature. Eventually, when all excess neutrons are shed, the system boils uniformly with a further supply of excitation energy, leaving behind a smaller and smaller residue at a characteristic boiling-point temperature of iso-symmetric matter.

Dark matter, neutrinos, and our solar system

CERN Document Server

Prakash, Nirmala

2013-01-01

Dark Matter, Neutrinos, and Our Solar System is a unique enterprise that should be viewed as an important contribution to our understanding of dark matter, neutrinos and the solar system. It describes these issues in terms of links, between cosmology, particle and nuclear physics, as well as between cosmology, atmospheric and terrestrial physics. It studies the constituents of dark matter (classified as hot warm and cold) first in terms of their individual structures (baryonic and non-baryonic, massive and non-massive, interacting and non-interacting) and second, in terms of facilities available to detect these structures (large and small). Neutrinos (an important component of dark matter) are treated as a separate entity. A detailed study of these elusive (sub-atomic) particles is done, from the year 1913 when they were found as byproducts of beta decay -- until the discovery in 2007 which confirmed that neutrino flavors were not more than three (as speculated by some). The last chapter of the book details t...

BLACK HOLE-NEUTRON STAR MERGERS WITH A HOT NUCLEAR EQUATION OF STATE: OUTFLOW AND NEUTRINO-COOLED DISK FOR A LOW-MASS, HIGH-SPIN CASE

International Nuclear Information System (INIS)

Deaton, M. Brett; Duez, Matthew D.; Foucart, Francois; O'Connor, Evan; Ott, Christian D.; Scheel, Mark A.; Szilagyi, Bela; Kidder, Lawrence E.; Muhlberger, Curran D.

2013-01-01

Neutrino emission significantly affects the evolution of the accretion tori formed in black hole-neutron star mergers. It removes energy from the disk, alters its composition, and provides a potential power source for a gamma-ray burst. To study these effects, simulations in general relativity with a hot microphysical equation of state (EOS) and neutrino feedback are needed. We present the first such simulation, using a neutrino leakage scheme for cooling to capture the most essential effects and considering a moderate mass (1.4 M ☉ neutron star, 5.6 M ☉ black hole), high-spin (black hole J/M 2 = 0.9) system with the K 0 = 220 MeV Lattimer-Swesty EOS. We find that about 0.08 M ☉ of nuclear matter is ejected from the system, while another 0.3 M ☉ forms a hot, compact accretion disk. The primary effects of the escaping neutrinos are (1) to make the disk much denser and more compact, (2) to cause the average electron fraction Y e of the disk to rise to about 0.2 and then gradually decrease again, and (3) to gradually cool the disk. The disk is initially hot (T ∼ 6 MeV) and luminous in neutrinos (L ν ∼ 10 54 erg s –1 ), but the neutrino luminosity decreases by an order of magnitude over 50 ms of post-merger evolution

Generation and use of process maps for hot extrusion of seamless tubes for nuclear applications

International Nuclear Information System (INIS)

Vaibhaw, Kumar; Jha, S.K.; Saibaba, N.; Jayaraj, R.N.

2009-01-01

Full text: Hot extrusion is known as significant bulk deformation step in manufacturing of seamless tube production. Elevated temperature deformation carried out above the recrystallization temperature would enable imposition of large strains in single step. This deformation causes a significant change in the microstructure of the material and depends on extrusion process parameters such as temperature and strain rate (Ram speed). Basic microstructure developed at this deformation stage has significant bearing on the final properties of the material fabricated with subsequent cold working steps. Zirconium alloys and special nuclear grade austenitic stainless steels are two important groups of materials used as structural and core components in thermal and fast reactors world wide respectively. The properties of former alloy are very sensitive to the thermo mechanical fabrication steps initiated with hot extrusion due to their anisotropic deformation behaviour. However, nuclear grade austenitic stainless steels have many variants from their commercial grades in terms of micro and macro alloy chemistry. Factors such as these significantly affect the workability of the materials and require proper selection of extrusion parameters especially working temperature and extrusion speed plays a key role in the quality of the product. Modern developments in processing technology envisage the application of processing maps based on dynamic material model for selection of hot extrusion parameters. The present paper is aimed at bringing out significance of the map in selection of working domain with respect to the industrial process conditions for both groups of nuclear materials mentioned earlier. Developed process maps of certain alloys suggest use of extremely slow strain rate and low temperature extrusion which can not be achieved during bulk processing due to design of equipment and heat transfer constraints in industrial scale production. Attempts are made to highlight

Symmetric and asymmetric nuclear matter in the Thomas-Fermi model at finite temperatures

International Nuclear Information System (INIS)

Strobel, K.; Weber, F.; Weigel, M.K.

1999-01-01

The properties of warm symmetric and asymmetric nuclear matter are investigated in the frame of the Thomas-Fermi approximation using a recent modern parameterization of the effective nucleon-nucleon interaction of Myers and Swiatecki. Special attention is paid to the liquid-gas phase transition, which is of special interest in modern nuclear physics. We have determined the critical temperature, critical density and the so-called flash temperature. Furthermore, the equation of state for cold neutron star matter is calculated. (orig.)

Properties of rho and eta mesons in nuclear matter

International Nuclear Information System (INIS)

Herrmann, M.; Sauermann, C.; Friman, B.L.; Technische Hochschule Darmstadt; Noerenberg, W.; Technische Hochschule Darmstadt

1993-10-01

The properties of ρ- and η-mesons in nuclear matter are studied within the scope of hadronic models. Unknown model parameters are obtained from fits to scattering data. - The treatment of the ρ-meson includes the coupling to two pions which, in matter, are strongly mixed with delta-particle-nucleon-hole states. The ρ-meson self-energy is evaluated in a current conserving approximation with in-medium pion propagators and vertex corrections. While the position of the original peak in the spectral function remains almost unchanged, its width grows rapidly with increasing density. Consequently, the ρ-meson strength function is strongly dispersed at high densities. Due to vertex corrections a new peak at a mass around 3m π emerges with increasing density, while the spectral function around the two-pion threshold is found to be smooth at all densities. The η-meson is strongly mixed with N * (1535)-particle-nucleon-hole states in nuclear matter. The corresponding dispersion relations with an upper and a lower branch look similar to those of the (π, ΔN -1 )-modes. However, since the N * is an S-wave resonance in the ηN-channel, the repulsion of the two branches survives at zero momentum. (orig.)

Nuclear matter equation of state and σ-meson parameters

Indian Academy of Sciences (India)

We try to determine phenomenologically the extent of in-medium modification of -meson parameters so that the saturation observables of the nuclear matter equation of state (EOS) are reproduced. To calculate the EOS we have used Brueckner–Bethe–Goldstone formalism with Bonn potential as two-body interaction.

Symmetric and asymmetric nuclear matter in the relativistic approach

International Nuclear Information System (INIS)

Huber, H.; Weber, F.; Weigel, M.K.

1995-01-01

Symmetric and asymmetric nuclear matter is studied in the framework of the relativistic Brueckner-Hartree-Fock and in the relativistic version of the so-called Λ 00 approximation. The equations are solved self-consistently in the full Dirac space, so avoiding the ambiguities in the choice of the effective scattering amplitude in matter. The calculations were performed for some modern meson-exchange potentials constructed by Brockmann and Machleidt. In some cases we used also the Groningen potentials. First, we examine the outcome for symmetric matter with respect to other calculations, which restrict themselves to positive-energy states only. The main part is devoted to the properties of asymmetric matter. In this case we obtain additionally to the good agreement with the parameters of symmetric matter, also a quite satisfactory agreement with the semiempirical macroscopic coefficients of asymmetric matter. Furthermore, we tested the assumption of a quadratic dependence of the asymmetry energy for a large range of asymmetries. Included is also the dependence of nucleon self-energies on density and neutron excess. For the purpose of comparison we discuss further the similarities and differences with relativistic Hartree and Hartree-Fock calculations and nonrelativistic Skyrme calculations

Mean free paths for high energy hadron collisions in nuclear matter

International Nuclear Information System (INIS)

Strugalski, Z.

1983-01-01

The mean free paths for various collisions of high energy pion in nuclear matter are determined experimentally using pion-xenon nucleus collision events at 3.5 GeV/c momentum. The relation between the mean free path lambdasub(i) for hadron-nucleon particle producing collisions in nuclear matter and corresponding cross section σsub(i) for particle producing collisions of this hadron with free nucleon is derived and discussed. This relation is lambdasub(i)=k/σsub(i), where lambdasub(i) is in nucleons per fm 2 and σ sub(i) - in fm 2 per nucleon, correspondingly, k=3.00+-0.26 is a coefficient accounting for the display of the nucleon inner structure in hadron-nucleus collisions

Nuclear matter properties using different sets of parameters in the Gogny interaction

International Nuclear Information System (INIS)

Ramadan, Kh.A.; Mansour, H.M.M.

2002-01-01

In the present work we use the finite range density dependent effective Gogny interaction to study the equation of state of polarized nuclear matter. Six sets of the interaction parameters are used and a comparison is made with the calculations of Friedman and Pandharipande using a realistic interaction. One of the parameter sets (D1) gives similar results for the properties of polarized nuclear matter while the other parameter sets (D1S, D250, D260, D280 and D300) yield results which are reasonably comparable with the realistic interaction calculation of Friedman and Pandharipande. (author)

The thermal curve of nuclear matter

International Nuclear Information System (INIS)

Ma, Y.G.; Peter, J.; Siwek, A.; Bocage, F.; Bougault, R.; Brou, R.; Colin, J.; Cussol, D.; Durand, D.; Genouin-Duhamel, E.; Gulminelli, F.; Lecolley, J.F.; Lefort, T.; Le Neindre, N.; Lopez, O.; Louvel, M.; Nguyen, A.D.; Steckmeyer, J.C.; Tamain, B.; Vient, E.

1997-01-01

Earlier measurements of nuclear matter thermal curve of liquid to gas phase transition presented two limitation: only one temperature measuring method was available and the mass number of the formed nuclei decreased from 190 to 50 when the excitation energy increased. To avoid these limitations experiments with the multidetector INDRA at GANIL were carried-out. Among the quasi-projectiles issued from the 36 Ar collisions at 52, 74, 95 A.MeV on the 58 Ni, nuclei of close masses were selected. The excitation energy was determined by the calorimetry of the charged products emitted by quasi-projectiles while the temperature was measured by three different methods. Very different apparent temperatures were obtained for the same excitation energy/nucleon. Only one curve displays a slope variation but no indication of plateau. With the quasi-projectiles obtained from the collisions of 129 Xe at 50 MeV/u on a 119 Sn target behaviors similar to those of 36 Ar were observed in the covered domain of excitation energy. To solve this puzzle and recover the initial temperatures of interest the only mean was to do a theoretical simulation in which one follows the de-excitation of the nuclei formed at different excitation energies and look for the thermal curve able to reproduce the observed temperatures. Two extreme possibilities were taken into account concerning the de-excitation process: either a sequential process established at E * /A≤ 3 MeV/u or a sudden multifragmentation in several hot fragments, most probably at E * /A≥ 10 MeV/u. In both cases it was possible to reproduce the whole set of experimental results concerning the 36 Ar projectile. The initial temperature increases steadily as a function of excitation energy showing no plateau or singular points. The results indicate that, being a system without external pressure, in its passage from the liquid phase to the gas phase the nucleus does not display necessarily a temperature plateau. Discussions on

Nuclear physics at Ganil; a compilation january 1983 december 1988

International Nuclear Information System (INIS)

1989-01-01

The results of some of the experiments carried out at GANIL from 1983 to 1988 are summarized. Theoretical and experimental work on the following fields are presented: nuclear structure, reaction mechanisms, hot nuclear matter, production and properties of exotic nuclei, collective motions in nuclei, peripheral collisions, multi-fragment emission, pions and photons and technical developments. A list of the papers from the experiments carried out at GANIL, together with scientific activities are given

Mass shift of σ-meson in nuclear matter

Indian Academy of Sciences (India)

Mass shift of σ-meson in nuclear matter. J R MORONES-IBARRA1, MÓNICA MENCHACA MACIEL1,∗. ,. AYAX SANTOS-GUEVARA2 and FELIPE ROBLEDO PADILLA1. 1Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Nuevo León, UANL,. Av. Universidad S/N Ciudad Universitaria, San Nicolás de los ...

Binding Energy and Compression Modulus of Infinite Nuclear Matter ...

African Journals Online (AJOL)

... MeV at the normal nuclear matter saturation density consistent with the best available density-dependent potentials derived from the G-matrix approach. The results of the incompressibility modulus, k∞ is in excellent agreement with the results of other workers. Journal of the Nigerian Association of Mathematical Physics, ...

The symmetry energy in nuclei and in nuclear matter

NARCIS (Netherlands)

Van Isacker, P.; Dieperink, A. E. L.

2006-01-01

We discuss to what extent information on ground-state properties of finite nuclei (energies and radii) can be used to obtain constraints on the symmetry energy in nuclear matter and its dependence on the density. The starting point is a generalized Weizsacker formula for ground-state energies. In

The symmetry energy in nuclei and in nuclear matter

NARCIS (Netherlands)

Dieperink, A. E. L.; Van Isacker, P.

We discuss to what extent information on ground-state properties of finite nuclei ( energies and radii) can be used to obtain constraints on the symmetry energy in nuclear matter and its dependence on the density. The starting point is a generalized Weizsacker formula for ground-state energies. In

Hot cell works and related irradiation tests in fission reactor for development of new materials for nuclear application

International Nuclear Information System (INIS)

Shikama, Tatsuo

1999-01-01

Present status of research works in Oarai Branch, Institute for Materials Research, Tohoku University, utilizing Japan Materials Testing Reactor and related hot cells will be described.Topics are mainly related with nuclear materials studies, excluding fissile materials, which is mainly aiming for development of materials for advanced nuclear systems such as a nuclear fusion reactor. Conflict between traditional and routined procedures and new demands will be described and future perspective is discussed. (author)

Neutrino neutral current interactions in nuclear matter

International Nuclear Information System (INIS)

Horowitz, C.J.; Wehrberger, K.

1991-01-01

Detailed knowledge of neutrino transport properties in matter is crucial for an understanding of the evolution of supernovae and of neutron star cooling. We investigate screening of neutrino scattering from a dense degenerate gas of electrons, protons and neutrons. We take into account correlations induced by the Coulomb interactions of the electrons and protons, and the strong interactions of the protons and neutrons. Nuclear matter is described by the σω model of quantum hadrodynamics. Results are presented for typical astrophysical scenarios. The differential cross section is strongly reduced at large energy transfer, where electrons dominate, and slightly reduced for small energy transfer, where nucleons dominate. At large densities, the nucleon effective mass is considerably lower than the free mass, and the region dominated by nucleons extends to larger energy transfer than for free nucleons. (orig.)

Pion Condensation and Alternating Layer Spin Model in Symmetric Nuclear Matter : Use of Extended Effective Nuclear Forces : Nuclear Physics

OpenAIRE

Teiji, KUNIHIRO; Tatsuyuki, TAKATSUKA; Ryozo, TAMAGAKI; Department of National Sciences, Ryukoku University; College of Humanities and Social Sciences, Iwate University; Department of Physics, Kyoto University

1985-01-01

Pion condensation in the symmetric nuclear matter is investigated on the basis of the ALS (alternating-layer-spin) model which provides a good description for the π^0 condensation. We perform energy calculations in a realistic way where the isobar (Δ)-mixing, the short range effects and the exchange energy of the interaction are taken into account. The Δ-mixing effect is built in the model state as previously done in the neutron matter. We preferentially employ G-0 force of Sprung and Banerje...

Collective effects on transport coefficients of relativistic nuclear matter. Pt. 2

International Nuclear Information System (INIS)

Mornas, L.

1993-04-01

The transport coefficients (thermal conductivity, shear and bulk viscosities) of symmetric nuclear matter and neutron matter are calculated in the Walecka model with a Boltzmann-Uehling-Uhlenbeck collision term by means of a Chapman-Enskog expansion in first order. The order of magnitude of the influence of collective effects induced by the presence of the mean σ and ω fields on these coefficients is evaluated. (orig.). 9 figs

Kaon dynamics in dense nuclear matter

International Nuclear Information System (INIS)

David, Ch.

1998-01-01

In this thesis a list of cross sections concerning the kaons and antikaons production, has been presented. A new method for the parametrisation of particles rescattering cross sections, based on the neural networks has been developed. Because of the influence of the nuclear matter on kaons properties, the effect of the optical potential parameters has been studied. In particular a term has been added to the vector part of this potential to determine the relative importance of this part compared to the scalar part. A new parametrisation of the resonance lifetime has been proposed. (A.L.B.)

Finite size effects in neutron star and nuclear matter simulations

Energy Technology Data Exchange (ETDEWEB)

Giménez Molinelli, P.A., E-mail: pagm@df.uba.ar; Dorso, C.O.

