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

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

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.

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.

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.

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.

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, ...

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

Conserving relativistic many-body approach: Equation of state, spectral function, and occupation probabilities of nuclear matter

International Nuclear Information System (INIS)

de Jong, F.; Malfliet, R.

1991-01-01

Starting from a relativistic Lagrangian we derive a ''conserving'' approximation for the description of nuclear matter. We show this to be a nontrivial extension over the relativistic Dirac-Brueckner scheme. The saturation point of the equation of state calculated agrees very well with the empirical saturation point. The conserving character of the approach is tested by means of the Hugenholtz--van Hove theorem. We find the theorem fulfilled very well around saturation. A new value for compression modulus is derived, K=310 MeV. Also we calculate the occupation probabilities at normal nuclear matter densities by means of the spectral function. The average depletion κ of the Fermi sea is found to be κ∼0.11

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.

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.

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)

Soil Quality of Restinga Forest: Organic Matter and Aluminum Saturation

Science.gov (United States)

Rodrigues Almeida Filho, Jasse; Casagrande, José Carlos; Martins Bonilha, Rodolfo; Soares, Marcio Roberto; Silva, Luiz Gabriel; Colato, Alexandre

2013-04-01

The restinga vegetation (sand coastal plain vegetation) consists of a mosaic of plant communities, which are defined by the characteristics of the substrates, resulting from the type and age of the depositional processes. This mosaic complex of vegetation types comprises restinga forest in advanced (high restinga) and medium regeneration stages (low restinga), each with particular differentiating vegetation characteristics. Of all ecosystems of the Atlantic Forest, restinga is the most fragile and susceptible to anthropic disturbances. The purpose of this study was evaluating the organic matter and aluminum saturation effects on soil quality index (SQI). Two locations were studied: State Park of the Serra do Mar, Picinguaba, in the city of Ubatuba (23°20' e 23°22' S / 44°48' e 44°52' W), and State Park of Cardoso Island in the city of Cananéia (25°03'05" e 25°18'18" S / 47°53'48" e 48° 05'42" W). The soil samples were collect at a depth of 0-10 cm, where concentrate 70% of vegetation root system. Was studied an additive model to evaluate soil quality index. The shallow root system development occurs due to low calcium levels, whose disability limits their development, but also can reflect on delay, restriction or even in the failure of the development vegetation. The organic matter is kept in the soil restinga ecosystem by high acidity, which reduces the decomposition of soil organic matter, which is very poor in nutrients. The base saturation, less than 10, was low due to low amounts of Na, K, Ca and Mg, indicating low nutritional reserve into the soil, due to very high rainfall and sandy texture, resulting in high saturation values for aluminum. Considering the critical threshold to 3% organic matter and for aluminum saturation to 40%, the IQS ranged from 0.95 to 0.1 as increased aluminum saturation and decreased the soil organic matter, indicating the main limitation to the growth of plants in this type of soil, when deforested.

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

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

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.

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.

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)

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.

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.

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

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-...

Static and Covariant Meson-Exchange Interactions in Nuclear Matter

International Nuclear Information System (INIS)

Carlson, B.V.; Hirata, D.

2011-01-01

The Dirac version of static meson exchange interactions provides a good description of low-energy NN scattering as well as very reasonable saturation properties in Dirac-Brueckner calculations of nuclear matter. We include retardation terms to make these interactions covariant and readjust the coupling constants so as to maintain a reasonable description of NN scattering. In this case, we find the Dirac-Brueckner approximation to nuclear matter to be extremely overbound. The Bonn meson-exchange interactions provide a good fit to low-energy nucleon-nucleon scattering and the deuteron binding energy using a static interaction and the Thompson form of the reduced two-nucleon interaction. We have readjusted the coupling constants of the these interactions to obtain almost equivalent fits to the scattering data and deuteron binding energy with a static interaction and the Blankenbecler-Sugar form of the reduced two-nucleon propagator and using both forms of the propagator with a covariant interaction. Dirac-Brueckner calculations using the static interactions furnish saturation properties similar to those found for the Bonn interactions. The covariant interactions, on the contrary, yield extreme overbinding and do not show signs of saturation before our calculations diverge. One of the advantages claimed for Dirac mean field calculations over nonrelativistic ones has been the fact that they yield reasonable saturation properties without the necessity of a three-body interaction. This is usually credited to the three-body effects introduced by virtual scattering through the Dirac sea states. These are included, in part, through the Dirac form of the self-energy in our calculations. However, we have explicitly excluded their contribution to the Brueckner scattering kernel. Dirac-Brueckner calculations in which both the positive and negative energy states are included in the scattering kernel result in less binding than those that include only the positive-energy ones

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.)

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.

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

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)

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.

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.)

Gluon Saturation and EIC

Energy Technology Data Exchange (ETDEWEB)

Sichtermann, Ernst

2016-12-15

The fundamental structure of nucleons and nuclear matter is described by the properties and dynamics of quarks and gluons in quantum chromodynamics. Electron-nucleon collisions are a powerful method to study this structure. As one increases the energy of the collisions, the interaction process probes regions of progressively higher gluon density. This density must eventually saturate. An high-energy polarized Electron-Ion Collider (EIC) has been proposed to observe and study the saturated gluon density regime. Selected measurements will be discussed, following a brief introduction.

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)

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...

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.

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.

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.)

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

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.

Recent Progress in Constraining the Equation of State of Dense Neutron-Rich Nuclear Matter with Heavy-Ion Reactions

International Nuclear Information System (INIS)

Li Baoan; Chen Liewen; Wen Dehua; Xiao Zhigang; Xu Chang; Yong Gaochan; Zhang Ming

2010-01-01

The nuclear symmetry energy E sym (ρ) is the most uncertain part of the Equation of State (EOS) of dense neutron-rich nuclear matter. In this talk, we discuss the underlying physics responsible for the uncertain E sym (ρ) especially at supra-saturation densities, the circumstantial evidence for a super-soft E sym (ρ) from analyzing π - /π + ratio in relativistic heavy-ion collisions and its impacts on astrophysics and cosmology.

A soluble model for the study of saturation in finite nuclei

International Nuclear Information System (INIS)

Grammaticos, B.

1979-01-01

The deviation of very small nuclear systems from saturation is studied. In the framework of a soluble one-dimensional model based on the energy density formalism simple expressions for the density profile, the deviation from nuclear matter density, the Fermi energy as a function of particle number are established. The binding energy of the nucleus is computed and the effect of the departure from saturation is identified as a term exponentially decaying for large A. A comparison with the theory of Krappe and Nix is also presented

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

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

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.

Saturation and nucleation in hot nuclear systems

International Nuclear Information System (INIS)

Deangelis, A.R.

1990-07-01

We investigate nuclear fragmentation in a supersaturated system using classical nucleation theory. This allows us to go outside the normally applied constraint of chemical equilibrium. The system is governed by a virial equation of state, which we use to find an expression for the density as a function of pressure and temperature. The evolution of the system is discussed in terms of the phase diagram. Corrections are included to account for the droplet surface and all charges contained in the system. Using this model we investigate and discuss the effects of temperature and saturation, and compare the results to those of other models of fragmentation. We also discuss the limiting temperatures of the system for the cases with and without chemical equilibrium. We find that large nuclei will be formed in saturated systems, even above the limiting temperature as previously defined. We also find that saturation and temperature dominate surface and Coulomb effects. The effects are quite large, thus even a qualitative inspection of the yields may give an indication of the conditions during fragmentation

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.

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

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

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.

Application of an effective gauge-invariant model to nuclear matter in the relativistic Hartree-Fock approximation

Energy Technology Data Exchange (ETDEWEB)

Bernardos, P. [Universidad de Cantabria, Departamento de Matematica Aplicada y Ciencias de la Computacion, 39005, Santander (Spain); Fomenko, V.N. [St Petersburg University for Railway Engineering, Department of Mathematics, 190031, St Petersburg (Russian Federation); Marcos, S.; Niembro, R. [Universidad de Cantabria, Departamento de Fisica Moderna, 39005, Santander (Spain); Lopez-Quelle, M. [Universidad de Cantabria, Departamento de Fisica Aplicada, 39005, Santander (Spain); Savushkin, L.N. [St Petersburg University for Telecommunications, Department of Physics, 191186, St Petersburg (Russian Federation)

2001-02-01

An effective nuclear model describing {omega}-, {rho}- and axial-mesons as gauge fields is applied to nuclear matter in the relativistic Hartree-Fock approximation. The isoscalar two-pion exchange is simulated by a scalar field s similar to that used in the conventional relativistic mean-field approach. Two more scalar fields are essential ingredients of the present treatment: the {sigma}-field, the chiral partner of the pion, and the {sigma}-field, the Higgs field for the {omega}-meson. Two versions of the model are used depending on whether the {sigma}-field is considered as a dynamical variable or 'frozen', by taking its mass as infinite. The model contains four free parameters in the first case and three in the second one which are fitted to the nuclear matter saturation conditions. The nucleon and meson effective masses, compressibility modulus and symmetry energy are calculated. The results prove the reliability of the Dirac-Hartree-Fock approach within the linear realization of the chiral symmetry. (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)

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

Study of the Λ(1116 interaction in cold nuclear matter

Directory of Open Access Journals (Sweden)

Arnold Oliver

2014-03-01

Full Text Available The interaction of Λ hyperons with baryonic nuclear matter at saturation density is expected to be attractive. The interaction strength was extracted from hypernuclei data. A different approach to obtain the potential depth of the Λ mean-field potential is to compare experimental data with transport simulations. We analyze experimental data of Λ hyperons measured with the HADES detector in p+93Nb reactions with a kinetic beam energy of 3.5 GeV carried by the proton. The high statistic of measured Λ hyperons allows us to perform a double differential analysis in Lorentz-invariant observables of transverse momentum and rapidity. We present the analysis method and a comparison with simulations.

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)

Correlations between the nuclear matter symmetry energy, its slope, and curvature

International Nuclear Information System (INIS)

Santos, B M; Delfino, A; Dutra, M; Lourenço, O

2015-01-01

By using point-coupling versions of finite range nuclear relativistic mean field models containing cubic and quartic self interactionsin the scalar field σ, a nonrelativistic limit is achieved. This approach allows for an analytical expression for the symmetry energy (J) as a function of its slope (L) in a unified form, namely, L = 3J + f(m*, ρ o , B o , K o ), where the quantities m*, p o , B o and K o are bulk parameters at the nuclear matter saturation density ρ o . This result establishes a linear correlation between L and J which is reinforced by exact relativistic calculations we have performed. An analogous analytical correlation can also be found for J, L and the symmetry energy curvature (K sym ). Based on these results, we propose a graphic constraint in L × J plane which finite range models should satisfy. (paper)

PARTON SATURATION, PRODUCTION, AND EQUILIBRATION IN HIGH ENERGY NUCLEAR COLLISIONS

International Nuclear Information System (INIS)

VENUGOPALAN, R.

1999-01-01

Deeply inelastic scattering of electrons off nuclei can determine whether parton distributions saturate at HERA energies. If so, this phenomenon will also tell us a great deal about how particles are produced, and whether they equilibrate, in high energy nuclear collisions

Can the nuclear symmetry potential at supra-saturation densities be negative?

International Nuclear Information System (INIS)

Yong Gaochan

2010-01-01

In the framework of an isospin-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport model, for the central 197 Au+ 197 Au reaction at an incident beam energy of 400 MeV/nucleon, the effect of nuclear symmetry potential at supra-saturation densities on the preequilibrium clusters emission is studied. It is found that for the positive symmetry potential at supra-saturation densities the neutron-to-proton ratio of lighter clusters with mass number A≤3[(n/p) A≤3 ] is larger than that of the heavier clusters with mass number A>3[(n/p) A>3 ], whereas for the negative symmetry potential at supra-saturation densities the (n/p) A≤3 is smaller than the (n/p) A>3 . This may be considered as a probe of the negative symmetry potential at supra-saturation densities.

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

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)

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

Effects of self-consistency in a Green's function description of saturation in nuclear matter

International Nuclear Information System (INIS)

Dewulf, Y.; Neck, D. van; Waroquier, M.

2002-01-01

The binding energy in nuclear matter is evaluated within the framework of self-consistent Green's function theory, using a realistic nucleon-nucleon interaction. The two-body dynamics is solved at the level of summing particle-particle and hole-hole ladders. We go beyond the on-shell approximation and use intermediary propagators with a discrete-pole structure. A three-pole approximation is used, which provides a good representation of the quasiparticle excitations, as well as reproducing the zeroth- and first-order energy-weighted moments in both the nucleon removal and addition domains of the spectral function. Results for the binding energy are practically independent of the details of the discretization scheme. The main effect of the increased self-consistency is to introduce an additional density dependence, which causes a shift towards lower densities and smaller binding energies, as compared to a (continuous choice) Brueckner calculation with the same interaction. Particle number conservation and the Hugenholz-Van Hove theorem are satisfied with reasonable accuracy

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

Phases of dense matter with non-spherical nuclei

Energy Technology Data Exchange (ETDEWEB)

Pethick, C J [NORDITA, Copenhagen (Denmark); [Dept. of Physics, Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States); Ravenhall, D G [Dept. of Physics, Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States)

1998-06-01

A brief review is given of some of the important physics related to phases with non-spherical nuclei that can exist in neutron stars and in matter in stellar collapse at densities just below the saturation density of nuclear matter. Comparisons are made with other systems that exhibit similar liquid-crystal-like phases, both in nuclear physics and in condensed matter physics. A short account is given of recent work on the elastic properties of these phases, and their vibration spectrum, as well as on neutron superfluid gaps. (orig.)

Constraining the EOS of Neutron-Rich Nuclear Matter and Properties of Neutron Stars with Heavy-Ion Reactions

International Nuclear Information System (INIS)

Li Baoan; Worley, Aaron; Chen, L.-W.; Ko, Che Ming; Krastev, Plamen G.; Wen Dehua; Xiao Zhigang; Zhang Ming; Xu Jun; Yong Gaochan

2009-01-01

Heavy-ion reactions especially those induced by radioactive beams provide useful information about the density dependence of the nuclear symmetry energy, thus the Equation of State of neutron-rich nuclear matter, relevant for many astrophysical studies. The latest developments in constraining the symmetry energy at both sub- and supra-saturation densities from analyses of the isopsin diffusion and the π - /π + ratio in heavy-ion collisions using the IBUU04 transport model are discussed. Astrophysical ramifications of the partially constrained symmetry energy on properties of neutron star crusts, gravitational waves emitted by deformed pulsars and the w-mode oscillations of neutron stars are presented briefly.

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)

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)

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

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)

Short-range correlations in quark and nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Froemel, Frank

2007-06-15

In the first part of this thesis, the role of short-range correlations in quark matter is explored within the framework of the Nambu-Jona-Lasinio model. Starting from a next-to-leading order expansion in the inverse number of the quark colors, a fully self-consistent model constructed that employs the close relations between spectral functions and self-energies. In contrast to the usual quasiparticle approximations, this approach allows the investigation of the collisional broadening of the quark spectral function. Numerical calculations at various chemical potentials and zero temperature show that the short-range correlations do not only induce a finite width of the spectral function but also have some influence on the structure of the chiral phase transition. In the second part of this thesis, the temperature and density dependence of the nucleon spectral function in symmetric nuclear matter is investigated. The short-range correlations can be well described by a simple, self-consistent model on the one-particle-two-hole and two-particle-one-hole level (1p2h, 2p1h). The thermodynamically consistent description of the mean-field properties of the nucleons is ensured by incorporating a Skyrme-type potential. Calculations at temperatures and densities that can also be found in heavy-ion collisions or supernova explosions and the formation of neutron stars show that the correlations saturate at high temperatures and densities. (orig.)

$J/\\Psi$ 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.

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

Properties of Strange Matter in a Model with Effective Lagrangian

Institute of Scientific and Technical Information of China (English)

WANG Ping; SU Ru-Keng; SONG Hong-Qiu; ZHANG Li-Liang

2001-01-01

The strange hadronic matter with nucleons, A-hyperons and E-hyperons is studied by using an effective nuclear model in a mean-field approximation. The density and strangeness fraction dependence of the effective baryon masses as well as the saturation properties and stabilities of the strange hadronic matter are discussed.``

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

White Matter Damage Relates to Oxygen Saturation in Children With Sickle Cell Anemia Without Silent Cerebral Infarcts.

Science.gov (United States)

Kawadler, Jamie M; Kirkham, Fenella J; Clayden, Jonathan D; Hollocks, Matthew J; Seymour, Emma L; Edey, Rosanna; Telfer, Paul; Robins, Andrew; Wilkey, Olu; Barker, Simon; Cox, Tim C S; Clark, Chris A

2015-07-01

Sickle cell anemia is associated with compromised oxygen-carrying capability of hemoglobin and a high incidence of overt and silent stroke. However, in children with no evidence of cerebral infarction, there are changes in brain morphometry relative to healthy controls, which may be related to chronic anemia and oxygen desaturation. A whole-brain tract-based spatial statistics analysis was carried out in 25 children with sickle cell anemia with no evidence of abnormality on T2-weighted magnetic resonance imaging (13 male, age range: 8-18 years) and 14 age- and race-matched controls (7 male, age range: 10-19 years) to determine the extent of white matter injury. The hypotheses that white matter damage is related to daytime peripheral oxygen saturation and steady-state hemoglobin were tested. Fractional anisotropy was found to be significantly lower in patients in the subcortical white matter (corticospinal tract and cerebellum), whereas mean diffusivity and radial diffusivity were higher in patients in widespread areas. There was a significant negative relationship between radial diffusivity and oxygen saturation (Plevel negative relationship between radial diffusivity and hemoglobin (Pcell anemia, and provides for the first time direct evidence of a relationship between brain microstructure and markers of disease severity (eg, peripheral oxygen saturation and steady-state hemoglobin). This study suggests that diffusion tensor imaging metrics may serve as a biomarker for future trials of reducing hypoxic exposure. © 2015 American Heart Association, Inc.

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

Nuclear matter in all its states

International Nuclear Information System (INIS)

Bonche, P.; Cugnon, J.; Babinet, R.; Mathiot, J.F.; Van Hove, L.; Buenerd, M.; Galin, J.; Lemaire, M.C.; Meyer, J.

1986-01-01

This report includes the nine lectures which have been presented at the Joliot-Curie School of Nuclear Physics in 1985. The subjects covered are the following: thermodynamic description of excited nuclei; heavy ion reactions at high energy (theoretical approach); heavy ion reactions at high energy (experimental approach); relativistic nuclear physics and quark effects in nuclei; quark matter; nuclear compressibility and its experimental determinations; hot nuclei; anti p-nucleus interaction; geant resonances at finite temperature [fr

Extreme states in nuclear matter

International Nuclear Information System (INIS)

Rafelski, J.; Frankfurt Univ.

1981-01-01

Theory of hot nuclear fireballs consisting of all possible finite size hadronic constituents in chemical and thermal equilibrium is presented. As a complement of this hadronic gas phase characterized by maximal temperature and energy density, the quark bag description of the hadronic fireball is considered. Preliminary calculations of temperatures and mean transverse momenta of particles emitted in high multiplicity relativistic nuclear collisions together with some considereations on the observability of quark matter are offered. (orig.)

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.)

Transport Properties in Nuclear Pasta

Science.gov (United States)

Caplan, Matthew; Horowitz, Charles; Berry, Donald; da Silva Schneider, Andre

2016-09-01

At the base of the inner crust of neutron stars, where matter is near the nuclear saturation density, nuclear matter arranges itself into exotic shapes such as cylinders and slabs, called `nuclear pasta.' Lepton scattering from these structures may govern the transport properties of the inner crust; electron scattering from protons in the pasta determines the thermal and electrical conductivity, as well as the shear viscosity of the inner crust. These properties may vary in pasta structures which form at various densities, temperatures, and proton fractions. In this talk, we report on our calculations of lepton transport in nuclear pasta and the implication for neutron star observables.

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

Coherent scattering of neutrinos by 'nuclear pasta' in dense matter

International Nuclear Information System (INIS)

Sonoda, Hidetaka

2007-01-01

We examine coherent scattering cross section of neutrino and nucleon systems via weak-neutral current at subnuclear densities, which will be important in supernova cores. Below melting density and temparature of nuclei, nuclear shape becomes rodlike and slablike; this is called nuclear 'pasta'. Transition of structure will greatly influence coherent effects which can not easily be predicted. We calculate static structure factor of nuclear matter using data of several nuclear models, and discuss the effects of existence of nuclear pasta on neutrino opacity in hot dense matter

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)

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.

Symmetry Parameter Constraints from a Lower Bound on Neutron-matter Energy

Energy Technology Data Exchange (ETDEWEB)

Tews, Ingo [Institute for Nuclear Theory, University of Washington, Seattle, WA 98195-1550 (United States); Lattimer, James M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States); Ohnishi, Akira [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Kolomeitsev, Evgeni E., E-mail: itews@uw.edu, E-mail: james.lattimer@stonybrook.edu, E-mail: ohnishi@yukawa.kyoto-u.ac.jp, E-mail: e.kolomeitsev@gsi.de [Faculty of Natural Sciences, Matej Bel University, Tajovskeho 40, SK-97401 Banska Bystrica (Slovakia)

2017-10-20

We propose the existence of a lower bound on the energy of pure neutron matter (PNM) on the basis of unitary-gas considerations. We discuss its justification from experimental studies of cold atoms as well as from theoretical studies of neutron matter. We demonstrate that this bound results in limits to the density-dependent symmetry energy, which is the difference between the energies of symmetric nuclear matter and PNM. In particular, this bound leads to a lower limit to the volume symmetry energy parameter S {sub 0}. In addition, for assumed values of S {sub 0} above this minimum, this bound implies both upper and lower limits to the symmetry energy slope parameter L , which describes the lowest-order density dependence of the symmetry energy. A lower bound on neutron-matter incompressibility is also obtained. These bounds are found to be consistent with both recent calculations of the energies of PNM and constraints from nuclear experiments. Our results are significant because several equations of state that are currently used in astrophysical simulations of supernovae and neutron star mergers, as well as in nuclear physics simulations of heavy-ion collisions, have symmetry energy parameters that violate these bounds. Furthermore, below the nuclear saturation density, the bound on neutron-matter energies leads to a lower limit to the density-dependent symmetry energy, which leads to upper limits to the nuclear surface symmetry parameter and the neutron-star crust–core boundary. We also obtain a lower limit to the neutron-skin thicknesses of neutron-rich nuclei. Above the nuclear saturation density, the bound on neutron-matter energies also leads to an upper limit to the symmetry energy, with implications for neutron-star cooling via the direct Urca process.

Properties of nuclear and neutron matter in a relativistic Hartree-Fock theory

International Nuclear Information System (INIS)

Horowitz, C.J.; Serot, B.D.

1983-01-01

Relativistic-Hartree-Fock (HF) equations are derived for an infinite system of mesons and baryons in the framework of a renormalizable relativistic quantum field theory. The derivation is based on a diagrammatic approach and Dyson's equation for the baryon propagator. The result is a set of coupled, nonlinear integral equations for the baryon self-energy with a self-consistency condition on the single-particle spectrum. The HF equations are solved for nuclear and neutron matter in the Walecka model, which contains neutral scalar and vector mesons. After renormalizing model parameters to reproduce nuclear matter saturation properties, HF results at low to moderate densities are similar to those in the mean-field (Hartree) approximation. Self-consistent exchange corrections to the Hartree equation of state become negligible at high densities. Rho- and pi-meson exchanges are incorporated using a renormalizable gauge-theory model. A chiral transformation of the lagrangian is used to replace the pseudoscalar πN coupling with a pseudovector coupling, for which one-pion exchange is a reasonable first approximation. This transformation maintains the model's renormalizability so that corrections may be evaluated. Pion exchange has a small effect on the HF results of the Walecka model and brings HF results in closer in closer agreement with the mean-field theory. The diagrammatic techniques used here retain the mesonic degrees of freedom and are simple enough to be extended to more refined self-consistent approximations. (orig.)

Quark matter in a chiral chromodielectric model

International Nuclear Information System (INIS)

Broniowski, W.; Kutschera, M.; Cibej, M.; Rosina, M.