2015-01-15

In this work we study molecular dynamics simulations of symmetric nuclear and neutron star matter using a semi-classical nucleon interaction model. Our aim is to gain insight on the nature of the so-called “finite size effects”, unavoidable in this kind of simulations, and to understand what they actually affect. To do so, we explore different geometries for the periodic boundary conditions imposed on the simulation cell: cube, hexagonal prism and truncated octahedron. For nuclear matter simulations we show that, at sub-saturation densities and low temperatures, the solutions are non-homogeneous structures reminiscent of the “nuclear pasta” phases expected in neutron star matter simulations, but only one structure per cell and shaped by specific artificial aspects of the simulations—for the same physical conditions (i.e. number density and temperature) different cells yield different solutions. The particular shape of the solution at low enough temperature and a given density can be predicted analytically by surface minimization. We also show that even if this behavior is due to the imposition of periodic boundary conditions on finite systems, this does not mean that it vanishes for very large systems, and it is actually independent of the system size. We conclude that, for nuclear matter simulations, the cells' size sets the only characteristic length scale for the inhomogeneities, and the geometry of the periodic cell determines the shape of those inhomogeneities. To model neutron star matter we add a screened Coulomb interaction between protons, and perform simulations in the three cell geometries. Our simulations indeed produce the well known nuclear pasta, with (in most cases) several structures per cell. However, we find that for systems not too large results are affected by finite size in different ways depending on the geometry of the cell. In particular, at the same certain physical conditions and system size, the hexagonal prism yields a

The peculiar velocities of rich clusters in the hot and cold dark matter scenarios

Science.gov (United States)

Rhee, George F.; West, Michael J.; Villumsen, Jens V.

1993-01-01

We present the results of a study of the peculiar velocities of rich clusters of galaxies. The peculiar motion of rich clusters in various cosmological scenarios is of interest for a number of reasons. Observationally, one can measure the peculiar motion of clusters to greater distances than galaxies because cluster peculiar motions can be determined to greater accuracy. One can also test the slope of distance indicator relations using clusters to see if galaxy properties vary with environment. We have used N-body simulations to measure the amplitude and rms cluster peculiar velocity as a function of bias parameter in the hot and cold dark matter scenarios. In addition to measuring the mean and rms peculiar velocity of clusters in the two models, we determined whether the peculiar velocity vector of a given cluster is well aligned with the gravity vector due to all the particles in the simulation and the gravity vector due to the particles present only in the clusters. We have investigated the peculiar velocities of rich clusters of galaxies in the cold dark matter and hot dark matter galaxy formation scenarios. We have derived peculiar velocities and associated errors for the scenarios using four values of the bias parameter ranging from b = 1 to b = 2.5. The growth of the mean peculiar velocity with scale factor has been determined and compared to that predicted by linear theory. In addition, we have compared the orientation of force and velocity in these simulations to see if a program such as that proposed by Bertschinger and Dekel (1989) for elliptical galaxy peculiar motions can be applied to clusters. The method they describe enables one to recover the density field from large scale redshift distance samples. The method makes it possible to do this when only radial velocities are known by assuming that the velocity field is curl free. Our analysis suggests that this program if applied to clusters is only realizable for models with a low value of the bias

Equilibration of matter near the QCD critical point

International Nuclear Information System (INIS)

Bravina, L V; Arsene, I; Nilsson, M S; Tywoniuk, K; Zabrodin, E E

2006-01-01

The relaxation of hot and dense nuclear matter to local equilibrium in the central zone of heavy-ion collisions at energies around 40 A GeV is studied within the microscopic transport model. Dynamical calculations performed for the central cell in the reaction are compared to the predictions of the thermal statistical model. It is found that kinetic, thermal and chemical equilibrations of the expanding hadronic matter are nearly approached for the period of 10-18 fm/c. Within this time, the matter in the cell expands almost isentropically. It is quite interesting that in the T-μ B plane the system crosses the critical point predicted by lattice QCD calculations. Similar to the cells studied at lower (AGS) and higher (SPS, RHIC) energies, the central cell at 40 A GeV possesses negative (though small) net strangeness. Several peculiarities are observed as well. These features can be attributed to the transition from baryon-dominated to meson-dominated matter, discussed recently

Development of maintenance equipment for nuclear material fabrication equipment in a highly active hot cell

International Nuclear Information System (INIS)

Park, J. J.; Yang, M. S.; Kim, K. H. and others

2000-09-01

This report presents the development of a maintenance system for a highly contaminated nuclear material handling equipment at a hot-cell. This maintenance system has mainly three subsystems - a gamma-radiation measurement module for detecting a gamma-radiation level and identifying its distribution in-situ, a dry-type decontamination device for cleaning up contaminated particles, and a maintenance chamber for isolating contaminated equipment. The mechanical design considerations, controller, capabilities and remote operation and manipulation of the maintenance system are described. Such subsystems developed were installed and tested in the IMEF (Irradiated Material Examination Facility) M6 hot-cell after mock-up tests and performed their specific tasks successfully

Development of maintenance equipment for nuclear material fabrication equipment in a highly active hot cell

Energy Technology Data Exchange (ETDEWEB)

Park, J. J.; Yang, M. S.; Kim, K. H. and others

2000-09-01

This report presents the development of a maintenance system for a highly contaminated nuclear material handling equipment at a hot-cell. This maintenance system has mainly three subsystems - a gamma-radiation measurement module for detecting a gamma-radiation level and identifying its distribution in-situ, a dry-type decontamination device for cleaning up contaminated particles, and a maintenance chamber for isolating contaminated equipment. The mechanical design considerations, controller, capabilities and remote operation and manipulation of the maintenance system are described. Such subsystems developed were installed and tested in the IMEF (Irradiated Material Examination Facility) M6 hot-cell after mock-up tests and performed their specific tasks successfully.

Methods of investigation of nuclear matter under the conditions characteristics for transition to quark-gluon plasma

CERN Document Server

Leksin, G A

2002-01-01

Features of deep inelastic nuclear reactions proceeding on dense fluctuations of nuclear matter (fluctons) are briefly considered. Fluctons, which can be many-quark bags or drops of quark-gluon plasma, are studied. Their properties are discussed, viz., characteristic parameters of nuclear matter inside a flucton - temperature and density close to the critical values for a phase transition. These values can be reached or exceeded if the flucton-flucton collision events are separated. The separation method is discussed

Chiral approach to nuclear matter: role of two-pion exchange with virtual delta-isobar excitation

Science.gov (United States)

Fritsch, virtual delta-isobar excitation S.; Kaiser, N.; Weise, W.

2005-04-01

We extend a recent three-loop calculation of nuclear matter by including the effects from two-pion exchange with single and double virtual Δ(1232)-isobar excitation. Regularization dependent short-range contributions from pion-loops are encoded in a few NN-contact coupling constants. The empirical saturation point of isospin-symmetric nuclear matter, E=-16 MeV, ρ=0.16 fm, can be well reproduced by adjusting the strength of a two-body term linear in density (and tuning an emerging three-body term quadratic in density). The nuclear matter compressibility comes out as K=304 MeV. The real single-particle potential U(p,k) is substantially improved by the inclusion of the chiral πNΔ-dynamics: it grows now monotonically with the nucleon momentum p. The effective nucleon mass at the Fermi surface takes on a realistic value of M(k)=0.88M. As a consequence of these features, the critical temperature of the liquid-gas phase transition gets lowered to the value T≃15 MeV. In this work we continue the complex-valued single-particle potential U(p,k)+iW(p,k) into the region above the Fermi surface p>k. The effects of 2 π-exchange with virtual Δ-excitation on the nuclear energy density functional are also investigated. The effective nucleon mass associated with the kinetic energy density is M(ρ)=0.64M. Furthermore, we find that the isospin properties of nuclear matter get significantly improved by including the chiral πNΔ-dynamics. Instead of bending downward above ρ as in previous calculations, the energy per particle of pure neutron matter E(k) and the asymmetry energy A(k) now grow monotonically with density. In the density regime ρ=2ρnuclear physics our results agree well with sophisticated many-body calculations and (semi)-empirical values.

Cladding nuclear steels - the application of plasma-arc hot wire surfacing

International Nuclear Information System (INIS)

Trarbach, K.O.

1981-01-01

The effect of one and two layer plasma-arc hot wire cladding on the HAZ microstructure of the fine grained structural steel 22 NiMoCr 3 7, which is similar to ASTM A 508, class 2, and steel 20 MnMoNi 5 5, similar to ASTM A 533, grade B, class 1 is determined. Attention is directed particularly to the behaviour of the susceptible region, and the consumables considered are cladding materials X 2 CrNiNb 19 9, similar to ER 347 Elc, and S-NiCr 20 Nb, similar to ER NiCr-3 (Inconel 82). Results of corrosion resistance tests show that this cladding technique can be recommended for manufacture of equipment for the chemical industry to avoid corrosion failure. Plasma-arc hot wire surfacing is also shown to be capable of depositing single or double clad layers to meet the highest safety requirements and could be applied to nuclear power plants for the special manufacture of wear resistant parts and for protection of equipment subject to a variety of corrosive environments. (U.K.)

Is a condensed state of nuclear matter possible?

International Nuclear Information System (INIS)

D'yakonov, D.I.; Mirlin, A.D.

1988-01-01

Nucleon chiral models naturally lead to the concept of ''generalized'' or ''classical'' nucleons which are characterized by a definite orientation in spin-isospin space. Nucleons and Δ resonances are different rotational states of generalized nucleons. Interaction of two generalized nucleons is sharply anisotropic and at a definite relative orientation leads to very strong attraction. This gives an idea of possible existence of a condensed state of nuclear matter, i.e. of a crystal or Fermi liquid with a short-range order which consists of N and Δ coherent superpositions. The variational estimate shows that at densities a few times that of the standard nuclear density this condensed state may be energetically favourable

The effects of the tensor coupling term in the Zimanyi-Moszkowski model for unpolarized nuclear matter

International Nuclear Information System (INIS)

Ru-Keng Su; Li Li; Hong-Qiu Song

1998-01-01

The effects of the tensor coupling term on nuclear matter in the Zimanyi-Moszkowki (ZM) model are investigated. It is shown that the tensor coupling term in the ZM model leaves the thermodynamical properties of nuclear matter almost unchanged. The corrections of tensor coupling to the critical point of the liquid-gas phase transition are given. (author)

Nuclear matter calculations with a pseudoscalar-pseudovector chiral model

Energy Technology Data Exchange (ETDEWEB)

Niembro, R.; Marcos, S.; Bernardos, P. [University of Cantabria, Faculty of Sciences, Department of Modern Physics, 39005 Santander (Spain); Fomenko, V.N. [St Petersburg University for Railway Engineering, Department of Mathematics, 197341 St Petersburg (Russian Federation); Savushkin, L.N. [St Petersburg University for Telecomunications, Department of Physics, 191065 St Petersburg (Russian Federation); Lopez-Quelle, M. [University of Cantabria, Faculty of Sciences, Department of Applied Physics, 39005 Santander, Spain (Spain)

1998-10-01

A mixed pseudoscalar-pseudovector {pi}N coupling relativistic Lagrangian is obtained from a pure pseudoscalar chiral one, by transforming the nucleon field according to a generalized Weinberg transformation, which depends on a mixing parameter. The interaction is generated by the {sigma}, {omega} and {pi} meson exchanges. Within the Hartree-Fock context, pion polarization effects, including the {delta} isobar, are considered in the random phase approximation in nuclear matter. These effects are interpreted, in a non-relativistic framework, as a modification of the range and intensity of a Yukawa-type potential by means of a simple function which takes into account the nucleon-hole and {delta}-hole excitations. Results show stability of relativistic nuclear matter against pion condensation. Compression modulus is diminished by the combined effects of the nucleon and {delta} polarization towards the usually accepted experimental values. The {pi}N interaction strength used in this paper is less than the conventional one to ensure the viability of the model. The fitting parameters of the model are the scalar meson mass m{sub {sigma}} and the {omega}-N coupling constant g{sub {omega}}. (author)

Analytical relations between nuclear symmetry energy and single-nucleon potentials in isospin asymmetric nuclear matter

International Nuclear Information System (INIS)

Xu Chang; Li Baoan; Chen Liewen; Ko, Che Ming

2011-01-01

Using the Hugenholtz-Van Hove theorem, we derive general expressions for the quadratic and quartic symmetry energies in terms of the isoscalar and isovector parts of single-nucleon potentials in isospin asymmetric nuclear matter. These expressions 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.

Nucleon-nucleon correlations in dense nuclear matter

International Nuclear Information System (INIS)

Alm, T.

1993-02-01

In this thesis new results on the problematics of the formation of nucleon-nucleon correlations in nuclear matter could be presented. Starting from a general study of the two-particle problem in matter we studied the occurrence of a suprafluid phase (pair condensate of nucleons). The Gorkov decoupling by means of anomalous Green functions was generalized, so that also Cooper pairs with spin 1 (triplet pairing) can be described. A generalized gap equation resulted, which permits to determine the order parameters of the suprafluied phase in arbitrary channels of the nucleon-nucleon scattering states. This equation was solvd in the 1 S 0 -, in the 3 P 2 - 3 F 2 , and in the 3 S 1 - 3 D 1 channel under application of realistic nucleon-nucleon potentials. The behaviour of the resulting gap parameters in the single channels was studied as function of density and temperature. (orig.) [de

Research in nuclear astrophysics: stellar collapse and supernovae: Annual performance report, December 1, 1987--November 30, 1988

International Nuclear Information System (INIS)

Lattimer, J.M.; Yahil, A.

1988-01-01

This annual performance report summarizes the activity in the nuclear astrophysics research program in the Earth and Space Scienes Department at Stony Brook. The central themes in the projects that comprise this program are supernovae, neutron star formation, and the equation of state of hot, dense metter. There is a close coupling between the physics of nuclear matter and weak interactions on the one hand, and supernovae and neutron stars on the other. The properties of nuclear matter might at present best be delineated by astrophysical considerations. We have been active in researching both the nuclear physics of the equation of state and the astrophysics of stellar collapse, neutrino emission, and neutron star formation. 11 refs

Remarks on theoretical hot-atom chemistry

International Nuclear Information System (INIS)

Inokuti, Mitio

1993-01-01

The publication of the 'Handbook of Hot Atom Chemistry', following the earlier volume 'Recent Trend and Application', was a major milestone in physical chemistry. Theoretical treatments of hot atom chemistry must address two classes of problems. The first class concerns the individual collisions of hot atoms with other atoms or molecules. The second class concerns the description of the consequences of the many collisions of hot atoms and their chemical environment. Most of the remarks pertain to the problems of the first class. The central issue is the adiabaticity of nuclear motions versus electronic motions. To be precise, any atomic core motion should be mentioned rather than pure nuclear motion, because tightly bound core electrons are largely irrelevant to the chemistry. When nuclear motions are sufficiently slow, or for other reasons that can be regarded as adiabatic, the collision problem is basically straightforward, therefore, interatomic and intermolecular forces can be assumed, and their consequences for nuclear motions are calculable in principle. In the case of non-adiabaticity being important, much more difficult problems arise, and it is briefly discussed, and the work by Phelps is cited. (K.I.)

Nuclear symmetry energy and stability of matter in neutron stars

International Nuclear Information System (INIS)

Kubis, Sebastian

2007-01-01

It is shown that the nuclear symmetry energy is the key quantity in the stability consideration in neutron star matter. The symmetry energy controls the position of crust-core transition and also may lead to new effects in the inner core of neutron star

BLACK HOLE-NEUTRON STAR MERGERS WITH A HOT NUCLEAR EQUATION OF STATE: OUTFLOW AND NEUTRINO-COOLED DISK FOR A LOW-MASS, HIGH-SPIN CASE

Energy Technology Data Exchange (ETDEWEB)

Deaton, M. Brett; Duez, Matthew D. [Department of Physics and Astronomy, Washington State University, Pullman, WA 99164 (United States); Foucart, Francois; O' Connor, Evan [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, Ontario M5S 3H8 (Canada); Ott, Christian D.; Scheel, Mark A.; Szilagyi, Bela [TAPIR, MC 350-17, California Institute of Technology, Pasadena, CA 91125 (United States); Kidder, Lawrence E.; Muhlberger, Curran D., E-mail: mbdeaton@wsu.edu, E-mail: m.duez@wsu.edu [Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853 (United States)

2013-10-10

Neutrino emission significantly affects the evolution of the accretion tori formed in black hole-neutron star mergers. It removes energy from the disk, alters its composition, and provides a potential power source for a gamma-ray burst. To study these effects, simulations in general relativity with a hot microphysical equation of state (EOS) and neutrino feedback are needed. We present the first such simulation, using a neutrino leakage scheme for cooling to capture the most essential effects and considering a moderate mass (1.4 M{sub ☉} neutron star, 5.6 M{sub ☉} black hole), high-spin (black hole J/M {sup 2} = 0.9) system with the K{sub 0} = 220 MeV Lattimer-Swesty EOS. We find that about 0.08 M{sub ☉} of nuclear matter is ejected from the system, while another 0.3 M{sub ☉} forms a hot, compact accretion disk. The primary effects of the escaping neutrinos are (1) to make the disk much denser and more compact, (2) to cause the average electron fraction Y{sub e} of the disk to rise to about 0.2 and then gradually decrease again, and (3) to gradually cool the disk. The disk is initially hot (T ∼ 6 MeV) and luminous in neutrinos (L{sub ν} ∼ 10{sup 54} erg s{sup –1}), but the neutrino luminosity decreases by an order of magnitude over 50 ms of post-merger evolution.