1989-03-01

Zero and finite temperature quark matter is studied in a chiral chromodielectric model with quark, meson and chromodielectric degrees of freedom. Mean field approximation is used. Two cases are considered: two-flavor and three-flavor quark matter. It is found that at sufficiently low densities and temperatures the system is in a chirally broken phase, with quarks acquiring effective masses of the order of 100 MeV. At higher densities and temperatures a chiral phase transition occurs and the quarks become massless. A comparison to traditional nuclear physics suggests that the chirally broken phase with massive quark gas may be the ground state of matter at densities of the order of a few nuclear saturation densities. 24 refs., 5 figs. (author)

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

Integrating plant litter quality, soil organic matter stabilization, and the carbon saturation concept.

Science.gov (United States)

Castellano, Michael J; Mueller, Kevin E; Olk, Daniel C; Sawyer, John E; Six, Johan

2015-09-01

Labile, 'high-quality', plant litters are hypothesized to promote soil organic matter (SOM) stabilization in mineral soil fractions that are physicochemically protected from rapid mineralization. However, the effect of litter quality on SOM stabilization is inconsistent. High-quality litters, characterized by high N concentrations, low C/N ratios, and low phenol/lignin concentrations, are not consistently stabilized in SOM with greater efficiency than 'low-quality' litters characterized by low N concentrations, high C/N ratios, and high phenol/lignin concentrations. Here, we attempt to resolve these inconsistent results by developing a new conceptual model that links litter quality to the soil C saturation concept. Our model builds on the Microbial Efficiency-Matrix Stabilization framework (Cotrufo et al., 2013) by suggesting the effect of litter quality on SOM stabilization is modulated by the extent of soil C saturation such that high-quality litters are not always stabilized in SOM with greater efficiency than low-quality litters. © 2015 John Wiley & Sons Ltd.

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

The phases of isospin-asymmetric matter in the two-flavor NJL model

Energy Technology Data Exchange (ETDEWEB)

Lawley, S. [Special Research Centre for the Subatomic Structure of Matter, University of Adelaide, Adelaide, SA 5005 (Australia) and Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)]. E-mail: slawley@jlab.org; Bentz, W. [Department of Physics, School of Science, Tokai University, Hiratsuka-shi, Kanagawa 259-1292 (Japan); Thomas, A.W. [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2006-01-19

We investigate the phase diagram of isospin-asymmetric matter at T=0 in the two-flavor Nambu-Jona-Lasinio model. Our approach describes the single nucleon as a confined quark-diquark state, the saturation properties of nuclear matter at normal densities, and the phase transition to normal or color superconducting quark matter at higher densities. The resulting equation of state of charge-neutral matter and the structure of compact stars are discussed.

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

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

Phase diagram of nuclear 'pasta' and its uncertainties in supernova cores

International Nuclear Information System (INIS)

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

2008-01-01

We examine the model dependence of the phase diagram of inhomogeneous nulcear matter in supernova cores using the quantum molecular dynamics (QMD). Inhomogeneous matter includes crystallized matter with nonspherical nuclei--''pasta'' phases--and the liquid-gas phase-separating nuclear matter. Major differences between the phase diagrams of the QMD models can be explained by the energy of pure neutron matter at low densities and the saturation density of asymmetric nuclear matter. We show the density dependence of the symmetry energy is also useful to understand uncertainties of the phase diagram. We point out that, for typical nuclear models, the mass fraction of the pasta phases in the later stage of the collapsing cores is higher than 10-20%

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

Three-body forces in nuclear matter from intermediate Δ-states in three-nucleon clusters

International Nuclear Information System (INIS)

Kouki, T.; Smulter, L.E.W.; Green, A.M.

1976-10-01

The three-body force contribution in nuclear matter is treated as a three-nucleon cluster, in which one of the nucleons becomes, in an intermediate state, a Δ(1236). All exchange diagrams are calculated and found to significantly reduce the energy per particle from the direct graph. This is contrary to earlier estimates of the exchanges, using more approximate approaches. The resulting attractive contribution is rather small, -1.1 MeV at ksub(F)=1.4 fm -1 , but the roughly linear density dependence has a crucial effect on the saturation properties. The sensitivity of the results to the correlations used, and to the two-body force spin structure, is displayed. The energy per particle from clusters with three intermediate Δ's is also estimated. (author)

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

Theoretical studies in medium-energy nuclear and hadronic physics

International Nuclear Information System (INIS)

Horowitz, C.J.; Macfarlane, M.H.; Matsui, Tetsuo; Serot, B.D.

1991-01-01

In the period covered by this report (April 1, 1991 to March 31, 1992), work focused on six main areas: (1) Relativistic Theories of Nuclear Structure and Saturation, (2) Relativistic Descriptions of Proton-Nucleus and Electron-Nucleus Scattering, (3) Nonrelativistic Theory of Nucleon-Nucleus Reactions, (4) Relativistic Many-Body Theory at Finite Temperature and Density, (5) Neutrino Interactions in Dense Matter, (6) Quark Models of Nuclear and Quark Matter

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

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.

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)

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

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

Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars

International Nuclear Information System (INIS)

Li Baoan; Chen Liewen; Gearheart, Michael; Hooker, Joshua; Krastev, Plamen G; Lin Weikang; Newton, William G; Wen Dehua; Xu Chang; Ko Cheming; Xu Jun

2011-01-01

Significant progress has been made in recent years in constraining the density dependence of nuclear symmetry energy using terrestrial nuclear laboratory data. Around and below the nuclear matter saturation density, the experimental constraints start to merge in a relatively narrow region. At supra-saturation densities, there are, however, still large uncertainties. After summarizing the latest experimental constraints on the density dependence of nuclear symmetry energy, we highlight a few recent studies examining imprints of nuclear symmetry energy on the binding energy, energy release during hadron-quark phase transitions as well as the ω-mode frequency and damping time of gravitational wave emission of neutron stars.

Probing the nuclear symmetry energy with heavy-ion collisions

Directory of Open Access Journals (Sweden)

De Filippo E.

2015-01-01

Full Text Available Heavy ion collisions (HIC have been widely used to extract the parametrization of symmetry energy term of nuclear equation of state as a function of barionic density. HIC in fact are a unique tool in terrestrial laboratories to explore the symmetry energy around the saturation density (ρ0 = 0.16fm−3 from sub-saturation densities (Fermi energies towards compressed nuclear matter (ρ > 2 − 3ρ0 that can be reached at relativistic energies, as a function of different conditions of temperature, mass asymmetry and isospin. One of the main study at present is to reach a coherent description of EOS of asymmetric nuclear matter from heavy ion collisions of stable and exotic nuclei, nuclear structure studies and astrophysical observations. In this work an overview of the current status of the research is shortly reviewed together with new perspectives aimed to reduce the present experimental and theoretical uncertainties.

Meson production in nuclear collisions and the equation of state of hadronic matter

International Nuclear Information System (INIS)

Grosse, E.

1993-01-01

Whereas nuclear matter at saturation, i.e. at its ground state density [ρ o ≅ 1 nucleon per 6 fm 3 ] is realized in the center of nuclei, it is compressed to much higher density in neutron stars and during explosive stellar processes like novae and supernovae. The hard core repulsion in the nucleon-nucleon potential and also the Pauli principle counteract such a compression and the stiffness of the equation of state of this matter is determined by these two effects - at least up to a certain density. For very high density and temperature it is believed that the nucleons dissociate into a plasma of quarks and gluons. On the other hand there are detailed theoretical arguments and also experimental evidence shown here, that in the intermediate density range the equation of state is influenced by a different scenario. The conversion of nucleons into heavier baryons leads directly to an additional mass density and at the same time their different quantum numbers allow a higher particle number in a given volume of phase space. The heavy baryons in question are nucleon resonances (Δ,N*) and to smaller extent also hyperons; to conserve strangeness the formation of the latter is associated with the production of kaons whereas Δ's and N*'s are strongly coupled to the pions in the hadronic matter in the collision zone. (author)

Calculation of the binding energy per nucleon and the quasi-particle interation in nuclear matter under consideration of relativistic medium effects

International Nuclear Information System (INIS)

Hippchen, T.

1985-12-01

In a first part, nuclear matter calculations have been performed in the Dirac-Brueckner approach using a) a nucleon-nucleon potential of one-boson-exchange (OBE) type and b) a more realistic interaction in which the fictitious σ-exchange of the OBE-model is replaced by explicit 2π- and πρ-exchange diagrams. Both potential models yield the correct empirical binding energy and saturation density. It turns out that the total sum of relativistic effects caused by the emplicit 2 π- and πρ-exchanges is comparable to those due to σ-exchange. In a second part, the nuclear quasiparticle interaction, i.e. the Landau parameters, have been calculated in the central (F), isospin (F'), spin (G) and spin-isospin (G') channel, in an analogous way. Compared to nonrelativistic calculations (including conventional medium corrections like Pauli and dispersion effects), a strong improvement has been found, especially in the F- and G-channel. Finally, the influence of A 1 -exchange is studied, in NN scattering and in nuclear matter. It turns out that, after a suitable and necessary readjustment of some meson parameters, its role is negligibly small. (orig.)

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.

Isospin effects on collective nuclear dynamics

CERN Document Server

Di Toro, M; Baran, V; Larionov, A B

1999-01-01

We suggest several ways to study properties of the symmetry term in the nuclear equation of state, EOS, from collective modes in beta-unstable nuclei. After a general discussion on compressibility and saturation density in asymmetric nuclear matter we show some predictions on the collective response based on the solution of generalized Landau dispersion relations. Isoscalar-isovector coupling, disappearance of collectivity and possibility of new instabilities in low and high density regions are discussed with accent on their relation to the symmetry term of effective forces. The onset of chemical plus mechanical instabilities in a dilute asymmetric nuclear matter is discussed with reference to new features in fragmentation reactions.

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

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

Nuclear reaction matrix and nuclear forces

International Nuclear Information System (INIS)

Nagata, Sinobu; Bando, Hiroharu; Akaishi, Yoshinori.

1979-01-01

An essentially exact method of solution is presented for the reaction- matrix (G-matrix) equation defined with the orthogonalized plane-wave intermediate spectrum for high-lying two-particle states. The accuracy is examined for introduced truncations and also in comparison with the Tsai-Kuo and Sauer methods. Properties of the G-matrix are discussed with emphasis on the relation with the saturation mechanism, especially overall saturation from light to heavy nuclei. Density and starting-energy dependences of the G-matrix are separately extracted and discussed. It is demonstrated that the triplet-even tensor component of the nuclear force is principally responsible for these dependences and hence for the saturation mechanism. In this context different nuclear potentials are used in the renormalized Brueckner calculation for energies of closed-shell nuclei in the harmonic oscillator basis. A semi-phenomenological ''two-body potential'' is devised so that it can reproduce the saturation energies and densities of nuclear matter and finite nuclei in the lowest-order Brueckner treatment. It is composed of a realistic N-N potential and two additional parts; one incorporates the three-body force effect and the other is assumed to embody higher-cluster correlations in G. The tensor component in the triplet-even state of this potential is enhanced by the three-body force effect. The G-matrix is represented in the effective local form and decomposed into central, LS and tensor components. (author)

Antikaons in infinite nuclear matter and nuclei

International Nuclear Information System (INIS)

Moeller, M.

2007-01-01

In this work we studied the properties of antikaons and hyperons in infinite cold nuclear matter. The in-medium antikaon-nucleon scattering amplitude and self-energy has been calculated within a covariant many-body framework in the first part. Nuclear saturation effects have been taken into account in terms of scalar and vector nucleon mean-fields. In the second part of the work we introduced a non-local method for the description of kaonic atoms. The many-body approach of anti KN scattering can be tested by the application to kaonic atoms. A self-consistent and covariant many-body approach has been used for the determination of the antikaon spectral function and anti KN scattering amplitudes. It considers s-, p- and d-waves and the application of an in-medium projector algebra accounts for proper mixing of partial waves in the medium. The on-shell reduction scheme is also implemented by means of the projector algebra. The Bethe-Salpeter equation has been rewritten, so that the free-space anti KN scattering can be used as the interaction kernel for the in-medium scattering equation. The latter free-space scattering is based on a realistic coupled-channel dynamics and chiral SU(3) Lagrangian. Our many-body approach is generalized for the presence of large scalar and vector nucleon mean-fields. It is supplemented by an improved renormalization scheme, that systematically avoids the occurrence of medium-induced power-divergent structures and kinematical singularities. A modified projector basis has been introduced, that allows for a convenient inclusion of nucleon mean-fields. The description of the results in terms of the 'physical' basis is done with the help of a recoupling scheme based on the projector algebra properties. (orig.)