Charm and Hidden Charm Scalar Resonances in Nuclear Matter

NARCIS (Netherlands)

Tolos, Laura; Molina, Raquel; Gamermann, Daniel; Oset, Eulogio

2009-01-01

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 nuclear matter. 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 MeV

Finite size effects in liquid-gas phase transition of asymmetric nuclear matter

International Nuclear Information System (INIS)

Pawlowski, P.

2001-01-01

Full text: Since the nuclear equation of state has been studied in astrophysical context as an element of neutron star or super-nova theories - a call for an evidence was produced in experimental nuclear physics. Heavy-ion collisions became a tool of study on thermodynamic properties of nuclear matter. A particular interest has been inspired here by critical behavior of nuclear systems, as a phase transition of liquid-gas type. A lot of efforts was put to obtain an experimental evidence of such a phenomenon in heavy-ion collisions. With the use of radioactive beams and high performance identification systems in a near future it will be possible to extend experimental investigation to asymmetric nuclear systems, where neutron-to-proton ratio is far from the stability line. This experimental development needs a corresponding extension of theoretical studies. To obtain a complete theory of the liquid-gas phase transition in small nuclear systems, produced in violent heavy-ion collisions, one should take into account two facts. First, that the nuclear matter forming nuclei is composed of protons and neutrons; this complicates the formalism of phase transitions because one has to deal with two separate, proton and neutron, densities and chemical potentials. The second and more important is that the surface effects are very strong in a system composed of a few hundreds of nucleons. This point is especially difficult to hold, because surface becomes an additional, independent state parameter, depending strongly on the geometrical configuration of the system, and introducing a non-local term in the equation of state. In this presentation we follow the recent calculation by Lee and Mekjian on the finite-size effects in small (A = 10 2 -10 3 ) asymmetric nuclear systems. A zero-range isospin-dependent Skyrme force is used to obtain a density and isospin dependent potential. The potential is then completed by additional terms giving contributions from surface and Coulomb

Hadron structure in a simple model of quark/nuclear matter

International Nuclear Information System (INIS)

Horowitz, C.J.; Moniz, E.J.; Negele, J.W.

1985-01-01

We study a simple model for one-dimensional hadron matter with many of the essential features needed for examining the transition from nuclear to quark matter and the limitations of models based upon hadron rather than quark degrees of freedom. The dynamics are generated entirely by the quark confining force and exchange symmetry. Using Monte Carlo techniques, the ground-state energy, single-quark momentum distribution, and quark correlation function are calculated for uniform matter as a function of density. The quark confinement scale in the medium increases substantially with increasing density. This change is evident in the correlation function and momentum distribution, in qualitative agreement with the changes observed in deep-inelastic lepton scattering. Nevertheless, the ground-state energy is smooth throughout the transition to quark matter and is described remarkably well by an effective hadron theory based on a phenomenological hadron-hadron potential

Saturation properties of asymmetric nuclear matter to be obtained from unstable nuclei

Energy Technology Data Exchange (ETDEWEB)

Oyamatsu, Kazuhiro [Aichi Shukutoku Univ., Dept. of Media Production and Theories, Nagakute, Aichi (Japan); Iida, Kei [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

2002-09-01

We examine relations among the parameters characterizing the phenomenological equation of state (EOS) of nearly symmetric, uniform nuclear matter near the saturation density from experimental data on radii and masses of stable nuclei. The EOS parameters of interest are the symmetry energy S{sub 0}, the symmetry energy density-derivative coefficient L and the incompressibility K{sub 0} at the normal nuclear density. The calculations of the nuclear properties were performed with a simplified Thomas-Fermi model. We find a constraint on (K{sub 0}, L) values from the slope of the saturation line (the line joining the saturation points of asymmetric matter EOS with fixed proton abundance). A strong correlation between S{sub 0} and L, which was discussed in the Skyrme Hartree-Fock theory for relatively small L values, is found to hold for such larger values as a relativistic mean field theory predicts. In the light of the uncertainties in the (K{sub 0}, L) values, we calculate radii of unstable nuclei as expected to be produced in future facilities. We find that the matter radii depend strongly on L almost independently of K{sub 0}, and that systematic detection of the radii of such nuclei will help to determine the L value. (author)

Operation of the nuclear fuel cycle test facilities -Operation of the hot test loop facilities

International Nuclear Information System (INIS)

Chun, S. Y.; Jeong, M. K.; Park, C. K.; Yang, S. K.; Won, S. Y.; Song, C. H.; Jeon, H. K.; Jeong, H. J.; Cho, S.; Min, K. H.; Jeong, J. H.

1997-01-01

A performance and reliability of a advanced nuclear fuel and reactor newly designed should be verified by performing the thermal hydraulics tests. In thermal hydraulics research team, the thermal hydraulics tests associated with the development of an advanced nuclear fuel and reactor haven been carried out with the test facilities, such as the Hot Test Loop operated under high temperature and pressure conditions, Cold Test Loop, RCS Loop and B and C Loop. The objective of this project is to obtain the available experimental data and to develop the advanced measuring techniques through taking full advantage of the facilities. The facilities operated by the thermal hydraulics research team have been maintained and repaired in order to carry out the thermal hydraulics tests necessary for providing the available data. The performance tests for the double grid type bottom end piece which was improved on the debris filtering effectivity were performed using the PWR-Hot Test Loop. The CANDU-Hot Test Loop was operated to carry out the pressure drop tests and strength tests of CANFLEX fuel. The Cold Test Loop was used to obtain the local velocity data in subchannel within HANARO fuel bundle and to study a thermal mixing characteristic of PWR fuel bundle. RCS thermal hydraulic loop was constructed and the experiments have been carried out to measure the critical heat flux. In B and C Loop, the performance tests for each component were carried out. (author). 19 tabs., 78 figs., 19 refs

Operation of the nuclear fuel cycle test facilities -Operation of the hot test loop facilities

Energy Technology Data Exchange (ETDEWEB)

Chun, S. Y.; Jeong, M. K.; Park, C. K.; Yang, S. K.; Won, S. Y.; Song, C. H.; Jeon, H. K.; Jeong, H. J.; Cho, S.; Min, K. H.; Jeong, J. H.

1997-01-01

A performance and reliability of a advanced nuclear fuel and reactor newly designed should be verified by performing the thermal hydraulics tests. In thermal hydraulics research team, the thermal hydraulics tests associated with the development of an advanced nuclear fuel and reactor haven been carried out with the test facilities, such as the Hot Test Loop operated under high temperature and pressure conditions, Cold Test Loop, RCS Loop and B and C Loop. The objective of this project is to obtain the available experimental data and to develop the advanced measuring techniques through taking full advantage of the facilities. The facilities operated by the thermal hydraulics research team have been maintained and repaired in order to carry out the thermal hydraulics tests necessary for providing the available data. The performance tests for the double grid type bottom end piece which was improved on the debris filtering effectivity were performed using the PWR-Hot Test Loop. The CANDU-Hot Test Loop was operated to carry out the pressure drop tests and strength tests of CANFLEX fuel. The Cold Test Loop was used to obtain the local velocity data in subchannel within HANARO fuel bundle and to study a thermal mixing characteristic of PWR fuel bundle. RCS thermal hydraulic loop was constructed and the experiments have been carried out to measure the critical heat flux. In B and C Loop, the performance tests for each component were carried out. (author). 19 tabs., 78 figs., 19 refs.

X-ray investigations of the hot ISM

Science.gov (United States)

Sanders, W. T.

1993-01-01

At energies less than one keV, the intensity of the galactic x-ray background dominates that of the extragalactic background in almost every direction on the sky. Below 1/4 keV, the galactic x-ray background has a galactic stellar component, but the dominant emitter seems to be hot interstellar matter. The origin of the general 3/4 keV x-ray background remains uncertain, but one component must also be the contribution from hot interstellar matter. An overview is given of recent x-ray investigations of the hot interstellar medium using data from the ROSAT X-ray Telescope/Position-Sensitive Proportional Counter (XRT/PSPC) instrument. Several prominent features in the low energy x-ray background that are interpreted as fossil supernova remnants are discussed.

Dynamic electron-ion collisions and nuclear quantum effects in quantum simulation of warm dense matter

Science.gov (United States)

Kang, Dongdong; Dai, Jiayu

2018-02-01

The structural, thermodynamic and transport properties of warm dense matter (WDM) are crucial to the fields of astrophysics and planet science, as well as inertial confinement fusion. WDM refers to the states of matter in a regime of temperature and density between cold condensed matter and hot ideal plasmas, where the density is from near-solid up to ten times solid density, and the temperature between 0.1 and 100 eV. In the WDM regime, matter exhibits moderately or strongly coupled, partially degenerate properties. Therefore, the methods used to deal with condensed matter and isolated atoms need to be properly validated for WDM. It is therefore a big challenge to understand WDM within a unified theoretical description with reliable accuracy. Here, we review the progress in the theoretical study of WDM with state-of-the-art simulations, i.e. quantum Langevin molecular dynamics and first principles path integral molecular dynamics. The related applications for WDM are also included.

DS Mesons in Asymmetric Hot and Dense Hadronic Matter

Directory of Open Access Journals (Sweden)

Divakar Pathak

2015-01-01

Full Text Available The in-medium properties of DS mesons are investigated within the framework of an effective hadronic model, which is a generalization of a chiral SU(3 model, to SU(4, in order to study the interactions of the charmed hadrons. In the present work, the DS mesons are observed to experience net attractive interactions in a dense hadronic medium, hence reducing the masses of the DS+ and DS- mesons from the vacuum values. While this conclusion holds in both nuclear and hyperonic media, the magnitude of the mass drop is observed to intensify with the inclusion of strangeness in the medium. Additionally, in hyperonic medium, the mass degeneracy of the DS mesons is observed to be broken, due to opposite signs of the Weinberg-Tomozawa interaction term in the Lagrangian density. Along with the magnitude of the mass drops, the mass splitting between DS+ and DS- mesons is also observed to grow with an increase in baryonic density and strangeness content of the medium. However, all medium effects analyzed are found to be weakly dependent on isospin asymmetry and temperature. We discuss the possible implications emanating from this analysis, which are all expected to make a significant difference to observables in heavy ion collision experiments, especially the upcoming Compressed Baryonic Matter (CBM experiment at the future Facility for Antiproton and Ion Research (FAIR, GSI, where matter at high baryonic densities is planned to be produced.

Conversion width of Σ-hyperon in nuclear matter

International Nuclear Information System (INIS)

Filimonov, V.A.

1983-01-01

Width G of ΣN→ΛN conversion for Σ - hyperon in nuclear matter on the base of one-boson exchange model is calculated. Essential compensation of contributions of diffe-- rent mesons to amplitude of the conversiop is shown to take place. As a result G decreases approximately twice as compaped with the value from exchange only by π-meson. Without accout of Pauli principle it is obtained G=15-25 MeV

Leptogenesis as an origin of hot dark matter and baryon asymmetry in the E6 inspired SUSY models

Science.gov (United States)

Nevzorov, R.

2018-04-01

We explore leptogenesis within the E6 inspired U (1) extension of the MSSM in which exact custodial symmetry forbids tree-level flavour-changing transitions and the most dangerous baryon and lepton number violating operators. This supersymmetric (SUSY) model involves extra exotic matter beyond the MSSM. In the simplest phenomenologically viable scenarios the lightest exotic fermions are neutral and stable. These states should be substantially lighter than 1eV forming hot dark matter in the Universe. The low-energy effective Lagrangian of the SUSY model under consideration possesses an approximate global U(1)E symmetry associated with the exotic states. The U(1)E symmetry is explicitly broken because of the interactions between the right-handed neutrino superfields and exotic matter supermultiplets. As a consequence the decays of the lightest right-handed neutrino/sneutrino give rise to both U(1)E and U(1) B - L asymmetries. When all right-handed neutrino/sneutrino are relatively light ∼106-107GeV the appropriate amount of the baryon asymmetry can be induced via these decays if the Yukawa couplings of the lightest right-handed neutrino superfields to the exotic matter supermultiplets vary between ∼10-4-10-3.

Nuclear matter studies with density-dependent meson-nucleon coupling constants

International Nuclear Information System (INIS)

Banerjee, M.K.; Tjon, J.A.; Banerjee, M.K.; Tjon, J.A.

1997-01-01

Due to the internal structure of the nucleon, we should expect, in general, that the effective meson nucleon parameters may change in nuclear medium. We study such changes by using a chiral confining model of the nucleon. We use density-dependent masses for all mesons except the pion. Within a Dirac-Brueckner analysis, based on the relativistic covariant structure of the NN amplitude, we show that the effect of such a density dependence in the NN interaction on the saturation properties of nuclear matter, while not large, is quite significant. Due to the density dependence of the g σNN , as predicted by the chiral confining model, we find, in particular, a looping behavior of the binding energy at saturation as a function of the saturation density. A simple model is described, which exhibits looping and which is shown to be mainly caused by the presence of a peak in the density dependence of the medium modified σN coupling constant at low density. The effect of density dependence of the coupling constants and the meson masses tends to improve the results for E/A and density of nuclear matter at saturation. From the present study we see that the relationship between binding energy and saturation density may not be as universal as found in nonrelativistic studies and that more model dependence is exhibited once medium modifications of the basic nuclear interactions are considered. copyright 1997 The American Physical Society

The evolution of X-ray clusters in a cold plus hot dark matter universe

Science.gov (United States)

Bryan, Greg L.; Klypin, Anatoly; Loken, Chris; Norman, Michael L.; Burns, Jack O.

1994-01-01

We present the first self-consistently computed results on the evolution of X-ray properties of galaxy clusters in a cold + hot dark matter (CHDM) model. We have performed a hydrodynamic plus N-body simulation for the COBE-compatible CHDM model with standard mass components: Omega(sub hot) = 0.3, Omega (sub cold) = 0.6 and Omega(sub baryon) = 0.1 (h = 0.5). In contrast with the CDM model, which fails to reproduce the observed temperature distribution function dN/dT (Bryan et al. 1994b), the CHDM model fits the observational dN/dT quite well. Our results on X-ray luminosity are less firm but even more intriguing. We find that the resulting X-ray luminosity functions at redshifts z = 0.0, 0.2, 0.4, 0.7 are well fit by observations, where they overlap. The fact that both temperatures and luminosities provide a reasonable fit to the available observational data indicates that, unless we are missing some essential physics, there is neither room nor need for a large fraction of gas in rich clusters: 10% (or less) in baryons is sufficient to explain their X-ray properties. We also see a tight correlation between X-ray luminosity and gas temperature.

Nonstatic, self-consistent πN t matrix in nuclear matter

International Nuclear Information System (INIS)

Van Orden, J.W.

1984-01-01

In a recent paper, a calculation of the self-consistent πN t matrix in nuclear matter was presented. In this calculation the driving term of the self-consistent equation was chosen to be a static approximation to the free πN t matrix. In the present work, the earlier calculation is extended by using a nonstatic, fully-off-shell free πN t matrix as a starting point. Right-hand pole and cut contributions to the P-wave πN amplitudes are derived using a Low expansion and include effects due to recoil of the interacting πN system as well as the transformation from the πN c.m. frame to the nuclear rest frame. The self-consistent t-matrix equation is rewritten as two integral equations which modify the pole and cut contributions to the t matrix separately. The self-consistent πN t matrix is calculated in nuclear matter and a nonlocal optical potential is constructed from it. The resonant contribution to the optical potential is found to be broadened by 20% to 50% depending on pion momentum and is shifted upward in energy by approximately 10 MeV in comparison to the first-order optical potential. Modifications to the nucleon pole contribution are found to be negligible

The quark matter

International Nuclear Information System (INIS)

Rho, Mannque.

1980-04-01

The present status of our understanding of the physics of hadronic (nuclear or neutron) matter under extreme conditions, in particular at high densities is discussed. This is a problem which challenges three disciplines of physics: nuclear physics, astrophysics and particle physics. It is generally believed that we now have a correct and perhaps ultimate theory of the strong interactions, namely quantum chromodynamics (QCD). The constituents of this theory are quarks and gluons, so highly dense matters should be describable in terms of these constituents alone. This is a question that addresses directly to the phenomenon of quark confinement, one of the least understood aspects in particle physics. For nuclear physics, the possibility of a phase change between nuclear matter and quark matter introduces entirely new degrees of freedom in the description of nuclei and will bring perhaps a deeper understanding of nuclear dynamics. In astrophysics, the properties of neutron stars will be properly understood only when the equation of state of 'neutron' matter at densities exceeding that of nuclear matter can be realiably calculated. Most fascinating is the possibility of quark stars existing in nature, not entirely an absurd idea. Finally the quark matter - nuclear matter phase transition must have occured in the early stage of universe when matter expanded from high temperature and density; this could be an essential ingredient in the big-bang cosmology

Relativistic mean-field approximation with density-dependent screening meson masses in nuclear matter

International Nuclear Information System (INIS)

Sun, Baoxi; Lu, Xiaofu; Shen, Pengnian; Zhao, Enguang

2003-01-01

The Debye screening masses of the σ, ω and neutral ρ mesons and the photon are calculated in the relativistic mean-field approximation. As the density of the nucleon increases, all the screening masses of mesons increase. A different result with Brown–Rho scaling is shown, which implies a reduction in the mass of all the mesons in the nuclear matter, except the pion. Replacing the masses of the mesons with their corresponding screening masses in the Walecka-1 model, five saturation properties of the nuclear matter are fixed reasonably, and then a density-dependent relativistic mean-field model is proposed without introducing the nonlinear self-coupling terms of mesons. (author)

From meson- and photon-nucleon scattering to vector mesons in nuclear matter

International Nuclear Information System (INIS)

Wolf, Gy.; Lutz, M.F.M.; Friman, B.

2003-01-01

A relativistic and unitary approach to pion- and photon-nucleon scattering taking into account the πN, ρN, ωN, ηN, πΔ, KΛ and KΣ channels is presented. The scheme dynamically generates the s- and d-wave baryon resonances N(1535), N(1650), N(1520) and N(1700) and as well as Δ(1620) and Δ(1700) in terms of quasi-local two-body interaction terms. A fair description of the experimental data relevant to the properties of slow vector mesons in nuclear matter is obtained. The resulting s-wave ρ- and ω-meson-nucleon scattering amplitudes which define the leading density modification of the ρ- and ω-meson spectral functions in nuclear matter are presented. (author)

Cold Nuclear Matter Effects on J/psi Production: Intrinsic and Extrinsic Transverse Momentum Effects

Energy Technology Data Exchange (ETDEWEB)

Ferreiro, E.G.; /Santiago de Compostela U.; Fleuret, F.; /Ecole Polytechnique; Lansberg, J.P.; /Heidelberg U.; Rakotozafindrabe, A.; /SPhN, DAPNIA, Saclay

2010-08-26

Cold nuclear matter effects on J/{psi} production in proton-nucleus and nucleus-nucleus collisions are evaluated taking into account the specific J/{psi}-production kinematics at the partonic level, the shadowing of the initial parton distributions and the absorption in the nuclear matter. We consider two different parton processes for the c{bar c}-pair production: one with collinear gluons and a recoiling gluon in the final state and the other with initial gluons carrying intrinsic transverse momentum. Our results are compared to RHIC observables. The smaller values of the nuclear modification factor R{sub AA} in the forward rapidity region (with respect to the mid rapidity region) are partially explained, therefore potentially reducing the need for recombination effects.

Self-Energy of Decuplet Baryons in Nuclear Matter

OpenAIRE

Ouellette, Stephen M.; Seki, Ryoichi

1997-01-01

We calculate, in chiral perturbation theory, the change in the self-energy of decuplet baryons in nuclear matter. These self-energy shifts are relevant in studies of meson-nucleus scattering and of neutron stars. Our results are leading order in an expansion in powers of the ratio of characteristic momenta to the chiral symmetry-breaking scale (or the nucleon mass). Included are contact diagrams generated by 4-baryon operators, which were neglected in earlier studies for the $\\Delta$ isomulti...

Chiral approach to nuclear matter: Role of two-pion exchange with virtual delta-isobar excitation

OpenAIRE

Fritsch, S.; Kaiser, N.; Weise, W.

2004-01-01

We extend a recent three-loop calculation of nuclear matter in chiral perturbation theory by including the effects from two-pion exchange with single and double virtual $\\Delta(1232)$-isobar excitation. Regularization dependent short-range contributions from pion-loops are encoded in a few NN-contact coupling constants. The empirical saturation point of isospin-symmetric nuclear matter, $\\bar E_0 = -16 $MeV, $\\rho_0 = 0.16 $fm$^{-3}$, can be well reproduced by adjusting the strength of a two-...

Rare isotopes and the sound of dilute nuclear matter

Science.gov (United States)

Papakonstantinou, P.

2018-04-01

Dilute baryonic matter, at densities below the normal saturation density of symmetric matter, is found on the crust of neutron stars and in collapsing supernova matter, its properties determining the evolution of those stellar objects. It is also readily found on the surface of ordinary and exotic atomic nuclei and lives fleetingly in the form of space-extended resonances of excited nucleons. Liminal states of nuclear matter, between saturation and full evaporation or clusterization, are manifest in the structure of symmetric nuclei through clustering and of very asymmetric rare species in haloes and the neutron skin; they stand literally at the threshold of a nucleus's response to hadronic probes, including processes which hinder or enable fusion. In this contribution I focus on excited states, and in particular exotic or not-so-exotic dipole excitation modes of N = Z nuclei and neutron-rich species, including new theoretical results on threshold strength. Modes of special interest are vibrations of and within diffuse surface layers and alpha-cluster oscillations. The modeling of such processes is relevant, directly or indirectly, for the description of reactions at astrophysical energies.

Research in nuclear astrophysics: Stellar collapse and supernovae

International Nuclear Information System (INIS)

Lattimer, J.M.; Yahil, A.

1990-01-01

The interaction between nuclear theory and some outstanding problems in astrophysics has been examined. We have been actively researching both the astrophysics of gravitational collapse, neutron star birth, and the emission of neutrinos from supernovae, on the one hand, and the nuclear physics of the equation of state of hot, dense matter on the other hand. There is close coupling between nuclear theory and supernova and neutron star phenomenon; in fact, nuclear matter properties, especially supernuclear densities, might be best delineated by astrophysical considerations. Our research has also focused on the neutrinos emitted from supernovae, since they are the only available observables of the internal supernova mechanism. The recent observations of neutrinos from SN 1987A proved to be in remarkable agreement with models we pioneered prior to its explosion. We have also developed a novel hydrodynamical code in which shocks are treated via Riemann resolution rather than with artificial viscosity. We have also extended models of the neutrino emission and cooling of neutron stars to include the effects of rotation. The Lattimer compressible liquid drop model is the basis of our equation of state. We have developed a rapid version for use in hydrodynamic codes that retains essentially all the physics of earlier, more detailed equations of state. We have also focused on the nuclei-nuclear matter phase transition just below nuclear matter density, including the probable nuclear deformations and the possible ''inside-out'' phase of bubbles, which could be of major importance in supernovae models. Work also progressed toward understanding the origin of the r-process elements, through focusing on the neutron star decompression model

Intrinsic neutron background of nuclear emulsions for directional Dark Matter searches

Science.gov (United States)

Alexandrov, A.; Asada, T.; Buonaura, A.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Di Vacri, M. L.; Furuya, S.; Galati, G.; Gentile, V.; Katsuragawa, T.; Laubenstein, M.; Lauria, A.; Loverre, P. F.; Machii, S.; Monacelli, P.; Montesi, M. C.; Naka, T.; Pupilli, F.; Rosa, G.; Sato, O.; Strolin, P.; Tioukov, V.; Umemoto, A.; Yoshimoto, M.

2016-07-01

Recent developments of the nuclear emulsion technology led to the production of films with nanometric silver halide grains suitable to track low energy nuclear recoils with submicrometric length. This improvement opens the way to a directional Dark Matter detection, thus providing an innovative and complementary approach to the on-going WIMP searches. An important background source for these searches is represented by neutron-induced nuclear recoils that can mimic the WIMP signal. In this paper we provide an estimation of the contribution to this background from the intrinsic radioactive contamination of nuclear emulsions. We also report the neutron-induced background as a function of the read-out threshold, by using a GEANT4 simulation of the nuclear emulsion, showing that it amounts to about 0.06 per year per kilogram, fully compatible with the design of a 10 kg × year exposure.

Big Bang synthesis of nuclear dark matter

International Nuclear Information System (INIS)

Hardy, Edward; Lasenby, Robert; March-Russell, John; West, Stephen M.

2015-01-01

We investigate the physics of dark matter models featuring composite bound states carrying a large conserved dark “nucleon” number. The properties of sufficiently large dark nuclei may obey simple scaling laws, and we find that this scaling can determine the number distribution of nuclei resulting from Big Bang Dark Nucleosynthesis. For plausible models of asymmetric dark matter, dark nuclei of large nucleon number, e.g. ≳10 8 , may be synthesised, with the number distribution taking one of two characteristic forms. If small-nucleon-number fusions are sufficiently fast, the distribution of dark nuclei takes on a logarithmically-peaked, universal form, independent of many details of the initial conditions and small-number interactions. In the case of a substantial bottleneck to nucleosynthesis for small dark nuclei, we find the surprising result that even larger nuclei, with size ≫10 8 , are often finally synthesised, again with a simple number distribution. We briefly discuss the constraints arising from the novel dark sector energetics, and the extended set of (often parametrically light) dark sector states that can occur in complete models of nuclear dark matter. The physics of the coherent enhancement of direct detection signals, the nature of the accompanying dark-sector form factors, and the possible modifications to astrophysical processes are discussed in detail in a companion paper.

Isospin-dependent properties of asymmetric nuclear matter in relativistic mean-field models

OpenAIRE

Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An

2007-01-01

Using various relativistic mean-field models, including the nonlinear ones with meson field self-interactions, those with density-dependent meson-nucleon couplings, and the point-coupling models without meson fields, we have studied the isospin-dependent bulk and single-particle properties of asymmetric nuclear matter. In particular, we have determined the density dependence of nuclear symmetry energy from these different relativistic mean-field models and compare the results with the constra...

Phase transition in dense nuclear matter with quark and gluon condensates

International Nuclear Information System (INIS)

Ellis, J.; Kapusta, J.I.; Olive, K.A.

1991-01-01

Nuclear matter is expected to modify the expectation values of the quark and gluon condensates. We utilize the chiral and scale symmetries of QCD to describe the interaction between these condensates and hadrons. We solve the resulting equations self-consistently in the relativistic mean field approximation. In order that these QCD condensates be driven towards zero at high density their coupling to sigma and vector mesons must be such that the masses of these mesons do not decrease with density. In this case a physically sensible phase transition to quark matter ensures. (orig.)

Towards a chiral effective field theory of nuclear matter

International Nuclear Information System (INIS)

Mallik, S.

2008-01-01

As a preliminary attempt to formulate an effective theory of nuclear matter, we undertake to calculate the effective pole parameters of nucleon in such a medium. We begin with the virial expansion of these parameters to leading order in nucleon number density in terms of the on-shell NN scattering amplitude. We then proceed to calculate the same parameters in the effective theory, getting a formula for the nucleon mass-shift to leading order, that was known already to give too large a value to be acceptable at normal nuclear density. At this point the virial expansion suggests a modification of this formula, which we carry out following Weinberg's method for the two-nucleon system in the effective theory. The results are encouraging enough to attempt a complete, next-to-leading order calculation of the off-shell nucleon spectral function in nuclear medium. (author)

General aspects of the nucleon-nucleon interaction and nuclear matter properties

Energy Technology Data Exchange (ETDEWEB)

Plohl, Oliver

2008-07-25

The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

General aspects of the nucleon-nucleon interaction and nuclear matter properties

International Nuclear Information System (INIS)

Plohl, Oliver

2008-01-01

The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

Dark matter and cosmology

Energy Technology Data Exchange (ETDEWEB)

Schramm, D.N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ``cold`` and ``hot`` non-baryonic candidates is shown to depend on the assumed ``seeds`` that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

Dark matter and cosmology

Energy Technology Data Exchange (ETDEWEB)

Schramm, D.N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the {Omega} = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between cold'' and hot'' non-baryonic candidates is shown to depend on the assumed seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed.

Dark matter and cosmology

International Nuclear Information System (INIS)

Schramm, D.N.

1992-03-01

The cosmological dark matter problem is reviewed. The Big Bang Nucleosynthesis constraints on the baryon density are compared with the densities implied by visible matter, dark halos, dynamics of clusters, gravitational lenses, large-scale velocity flows, and the Ω = 1 flatness/inflation argument. It is shown that (1) the majority of baryons are dark; and (2) non-baryonic dark matter is probably required on large scales. It is also noted that halo dark matter could be either baryonic or non-baryonic. Descrimination between ''cold'' and ''hot'' non-baryonic candidates is shown to depend on the assumed ''seeds'' that stimulate structure formation. Gaussian density fluctuations, such as those induced by quantum fluctuations, favor cold dark matter, whereas topological defects such as strings, textures or domain walls may work equally or better with hot dark matter. A possible connection between cold dark matter, globular cluster ages and the Hubble constant is mentioned. Recent large-scale structure measurements, coupled with microwave anisotropy limits, are shown to raise some questions for the previously favored density fluctuation picture. Accelerator and underground limits on dark matter candidates are also reviewed

77 FR 11168 - In the Matter of Exelon Corporation; Constellation Energy Group, Inc.; Nine Mile Nuclear Station...

Science.gov (United States)

2012-02-24

... and NPF-69] In the Matter of Exelon Corporation; Constellation Energy Group, Inc.; Nine Mile Nuclear..., LLC (Exelon Ventures), and Constellation Energy Nuclear Group, LLC (CENG), acting on behalf of itself... Nuclear Advisory Committee of Constellation Energy Nuclear Group, LLC, shall prepare an Annual Report...

Comments on nucleon mean free paths in nuclear matter

International Nuclear Information System (INIS)

Blann, M.

1977-01-01

It is suggested that recent evidence cited for a fourfold increase in the mean free path of nucleons in nuclear matter results from an error in formulation of the exciton model. The literature cited as being in support of the longer mean free path is reviewed and found to be in disagreement with the new value, and in quite reasonable agreement with results used over the past 30 years. (Auth.)

Time characteristics for the spinodal decomposition in nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Idier, D.; Farine, M.; Benhassine, B.; Remaud, B.; Sebille, F.

1992-12-31

Dynamics of the fluctuation growth are studied. Time characteristics are key quantities to determine the conditions under which spinodal decomposition could be observed. Dynamical instabilities arising from fluctuations in spinodal zone for nuclear matter are studied using Skyrme type interactions within a pseudo-particle model. Typical times for cluster formation are extracted. The numerical treatment is based on the Vlasov phase space transport equation. (K.A.) 11 refs.; 7 figs.

Time characteristics for the spinodal decomposition in nuclear matter

International Nuclear Information System (INIS)

Idier, D.; Farine, M.; Benhassine, B.; Remaud, B.; Sebille, F.

1992-01-01

Dynamics of the fluctuation growth are studied. Time characteristics are key quantities to determine the conditions under which spinodal decomposition could be observed. Dynamical instabilities arising from fluctuations in spinodal zone for nuclear matter are studied using Skyrme type interactions within a pseudo-particle model. Typical times for cluster formation are extracted. The numerical treatment is based on the Vlasov phase space transport equation. (K.A.) 11 refs.; 7 figs

Chemical effects of nuclear transformations symposium in Prague

Energy Technology Data Exchange (ETDEWEB)

NONE

1961-01-15

The Symposium on Chemical Effects of Nuclear Transformations showed that interest in the subject matter is far from being exclusively academic. Though a large number of the papers dealt with theoretical aspects, it was felt that hot atom reactions provided a valuable means by which a large number of radioactive isotopes and labelled compounds could be prepared practically free from their inactive counterparts. Such so-called carrier-free preparations are in great demand for industrial, medical and scientific applications. Discussions showed that a detailed knowledge o: the characteristics of radiation damage was essential to the successful development of nuclear power Nuclear transformations in solids provide a method of generating such damage and at the same time leave radioactive products that permit the study of the subsequent repair. This technique permits studies a' levels of damage much below those that are necessary with the less sensitive purely physical procedures. A number of papers emphasized the theoretical importance of the insight which hot atom chemistry gives into the mechanism of reactions occurring at abnormal temperatures.

S-matrix approach to the equation of state of dilute nuclear matter

Indian Academy of Sciences (India)

2014-04-01

matrix framework, a method is presented to calculate the equation of state of dilute warm nuclear matter. The result is a model-independent virial series for the pressure and density that systematically includes contributions from ...

b-jet tagged nuclear modification factors in heavy ion collisions with CMS

CERN Document Server

Jung, Kurt

2014-01-01

The energy loss of jets in heavy-ion collisions is expected to depend on the flavor of the fragmenting parton. Thus, measurements of jet quenching as a function of flavor place powerful constraints on the thermodynamical and transport properties of the hot and dense medium. Measurements of the nuclear modification factors of the heavy-flavor-tagged jets in both PbPb and pPb collisions can quantify such energy loss effects. Specifically, pPb measurements provide crucial insights into the behavior of the cold nuclear matter effect, which is required to fully understand the hot and dense medium effects on jets in PbPb collisions. In this talk, we present the b-jet spectra and the first measurement of the nuclear modification factors as a function of transverse momentum and pseudorapidity, using the high statistics pp, pPb and PbPb data taken in 2011 and 2013.

Dark Matter

International Nuclear Information System (INIS)

Holt, S. S.; Bennett, C. L.