Symmetry energy of nucleonic matter with tensor correlations

Science.gov (United States)

Hen, Or; Li, Bao-An; Guo, Wen-Jun; Weinstein, L. B.; Piasetzky, Eli

2015-02-01

The nuclear symmetry energy (Esym(ρ ) ) is a vital ingredient of our understanding of many processes, from heavy-ion collisions to neutron stars structure. While the total nuclear symmetry energy at nuclear saturation density (ρ0) is relatively well determined, its value at supranuclear densities is not. The latter can be better constrained by separately examining its kinetic and potential terms and their density dependencies. The kinetic term of the symmetry energy, Esymkin(ρ0) , equals the difference in the per-nucleon kinetic energy between pure neutron matter (PNM) and symmetric nuclear matter (SNM), often calculated using a simple Fermi gas model. However, experiments show that tensor force induced short-range correlations (SRC) between proton-neutron pairs shift nucleons to high momentum in SNM, where there are equal numbers of neutrons and protons, but have almost no effect in PNM. We present an approximate analytical expression for Esymkin(ρ0) of correlated nucleonic matter. In our model, Esymkin(ρ0) =-10 MeV, which differs significantly from +12.5 MeV for the widely-used free Fermi gas model. This result is consistent with our analysis of recent data on the free proton-to-neutron ratios measured in intermediate energy nucleus-nucleus collisions as well as with microscopic many-body calculations, and previous phenomenological extractions. We then use our calculated Esymkin(ρ ) in combination with the known total symmetry energy and its density dependence at saturation density to constrain the value and density dependence of the potential part and to extrapolate the total symmetry energy to supranuclear densities.

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.)

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

Sound modes in hot nuclear matter

International Nuclear Information System (INIS)

Kolomietz, V. M.; Shlomo, S.

2001-01-01

The propagation of the isoscalar and isovector sound modes in a hot nuclear matter is considered. The approach is based on the collisional kinetic theory and takes into account the temperature and memory effects. It is shown that the sound velocity and the attenuation coefficient are significantly influenced by the Fermi surface distortion (FSD). The corresponding influence is much stronger for the isoscalar mode than for the isovector one. The memory effects cause a nonmonotonous behavior of the attenuation coefficient as a function of the relaxation time leading to a zero-to-first sound transition with increasing temperature. The mixing of both the isoscalar and the isovector sound modes in an asymmetric nuclear matter is evaluated. The condition for the bulk instability and the instability growth rate in the presence of the memory effects is studied. It is shown that both the FSD and the relaxation processes lead to a shift of the maximum of the instability growth rate to the longer-wavelength region

Probing the density content of the nuclear symmetry energy

Indian Academy of Sciences (India)

Abstract. The nature of equation of state for the neutron star matter is crucially governed by the density dependence of the nuclear symmetry energy. We attempt to probe the behaviour of the nuclear symmetry energy around the saturation density by exploiting the empirical values for volume and surface symmetry energy ...

Hot nuclear matter in the modified quark-meson coupling model with quark-quark correlations

International Nuclear Information System (INIS)

Zakout, I.; Jaqaman, H.R.

2000-01-01

Short-range quark-quark correlations in hot nuclear matter are examined within the modified quark-meson coupling (MQMC) model by adding repulsive scalar and vector quark-quark interactions. Without these correlations, the bag radius increases with the baryon density. However, when the correlations are introduced the bag size shrinks as the bags overlap. Also as the strength of the scalar quark-quark correlation is increased, the decrease of the effective nucleon mass M* N with the baryonic density is slowed down and tends to saturate at high densities. Within this model we study the phase transition from the baryon-meson phase to the quark-gluon plasma (QGP) phase with the latter modelled as an ideal gas of quarks and gluons inside a bag. Two models for the QGP bag parameter are considered. In one case, the bag is taken to be medium-independent and the phase transition from the hadron phase to QGP is found to occur at five to eight times ordinary nuclear matter density for temperatures less than 60 MeV. For lower densities, the transition takes place at a higher temperature, reaching up to 130 MeV at zero density. In the second case, the QGP bag parameter is considered to be medium-dependent as in the MQMC model for the hadronic phase. In this case, it is found that the phase transition occurs at much lower densities. (author)

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.

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)

Nuclear phenomena derived from quark-gluon strings

DEFF Research Database (Denmark)

Bohr, Henrik; Providencia, Constanca; Providencia, Joao da

2005-01-01

provided that the chiral fields are identified with the two-particle strings, which are natural in a QCD framework. Moreover, the model is able to reconcile qualitatively such aspects of hadronic physics as saturation density and binding energy of nuclear matter, surface density of finite nuclei, mass......, for the occurrence of the phases of nuclear matter. The model exhibits a quark deconfinement transition and chiral restoration, which are ingredients of QCD and give qualitatively correct numerics. The effective model is shown to be isomorphic to the Nambu-Jona-Lasinio model and exhibits the correct chirality...

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.)

Neutron matter, symmetry energy and neutron stars

Energy Technology Data Exchange (ETDEWEB)

Stefano, Gandolfi [Los Alamos National Laboratory (LANL); Steiner, Andrew W [ORNL

2016-01-01

Recent progress in quantum Monte Carlo with modern nucleon-nucleon interactions have enabled the successful description of properties of light nuclei and neutron-rich matter. Of particular interest is the nuclear symmetry energy, the energy cost of creating an isospin asymmetry, and its connection to the structure of neutron stars. Combining these advances with recent observations of neutron star masses and radii gives insight into the equation of state of neutron-rich matter near and above the saturation density. In particular, neutron star radius measurements constrain the derivative of the symmetry energy.

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

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

Particle Correlations in Saturated QCD Matter

CERN Document Server

Baier, R; Nardi, M; Wiedemann, Urs Achim; Baier, Rudolf; Kovner, Alex; Nardi, Marzia; Wiedemann, Urs Achim

2005-01-01

We study quantitatively angular correlations in the two-particle spectrum produced by an energetic probe scattering off a dense hadronic target with sizeable saturation momentum. To this end, two parton inclusive cross sections for arbitrary projectiles with small color charge density are derived in the eikonal formalism. Our results are the following: For large momenta of the observed particles, the perturbative limit with characteristic back-to-back correlation is recovered. As the trigger momenta get closer to the saturation scale Q_s, the angular distribution broadens. When the momenta are significantly smaller than Q_s, the azimuthal distribution is broad but still peaked back-to-back. However, in a narrow momentum range (0.5 - 1.5) Q_s, we observe that the azimuthal correlation splits into a double peak with maxima displaced away from 180 degree. We argue that it is the soft multiple scattering physics that is responsible for the appearance of this shift in the angle of maximal correlation. We also poin...

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)

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.)

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.

Gluon saturation in a saturated environment

International Nuclear Information System (INIS)

Kopeliovich, B. Z.; Potashnikova, I. K.; Schmidt, Ivan

2011-01-01

A bootstrap equation for self-quenched gluon shadowing leads to a reduced magnitude of broadening for partons propagating through a nucleus. Saturation of small-x gluons in a nucleus, which has the form of transverse momentum broadening of projectile gluons in pA collisions in the nuclear rest frame, leads to a modification of the parton distribution functions in the beam compared with pp collisions. In nucleus-nucleus collisions all participating nucleons acquire enhanced gluon density at small x, which boosts further the saturation scale. Solution of the reciprocity equations for central collisions of two heavy nuclei demonstrate a significant, up to several times, enhancement of Q sA 2 , in AA compared with pA collisions.

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

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)

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 ...

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.

An effective equation of state for dense matter with strangeness

International Nuclear Information System (INIS)

Balberg, S.; Gal, A.

1997-01-01

An effective equation of state which generalizes the Lattimer-Swesty equation for nuclear matter is presented for matter at supernuclear densities including strange baryons. It contains an adjustable baryon potential energy density, based on models of local potentials for the baryon-baryon interactions. The features of the equation rely on the properties of nuclei for the nucleon-nucleon interactions, and mainly on experimental data from hypernuclei for the hyperon-nucleon and hyperon-hyperon interactions. The equation is used to calculate equilibrium compositions and thermodynamic properties of high density matter with strangeness in two astrophysical contexts: neutron star matter (transparent to neutrinos) and proto-neutron star matter (opaque to neutrinos). The effective equation of state reproduces typical properties of high density matter found in theoretical microscopic models. Of these, the main result is that hyperons appear in both types of matter at about twice the nuclear saturation density, and that their appearance significantly softens the equation of state. The range of maximal masses of neutron stars found in a comprehensive parameter survey is 1.4-1.7 M s un. Another typical result is that the maximal mass of a proto-neutron star with strange baryons is higher than that of an evolved neutron star (opposite to the case of nuclear matter), setting the stage for a ''delayed collapse'' scenario. (orig.)

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.

Asymmetric nuclear matter and neutron star properties within the extended Brueckner theory

Energy Technology Data Exchange (ETDEWEB)

Hassaneen, Khaled S.A. [Sohag University, Physics Department, Faculty of Science, Sohag (Egypt); Taif University, Physics Department, Faculty of Science, Taif (Saudi Arabia)

2017-01-15

Microscopically, the equation of state (EOS) and other properties of asymmetric nuclear matter at zero temperature have been investigated extensively by adopting the non-relativistic Brueckner-Hartree-Fock (BHF) and the extended BHF approaches by using the self-consistent Green's function approach or by including a phenomenological three-body force. Once three-body forces are introduced, the phenomenological saturation point is reproduced and the theory is applied to the study of neutron star properties. We can calculate the total mass and radius for neutron stars using various equations of state at high densities in β-equilibrium without hyperons. A comparison with other microscopic predictions based on non-relativistic and density-dependent relativistic mean-field calculations has been done. It is found that relativistic EOS yields however larger mass and radius for neutron star than predictions based on non-relativistic approaches. Also the three-body force plays a crucial role to deduce the theoretical value of the maximum mass of neutron stars in agreement with recent measurements of the neutron star mass. (orig.)

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

Properties of nuclear and neutron matter using D1 Gogny force

International Nuclear Information System (INIS)

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

2004-01-01

In the present work, we investigate the equation of state of hot and cold nuclear and neutron matter using the Gogny effective interaction. The binding energy per particle, symmetry energies, free energy, and pressure are calculated as a function of the density ρ, fm -3 , for the nuclear and neutron matter. The results are comparable with previous theoretical estimates using the Seyler-Blanchard effective interaction and the famous calculation of Friedman and Pandharipande using a realistic interaction

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...

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.

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)

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)

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.”

Nuclear Statistical Equilibrium for compact stars: modelling the nuclear energy functional

International Nuclear Information System (INIS)

Aymard, Francois

2015-01-01

The core collapse supernova is one of the most powerful known phenomena in the universe. It results from the explosion of very massive stars after they have burnt all their fuel. The hot compact remnant, the so-called proto-neutron star, cools down to become an inert catalyzed neutron star. The dynamics and structure of compact stars, that is core collapse supernovae, proto-neutron stars and neutron stars, are still not fully understood and are currently under active research, in association with astrophysical observations and nuclear experiments. One of the key components for modelling compact stars concerns the Equation of State. The task of computing a complete realistic consistent Equation of State for all such stars is challenging because a wide range of densities, proton fractions and temperatures is spanned. This thesis deals with the microscopic modelling of the structure and internal composition of baryonic matter with nucleonic degrees of freedom in compact stars, in order to obtain a realistic unified Equation of State. In particular, we are interested in a formalism which can be applied both at sub-saturation and super-saturation densities, and which gives in the zero temperature limit results compatible with the microscopic Hartree-Fock-Bogoliubov theory with modern realistic effective interactions constrained on experimental nuclear data. For this purpose, we present, for sub-saturated matter, a Nuclear Statistical Equilibrium model which corresponds to a statistical superposition of finite configurations, the so-called Wigner-Seitz cells. Each cell contains a nucleus, or cluster, embedded in a homogeneous electron gas as well as a homogeneous neutron and proton gas. Within each cell, we investigate the different components of the nuclear energy of clusters in interaction with gases. The use of the nuclear mean-field theory for the description of both the clusters and the nucleon gas allows a theoretical consistency with the treatment at saturation

New relativistic effective interaction for finite nuclei, infinite nuclear matter, and neutron stars

Science.gov (United States)

Kumar, Bharat; Patra, S. K.; Agrawal, B. K.