1995-01-01

These proceedings represent papers presented at the Astrophysics conference in Maryland, organized by NASA Goddard Space Flight Center and the University of Maryland. The topics covered included low mass stars as dark matter, dark matter in galaxies and clusters, cosmic microwave background anisotropy, cold and hot dark matter, and the large scale distribution and motions of galaxies. There were eighty five papers presented. Out of these, 10 have been abstracted for the Energy Science and Technology database

Heavy Quark and Quarkonium Transport in High Energy Nuclear Collisions

Energy Technology Data Exchange (ETDEWEB)

Zhou, Kai [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China); Institute for Theoretical Physics, Johann Wolfgang Goethe-University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany); Dai, Wei [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China); Xu, Nu [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Zhuang, Pengfei [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China)

2016-12-15

The strong interaction between heavy quarks and the quark gluon plasma makes the open and hidden charm hadrons be sensitive probes of the deconfinement phase transition in high energy nuclear collisions. Both the cold and hot nuclear matter effects change with the colliding energy and significantly influence the heavy quark and charmonium yield and their transverse momentum distributions. The ratio of averaged quarkonium transverse momentum square and the elliptic flow reveal the nature of the QCD medium created in heavy ion collisions at SPS, RHIC and LHC energies.

Heavy Quark and Quarkonium Transport in High Energy Nuclear Collisions

International Nuclear Information System (INIS)

Zhou, Kai; Dai, Wei; Xu, Nu; Zhuang, Pengfei

2016-01-01

The strong interaction between heavy quarks and the quark gluon plasma makes the open and hidden charm hadrons be sensitive probes of the deconfinement phase transition in high energy nuclear collisions. Both the cold and hot nuclear matter effects change with the colliding energy and significantly influence the heavy quark and charmonium yield and their transverse momentum distributions. The ratio of averaged quarkonium transverse momentum square and the elliptic flow reveal the nature of the QCD medium created in heavy ion collisions at SPS, RHIC and LHC energies.

Institute of Nuclear Physics of Orsay - IPNO. Activity report 2002-2003

International Nuclear Information System (INIS)

2004-01-01

The Institute of Nuclear Physics of Orsay (IPN Orsay) is undertaking nuclear physics research that is centered on the nature of matter and its ultimate constituents. By the nature of its scientific activities, the IPN is at the heart of a wide range of international collaborations. IPN Orsay is a unit of both the CNRS (National Centre of Scientific Research) and of the Paris-Sud University. It plays a vital role in experiments being carried out by wide-ranging collaborations at major experimental facilities most notably in Europe, the United States and Japan. Its own facilities allows the IPN to carry out fundamental theoretical and experimental research studies in nuclear physics, astro-particle physics, radiochemistry but also in pluri-disciplinary activities. This document presents the activity of the Institute during the 2002-2003 years: 1 - Scientific activities: Nuclear structure; Hadronic physics and matter; Astro-particles; Theoretical physics; Hot nuclei; Energy and Environment; Particle Matter Interactions; Physics-Biology-Medicine Interfaces in Neurobiology, Oncology and Genomic; Knowledge dissemination and communication; 2 - Technical activities: General and technical departments; Instrumentation/Detectors; Accelerators Division; 3 - Appendixes: Publications, meetings, seminars, workshops, PhDs, Staff

Institute of Nuclear Physics of Orsay - IPNO. Activity report 2006/2007

International Nuclear Information System (INIS)

2008-01-01

The Institute of Nuclear Physics of Orsay (IPN Orsay) is undertaking nuclear physics research that is centered on the nature of matter and its ultimate constituents. By the nature of its scientific activities, the IPN is at the heart of a wide range of international collaborations. IPN Orsay is a unit of both the CNRS (National Centre of Scientific Research) and of the Paris-Sud University. It plays a vital role in experiments being carried out by wide-ranging collaborations at major experimental facilities most notably in Europe, the United States and Japan. Its own facilities allows the IPN to carry out fundamental theoretical and experimental research studies in nuclear physics, astro-particle physics, radiochemistry but also in pluri-disciplinary activities. This document presents the activity of the Institute during the 2006-2007 years: 1 - Scientific activities: Nuclear structure; Hadronic physics and matter; Astro-particles; Theoretical physics; Hot nuclei; Energy and Environment; Particle Matter Interactions; Knowledge dissemination and communication; 2 - Administration; 3 - Technical activities: General and technical departments; Accelerators Division; 4 - Appendixes: Publications, Proceedings, Conferences, workshops, collaboration meetings, Seminars, Schools and lectures, PhDs, accreditations to supervise research, Books and works, Staff, Visitors

Low mass dielectrons radiated off cold nuclear matter measured with HADES

Directory of Open Access Journals (Sweden)

Lorenz M.

2014-03-01

Full Text Available The High Acceptance DiElectron Spectrometer HADES [1] is installed at the Helmholtzzentrum für Schwerionenforschung (GSI accelerator facility in Darmstadt. It investigates dielectron emission and strangeness production in the 1-3 AGeV regime. A recent experiment series focusses on medium-modifications of light vector mesons in cold nuclear matter. In two runs, p+p and p+Nb reactions were investigated at 3.5 GeV beam energy; about 9·109 events have been registered. In contrast to other experiments the high acceptance of the HADES allows for a detailed analysis of electron pairs with low momenta relative to nuclear matter, where modifications of the spectral functions of vector mesons are predicted to be most prominent. Comparing these low momentum electron pairs to the reference measurement in the elementary p+p reaction, we find in fact a strong modification of the spectral distribution in the whole vector meson region.

Hot Strange Hadronic Matter in an Effective Model

Institute of Scientific and Technical Information of China (English)

QIAN Wei-Liang; SU Ru-Keng; SONG Hong-Qiu

2003-01-01

An effective model used to describe the strange hadronic matter with nucleons, Λ-hyperons, and Ξ-hyperonsis extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fractiondependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy andpressure, as well as the equation of state of the matter, are given.

Medium dependence of vector meson properties in heavy ion collisions

International Nuclear Information System (INIS)

Faessler, Amand; Fuchs, Christian

2007-01-01

Heavy ion collisions produce dense and hot nuclear matter. Dileptons give information about this hot and dense phase. The dileptons are produced by vector mesons. Theoretical calculation of dilepton production in the DLS (Berkeley), the HADES (GSI) experiments and the CERES, HELIOS and NA60 data from CERN give information about possible modifications of the vector meson properties in hot and dense nuclear matter. Here the description in relativistic quantum molecular dynamics of heavy ion collisions and dilepton production are presented and compared with data. (authors) Key words: heavy ion collisions; dense and hot nuclear matter; dileptons; medium dependence

Properties of ΣQ*, ΞQ* and ΩQ* heavy baryons in cold nuclear matter

Science.gov (United States)

Azizi, K.; Er, N.

2018-02-01

The in-medium properties of the heavy spin-3/2 ΣQ*, ΞQ* and ΩQ* baryons with Q being b or c quark are investigated. The shifts in some spectroscopic parameters of these particles due to the saturated cold nuclear matter are calculated. The variations of those parameters with respect to the changes in the density of the cold nuclear medium are studied, as well. It is observed that the parameters of ΣQ* baryons are considerably affected by the nuclear matter compared to the ΞQ* and ΩQ* particles that roughly do not see the medium. The results obtained may be used in analyses of the data to be provided by the in-medium experiments like PANDA.

Hot Strange Hadronic Matter in an Effective Model

Institute of Scientific and Technical Information of China (English)

QIANWei-Liang; SURu-Keng; SONGHong-Qiu

2003-01-01

An effective model used to describe the strange hadronic matter with nucleons, A-hyperons, and [I]-hyperons is extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fraction dependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy and pressure, as well as the equation of state of the matter, are given.

Time scales for spinodal decomposition in nuclear matter with pseudoparticle models

International Nuclear Information System (INIS)

Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

1993-01-01

Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudoparticle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed

Time scales for spinodal decomposition in nuclear matter with pseudoparticle models

Energy Technology Data Exchange (ETDEWEB)

Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F. (Laboratoire de Physique Nucleaire CNRS/IN2P3, Universite de Nantes, 2, rue de la Houssiniere, 44072 Nantes (France))

1993-08-01

Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudoparticle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed.

Can we really measure the internal energy of hot nuclei with a 4 {pi} detection array?

Energy Technology Data Exchange (ETDEWEB)

Vient, E.; Genouin-Duhamel, E.; Steckmeyer, J.C. [and others

2001-10-01

The second generation of high quality detection arrays gave hope to nuclear physicists to finally obtain an experimental equation of state of nuclear matter. In spite of this progress, the measurement of the internal energy of a hot nucleus remains a very difficult task. This paper illustrates this difficulty by a methodological study of a classical technique of excitation energy measurement used in the Fermi energy range. The aim of this study is to verify the validity, the accuracy and the experimental limits of these measurements. It is shown that it is difficult to have a real experimental mastery of the source reconstruction and calorimetry at least for limited bombarding energies and violent collisions. (authors)

Can we really measure the internal energy of hot nuclei with a 4 π detection array?

International Nuclear Information System (INIS)

Vient, E.; Genouin-Duhamel, E.; Steckmeyer, J.C.

2001-10-01

The second generation of high quality detection arrays gave hope to nuclear physicists to finally obtain an experimental equation of state of nuclear matter. In spite of this progress, the measurement of the internal energy of a hot nucleus remains a very difficult task. This paper illustrates this difficulty by a methodological study of a classical technique of excitation energy measurement used in the Fermi energy range. The aim of this study is to verify the validity, the accuracy and the experimental limits of these measurements. It is shown that it is difficult to have a real experimental mastery of the source reconstruction and calorimetry at least for limited bombarding energies and violent collisions. (authors)

Application of Cyclone to Removal of Hot Particulate in Hot Cell

International Nuclear Information System (INIS)

Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung, Chong Hun; Oh, Won Zin

2005-01-01

The size and main ingredient of hot particulate generated during the nuclide experiment in hot cells of nuclear facilities were 0.5300 μm and UO 2 . A cyclone filter equipment which consists of a cyclone and Bag/HEPA filter was devised to remove hot particulate generated during the nuclide experiment in hot cells of nuclear facilities. The experimental conditions to maximize the collection efficiency of hot particulate were suggested through experiments done with the cyclone filter equipment. With the large size of simulated particulate, the collection efficiency of the particulate was high. When the size of simulated particulate was more than 5 μm, the collection efficiency of the particulate was more than 80% and when the size of simulated particulate was less than 1.0 μm, the collection efficiency decreased by less than. If the inflow velocity of simulated particulate was increased, the collection efficiency of the particulate was also increased. When the inflow velocity of simulated particulate was more than 12 m/sec, the collection efficiency was higher than , but after 17 m/sec inflow velocity, no change observed. The collection efficiency of the simulated particulate can be enhanced with the length of vortex finder inside the chamber. With the length of vortex finder, 7.2 cm, the observed collection efficiency of the particulate was the maximum. Moreover, when the sub-cone was attached under the cyclone, the collection efficiency of cyclone increased 2%. It was found that effect by attachment of sub-cone was not serious.

Nucleonics, and nuclear matter in 10-20 secs. before the close of open-quotes Big Bangclose quotes

International Nuclear Information System (INIS)

Ayub, S.M.

1995-01-01

The Nuclear picture 10 -20 secs. after the thermonuclear creation of the Universe ∼8 Billion years ago (as also evidenced by Hubble Telescope) was published. Relativity concepts predict the Nuclear picture l0 -20 secs. before the open-quote G close-quote collapse of the Universe, by the progressive decline of expansion,and H. Constant. No double-nuclei, anymore. Only Neutrinos, as predicted by International Scientists, and fragments of Black Holes. Universe open-quote r close-quote=60 Billion Light-Years. At the Zero Point, N.Force,and 3 other Forces merging into Super-G. Time, Space, becoming identical, and all Physical Laws vanishing. The final will be Nuclear Matter compact of ∼ 10Km., open-quote r close-quote, P=10 15 -10 18 Temp. > 10 10 Deg. C. P> 10 18 will cause another thermonuclear Bang'. Super-computers, also, cannot predict beyond this point. There will be the Creator, and a compact of Nuclear Matter. In the absence of Physical Laws, there can be no further predictability. What initiated by the N. Force, has culminated into a compact of Nuclear Matter- - how interesting exclamation point

Workshop on instrumentation and analyses for a nuclear fuel reprocessing hot pilot plant

International Nuclear Information System (INIS)

Babcock, S.M.; Feldman, M.J.; Wymer, R.G.; Hoffman, D.

1980-05-01

In order to assist in the study of instrumentation and analytical needs for reprocessing plants, a workshop addressing these needs was held at Oak Ridge National Laboratory from May 5 to 7, 1980. The purpose of the workshop was to incorporate the knowledge of chemistry and of advanced measurement techniques held by the nuclear and radiochemical community into ideas for improved and new plant designs for both process control and inventory and safeguards measurements. The workshop was athended by experts in nuclear and radiochemistry, in fuel recycle plant design, and in instrumentation and analysis. ORNL was a particularly appropriate place to hold the workshop since the Consolidated Fuel Reprocessing Program (CFRP) is centered there. Requirements for safeguarding the special nuclear materials involved in reprocessing, and for their timely measurement within the process, within the reprocessing facility, and at the facility boundaries are being studied. Because these requirements are becoming more numerous and stringent, attention is also being paid to the analytical requirements for these special nuclear materials and to methods for measuring the physical parameters of the systems containing them. In order to provide a focus for the consideration of the workshop participants, the Hot Experimental Facility (HEF) being designed conceptually by the CFRP was used as a basis for consideration and discussions

Thermodynamics of compact-star matter within an Ising approach

International Nuclear Information System (INIS)

Chomaz, P.; Ducoin, C.; Gulminelli, F.; Hasnaoui, K.; Napolitani, P.

2007-01-01

In the formation and evolution of compact stars, nuclear matter explores high thermal excursions and is the site of intense neutrino emission. Neutrino transport as well as structural properties of this matter depend on the presence of inhomogeneous phases (named 'pasta' phases), which are the result of Coulomb frustration of the Liquid-Gas phase transition. We take into account charge fluctuations by employing a frustrated lattice-gas model to which we impose a neutrality constraint by the addition of an homogeneous background of charge, representing delocalized electrons. Within this schematic model we highlight a generic feature of the phase-transition phenomenology: the temperature interval where pasta phases are formed is enhanced by Coulomb-frustration effects. This result is at variance with the behaviour of frustrated ferromagnetic systems as well as hot nuclei and mean-field approaches. Moreover, the region of phase coexistence is not found to end upon a critical point, indicating that no critical opalescence can occur in compact-star matter

Thermodynamics of compact-star matter within an Ising approach

Energy Technology Data Exchange (ETDEWEB)

Chomaz, P. [Ganil (DSM-CEA/IN2P3-CNRS), Blvd. H. Becquerel, BP 55027, F-14076 Caen cedex 5 (France); Ducoin, C. [Ganil (DSM-CEA/IN2P3-CNRS), Blvd. H. Becquerel, BP 55027, F-14076 Caen cedex 5 (France); LPC - IN2P3-CNRS/Ensicaen et Universite, F-14076 Caen cedex (France); Gulminelli, F. [LPC - IN2P3-CNRS/Ensicaen et Universite, F-14076 Caen cedex (France); Hasnaoui, K. [Ganil (DSM-CEA/IN2P3-CNRS), Blvd. H. Becquerel, BP 55027, F-14076 Caen cedex 5 (France); Napolitani, P. [Ganil (DSM-CEA/IN2P3-CNRS), Blvd. H. Becquerel, BP 55027, F-14076 Caen cedex 5 (France); LPC - IN2P3-CNRS/Ensicaen et Universite, F-14076 Caen cedex (France)

2007-05-01

In the formation and evolution of compact stars, nuclear matter explores high thermal excursions and is the site of intense neutrino emission. Neutrino transport as well as structural properties of this matter depend on the presence of inhomogeneous phases (named 'pasta' phases), which are the result of Coulomb frustration of the Liquid-Gas phase transition. We take into account charge fluctuations by employing a frustrated lattice-gas model to which we impose a neutrality constraint by the addition of an homogeneous background of charge, representing delocalized electrons. Within this schematic model we highlight a generic feature of the phase-transition phenomenology: the temperature interval where pasta phases are formed is enhanced by Coulomb-frustration effects. This result is at variance with the behaviour of frustrated ferromagnetic systems as well as hot nuclei and mean-field approaches. Moreover, the region of phase coexistence is not found to end upon a critical point, indicating that no critical opalescence can occur in compact-star matter.

Thermodynamics of compact-star matter within an Ising approach

Science.gov (United States)

Chomaz, P.; Ducoin, C.; Gulminelli, F.; Hasnaoui, K.; Napolitani, P.

2007-05-01

In the formation and evolution of compact stars, nuclear matter explores high thermal excursions and is the site of intense neutrino emission. Neutrino transport as well as structural properties of this matter depend on the presence of inhomogeneous phases (named "pasta" phases), which are the result of Coulomb frustration of the Liquid-Gas phase transition. We take into account charge fluctuations by employing a frustrated lattice-gas model to which we impose a neutrality constraint by the addition of an homogeneous background of charge, representing delocalised electrons. Within this schematic model we highlight a generaic feature of the phase-transition phenomenology: the temperature interval where pasta phases are formed is enhanced by Coulomb-frustration effects. This result is at variance with the behaviour of frustrated ferromagnetic systems as well as hot nuclei and mean-field approaches. Moreover, the region of phase coexistence is not found to end upon a critical point, indicating that no critical opalescence can occur in compact-star matter.

Thermostatic properties of semi-infinite polarized nuclear matter

International Nuclear Information System (INIS)

Abd-Alla, M.; Hassan, M.Y.M.; Ramadan, S.

1988-03-01

The surface and curvature properties of semi-infinite polarized nuclear matter (SPNM) are calculated using an expansion for the Fermi integrals up to T 2 . A density matrix expansion is obtained for a modified form of Seyler-Blanchard interaction. New parameters that characterize the surface and curvature properties of SPNM are introduced. The level density parameter is extracted from the low temperature expansion of the free energy and compared with previous calculations. A reasonable agreement is obtained for the parameters calculated before. (author). 78 refs, 1 fig., 5 tabs

Mass shift of σ-meson in nuclear matter

International Nuclear Information System (INIS)

Morones-Ibarra, J.R.; Maciel, Mónica Menchaca; Padilla, Felipe Robledo; Santos-Guevara, Ayax

2013-01-01

The propagation of σ-meson in nuclear matter is studied in the Walecka model, by assuming that sigma couples to a pair of nucleon-antinucleon states to particle-hole states. The in-medium effect of σ-ω mixing is also studied. For completeness, the coupling of sigma to two virtual pions was also considered. It is found that the σ-meson mass decreases with respect to its value in vacuum and that the contribution of the σ-ω mixing effect on the mass shift is relatively small. (author)

Studies of nuclei under the extreme conditions of density, temperature, isospin asymmetry and the phase diagram of hadronic matter

Energy Technology Data Exchange (ETDEWEB)

Mekjian, Aram [Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy

2016-10-18

The main emphasis of the entire project is on issues having to do with medium energy and ultra-relativistic energy and heavy ion collisions. A major goal of both theory and experiment is to study properties of hot dense nuclear matter under various extreme conditions and to map out the phase diagram in density or chemical potential and temperature. My studies in medium energy nuclear collisions focused on the liquid-gas phase transition and cluster yields from such transitions. Here I developed both the statistical model of nuclear multi-fragmentation and also a mean field theory.

Effects of Brown-Rho scalings in nuclear matter, neutron stars and finite nuclei

Science.gov (United States)

Kuo, T. T. S.; Dong, Huan

2011-01-01

We have carried out calculations for nuclear matter, neutron stars and finite nuclei using NN potentials with and without the medium-dependent modifications based on the Brown-Rho (BR) scalings. Using the Vlow-k low-momentum interactions derived from such potentials, the equations of state (EOS) for symmetric and asymmetric nuclear matter, for densities up to ~ 5ρ0, are calculated using a RPA method where the particle-particle hole-hole ring diagrams are summed to all orders. The medium effects from both a linear BR scaling (BR1) and a non-linear one (BR2) are considered, and they both are essential for our EOSs to reproduce the nuclear matter saturation properties. For densities ρ below ρ0, results from BR1 and BR2 are close to each other. For higher densities, the EOS given by BR2 is more desirable and is well reproduced by that given by the interaction (Vlow-k+TBF) where Vlow-k is the unsealed low-momentum interaction and TBF is an empirical Skyrme three-body force. The moment of inertia of neutron stars is ~ 60 and ~ 25Modotkm2 respectively with and without the inclusion of the above BR2 medium effects. Effects from the BR scaling are important for the long half-life, ~ 5000yrs, of the 14C - 14N β-decay.

Toward the fundamental theory of nuclear matter physics: The microscopic theory of nuclear collective dynamics

International Nuclear Information System (INIS)

Sakata, F.; Marumori, T.; Hashimoto, Y.; Tsukuma, H.; Yamamoto, Y.; Terasaki, J.; Iwasawa, Y.; Itabashi, H.

1992-01-01

Since the research field of nuclear physics is expanding rapidly, it is becoming more imperative to develop the microscopie theory of nuclear matter physics which provides us with a unified understanding of diverse phenomena exhibited by nuclei. An estabishment of various stable mean-fields in nuclei allows us to develop the microscopie theory of nuclear collective dynamics within the mean-field approximation. The classical-level theory of nuclear collective dynamics is developed by exploiting the symplectic structure of the timedependent Hartree-Fock (TDHF)-manifold. The importance of exploring the single-particle dynamics, e.g. the level-crossing dynamics in connection with the classical order-to-chaos transition mechanism is pointed out. Since the classical-level theory os directly related to the full quantum mechanical boson expansion theory via the symplectic structure of the TDHF-manifold, the quantum theory of nuclear collective dynamics is developed at the dictation of what os developed on the classical-level theory. The quantum theory thus formulated enables us to introduce the quantum integrability and quantum chaoticity for individual eigenstates. The inter-relationship between the classical-level and quantum theories of nuclear collective dynamics might play a decisive role in developing the quantum theory of many-body problems. (orig.)

Hyperon interactions in nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Dhar, Madhumita; Lenske, Horst [Institut fuer Theoretische Physik, Universitaet Giessen (Germany)

2014-07-01

Baryon-baryon interactions within the SU(3)-octet are investigated in free space and nuclear matter. A meson exchange model is used for determining the interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. In-medium effects have been incorporated by including a two particle Pauli projection operator in the scattering equation. The coupling of the various channels of total strangeness S=-1,-2 and conserved total charge is studied in detail. Calculations and the corresponding results are compared for using the isospin and the particle basis. Matrix elements are compared in detail, in particular discussing mixing effects of different hyperon channels. Special attention is paid to the physical thresholds. The density dependence of interaction is clearly seen in the variation of the in-medium low-energy parameters. The approach is compared to descriptions derived from chiral-EFT and other meson-exchange models e.g. the Nijmegen and the Juelich model.

The origin, composition and distribution of 'hot particles' derived from the nuclear industry and dispersed in the environment

International Nuclear Information System (INIS)

Hamilton, E.I.; Clifton, R.J.

1987-10-01

Today, recent sediments of the Esk estuary, Cumbria, contain few hot particles derived from BNF compared with those deposited during peak releases of 1972-74. Overall the hot particles account for about 10% of the total alpha particle activity of the sediments. At some horizons, in buried sediments, concentrations of hot particles probably represent rapid transport on the sea surface under conditions of minimum erosion. Similar particles, usually less well defined, occur in accreting sediments but are corroded. Representative types of the most radioactive particles have been isolated and contain Pu, Am and Cm but only trace amounts of naturally occuring alpha emitters. Microprobe analysis of these particles often shows the presence of fairly pure uranium as the major element. On the basis of radioactivity and elemental composition many of these particles appear to be irradiated nuclear fuel debris. (author)

Analysis of the doubly heavy baryons in the nuclear matter with the QCD sum rules

International Nuclear Information System (INIS)

Wang, Zhi-Gang

2012-01-01

In this article, we study the doubly heavy baryon states Ξ cc , Ω cc , Ξ bb and Ω bb in the nuclear matter using the QCD sum rules, and derive three coupled QCD sum rules for the masses, vector self-energies and pole residues. The predictions for the mass-shifts in the nuclear matter ΔM Ξ cc =-1.11simGeV, ΔM Ω cc =-0.33∝GeV, ΔM Ξ bb =-3.37∝GeV and ΔM Ω bb =-1.05∝GeV can be confronted with experimental data in the future. (orig.)

Formation and disintegration of high-density nuclear matter in heavy-ion collisions

International Nuclear Information System (INIS)

Kitazoe, Yasuhiro; Matsuoka, Kazuo; Sano, Mitsuo

1976-01-01

The formation of high-density nuclear matter which may be expected to be attained in high-energy heavy-ion collisions and the subsequent disintegration of dense matter are investigated by means of the hydrodynamics. Head-on collisions of identical nuclei are considered in the nonrelativistic approximation. The compressed density cannot exceed 4 times of the normal one so long as the freedom of only nucleons is considered, and can become higher than 4 times when other freedoms such as the productions of mesons and also nucleon isobars are additionally taken into account. The angular distributions for ejected particles predominate both forwards and backwards at low collision energies, corresponding to the formation of nuclear density less than 2 times of the normal density and become isotropic at the point of 2 times of the normal one. As the collision energy increases further, lateral ejection is intensified gradually. (auth.)

Relativistic mean field theory with density dependent coupling constants for nuclear matter and finite nuclei with large charge asymmetry

Energy Technology Data Exchange (ETDEWEB)

Typel, S; Wolter, H H [Sektion Physik, Univ. Muenchen, Garching (Germany)

1998-06-01

Nuclear matter and ground state properties for (proton and neutron) semi-closed shell nuclei are described in relativistic mean field theory with coupling constants which depend on the vector density. The parametrization of the density dependence for {sigma}-, {omega}- and {rho}-mesons is obtained by fitting to properties of nuclear matter and some finite nuclei. The equation of state for symmetric and asymmetric nuclear matter is discussed. Finite nuclei are described in Hartree approximation, including a charge and an improved center-of-mass correction. Pairing is considered in the BCS approximation. Special attention is directed to the predictions for properties at the neutron and proton driplines, e.g. for separation energies, spin-orbit splittings and density distributions. (orig.)

Di-nucleon structures in homogeneous nuclear matter based on two- and three-nucleon interactions

Energy Technology Data Exchange (ETDEWEB)

Arellano, Hugo F. [University of Chile, Department of Physics - FCFM, Santiago (Chile); CEA, DAM, DIF, Arpajon (France); Isaule, Felipe [University of Chile, Department of Physics - FCFM, Santiago (Chile); Rios, Arnau [University of Surrey, Department of Physics, Faculty of Engineering and Physical Sciences, Guildford (United Kingdom)

2016-09-15

We investigate homogeneous nuclear matter within the Brueckner-Hartree-Fock (BHF) approach in the limits of isospin-symmetric nuclear matter (SNM) as well as pure neutron matter at zero temperature. The study is based on realistic representations of the internucleon interaction as given by Argonne v{sub 18}, Paris, Nijmegen I and II potentials, in addition to chiral N{sup 3}LO interactions, including three-nucleon forces up to N{sup 2}LO. Particular attention is paid to the presence of di-nucleon bound states structures in {sup 1}S{sub 0} and {sup 3}SD{sub 1} channels, whose explicit account becomes crucial for the stability of self-consistent solutions at low densities. A characterization of these solutions and associated bound states is discussed. We confirm that coexisting BHF single-particle solutions in SNM, at Fermi momenta in the range 0.13-0.3 fm{sup -1}, is a robust feature under the choice of realistic internucleon potentials. (orig.)

Hot nuclear matter and thermodynamical equilibrium

International Nuclear Information System (INIS)

Borderie, B.; Bacri, C.O.; Dore, D.; Frankland, J.D.; Plagnol, E.; Rivet, M.F.; Tassan-Got, L.

1999-01-01

Quasi-complete events from collisions between 36 Ar and 58 Ni corresponding to vaporized sources have been detected with the multidetector INDRA over the excitation energy range 10 - 28 AMeV. For the first time complete information concerning kinematical properties of emitted particles and chemical composition (mean values but also variances) are derived. Despite the very extreme conditions in which such sources are produced (binary collisions with short reaction times and source life-times), their properties are in agreement with the results of a statistical model including a final state excluded volume interaction and describing a gas of fermions and bosons in thermodynamical equilibrium. (authors)

Solar Hot Water System Matter in Turkey (Mersin Case

Directory of Open Access Journals (Sweden)

Müjgan ŞEREFHANOĞLU SÖZEN

2010-01-01

Full Text Available When the effects of sustainability on the construction sector have been taken into consideration, solar active systems on buildings emerge as an important design issue in the context of renewal energy usage. Solar hot water systems such as those widely used in Turkey are inefficient and have a negative effect on a building’s aesthetic and the urban view in general because of the poor quality of installation. Natural circulated open loop systems are commonly used, particularly in the south of Turkey, as they are highly economical and require no regulation to install. Solar hot water systems tend to be clustered together on the roofs, causing visual pollution, and this situation arises largely because are not considered part of the architectural design. It is therefore important to consider the negative effects of such systems in the form of treatment studies. This study aims to determine the positive effects that will be gained by the renovation of solar hot water systems in Mersin, a city in the southern region of Turkey.

Wigner-Kirkwood expansion of the phase-space density for half infinite nuclear matter

International Nuclear Information System (INIS)

Durand, M.; Schuck, P.

1987-01-01

The phase space distribution of half infinite nuclear matter is expanded in a ℎ-series analogous to the low temperature expansion of the Fermi function. Besides the usual Wigner-Kirkwood expansion, oscillatory terms are derived. In the case of a Woods-Saxon potential, a smallness parameter is defined, which determines the convergence of the series and explains the very rapid convergence of the Wigner-Kirkwood expansion for average (nuclear) binding energies

76 FR 11522 - In the Matter of Progress Energy Florida, Inc. (Combined License Application, Levy County Nuclear...

Science.gov (United States)

2011-03-02

... NUCLEAR REGULATORY COMMISSION [Docket Nos. 52-029-COL, 52-030-COL] In the Matter of Progress Energy Florida, Inc. (Combined License Application, Levy County Nuclear Power Plant, Units 1 and 2... by the Nuclear Regulatory Commission staff in this case. Mr. Dehmel has not previously performed any...

Self-consistent determination of quasiparticle properties in nuclear matter

International Nuclear Information System (INIS)

Oset, E.; Palanques-Mestre, A.

1981-01-01

The self-energy of nuclear matter is calculated by directing the attention to the energy and momentum dependent pieces which determine the quasiparticle properties. A microscopic approach is followed which starts from the boson exchange picture for the NN interaction, then the π-and p-mesons are shown to play a major role in the nucleon renormalization. The calculation is done self-consistently and the effective mass and pole strength determined as a function of the nuclear density and momentum. Particular emphasis is put on the non-static character of the interaction and its consequences. Finally a comparison is made with other calculations and with experimental results. The consequences of the nucleon renormalization in pion condensation are also examined with the result that the critical density is pushed up appreciably. (orig.)

Nuclear matter flow in the Kr+Au collisions at 43 MeV/u

International Nuclear Information System (INIS)

Bougault, R.; Delaunay, F.; Genoux-Lubain, A.; Lebrun, C.; Lecolley, J.F.; Lefebvres, F.; Louvel, M.; Steckmeyer, J.C.; Aloff, J.C.; Bilwes, B.; Bilwes, R.; Glaser, M.; Rudolf, G.; Scheibling, F.; Stuttge, L.

1989-01-01

When heavy nuclei collide at energy far above the Coulomb barrier we may study the property of nuclear matter in temperature and also density regions far away from the equilibrium. We then hope to study dynamical effects related to the compressibility and the two body collision term. At relativistic energies, some collective effects (flow, bounce off) have been established from a shape analysis done with a large number of light particles with Z ≤ 10. For incident energies lower than 100 MeV/u we may expect that the number of nuclear species formed will be smaller and that a large part of the nuclear matter involved in the collision will be shared in a limited number of heavy fragments (Z ≥ 10). If dynamical effects are still present at GANIL energies they ought to manifest themselves through the properties of the produced fragments (masses, emission angles, velocities and correlated variables). We will present an analysis of heavy nuclei collisions at 43 MeV/u based on as exclusive as possible detection of large fragments

On superconductivity of matter at hight density and the effects of inducing nuclear chirality in molecular structures

DEFF Research Database (Denmark)

da Providëncia, J.; Jalkanen, Karl J.; Bohr, Henrik

2013-01-01

relativistic fluid of elementary particles is studied. We find that the magnetic field of spin polarized matter with densities of 2 to 30, where 0 is the equilibrium density of nuclear matter, is rather huge, of the order of 1017 Gauss. Finally we look at the chiral nature of nuclear forces and interactions...... as they possibly relate to chirality of nuclei (atoms) in molecules as a source of chirality in amino acids and hence in life. Previous works have not investigated the nuclear forces as a possible bias which initiated the bias towards L-amino acids as the building blocks on proteins, and later life....

Research in nuclear astrophysics: Stellar collapse and supernovae

International Nuclear Information System (INIS)

Lattimer, J.M.; Yahil, A.

1991-01-01

The interaction between nuclear theory and some outstanding problems in astrophysics is examined. We are actively researching the astrophysics of gravitational collapse, neutron star birth and neutrino emission, and neutron star cooling, on the one hand, and the nuclear physics of the equation of state of hot, dense matter on the other hand. There is close coupling between nuclear theory and supernova and neutron star phenomenon; some nuclear matter properties might be best delineated by astrophysical considerations. Our research has focused on the neutrinos emitted from supernovae, since they are the only available observables of the internal supernova mechanism. We are modifying our hydrodynamical code to use implicit differencing and to include multi-group neutrino diffusion and general relativity. In parallel, we are extending calculations of core collapse supernovae to long times after collapse by using a hybrid explicit-implicit hydrodynamical code and by using simplified neutrino transport. We hope to establish the existence or non-existence of the so-called long-term supernova mechanism. We are also extending models of the neutrino emission and cooling of neutron stars to include the effects of rotation and the direct Urca process that we recently discovered to be crucial. We have developed a rapid version of the dense matter equation of state for use in hydrodynamic codes that retains essentially all the physics of earlier, more detailed equations of state. This version also has the great advantage that nuclear physics inputs, such as the nuclear incompressibility, symmetry, energy, and specific heat, can be specified

Studying Cold Nuclear Matter with the MPC-EX of PHENIX

Science.gov (United States)

Grau, Nathan; Phenix Collaboration

2017-09-01

Highly asymmetric collision systems, such as d+Au, provide a unique environment to study cold nuclear matter. Potential measurements range from pinning down the modification of the nuclear wave function, i.e. saturation, to studying final state interactions, i.e. energy loss. The PHENIX experiment has enhanced the muon piston calorimeter (MPC) with a silicon-tungsten preshower, the MPC-EX. With its fine segmentation the MPC-EX extends the photon detection capability at 3 < | η | < 3.8. In this talk we review the current status of the detector, its calibration, and its identification capabilities using the 2016 d+Au dataset. We also discuss the specific physics observables the MPC-EX can measure.