2018-04-01

We carry out the study of finite nuclei, infinite nuclear matter, and neutron star properties with the newly developed relativistic force, the Institute of Physics Bhubaneswar-I (IOPB-I). Using this force, we calculate the binding energies, charge radii, and neutron-skin thickness for some selected nuclei. From the ground-state properties of superheavy nuclei (Z =120 ), it is noticed that considerable shell gaps appear at neutron numbers N =172 , 184, and 198, manifesting the magicity at these numbers. The low-density behavior of the equation of state for pure neutron matter is compatible with other microscopic models. Along with the nuclear symmetry energy, its slope and curvature parameters at the saturation density are consistent with those extracted from various experimental data. We calculate the neutron star properties with the equation of state composed of nucleons and leptons in β -equilibrium, which are in good agreement with the x-ray observations by Steiner [Astrophys. J. 722, 33 (2010), 10.1088/0004-637X/722/1/33] and Nättilä [Astron. Astrophys. 591, A25 (2016), 10.1051/0004-6361/201527416]. Based on the recent observation of GW170817 with a quasi-universal relation, Rezzolla et al. [Astrophys. J. Lett. 852, L25 (2018), 10.3847/2041-8213/aaa401] have set a limit for the maximum mass that can be supported against gravity by a nonrotating neutron star in the range 2.01 ±0.04 ≲M (M⊙)≲2.16 ±0.03 . We find that the maximum mass of the neutron star for the IOPB-I parametrization is 2.15 M⊙ . The radius and tidal deformability of a canonical neutron star of mass 1.4 M⊙ are 13.2 km and 3.9 ×1036g cm2s2 , respectively.

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.

Migrations of 60-Co and 137-Cs in Saturated and unsaturated Soil at Serpong Nuclear Research Center

International Nuclear Information System (INIS)

Lubis, E; Untara

1996-01-01

The migrations of 60-Co and 137-Cs in saturated and unsaturated soil at Serpong Nuclear Research Center was investigated. The objectives of this investigation are to find the geological and hydrological parameters, especially for estimating the migrations of radionuclides in porous media with advection-dispersion equations. The result showed that the porosity (η) and density (ρ ) of saturated soil are 27.6% and 1.35 g/cm3, and in the unsaturated soil are 18.9% and 1.41 g/cm3. The coefficients distributions (Kd) of 60-Co and 137-Cs in saturated and unsaturated soil are 1.6 - 8.9 and 3.2 - 7.7 respectively. The hydrodinamic coefficients (Dx) and dispersivity (αx) of C0-60 in saturated and unsaturated soil are 0.85 cm2/second and 2.4 x 10-3 cm, and for 137-Cs are 0.91 cm2/second and 2.54 x 10E3 cm

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-12-31

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 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

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.

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.)

Strangeness in hot and dense nuclear matter

International Nuclear Information System (INIS)

Nappi, E.

2009-01-01

Ultra-relativistic heavy-ion collisions are believed to provide the extreme conditions of energy densities able to lead to a transition to a short-lived state, called Quark-Gluon Plasma (QGP), where the quarks are no longer bound inside hadrons. The studies performed so far, formerly at SPS (CERN) and later at RHIC (BNL) allowed to achieve a multitude of crucial results consistent with the hypothesis that a new phase of the QCD matter has been indeed created. However, the emerging picture is that of the formation of a strongly interacting medium with negligibly small viscosity, a perfect liquid, rather than the ideal perturbative QCD parton-gas predicted by most theorists. The head-on collision between lead nuclei at the unprecedented energies of the forthcoming Large Hadron Collider (LHC) at CERN, due to start in 2008, will allow to measure the properties of compressed and excited nuclear matter at even higher initial densities and temperatures, far above the predicted QCD phase transition point. The longer duration of the quark-gluon plasma phase and the much more abundant production of hard probes, which depend much less on details of the later hadronic phase, will likely provide a consistent and uncontroversial experimental evidence of the QGP formation. Among the signals what witness the charge in the nature of the state of nuclear matter, the chemical equilibrium value of the strangeness plays a key role since it is directly sensitive to the matter properties and provides information on the link between the partonic and the hadronic phases. The aim of this course is to overview the underlying goals, the current status and the prospect of the physics of the nucleus-nucleus collisions at ultrarelativistic energies. Among the experimental methods adopted to investigate the challenging signatures of the QGP formation, emphasis on those related to the strangeness flavour will be given.

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.

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

Nuclear determination of saturation profiles in core plugs

International Nuclear Information System (INIS)

Sletsgaard, J.; Oelgaard, P.L.

1997-01-01

A method to determine liquid saturations in core plugs during flooding is of importance when the relative permeability and capillary pressure function are to be determined. This part of the EFP-95 project uses transmission of γ-radiation to determine these saturations. In γ-transmission measurements, the electron density of the given substance is measured. This is an advantage as compared to methods that use electric conductivity, since neither oil nor gas conducts electricity. At the moment a single 137 Cs-source is used, but a theoretical investigation of whether it is possible to determine three saturations, using two radioactive sources with different γ-energies, has been performed. Measurements were made on three core plugs. To make sure that the measurements could be reproduced, all the plugs had a point of reference, i.e. a mark so that it was possible to place the plug same way every time. Two computer programs for calculation of saturation and porosity and the experimental setup are listed. (EG)

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.

Accuracy in the quantification of chemical exchange saturation transfer (CEST) and relayed nuclear Overhauser enhancement (rNOE) saturation transfer effects.

Science.gov (United States)

Zhang, Xiao-Yong; Wang, Feng; Li, Hua; Xu, Junzhong; Gochberg, Daniel F; Gore, John C; Zu, Zhongliang

2017-07-01

Accurate quantification of chemical exchange saturation transfer (CEST) effects, including dipole-dipole mediated relayed nuclear Overhauser enhancement (rNOE) saturation transfer, is important for applications and studies of molecular concentration and transfer rate (and thereby pH or temperature). Although several quantification methods, such as Lorentzian difference (LD) analysis, multiple-pool Lorentzian fits, and the three-point method, have been extensively used in several preclinical and clinical applications, the accuracy of these methods has not been evaluated. Here we simulated multiple-pool Z spectra containing the pools that contribute to the main CEST and rNOE saturation transfer signals in the brain, numerically fit them using the different methods, and then compared their derived CEST metrics with the known solute concentrations and exchange rates. Our results show that the LD analysis overestimates contributions from amide proton transfer (APT) and intermediate exchanging amine protons; the three-point method significantly underestimates both APT and rNOE saturation transfer at -3.5 ppm (NOE(-3.5)). The multiple-pool Lorentzian fit is more accurate than the other two methods, but only at lower irradiation powers (≤1 μT at 9.4 T) within the range of our simulations. At higher irradiation powers, this method is also inaccurate because of the presence of a fast exchanging CEST signal that has a non-Lorentzian lineshape. Quantitative parameters derived from in vivo images of rodent brain tumor obtained using an irradiation power of 1 μT were also compared. Our results demonstrate that all three quantification methods show similar contrasts between tumor and contralateral normal tissue for both APT and the NOE(-3.5). However, the quantified values of the three methods are significantly different. Our work provides insight into the fitting accuracy obtainable in a complex tissue model and provides guidelines for evaluating other newly developed

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)

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.)

The temperature pulse propagation in interacting nuclear slabs

International Nuclear Information System (INIS)

Kozlowski, M.; Zurich Univ.

1989-01-01

Following the method developed by R.J. Swenson a non-Fourier equation for heat transfer in nuclear matter is obtained. The velocity of heat propagation is calculated and the value υ s = υ F /√3 is obtained. For two interacting nuclear slabs the temperature as a function of time is calculated. For a nucleon mean free path λ ≅ 3 fm the temperature saturation time is calculated and the value ≅ 160 fm/c is obtained. (orig.)

Nuclear physics in colourful worlds. Quantumchromodynamics and nuclear binding

International Nuclear Information System (INIS)

Muether, H.; Engelbrecht, C.A.; Brown, G.E.

1987-01-01

When quantumchromodynamics (QCD) is generalized from SU(3) to an SU(N c ) gauge theory, where N c is the number of colours, it depends on only two parameters: N c and the bare quark mass m q . A more general understanding of nuclear physics can be achieved by considering what it would be like in worlds with the number of colours different from 3, and bare quark masses different from the 'empirical' ones. Such an investigation can be carried out within a framework of meson-exchange interactions. The empirical binding energy of nuclear matter results from a very near cancellation between attractive and repulsive terms which are two orders of magnitude larger and may be expected to depend sensitively on the parameters of QCD. It is indeed found that our world is wedged into a small corner of the two-dimensional manifold of m q versus N c . If the number of colours were decreased by one, or the bare quark masses raised by more than 20%, nuclear matter would become unbound. By tracing the origin of this state of affairs, one obtains a clearer picture of the relative importance of various effects on the behaviour of the bulk nuclear matter. In particular, correlations like those embodied in the Coester band of saturation points appear to have a broader degree of validity than is implied by fits to the actual physical world only. (orig.)

Self consistent propagation of hyperons and antikaons in nuclear matter based on relativistic chiral SU(3) dynamics

International Nuclear Information System (INIS)

Lutz, M.F.M.; Korpa, C.L.

2001-05-01

We evaluate the antikaon spectral density in isospin symmetric nuclear matter. The in-medium antikaon-nucleon scattering process and the antikaon propagation is treated in a self consistent and relativistic manner where a maximally scheme-independent formulation is derived by performing a partial density resummation in terms of the free-space antikaon-nucleon scattering amplitudes. The latter amplitudes are taken from a relativistic and chiral coupled-channel SU(3) approach which includes s-, p- and d-waves systematically. Particular care is taken on the proper evaluation of the in-medium mixing of the partial waves. Our analysis establishes a rich structure of the antikaon spectral function with considerable strength at small energies. At nuclear saturation density we predict attractive mass shifts for the Λ(1405), Σ(1385) and Λ(1520) of about 130 MeV, 60 MeV and 100 MeV respectively. The hyperon states are found to exhibit at the same time an increased decay width of about 150 MeV for the s-wave Λ(1405), 70 MeV for the p-wave Σ(1385) and 100 MeV for the d-wave Λ(1520) resonance. (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.)

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.)

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

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.

arXiv Probing Nuclear PDF and Gluon Saturation At The LHC with Forward Direct Photons

CERN Document Server

Cosentino, Mauro Rogerio

2017-01-30

In relativistic nuclear collisions some of the important aspects to be addressed are the effects of the nuclear PDF and the gluon saturation. In the LHC the best way to address these questions is by means of pA collisions and in particular through the measurement of direct photon production in the forward direction. In order to achieve this measurement a new forward calorimeter (FoCal) is proposed as an upgrade to the ALICE experiment. The proposed detector will cover the range 3.5 4 GeV. We will discuss performance studies and demonstrate that extremely high-granularity calorimetry is required for such measurement. We will also present a few results from R\\&D for this project.

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

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.

The nuclear equation of state

International Nuclear Information System (INIS)

Kahana, S.

1986-01-01

The role of the nuclear equation of state in determining the fate of the collapsing cores of massive stars is examined in light of both recent theoretical advances in this subject and recent experimental measurements with relativistic heavy ions. The difficulties existing in attempts to bring the softer nuclear matter apparently required by the theory of Type II supernovae into consonance with the heavy ion data are discussed. Relativistic mean field theory is introduced as a candidate for derivation of the equation of state, and a simple form for the saturation compressibility is obtained. 28 refs., 4 figs., 1 tab

The nuclear equation of state

Energy Technology Data Exchange (ETDEWEB)

Kahana, S.

1986-01-01

The role of the nuclear equation of state in determining the fate of the collapsing cores of massive stars is examined in light of both recent theoretical advances in this subject and recent experimental measurements with relativistic heavy ions. The difficulties existing in attempts to bring the softer nuclear matter apparently required by the theory of Type II supernovae into consonance with the heavy ion data are discussed. Relativistic mean field theory is introduced as a candidate for derivation of the equation of state, and a simple form for the saturation compressibility is obtained. 28 refs., 4 figs., 1 tab.