Equidistant structure and effective nucleon mass in nuclear matter

International Nuclear Information System (INIS)

Tezuka, Hirokazu.

1981-11-01

The effective nucleon mass of the Equidistant Multi-Layer Structure (EMULS) is discussed self-consistently. In the density region where the Fermi gas state in nuclear matter is unstable against the density fluctuation, the EMULS gives lower binding energy. It is, however, shown that such a structure with an ordinary nucleon mass collapses due to too strong attraction. We point out that such a collapse can be avoided by taking account of an effective nucleon mass affected by the localization of nucleons. (author)

Quark mean field theory and consistency with nuclear matter

International Nuclear Information System (INIS)

Dey, J.; Tomio, L.; Dey, M.; Frederico, T.

1989-01-01

1/N c expansion in QCD (with N c the number of colours) suggests using a potential from meson sector (e.g. Richardson) for baryons. For light quarks a σ field has to be introduced to ensure chiral symmetry breaking ( χ SB). It is found that nuclear matter properties can be used to pin down the χ SB-modelling. All masses, M Ν , m σ , m ω are found to scale with density. The equations are solved self consistently. (author)

No pion condensate in nuclear matter due to fluctuations

International Nuclear Information System (INIS)

Kleinert, H.

1981-01-01

We show that if pion condensation occurs in a mean-field theory of infinite nuclear matter, fluctuations completely prevent the formation of a condensate as well as of the associated Goldstone mode. Thus if an increase of opalescence should ever be observed experimentally, it is these fluctuations which are measured rather than the scattering on the Goldstone modes. They preserve isotopic symmetry and increase very smoothly as the density passes the formerly critical density. There are no discontinuities in any thermodynamic quantitiy. (orig.)

Probing the nuclear matter at high baryon and isospin density with heavy ion collisions

International Nuclear Information System (INIS)

Di Toro, M.; Colonna, M.; Ferini, G.

2010-01-01

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. High Energy Collisions are studied in order to access nuclear matter properties at high density. Particular attention is devoted to the selection of observables sensitive to the poorly known symmetry energy at high baryon density, of large fundamental interest, even for the astrophysics implications. Using fully consistent covariant transport simulations built on effective field theories we are testing isospin observables ranging from nucleon/cluster emissions, collective flows (in particular the elliptic, squeeze out, part) and meson production. The possibility to shed light on the controversial neutron/proton effective mass splitting in asymmetric matter is also stressed. The "symmetry" repulsion at high baryon density will also lead to an "earlier" hadron-deconfinement transition in n-rich matter. The phase transition of hadronic to quark matter at high baryon and isospin density is analyzed. Nonlinear relativistic mean field models are used to describe hadronic matter, and the MIT bag model is adopted for quark matter. The boundaries of the mixed phase and the related critical points for symmetric and asymmetric matter are obtained. Isospin effects appear to be rather significant. The binodal transition line of the (T,ρ B ) diagram is lowered in a region accessible to heavy ion collisions in the energy range of the new planned FAIR/NICA facilities. Some observable effects of the mixed phase are suggested, in particular a neutron distillation mechanism. Theoretically a very important problem appears to be the suitable treatment of the isovector part of the interaction in effective QCD lagrangian approaches. (author)

Propagation of neutrinos in nuclear matter; Effets du milieu sur la propagation des neutrinos dans la matiere nucleaire

Energy Technology Data Exchange (ETDEWEB)

Margueron, J

2001-07-01

We study the elementary interactions between neutrinos and dense matter in a proto-neutron star. Equations of state obtained with different nuclear effective interactions (Skyrme, Gogny, Relativistic Lagrangians) are first discussed. Then, we characterize their stability in spin and isospin. We derive magnetic susceptibilities for all isospin asymmetry values as a function of Landau parameters G{sup {pi}}{sup {pi}}{sup '}{sub 0} (where {pi}, {pi}' = proton or neutron). From this work, we select a parametrization for each of the 3 effective forces: Sly230b,D1P,NL3. We calculate the pure neutron matter and asymmetric nuclear matter response functions with and without charge exchange, describing nuclear correlations in both approaches: non-relativistic (Hartree-Fock with Skyrme forces, then complete RPA) and relativistic (in the Hartree approximation). At the end, we calculate neutrino mean free paths neutral current and charged current reactions. Comparisons between relativistic and non-relativistic approaches allow us to identify relativistic effects in nuclear matter at densities as low as twice the saturation density. RPA correlations make the medium more transparent to neutrinos compared to free Fermi gas. The importance of the effective mass in mean free path calculations is also shown. (author)

Institute of Nuclear Physics of Orsay - IPNO. Activity report 2000-2001

International Nuclear Information System (INIS)

2002-01-01

The Institute of Nuclear Physics of Orsay (IPN Orsay) is undertaking nuclear physics research that is centered on the nature of matter and its ultimate constituents. By the nature of its scientific activities, the IPN is at the heart of a wide range of international collaborations. IPN Orsay is a unit of both the CNRS (National Centre of Scientific Research) and of the Paris-Sud University. It plays a vital role in experiments being carried out by wide-ranging collaborations at major experimental facilities most notably in Europe, the United States and Japan. Its own facilities allows the IPN to carry out fundamental theoretical and experimental research studies in nuclear physics, astro-particle physics, radiochemistry but also in pluri-disciplinary activities. This document presents the activity of the Institute during the 2000-2001 years: 1 - Scientific activities: exotic and hot nuclei; nucleon sub-structure; Mesons, Quarks and Gluons; Astro-particles; Theoretical physics (nuclear structure and reactions - N-body systems, fields theory applied to particle physics and to condensed matter physics); Radiochemistry; Physics of Downstream Cycle and Spallation Reactions; Particle Matter Interactions; Physics-Biology-Medicine Interfaces in Neurobiology, Oncology and Genomic; Science, Education, History and Society; 2 - Technical activities: General and technical departments; Detectors and associated instrumentation; Accelerators; Scientific and technical activities

Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems

Energy Technology Data Exchange (ETDEWEB)

Marini, P., E-mail: marini@cenbg.in2p3.fr [Grand Accélérateur National d' Ions Lourds, Bd. Henri Becquerel, BP 55027, 14076 Caen (France); Zheng, H. [Cyclotron Institute, Texas A& M University, College Station, TX-77843 (United States); Laboratori Nazionali del Sud, INFN, via Santa Sofia, 62, 95123 Catania (Italy); Boisjoli, M. [Grand Accélérateur National d' Ions Lourds, Bd. Henri Becquerel, BP 55027, 14076 Caen (France); Laboratoire de Physique Nucléaire, Université Laval, Québec, G1V 0A6 (Canada); Verde, G. [Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); INFN – Sezione di Catania, via Santa Sofia, 64, 95123 Catania (Italy); Chbihi, A. [Grand Accélérateur National d' Ions Lourds, Bd. Henri Becquerel, BP 55027, 14076 Caen (France); Napolitani, P.; Ademard, G. [Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); Augey, L. [Laboratoire de Physique Corpusculaire, ENSICAEN, Université de Caen Basse Normandie, CNRS/IN2P3, F-14050 Caen Cedex (France); Bhattacharya, C. [Variable Energy Cyclotron Center, Kolkata (India); Borderie, B. [Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); Bougault, R. [Laboratoire de Physique Corpusculaire, ENSICAEN, Université de Caen Basse Normandie, CNRS/IN2P3, F-14050 Caen Cedex (France); and others

2016-05-10

We report on first experimental observations of nuclear fermionic and bosonic components displaying different behaviours in the decay of hot Ca projectile-like sources produced in mid-peripheral collisions at sub-Fermi energies. The experimental setup, constituted by the coupling of the INDRA 4π detector array to the forward angle VAMOS magnetic spectrometer, allowed to reconstruct the mass, charge and excitation energy of the decaying hot projectile-like sources. By means of quantum-fluctuation analysis techniques, temperatures and local partial densities of bosons and fermions could be correlated to the excitation energy of the reconstructed system. The results are consistent with the production of dilute mixed systems of bosons and fermions, where bosons experience higher phase-space and energy density as compared to the surrounding fermionic gas. Our findings recall phenomena observed in the study of Bose condensates and Fermi gases in atomic traps despite the different scales.

Quasi-static electron density fluctuations of atoms in hot compressed matter

International Nuclear Information System (INIS)

Grimaldi, F.; Grimaldi-Lecourt, A.

1982-01-01

The standard theoretical methods for the calculation of properties of hot compressed matter lead to a description based on the Average Atom model. In this model the degenerate orbitals are populated with the Fermi-Dirac (FD) density, partitioned according to the binomial distribution. Since the one particle picture is inadequate to evaluate reliable optical properties, a method involving correlated population fluctuations, but limited to unrelaxed orbitals and lacking time dependence, has been examined. The probability distribution of fluctuations in a particular level is evaluated through a decoupling procedure. The method is carried out self consistently. For each level this leads to the definition of an effective 1st order ionization energy as a statistical sum of all possible transition energies. As a result the effective number of electrons exchanged with the outside weights the chemical potential. This defines an effective chemical potential μsup(k) for each level. In many cases of interest the statistics leads to FD type average occupation numbers. This allows a treatment of the continuum in a Thomas-Fermi like model using the effective ionization energy and μsup(k). We obtain a simultaneous description of charge rearrangements and net fluctuations in the Wigner-Seitz cell. The discussion is supported by numerical results for iron. (author)

Neutron optical potentials in unstable nuclei and the equation of state of asymmetric nuclear matter

International Nuclear Information System (INIS)

Oyamatsu, K.; Iida, K.

2003-01-01

Neutron single particle potential is one of the basic macroscopic properties to describe structure and reactions of nuclei in nuclear reactors and in the universe. However, the potential is quite uncertain for unstable nuclei primarily because the equation of state (EOS) of asymmetric nuclear matter is not known well. The present authors studied systematically the empirical EOS of asymmetric nuclear matter using a macroscopic nuclear model; about two hundred EOS's having empirically allowed values of L (symmetry energy density derivative coefficient) and K 0 (incompressibility) were obtained from the fittings to masses and radii of stable nuclei. It was suggested that the L value could be determined from global (Z, A) dependence of nuclear radii. In the present study, the single particle potential is examined assuming kinetic energies of non-interacting Fermi gases. The potential in a nucleus can be calculated easily, once the density distribution is solved using the effective nuclear interaction (EOS). Neutron and proton single particle potentials are calculated systematically for 80 Ni using the two hundred EOS's. It is found that the neutron-proton potential difference has clear and appreciable L dependence, while the potential for each species does not show such simple dependence on L. (author)

Nuclear Materials Characterization in the Materials and Fuels Complex Analytical Hot Cells

International Nuclear Information System (INIS)

Rodriquez, Michael

2009-01-01

As energy prices skyrocket and interest in alternative, clean energy sources builds, interest in nuclear energy has increased. This increased interest in nuclear energy has been termed the 'Nuclear Renaissance'. The performance of nuclear fuels, fuels and reactor materials and waste products are becoming a more important issue as the potential for designing new nuclear reactors is more immediate. The Idaho National Laboratory (INL) Materials and Fuels Complex (MFC) Analytical Laboratory Hot Cells (ALHC) are rising to the challenge of characterizing new reactor materials, byproducts and performance. The ALHC is a facility located near Idaho Falls, Idaho at the INL Site. It was built in 1958 as part of the former Argonne National Laboratory West Complex to support the operation of the second Experimental Breeder Reactor (EBR-II). It is part of a larger analytical laboratory structure that includes wet chemistry, instrumentation and radiochemistry laboratories. The purpose of the ALHC is to perform analytical chemistry work on highly radioactive materials. The primary work in the ALHC has traditionally been dissolution of nuclear materials so that less radioactive subsamples (aliquots) could be transferred to other sections of the laboratory for analysis. Over the last 50 years though, the capabilities within the ALHC have also become independent of other laboratory sections in a number of ways. While dissolution, digestion and subdividing samples are still a vitally important role, the ALHC has stand alone capabilities in the area of immersion density, gamma scanning and combustion gas analysis. Recent use of the ALHC for immersion density shows that extremely fine and delicate operations can be performed with the master-slave manipulators by qualified operators. Twenty milligram samples were tested for immersion density to determine the expansion of uranium dioxide after irradiation in a nuclear reactor. The data collected confirmed modeling analysis with very tight

3D2 pairing in asymmetric nuclear matter

International Nuclear Information System (INIS)

Alm, T.

1996-01-01

The superfluid 3 D 2 pairing instability in isospin-asymmetric nuclear matter is studied, using the Paris nucleon-nucleon interaction as an input. It is found that the critical temperature associated with the transition to the superfluid phase becomes strongly suppressed with increasing isospin asymmetry, and vanishes for asymmetry parameter values α (≡(n n -n p )/(n n +n p )) that are larger than several percent. It is shown that for neutron star models based on relativistic, field-theoretical equations of state, a large fraction of their interior may exist in a 3 D 2 -paired superfluid phase. The implications of such a 3 D 2 superfluid in massive neutron stars is discussed with respect to observable pulsar phenomena. Another interesting phenomenon, discussed in the paper, concerns the numerical finding of two critical superfluid temperatures for a given density in the case of isospin-asymmetric matter. Using the BCS cut-off ansatz, a mathematical expression for the critical temperature is derived which confirms this finding analytically. (orig.)

Experimental approach to Chernobyl hot particles

International Nuclear Information System (INIS)

Tcherkezian, V.; Shkinev, V.; Khitrov, L.; Kolesov, G.

1994-01-01

An experimental approach to the investigation of Chernobyl hot particles and some results are presented in this study. Hot particles (HP) were picked out from soil samples collected during the 1986-1990 radiogeochemical expeditions in the contaminated zone (within 30 km of the Nuclear Power Plant). A number of hot particles were studied to estimate their contribution to the total activity, investigate their surface morphology and determine the size distribution. Hot particles contribution to the total activity in the 30 km zone was found to be not less than 65%. Investigation of HP element composition (by neutron activation analysis and EPMA) and radionuclide composition (direct alpha- and gamma-spectrometry, including determination of Pu and Am in Hp) revealed certain peculiarities of HP, collected in the vicinity of the damaged Nuclear Power Plant. Some particles were shown to contain uranium and fission products in proportion to one another, correlating with those in the partially burnt fuel, which proves their 'fuel' origin. Another part of the HP samples has revealed element fractionation as well as the presence of some terrestrial components. (Author)

Hot-electron surface retention in intense short-pulse laser-matter interactions.

Science.gov (United States)

Mason, R J; Dodd, E S; Albright, B J

2005-07-01

Implicit hybrid plasma simulations predict that a significant fraction of the energy deposited into hot electrons can be retained near the surface of targets with steep density gradients illuminated by intense short-pulse lasers. This retention derives from the lateral transport of heated electrons randomly emitted in the presence of spontaneous magnetic fields arising near the laser spot, from geometric effects associated with a small hot-electron source, and from E fields arising in reaction to the ponderomotive force. Below the laser spot hot electrons are axially focused into a target by the B fields, and can filament in moderate Z targets by resistive Weibel-like instability, if the effective background electron temperature remains sufficiently low. Carefully engineered use of such retention in conjunction with ponderomotive density profile steepening could result in a reduced hot-electron range that aids fast ignition. Alternatively, such retention may disturb a deeper deposition needed for efficient radiography and backside fast ion generation.

Quark mean field theory and consistency with nuclear matter

International Nuclear Information System (INIS)

Dey, J.; Dey, M.; Frederico, T.; Tomio, L.

1990-09-01

1/N c expansion in QCD (with N c the number of colours) suggests using a potential from meson sector (e.g. Richardson) for baryons. For light quarks a σ field has to be introduced to ensure chiral symmetry breaking ( χ SB). It is found that nuclear matter properties can be used to pin down the χ SB-modelling. All masses, M N , m σ , m ω are found to scale with density. The equations are solved self consistently. (author). 29 refs, 2 tabs

Computational methods for the nuclear and neutron matter problems. Progress report

International Nuclear Information System (INIS)

Kalos, M.H.