Theoretical studies in medium-energy nuclear and hadronic physics

International Nuclear Information System (INIS)

Horowitz, C.J.; Macfarlane, M.H.; Serot, B.D.

1991-01-01

In the period covered by this report, work focused on five main areas: relativistic theories of nuclear structure and saturation; relativistic descriptions of proton-nucleus and electron-nucleus scattering; nonrelativistic theory of nucleon-nucleus reactions; relativistic many-body theory at finite temperature and density; and neutrino interactions in dense matter. This paper discusses this work

Thermodynamic instabilities in hot and dense nuclear matter

Directory of Open Access Journals (Sweden)

Lavagno A.

2016-01-01

Full Text Available We study the presence of thermodynamic instabilities in a hot and dense nuclear medium where a nuclear phase transition can take place. Similarly to the low density nuclear liquid-gas phase transition, we show that such a phase transition is characterized by pure hadronic matter with both mechanical instability (fluctuations on the baryon density that by chemical-diffusive instability (fluctuations on the strangeness concentration. The analysis is performed by requiring the global conservation of baryon number and zero net strangeness in the framework of an effective relativistic mean field theory with the inclusion of the Δ(1232-isobars, hyperons and the lightest pseudoscalar and vector meson degrees of freedom. It turns out that in this situation hadronic phases with different values of strangeness content may coexist, altering significantly meson-antimeson ratios.

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.)

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)

Hyperons in dense matter

International Nuclear Information System (INIS)

Dapo, Haris

2009-01-01

The hyperon-nucleon YN low momentum effective interaction (V low k ) allows for an extensive study of the behavior of hyperons in dense matter, together with an investigation of effects of the presence of hyperons on dense matter. The first step towards this goal is the construction of the matrix elements for the hyperon-nucleon low momentum potential. In order to assess the different properties of hyperons within these potentials we calculate the hyperon single-particle potentials in the Hartree-Fock approximation for all of the interactions. Their dependence on both momentum and density, is studied. The single-particle potentials are then used to determine the chemical potential of hyperons in neutron stars. For nucleonic properties, the nucleon-nucleon V low k can be used with the caveat that the calculation of the ground-state energy of symmetric nuclear matter does not correctly reproduce the properties of matter at saturation. With the nucleon-nucleon V low k one is unable to reach the densities needed for the calculation of neutron star masses. To circumvent this problem we use two approaches: in the first one, we parametrize the entire nucleonic sector. In the second one, we replace only the three-body force. The former will enable us to study neutron star masses, and the latter for studying the medium's response to the external probe. In this thesis we take the external probe to be the neutrino. By combining this parametrization with the YN V low k potential, we calculate the equation of state of equilibrated matter. Performing the calculation in the Hartree-Fock approximation at zero temperature, the concentrations of all particles are calculated. From these we can ascertain at which densities hyperons appear for a wide range of parameters. Finally, we calculate the masses of neutron stars with these concentrations. For the calculation of the medium's response to an external probe, we replace the three-body force with a density-dependent interaction. This

Modeling of gain saturation effects in active semiconductor photonic crystal waveguides

DEFF Research Database (Denmark)

Chen, Yaohui; Mørk, Jesper

2012-01-01

In this paper, we present a theoretical analysis of slow-light enhanced light amplification in an active semiconductor photonic crystal line defect waveguide. The impact of enhanced light-matter interactions on carrier-depletion-induced modal gain saturation is investigated.......In this paper, we present a theoretical analysis of slow-light enhanced light amplification in an active semiconductor photonic crystal line defect waveguide. The impact of enhanced light-matter interactions on carrier-depletion-induced modal gain saturation is investigated....

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 ...

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

Density dependence of the nuclear energy-density functional

Science.gov (United States)

Papakonstantinou, Panagiota; Park, Tae-Sun; Lim, Yeunhwan; Hyun, Chang Ho

2018-01-01

Background: The explicit density dependence in the coupling coefficients entering the nonrelativistic nuclear energy-density functional (EDF) is understood to encode effects of three-nucleon forces and dynamical correlations. The necessity for the density-dependent coupling coefficients to assume the form of a preferably small fractional power of the density ρ is empirical and the power is often chosen arbitrarily. Consequently, precision-oriented parametrizations risk overfitting in the regime of saturation and extrapolations in dilute or dense matter may lose predictive power. Purpose: Beginning with the observation that the Fermi momentum kF, i.e., the cubic root of the density, is a key variable in the description of Fermi systems, we first wish to examine if a power hierarchy in a kF expansion can be inferred from the properties of homogeneous matter in a domain of densities, which is relevant for nuclear structure and neutron stars. For subsequent applications we want to determine a functional that is of good quality but not overtrained. Method: For the EDF, we fit systematically polynomial and other functions of ρ1 /3 to existing microscopic, variational calculations of the energy of symmetric and pure neutron matter (pseudodata) and analyze the behavior of the fits. We select a form and a set of parameters, which we found robust, and examine the parameters' naturalness and the quality of resulting extrapolations. Results: A statistical analysis confirms that low-order terms such as ρ1 /3 and ρ2 /3 are the most relevant ones in the nuclear EDF beyond lowest order. It also hints at a different power hierarchy for symmetric vs. pure neutron matter, supporting the need for more than one density-dependent term in nonrelativistic EDFs. The functional we propose easily accommodates known or adopted properties of nuclear matter near saturation. More importantly, upon extrapolation to dilute or asymmetric matter, it reproduces a range of existing microscopic

Nuclear magnetic resonance and sound velocity measurements of chalk saturated with magnesium rich brine

DEFF Research Database (Denmark)

Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

2013-01-01

The use of low field Nuclear Magnetic Resonance (NMR) to determine petrophysical properties of reservoirs has proved to be a good technique. Together with sonic and electrical resistivity measurements, NMR can contribute to illustrate the changes on chalk elasticity due to different pore water...... solutions of the same ionic strength. Saturation with a solution that contained divalent ions caused a major shift on the distribution of the relaxation time. The changes were probably due to precipitats forming extra internal surface in the sample. Sonic velocities were relatively low in the MgCl2 solution...

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.)

Neutrino diffusion in the pasta phase matter within the Thomas-Fermi approach

Energy Technology Data Exchange (ETDEWEB)

Furtado, U.J.; Avancini, S.S. [Universidade Federal de Santa Catarina, Departamento de Fisica, CFM, CP. 476, Florianopolis - SC (Brazil); University of Coimbra, CFisUC, Department of Physics, Coimbra (Portugal); Marinelli, J.R.; Martarello, W. [Universidade Federal de Santa Catarina, Departamento de Fisica, CFM, CP. 476, Florianopolis - SC (Brazil); Providencia, C. [University of Coimbra, CFisUC, Department of Physics, Coimbra (Portugal)

2016-09-15

The behaviour and properties of neutrinos in non-uniform nuclear matter, surrounded by electrons and other neutrinos are studied in the protoneutron star early stage characterized by trapped neutrinos. The nuclear matter itself is modelled by a relativistic mean-field approach, and models with both constant couplings and density-dependent couplings are considered. The so-called nuclear pasta phases at sub-saturation densities, described using the Thomas-Fermi approximation and solved in a Wigner-Seitz cell, are included in the calculation. We obtain the neutrino total cross section and mean free path, taking into account scattering and absorption processes and we compare the final results obtained with different parametrizations. The solution for this problem is important for the understanding of neutrino diffusion in a newly born neutron star after a supernovae explosion. It is shown that the pasta phase will increase the neutrino mean free path by as much as an order of magnitude, therefore contributing for shorter emission time-scales. (orig.)

Neutrino diffusion in the pasta phase matter within the Thomas-Fermi approach

International Nuclear Information System (INIS)

Furtado, U.J.; Avancini, S.S.; Marinelli, J.R.; Martarello, W.; Providencia, C.

2016-01-01

The behaviour and properties of neutrinos in non-uniform nuclear matter, surrounded by electrons and other neutrinos are studied in the protoneutron star early stage characterized by trapped neutrinos. The nuclear matter itself is modelled by a relativistic mean-field approach, and models with both constant couplings and density-dependent couplings are considered. The so-called nuclear pasta phases at sub-saturation densities, described using the Thomas-Fermi approximation and solved in a Wigner-Seitz cell, are included in the calculation. We obtain the neutrino total cross section and mean free path, taking into account scattering and absorption processes and we compare the final results obtained with different parametrizations. The solution for this problem is important for the understanding of neutrino diffusion in a newly born neutron star after a supernovae explosion. It is shown that the pasta phase will increase the neutrino mean free path by as much as an order of magnitude, therefore contributing for shorter emission time-scales. (orig.)

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

Gluon saturation and baryon stopping in the SPS, RHIC, and LHC energy regions

International Nuclear Information System (INIS)

Li Shuang; Feng Shengqin

2012-01-01

A new geometrical scaling method with a gluon saturation rapidity limit is proposed to study the gluon saturation feature of the central rapidity region of relativistic nuclear collisions. The net-baryon number is essentially transported by valence quarks that probe the saturation regime in the target by multiple scattering. We take advantage of the gluon saturation model with geometric scaling of the rapidity limit to investigate net baryon distributions, nuclear stopping power and gluon saturation features in the SPS and RHIC energy regions. Predictions for net baryon rapidity distributions, mean rapidity loss and gluon saturation feature in central Pb + Pb collisions at the LHC are made in this paper. (authors)

Sub-saturation matter in compact stars: Nuclear modelling in the framework of the extended Thomas-Fermi theory

Energy Technology Data Exchange (ETDEWEB)

Aymard, François; Gulminelli, Francesca [CNRS and ENSICAEN, UMR6534, LPC, 14050 Caen cédex (France); Margueron, Jérôme [Institut de Physique Nucléaire de Lyon, Université Claude Bernard Lyon 1, IN2P3-CNRS, F-69622 Villeurbanne Cedex (France)

2015-02-24

A recently introduced analytical model for the nuclear density profile [1] is implemented in the Extended Thomas-Fermi (ETF) energy density functional. This allows to (i) shed a new light on the issue of the sign of surface symmetry energy in nuclear mass formulas, as well as to (ii) show the importance of the in-medium corrections to the nuclear cluster energies in thermodynamic conditions relevant for the description of core-collapse supernovae and (proto)-neutron star crust.

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 overhauser enhancement mediated chemical exchange saturation transfer imaging at 7 Tesla in glioblastoma patients.

Directory of Open Access Journals (Sweden)

Daniel Paech

Full Text Available BACKGROUND AND PURPOSE: Nuclear Overhauser Enhancement (NOE mediated chemical exchange saturation transfer (CEST is a novel magnetic resonance imaging (MRI technique on the basis of saturation transfer between exchanging protons of tissue proteins and bulk water. The purpose of this study was to evaluate and compare the information provided by three dimensional NOE mediated CEST at 7 Tesla (7T and standard MRI in glioblastoma patients. PATIENTS AND METHODS: Twelve patients with newly diagnosed histologically proven glioblastoma were enrolled in this prospective ethics committee-approved study. NOE mediated CEST contrast was acquired with a modified three-dimensional gradient-echo sequence and asymmetry analysis was conducted at 3.3 ppm (B1 = 0.7 µT to calculate the magnetization transfer ratio asymmetry (MTR(asym. Contrast enhanced T1 (CE-T1 and T2-weighted images were acquired at 3T and used for data co-registration and comparison. RESULTS: Mean NOE mediated CEST signal based on MTR(asym values over all patients was significantly increased (p<0.001 in CE-T1 tumor (-1.99 ± 1.22%, tumor necrosis (-1.36 ± 1.30% and peritumoral CEST hyperintensities (PTCH within T2 edema margins (-3.56 ± 1.24% compared to contralateral normal appearing white matter (-8.38 ± 1.19%. In CE-T1 tumor (p = 0.015 and tumor necrosis (p<0.001 mean MTR(asym values were significantly higher than in PTCH. Extent of the surrounding tumor hyperintensity was smaller in eight out of 12 patients on CEST than on T2-weighted images, while four displayed at equal size. In all patients, isolated high intensity regions (0.40 ± 2.21% displayed on CEST within the CE-T1 tumor that were not discernible on CE-T1 or T2-weighted images. CONCLUSION: NOE mediated CEST Imaging at 7 T provides additional information on the structure of peritumoral hyperintensities in glioblastoma and displays isolated high intensity regions within the CE-T1 tumor that cannot be acquired on CE-T1 or T2

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)

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

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

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

Hot metastable state of abnormal matter in relativistic nuclear field theory

International Nuclear Information System (INIS)

Glendenning, N.K.