1979-01-01

A brief report is given of progress on the development of Monte Carlo methods for the treatment of both simplified and realistic models of extensive neutron and nuclear matter and, eventually, of finite nuclei. A wide class of algorithms that may allow the efficient sampling of the integrands required in calculating the energy expectations with useful trial wave functions was devised

A review on the relativistic effective field theory with parameterized couplings for nuclear matter and neutron stars

Energy Technology Data Exchange (ETDEWEB)

Vasconcellos, C. A. Zen, E-mail: cesarzen@cesarzen.com [Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, 91501-970, Porto Alegre (Brazil); International Center for Relativistic Astrophysics Network (ICRANet), Piazza della Repubblica 10, 65122 Pescara (Italy)

2015-12-17

Nuclear science has developed many excellent theoretical models for many-body systems in the domain of the baryon-meson strong interaction for the nucleus and nuclear matter at low, medium and high densities. However, a full microscopic understanding of nuclear systems in the extreme density domain of compact stars is still lacking. The aim of this contribution is to shed some light on open questions facing the nuclear many-body problem at the very high density domain. Here we focus our attention on the conceptual issue of naturalness and its role in shaping the baryon-meson phase space dynamics in the description of the equation of state (EoS) of nuclear matter and neutrons stars. In particular, in order to stimulate possible new directions of research, we discuss relevant aspects of a recently developed relativistic effective theory for nuclear matter within Quantum Hadrodynamics (QHD) with genuine many-body forces and derivative natural parametric couplings. Among other topics we discuss in this work the connection of this theory with other known effective QHD models of the literature and its potentiality in describing a new physics for dense matter. The model with parameterized couplings exhausts the whole fundamental baryon octet (n, p, Σ{sup −}, Σ{sup 0}, Σ{sup +}, Λ, Ξ{sup −}, Ξ{sup 0}) and simulates n-order corrections to the minimal Yukawa baryon couplings by considering nonlinear self-couplings of meson fields and meson-meson interaction terms coupled to the baryon fields involving scalar-isoscalar (σ, σ∗), vector-isoscalar (ω, Φ), vector-isovector (ϱ) and scalar-isovector (δ) virtual sectors. Following recent experimental results, we consider in our calculations the extreme case where the Σ{sup −} experiences such a strong repulsion that its influence in the nuclear structure of a neutron star is excluded at all. A few examples of calculations of properties of neutron stars are shown and prospects for the future are discussed.

An ALARA-conscious hot particle control program

International Nuclear Information System (INIS)

Doolittle, W.W.; Bredvad, R.S.; Bevelacqua, J.J.

1992-01-01

In 1989 approximately twenty-five percent of the radiation dose received by the Point Beach Nuclear Plant (PBNP) Health Physics group was due to its hot particle control program. The Health Physics group initiated a review of the program with the objective of decreasing the dose expenditure for hot particle control while maintaining a high standard for hot particle detection and control. In this paper the methods and results of this evaluation are described. The components of the hot particle control program, rules of thumb, and radionuclide composition at PBNP are presented

Hot-pressing steatite bodies

International Nuclear Information System (INIS)

Aparicio Arroyo, E.

1967-01-01

Requirements for some special nuclear engineering ceramic shapes are: big size, impervious, dimensional accuracy and good mechanical and dielectric properties. Limitations of te conventional methods and advantages of te hot pressing techniques for the manufacturing of these shapes are discussed. Hot pressing characteristics of a certain steatite powder are studied. Occurrence of an optimum densification temperature just above the tale decomposition range is found. Experimental data show that the height/diameter ratio of the specimen has no effect on the sintering conditions. Increasing darkness from the graphite mould is detected above the optimum temperature. The hot-pressed steatite is compared with a fired dry-pressed sample of the same composition. (Author) 13 refs

Differential isospin-fractionation in dilute asymmetric nuclear matter

International Nuclear Information System (INIS)

Li Baoan; Chen Liewen; Ma Hongru; Xu Jun; Yong Gaochan

2007-01-01

The differential isospin-fractionation (IsoF) during the liquid-gas phase transition in dilute asymmetric nuclear matter is studied as a function of nucleon momentum. Within a self-consistent thermal model it is shown that the neutron/proton ratio of the gas phase becomes smaller than that of the liquid phase for energetic nucleons, although the gas phase is overall more neutron-rich. Clear indications of the differential IsoF consistent with the thermal model predictions are demonstrated within a transport model for heavy-ion reactions. Future comparisons with experimental data will allow us to extract critical information about the momentum dependence of the isovector strong interaction

Thermal hydrodynamic modeling and simulation of hot-gas duct for next-generation nuclear reactor

Energy Technology Data Exchange (ETDEWEB)

Lee, Injun [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Hong, Sungdeok; Kim, Chansoo [Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Bai, Cheolho; Hong, Sungyull [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Shim, Jaesool, E-mail: jshim@ynu.ac.kr [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

2016-12-15

Highlights: • Thermal hydrodynamic nonlinear model is presented to examine a hot gas duct (HGD) used in a fourth-generation nuclear power reactor. • Experiments and simulation were compared to validate the nonlinear porous model. • Natural convection and radiation are considered to study the effect on the surface temperature of the HGD. • Local Nusselt number is obtained for the optimum design of a possible next-generation HGD. - Abstract: A very high-temperature gas-cooled reactor (VHTR) is a fourth-generation nuclear power reactor that requires an intermediate loop that consists of a hot-gas duct (HGD), an intermediate heat exchanger (IHX), and a process heat exchanger for massive hydrogen production. In this study, a mathematical model and simulation were developed for the HGD in a small-scale nitrogen gas loop that was designed and manufactured by the Korea Atomic Energy Research Institute. These were used to investigate the effect of various important factors on the surface of the HGD. In the modeling, a porous model was considered for a Kaowool insulator inside the HGD. The natural convection and radiation are included in the model. For validation, the modeled external surface temperatures are compared with experimental results obtained while changing the inlet temperatures of the nitrogen working fluid. The simulation results show very good agreement with the experiments. The external surface temperatures of the HGD are obtained with respect to the porosity of insulator, emissivity of radiation, and pressure of the working fluid. The local Nusselt number is also obtained for the optimum design of a possible next-generation HGD.

Fire preparedness measures in buildings with hot laboratories

International Nuclear Information System (INIS)

Oberlaender, B.C.

2003-01-01

Important hot laboratory safety issues are the general design/construction of the building with respect to fire, fire prevention, fire protection, administrative controls, and risk assessment. Within the network of the European Working Group Hot Laboratories and Remote Handling items concerning 'fire preparedness measures in hot laboratories' were screened and studied. Two questionnaires were sent to European hot laboratories; the first in November 2002 on 'fire preparedness measures, fire detection and fire suppression/extinguishing in lead shielded cells, concrete shielded cells' and the second in June 2003 on 'Fire preparedness measures in buildings with hot laboratories'. The questionnaires were filled in by a total of ten hot laboratories in seven European countries. On request of participants the answers were evaluated and 'anonymised' for presentation and discussion at the plenary meeting. The answers showed that many European hot laboratories are implementing improvements to their fire protection programmes to comply with more stringent requirements of the national authorities. The recommendations ('International guidelines for the fire protection of Nuclear Power Plants') given by the insurance pools are followed up with national variations. An ISO standard (ISO 17873) is in progress giving criteria for the design and the operation of ventilation systems as well as fire hazard management in nuclear installations others than reactors

Self-energy of the Δ-isobar in nuclear matter for the Paris and the Green-Niskanen-Sainio potentials

International Nuclear Information System (INIS)

Dey, J.; Abdul Matin, M.; Samanta, B.C.

1985-11-01

A coupled channel calculation, with the compensated Paris potential and the isobar transition potential due to Green, Niskanen and Sainio, yields the nucleon and isobar self-energies in nuclear matter. Unlike the Reid soft core, the Paris potential is found to bind the isobar at small momentum by a potential of the order of 10 MeV. The change in the binding energy and the wound integral in nuclear matter, due to the explicit treatment of isobar degrees of freedom, is small. (author)

Hot Strange Hadronic Matter in an Effective Model

Science.gov (United States)

Qian, Wei-Liang; Su, Ru-Keng; Song, Hong-Qiu

2003-10-01

An effective model used to describe the strange hadronic matter with nucleons, Λ-hyperons, and Ξ-hyperons is extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fraction dependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy and pressure, as well as the equation of state of the matter, are given. The project supported in part by National Natural Science Foundation of China under Grant Nos. 10075071, 10047005, 19947001, 19975010, and 10235030, and the CAS Knowledge Innovation Project No. KJCX2-N11. Also supported by the State Key Basic Research Development Program under Grant No. G200077400 and the Exploration Project of Knowledge Innovation Program of the Chinese Academy of Sciences

Observation of Δ+→pπ0 decay in nuclear matter

International Nuclear Information System (INIS)

Matulewicz, T.; Aphecetche, L.; Charbonnier, Y.; Delagrange, H.; Martinez, G.; Schutz, Y.; Marques, F.M.

1997-01-01

The Δ baryonic resonances production and decay in nuclear matter have been studied. The heavy ion reaction of 180 A MeV Ar beam on Ca target was used to create the Δ resonances (at SIS GSI Darmstadt). The decay of Δ was measured by means of neutral pion π 0 decay product, two gamma quanta, registration. The Δ resonance invariant mass distribution has been determined

Investigation of the organic matter in inactive nuclear tank liquids

International Nuclear Information System (INIS)

Schenley, R.L.; Griest, W.H.

1990-08-01

Environmental Protection Agency (EPA) methodology for regulatory organics fails to account for the organic matter that is suggested by total organic carbon (TOC) analysis in the Oak Ridge National Laboratory (ORNL) inactive nuclear waste-tank liquids and sludges. Identification and measurement of the total organics are needed to select appropriate waste treatment technologies. An initial investigation was made of the nature of the organics in several waste-tank liquids. This report details the analysis of ORNL wastes

Microscopic equation of state calculations: 1. Nuclear matter. 2. Liquid helium 3

International Nuclear Information System (INIS)

Heyer, J.P.

1989-01-01

A new method for calculating the equation of state of extended Fermi systems is proposed and applied to nuclear matter and liquid 3 He. New techniques are developed for summing up the particle-particle (pp) and particle-hole (ph) ring diagrams to all orders in the calculation of the ground state shift ΔE 0 for many-body systems. Analytic expressions for ΔE pp P 0 , the contribution from all of the pp ring diagrams to ΔE 0 , and ΔE ph 0 , the corresponding contribution from all of the ph ring diagrams, have been obtained. It has been shown that the pp ring diagram sum may be written as an integral over frequency, involving the particle-particle Green's function. A similar integral expression is derived for the ph ring diagram sum. Two methods are developed for carrying out the frequency integrations, namely the multipole and transition amplitude methods. These methods have been tested on an exactly-solvable many-fermion model, a modified Lipkin model, and compared. The author has studied the instability of nuclear matter at both zero and finite temperature within the pp ring diagram framework. He has found using the Gogny D1 effective nucleon-nucleon interaction, complex eigenvalues of an RPA-type secular equation are obtained in a well-defined temperature-density region. When complex eigenvalues occur, the thermodynamic potential becomes complex. The possible connection between the occurrence of complex eigenvalues and liquid-gas phase separation is discussed. The pp ring diagrams are also found to lower the compression modulus of nuclear matter. Lastly, the pp ring diagram method is applied to the calculation of the ground state energy of normal and spin-polarized liquid 3 He. We have found a binding energy per particle (BE/A) of 1.45 degree K and 1.79 degree K for the normal and spin-polarized systems, respectively

Fermi liquid, clustering, and structure factor in dilute warm nuclear matter

Science.gov (United States)

Röpke, G.; Voskresensky, D. N.; Kryukov, I. A.; Blaschke, D.

2018-02-01

Properties of nuclear systems at subsaturation densities can be obtained from different approaches. We demonstrate the use of the density autocorrelation function which is related to the isothermal compressibility and, after integration, to the equation of state. This way we connect the Landau Fermi liquid theory well elaborated in nuclear physics with the approaches to dilute nuclear matter describing cluster formation. A quantum statistical approach is presented, based on the cluster decomposition of the polarization function. The fundamental quantity to be calculated is the dynamic structure factor. Comparing with the Landau Fermi liquid theory which is reproduced in lowest approximation, the account of bound state formation and continuum correlations gives the correct low-density result as described by the second virial coefficient and by the mass action law (nuclear statistical equilibrium). Going to higher densities, the inclusion of medium effects is more involved compared with other quantum statistical approaches, but the relation to the Landau Fermi liquid theory gives a promising approach to describe not only thermodynamic but also collective excitations and non-equilibrium properties of nuclear systems in a wide region of the phase diagram.

Equation of state of neutron-rich nuclear matter from chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Kaiser, Norbert; Strohmeier, Susanne [Technische Universitaet Muenchen (Germany)

2016-07-01

Based on chiral effective field theory, the equation of state of neutron-rich nuclear matter is investigated systematically. The contributing diagrams include one- and two-pion exchange together with three-body terms arising from virtual Δ(1232)-isobar excitations. The proper expansion of the energy per particle, anti E(k{sub f},δ) = anti E{sub n}(k{sub f}) + δB{sub 1}(k{sub f}) + δ{sup 5/3}B{sub 5/3}(k{sub f}) + δ{sup 2}B{sub 2}(k{sub f}) +.., for the system with neutron density ρ{sub n} = k{sub f}{sup 3}(1-δ)/3π{sup 2} and proton density ρ{sub p} = k{sub f}{sup 3}δ/3π{sup 2} is performed analytically for the various interaction contributions. One observes essential structural differences to the commonly used quadratic approximation. The density dependent coefficient B{sub 1}(k{sub f}) turns out to be unrelated to the isospin-asymmetry of nuclear matter. The coefficient B{sub 5/3}(k{sub f}) of the non-analytical δ{sup 5/3}-term receives contributions from the proton kinetic energy and from the one- and two-pion exchange interactions. The physical consequences for neutron star matter are studied.

Effective pion--nucleon interaction in nuclear matter

International Nuclear Information System (INIS)

Celenza, L.S.; Liu, L.C.; Nutt, W.; Shakin, C.M.

1976-01-01

We discuss the modification of the interaction between a pion and a nucleon in the presence of an infinite medium of nucleons (nuclear matter). The theory presented here is covariant and is relevant to the calculation of the pion--nucleus optical potential. The specific effects considered are the modifications of the nucleon propagator due to the Pauli principle and the modification of the pion and nucleon propagators due to collisions with nucleons of the medium. We also discuss in detail the pion self-energy in the medium, paying close attention to off-shell effects. These latter effects are particularly important because of the rapid variation with energy of the fundamental pion--nucleon interaction. Numerical results are presented, the main feature being the appearance of a significant damping width for the (3, 3) resonance

Hot Cell Post-Irradiation Examination and Poolside Inspection of Nuclear Fuel. Proceedings of the IAEA-HOTLAB Technical Meeting

International Nuclear Information System (INIS)

2013-04-01

The growing operational requirements for nuclear fuel, such as longer fuel cycles, higher burnups and wider use of transient regimes, require more robust fuel designs and more radiation resistant materials. Development of such advanced fuels is only possible with testing and analysis of their performance and application of adequate post-irradiation examination (PIE) methods and techniques. In addition, operational feedback data from poolside and PIE facilities are absolutely necessary for verification of fuel modelling codes and analysis of fuel failure mechanisms. For these reasons, the International Atomic Energy Agency (IAEA) has supported the international exchange of knowledge and sharing of best practices in the application of modern destructive and non-destructive methods of investigation of highly radioactive materials through a series of technical meetings (TMs), the last of which was held in 2006 in Buenos Aires. Since 1963, similar meetings, initially at the European level, have been organized by the Hot Laboratories and Remote Handling Working Group (HOTLAB), a partner in the development of the IAEA's Post Irradiation Examination Facilities Database (PIEDB), part of the IAEA's Integrated Nuclear Fuel Cycle Information System. With this successful partnership in mind, in 2010 the IAEA Technical Working Group on Fuel Performance and Technology recommended that a joint IAEA-HOTLAB TM be held on 'Hot Cell Post-Irradiation Examination and Pool-Side Inspection of Nuclear Fuel', covering questions relevant to the IAEA sub-programmes on 'Nuclear Power Reactor Fuel Engineering' and 'Management of Spent Fuel from Nuclear Power Reactors'. The TM was held on 23-27 May 2011, in Smolenice, Slovakia, with the participation of a large number of interested organizations and comprehensive coverage of major PIE and poolside inspection issues relating to both operation and storage of fuel for nuclear power reactors. The proceedings, summaries and conclusions of that joint

Molecular dynamics for dense matter

International Nuclear Information System (INIS)

Maruyama, Toshiki; Chiba, Satoshi; Watanabe, Gentaro

2012-01-01

We review a molecular dynamics method for nucleon many-body systems called quantum molecular dynamics (QMD), and our studies using this method. These studies address the structure and the dynamics of nuclear matter relevant to neutron star crusts, supernova cores, and heavy-ion collisions. A key advantage of QMD is that we can study dynamical processes of nucleon many-body systems without any assumptions about the nuclear structure. First, we focus on the inhomogeneous structures of low-density nuclear matter consisting not only of spherical nuclei but also of nuclear “pasta”, i.e., rod-like and slab-like nuclei. We show that pasta phases can appear in the ground and equilibrium states of nuclear matter without assuming nuclear shape. Next, we show our simulation of compression of nuclear matter which corresponds to the collapsing stage of supernovae. With the increase in density, a crystalline solid of spherical nuclei changes to a triangular lattice of rods by connecting neighboring nuclei. Finally, we discuss fragment formation in expanding nuclear matter. Our results suggest that a generally accepted scenario based on the liquid–gas phase transition is not plausible at lower temperatures. (author)