1987-01-01

Because of their non-linearity, the field equations of relativistic nuclear field theory admit of additional solutions besides the normal state of matter. One of these is a finite-temperature abnormal phase. Over a narrow range in temperature, matter can exist in the abnormal phase at zero pressure. This is a hot metastable state, for which there is a barrier against decay, because the field configuration is different than in the normal state, the baryon masses are far removed from their vacuum masses, there is an abundance of pairs also far removed from their vacuum masses, and a correspondingly high entropy. The abundance of baryon-antibaryon pairs is the glue that holds this matter together. The signals associated with this novel state are quite unusual. A fragment of such matter will cool by emitting a spectrum of black-body radiation, consisting principally of photons, lepton pairs and pions, rather than by baryon emission, because the latter are far removed from their vacuum masses. If produced at the upper end of its temperature range, a large fraction of the original energy, more than half in the examples studied here, is radiated in this way. The baryons and light elements produced in the eventual decay, after the abnormal matter has cooled to a domain where its pressure becomes positive, will account for only a fraction of the original energy. The energy domain of this state depends sensitively on the coupling constants, and within a reasonable range as determined by nuclear matter properties, can lie in the range of GeV to tens of GeV per nucleon. (orig.)

Anti-saturation system for surface nuclear magnetic resonance in efficient groundwater detection

Science.gov (United States)

Lin, Jun; Zhang, Yang; Yang, Yujing; Sun, Yong; Lin, Tingting

2017-06-01

Compared to other geophysical techniques, the surface nuclear magnetic resonance (SNMR) method could provide unique insights into the hydrologic properties of groundwater in the subsurface. However, the SNMR signal is in the order of nanovolts (10-9 V), and the complex environmental noise, i.e., the spike and the harmony noise (10-4 V), can reach up to 105 times the signal amplitude. Saturation of the amplifier is therefore a serious problem in current SNMR systems. In this study, we propose an anti-saturation method based on an instantaneous floating-point amplifier. The gain of a programmable amplifier is controlled by the value of the input signal. A regulating speed of 50 kS/s is thus achieved to satisfy the self-adaptive adjustment of the real-time SNMR system, which replaces the original man-made setting gain. A large dynamic range of 192.65 dB with a 24-bit high speed analog-digital converter module is then implemented. Compared to traditional SNMR instruments, whose magnification factor is fixed during the experiment, our system can effectively inhibit the distortion of the SNMR signal in both laboratory and field settings. Furthermore, an improved SNR, which is realized by the real-time SNMR system, enables the accurate inversion of the aquifer. Our study broadens the applicability of SNMR systems to use in and around developed areas.

Hyperons in dense matter

Energy Technology Data Exchange (ETDEWEB)

Dapo, Haris

2009-01-28

The hyperon-nucleon YN low momentum effective interaction (V{sub low} {sub k}) allows for an extensive study of the behavior of hyperons in dense matter, together with an investigation of effects of the presence of hyperons on dense matter. The first step towards this goal is the construction of the matrix elements for the hyperon-nucleon low momentum potential. In order to assess the different properties of hyperons within these potentials we calculate the hyperon single-particle potentials in the Hartree-Fock approximation for all of the interactions. Their dependence on both momentum and density, is studied. The single-particle potentials are then used to determine the chemical potential of hyperons in neutron stars. For nucleonic properties, the nucleon-nucleon V{sub low} {sub k} can be used with the caveat that the calculation of the ground-state energy of symmetric nuclear matter does not correctly reproduce the properties of matter at saturation. With the nucleon-nucleon V{sub low} {sub k} one is unable to reach the densities needed for the calculation of neutron star masses. To circumvent this problem we use two approaches: in the first one, we parametrize the entire nucleonic sector. In the second one, we replace only the three-body force. The former will enable us to study neutron star masses, and the latter for studying the medium's response to the external probe. In this thesis we take the external probe to be the neutrino. By combining this parametrization with the YN V{sub low} {sub k} potential, we calculate the equation of state of equilibrated matter. Performing the calculation in the Hartree-Fock approximation at zero temperature, the concentrations of all particles are calculated. From these we can ascertain at which densities hyperons appear for a wide range of parameters. Finally, we calculate the masses of neutron stars with these concentrations. For the calculation of the medium's response to an external probe, we replace the three

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

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.

Probing properties of neutron stars with terrestrial nuclear reactions

International Nuclear Information System (INIS)

Li Baoan; Chen Liewen; Ko, C.M.; Steiner, Andrew W.; Yong Gaochan

2006-01-01

Heavy-ion reactions induced by neutron-rich nuclei provide the unique opportunity in terrestrial laboratories to constrain the nuclear symmetry energy Esym in a broad density range. A conservative constraint, 32(ρ/ρ0)0.7 < Esym(ρ) < 32(ρ/ρ0)1.1, around the nuclear matter saturation density ρ0 has recently been obtained from analyzing the isospin diffusion data within a transport model for intermediate energy heavy-ion reactions. This subsequently puts a stringent constraint on properties of neutron stars, especially their radii and cooling mechanisms

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

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.

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...

Use of nuclear magnetic resonance of hydrogen in the characterization of saturated hydrocarbonic chains

International Nuclear Information System (INIS)

Costa Neto, A.; Soares, V.L.P.; Costa Neto, C.

1979-01-01

Alkanes and cycloalkanes are characterized by a methyl-methylene-methine groups proportion, the percentual absorption in prefixed regions and the pattern of the spectrum of nuclear magnetic resonance of hydrogen. The GPI is calculated from the contribution of the areas corresponding to prefixed regions of the hydrogen magnetic resonance spectra (60 Mc). These regions are (for the saturated hydrocarbons): 0,5-1,05ppm (X), 1,05ppm (Y) and 1,50-2,00ppm (Z). The validity of the index was verified for the homologous series of linear hydrocarbons and methyl-, dimethyl-, ethyl-, cyclopentyl- and cyclohexyl-branched hydrocarbons. Its application to shale oil chemistry (xistoquimica) is discussed. (author) [pt

A generalized Bethe-Weizaecker mass formula for strange hadronic matter

International Nuclear Information System (INIS)

Dover, C.B.; Gal, A.

1993-01-01

We extend the Bethe- Weizsaecker nuclear mass formula to strange hadronic matter composed of nucleons, lambdas and cascade hyperons. The generalized formula contains several volume and symmetry terms constrained by phenomenologically determined Λ-nuclear, Ξ-nuclear and ΛΛ interaction parameters and by hyperon-hyperon (ΛΛ, ΛΞ, ΞΞ) interaction parameters suggested by one-boson-exchange models. We confirm that multi-Λ hypernuclei are generally unstable to ΛΛ→ΞN conversion. For strange hadronic matter we determine, as function of the baryon number A, the line of strong-interaction stability, along which a large strangeness fraction vertical stroke /Svertical stroke /A∝0.5-1.1 and a low charge fraction q/A< or ∼0.2 hold, and no fission occurs. The binding energy per baryon increases monotonically to its bulk limit, B/A→38 MeV, vertical stroke /Svertical stroke /A→ 1.1 and q/A→0 for the parameters adopted here assuming that the hyperon species saturate at densities similar to those of protons and neutrons in nuclei. Even in the extreme limit of vanishingly small hyperon-hyperon interaction strengths, strange hadronic matter with B/A→15 MeV, vertical stroke /Svertical stroke /A→0.7 and q/A→0 in the bulk limit should exist and our mass formula reproduces semi-quantitatively recent mean-field calculations which implicitly assumed weak hyperon-hyperon interactions. (orig.)

A generalized Bethe-Weizsaecker mass formula for strange hadronic matter

International Nuclear Information System (INIS)

Dover, C.B.; Washington Univ., Seattle, WA; Gal, A.; Washington Univ., Seattle, WA

1992-12-01

The Bethe-Weizsaecker nuclear mass formula is extended to strange hadronic matter composed of nucleons, lambdas and cascade hyperons. The generalized formula contains several volume and symmetry terms constrained by phenomenologically determined λ-nuclear, ξ-nuclear and λλ interaction parameters and by hyperon-hyperon (λλ, λξ, ξξ) interaction parameters suggested by One-Boson-Exchange models. We find that hypernuclei are generally unstable to λλ → ξN conversion. For strange hadronic matter, as function of the baryon number A, the line of strong-interaction stability, along which a large strangeness fraction |S|/A ∼ 0.5 - 1.1 and a low charge fraction q/A approx-lt 0.2 hold, and no fission occurs, is determined. The binding energy per baryon increases monotonically to its bulk limit, B/A → 38 MeV, |S|/A → 1.1 and q/A → 0 for the parameters adopted here assuming that the hyperon species saturate at densities similar to those of protons and neutrons in nuclei. Even in the extreme limit of vanishingly small hyperon-hyperon interaction strengths, strange hadronic matter with B/A → 15 MeV, |S|/A → 0.7 and q/A → 0 in the bulk limit should exist; the mass formula reproduces semi-quantitatively recent mean-field calculations which implicitly assumed weak hyperon-hyperon interactions

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)

Isospin and momentum dependence of liquid-gas phase transition in hot asymmetric nuclear matter

International Nuclear Information System (INIS)

Xu, Jun; Ma, Hongru; Chen, Liewen; Li, Baoan

2008-01-01

The liquid-gas phase transition in hot neutron-rich nuclear matter is investigated within a self-consistent thermal model using different interactions with or without isospin and/or momentum dependence. The boundary of the phase-coexistence region is shown to be sensitive to the density dependence of the nuclear symmetry energy as well as the isospin and momentum dependence of the nuclear interaction. (author)

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...

New concept for nuclear force: implications for nuclear structure and hadronic processes

International Nuclear Information System (INIS)

Kukulin, V.I.

2005-01-01

Full text: A new concept for nuclear force is discussed. The concept is based on idea about production of the intermediate six-quark bag (dibaryon) dressed with meson fields main of which are π-, σ-, p-, and ω-fields. The whole approach has been strongly motivated by our previous detailed analysis of various inner contradictions and inconsistencies in the conventional meson-exchange (i.e. Yukawa like) mechanism of nuclear force. The new force model predicts inevitable strong attractive 3N-force of scalar nature originated from σ-exchange between the dressed dibaryon and third nucleon. This new 3N-force has been demonstrated earlier to result in, at least, a half the total binding energy in lightest nuclei and contribute strongly to all nuclear properties like r. m. s. charge radius, nucleon momentum distribution, new electromagnetic currents and leads, very likely, to new understanding of saturation properties in nuclear matter. In the talk many other implications of the suggested new force model in hadronic and nuclear physics will be discussed

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

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 ...

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.

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.

Systematics of strong nuclear amplification of gluon saturation from exclusive vector meson production in high energy electron-nucleus collisions

Science.gov (United States)

Mäntysaari, Heikki; Venugopalan, Raju

2018-06-01

We show that gluon saturation gives rise to a strong modification of the scaling in both the nuclear mass number A and the virtuality Q2 of the vector meson production cross-section in exclusive deep-inelastic scattering off nuclei. We present qualitative analytic expressions for how the scaling exponents are modified as well as quantitative predictions that can be tested at an Electron-Ion Collider.

High speed drying of saturated steam

International Nuclear Information System (INIS)

Marty, C.; Peyrelongue, J.P.

1993-01-01

This paper describes the development of the drying process for the saturated steam used in the PWR nuclear plant turbines in order to prevent negative effects of water on turbine efficiency, maintenance costs and equipment lifetime. The high speed drying concept is based on rotating the incoming saturated steam in order to separate water which is more denser than the steam; the water film is then extracted through an annular slot. A multicellular modular equipment has been tested. Applications on high and low pressure extraction of various PWR plants are described (Bugey, Loviisa)

Cold exposure rapidly induces virtual saturation of brown adipose tissue nuclear T3 receptors

International Nuclear Information System (INIS)

Bianco, A.C.; Silva, J.E.

1988-01-01

Cold exposure induces a rapid increase in uncoupling protein (UCP) concentration in the brown adipose tissue (BAT) of euthyroid, but not hypothyroid, rats. To normalize this response with exogenous 3,5,3'-triiodothyronine (T 3 ), it is necessary to cause systemic hyperthyroidism. In contrast, the same result can be obtained with just replacement doses of thyroxine (T 4 ) and, in euthyroid rats, the normal response of UCP to cold occurs without hyperthyroid plasma T 3 levels. Consequently, the authors explored the possibility that the cold-induced activation of the type II 5'-deiodinase resulted in high levels of nuclear T 3 receptor occupancy in euthyroid rats. Studies were performed with pulse injections of tracer T 3 or T 4 in rats exposed to 4 degree C for different lengths of time (1 h-3 wk). Within 4 h of cold exposure, they observed a significant increase in the nuclear [ 125 I]T 3 derived from the tracer [ 125 I]T 4 injections (T 3 [T 4 ]) and a significant reduction in the nuclear [ 125 I]T 3 derived from [ 125 I]T 3 injections (T 3 [T 3 ]). The number of BAT nuclear T 3 receptors did not increase for up to 3 wk of observation at 4 degree C. The mass of nuclear-bound T 3 was calculated from the nuclear tracer [ 125 I]T 3 [T 3 ] and [ 125 I]T 3 [T 4 ] at equilibrium and the specific activity of serum T 3 and T 4 , respectively. By 4 h after the initiation of the cold exposure, the receptors were >95% occupied and remained so for the 3 weeks of observation. They conclude that the simultaneous activation of the deiodinase with adrenergic BAT stimulation serves the purpose of nearly saturating the nuclear T 3 receptors. This makes possible the realization of the full thermogenic potential of the tissue without causing systemic hyperthyroidism

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

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)

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.

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.)

Saturated steam turbines for power reactors of WWER-type

International Nuclear Information System (INIS)

Czwiertnia, K.

1978-01-01

The publication deals with design problems of large turbines for saturated steam and with problem of output limitations of single shaft normal speed units. The possibility of unification of conventional and nuclear turbines, which creates the economic basis for production of both types of turbines by one manufacturer based on standarized elements and assemblies is underlined. As separate problems the distribution of nuclear district heating power systems are considered. The choice of heat diagram for district heating saturated steam turbines, the advantages of different diagrams and evaluaton for further development are presented. On this basis a program of unified turbines both condensing and district heating type suitable for Soviet reactors of WWER-440 and WWER-1000 type for planned development of nuclear power in Poland is proposed. (author)

Uncertainties in sealing a nuclear waste repository in partially saturated tuff

International Nuclear Information System (INIS)

Tillerson, J.R.; Fernandez, J.A.; Hinkebein, T.E.

1989-01-01

Sealing a nuclear waste repository in partially saturated tuff presents unique challenges to assuring performance of sealing components. Design and performance of components for sealing shafts, ramps, drifts, and exploratory boreholes depend on specific features of both the repository design and the site; of particular importance is the hydrologic environment in the unsaturated zone, including the role of fracture flow. Repository design features important to sealing of a repository include the size and location of shaft and ramp accesses, excavation methods, and the underground layout features such as grade (drainage direction) and location relative to geologic structure. Uncertainties about seal components relate to the postclosure environment for the seals, the emplacement methods, the material properties, and the potential performance of the components. An approach has been developed to reduce uncertainties and to increase confidence in seal performance; it includes gathering extensive site characterization data, establishing conservative design requirements, testing seal components in laboratory and field environments, and refining designs of both the seals and the repository before seals are installed. 9 refs., 5 figs., 2 tabs

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

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.)

Search for gluon saturation at Bjorken-x $\\in [10^{−6}, 10^{−4}]$ with the LHCb detector(ID:39)

CERN Document Server

Da Silva, Cesar Luiz

2018-01-01

A new state of matter, where gluons have overlapping wave functions, has been in the minds of particle and nuclear physicists for decades. This gluon saturated state could explain several recent observations such as particle production and collectivity observed in p+p, p+A and A+A collisions at RHIC and LHC. The LHCb experiment is a forward spectrometer with vertexing, tracking, $p, K, \\pi, e, \\mu$ identification and calorimetry in the pseudorapidity region 2< $\\eta$ <5. LHCb is therefore well suited to study the gluon density of hadrons in at small Bjorken-x values $(x∼10^{−6}−10^{−5})$, down to two orders of magnitude smaller than HERA. The status of the analysis efforts aimed at finding the gluon saturation scale at LHCb using isolated photon yields and their correlations with hadrons and jets will be shown. In addition, the concept and R&D efforts of a new particle tracker inside the LHCb magnet to improve measurements of small Q2 processes, where gluon saturation is expected, will be pr...

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.)

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....

A new equation of state for core-collapse supernovae based on realistic nuclear forces and including a full nuclear ensemble

International Nuclear Information System (INIS)

Furusawa, S; Togashi, H; Nagakura, H; Sumiyoshi, K; Yamada, S; Suzuki, H; Takano, M

2017-01-01

We have constructed a nuclear equation of state (EOS) that includes a full nuclear ensemble for use in core-collapse supernova simulations. It is based on the EOS for uniform nuclear matter that two of the authors derived recently, applying a variational method to realistic two- and three-body nuclear forces. We have extended the liquid drop model of heavy nuclei, utilizing the mass formula that accounts for the dependences of bulk, surface, Coulomb and shell energies on density and/or temperature. As for light nuclei, we employ a quantum-theoretical mass evaluation, which incorporates the Pauli- and self-energy shifts. In addition to realistic nuclear forces, the inclusion of in-medium effects on the full ensemble of nuclei makes the new EOS one of the most realistic EOSs, which covers a wide range of density, temperature and proton fraction that supernova simulations normally encounter. We make comparisons with the FYSS EOS, which is based on the same formulation for the nuclear ensemble but adopts the relativistic mean field theory with the TM1 parameter set for uniform nuclear matter. The new EOS is softer than the FYSS EOS around and above nuclear saturation densities. We find that neutron-rich nuclei with small mass numbers are more abundant in the new EOS than in the FYSS EOS because of the larger saturation densities and smaller symmetry energy of nuclei in the former. We apply the two EOSs to 1D supernova simulations and find that the new EOS gives lower electron fractions and higher temperatures in the collapse phase owing to the smaller symmetry energy. As a result, the inner core has smaller masses for the new EOS. It is more compact, on the other hand, due to the softness of the new EOS and bounces at higher densities. It turns out that the shock wave generated by core bounce is a bit stronger initially in the simulation with the new EOS. The ensuing outward propagations of the shock wave in the outer core are very similar in the two simulations, which

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.)

Onset of superfluidity in hot asymmetric nuclear matter

International Nuclear Information System (INIS)

Alm, T.; Roepke, G.; Friman, B.L.

1991-05-01

The onset of superfluidity in hot asymmetric nuclear matter is studied within a generalized Beth-Uhlenbeck approach. The finite tempeature t-matrix is of the Bethe-Goldstone type and contains hole-hole propagation not considered in the Brueckner G-matrix approach. It is shown that the phase contour for the onset of superfluidity in this approach is identical to that obtained within Gorkov's approach to BCS theory. Results for the realistic Paris potential imply that the critical temperature in the neutron-proton triplet channel is on the order of 6-8 MeV and thus much larger than that for singlet pairing. (orig.)

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)

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.)

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

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.)

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.

Saturated Zone Flow and Transport Expert Elicitation Project

Energy Technology Data Exchange (ETDEWEB)

Coppersmith, Kevin J.; Perman, Roseanne C.

1998-01-01

This report presents results of the Saturated Zone Flow and Transport Expert Elicitation (SZEE) project for Yucca Mountain, Nevada. This project was sponsored by the US Department of Energy (DOE) and managed by Geomatrix Consultants, Inc. (Geomatrix), for TRW Environmental Safety Systems, Inc. The DOE's Yucca Mountain Site Characterization Project (referred to as the YMP) is intended to evaluate the suitability of the site for construction of a mined geologic repository for the permanent disposal of spent nuclear fuel and high-level radioactive waste. The SZEE project is one of several that involve the elicitation of experts to characterize the knowledge and uncertainties regarding key inputs to the Yucca Mountain Total System Performance Assessment (TSPA). The objective of the current project was to characterize the uncertainties associated with certain key issues related to the saturated zone system in the Yucca Mountain area and downgradient region. An understanding of saturated zone processes is critical to evaluating the performance of the potential high-level nuclear waste repository at Yucca Mountain. A major goal of the project was to capture the uncertainties involved in assessing the saturated flow processes, including uncertainty in both the models used to represent the physical processes controlling saturated zone flow and transport, and the parameter values used in the models. So that the analysis included a wide range of perspectives, multiple individual judgments were elicited from members of an expert panel. The panel members, who were experts from within and outside the Yucca Mountain project, represented a range of experience and expertise. A deliberate process was followed in facilitating interactions among the experts, in training them to express their uncertainties, and in eliciting their interpretations. The resulting assessments and probability distributions, therefore, provide a reasonable aggregate representation of the knowledge and

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

Effect Of Intraruminal Infussion Of Saturated And Unsaturated Fatty ...

African Journals Online (AJOL)

This study describes the effect of intraruminal infusion of diferent proportions of palmitic (saturated fatty acid) and linolenic (unsaturated fatty acid) on rumen degradability of organic matter fraction of Pennisetium purpureum, total volatile fatty acid and total methane productions in West African Dwarf sheep. Five combination ...

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)

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

Three-body forces, relativistic effects, isobars, and pions in nuclear systems

International Nuclear Information System (INIS)

Wiringa, R.B.

1983-01-01

Conventional microscopic calculations in nuclear physics start from a nonrelativistic Hamiltonian. The many-body Schroedinger equation is then solved to obtain the ground state energy, wave function, and expectation values of other quantities of interest. Such a procedure gives a qualitative description of nuclear saturation properties, but it is now well established that the simple H is quantitatively inadequate. For example, the light nuclei are underbound with too large a charge radius, while nuclear matter is overbound at far too high a density. This note reviews recent studies that go beyond the simple H. These include 1) the introduction of three-nucleon potentials, 2) estimates of relativistic effects, 3) the introduction of isobar degrees of freedom in the two-body potential, and 4) probing the influence of pion degrees of freedom on nuclear systems

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

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)

Molecular dynamics for dense matter

Science.gov (United States)

Maruyama, Toshiki; Watanabe, Gentaro; Chiba, Satoshi

2012-08-01

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.

Time scales for spinodal decomposition in nuclear matter with pseudo-particle model

Energy Technology Data Exchange (ETDEWEB)

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

1993-12-31

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 pseudo-particle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed. (author) 12 refs.; 6 figs.; 1 tab.

Time scales for spinodal decomposition in nuclear matter with pseudo-particle model

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 pseudo-particle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed. (author) 12 refs.; 6 figs.; 1 tab

Measurement of Quark Energy Loss in Cold Nuclear Matter at Fermilab E906/SeaQuest

Energy Technology Data Exchange (ETDEWEB)

Lin, Po-Ju [Univ. of Colorado, Boulder, CO (United States)

2017-01-01

Parton energy loss is a process within QCD that draws considerable interest. The measurement of parton energy loss can provide valuable information for other hard-scattering processes in nuclei, and also serves as an important tool for exploring the properties of the quark-gluon plasma (QGP). Quantifying the energy loss in cold nuclear matter will help to set a baseline relative to energy loss in the QGP. With the Drell-Yan process, the energy loss of incoming quarks in cold nuclear matter can be ideally investigated since the final state interaction is expected to be minimal. E906/SeaQuest is a fixed-target experiment using the 120 GeV proton beam from the Fermilab Main Injector and has been collecting data from p+p, p+d, p+C, p+Fe, and p+W collisions. Within the E906 kinematic coverage of Drell-Yan production via the dimuon channel, the quark energy loss can be measured in a regime where other nuclear effects are expected to be small. In this thesis, the study of quark ener gy loss from different cold nuclear targets is presented.

Discovery potential for directional dark matter detection with nuclear emulsions

Science.gov (United States)

Guler, A. M.; NEWSdm Collaboration

2017-06-01

Direct Dark Matter searches are nowadays one of the most exciting research topics. Several Experimental efforts are concentrated on the development, construction, and operation of detectors looking for the scattering of target nuclei with Weakly Interactive Massive Particles (WIMPs). In this field a new frontier can be opened by directional detectors able to reconstruct the direction of the WIMP-recoiled nucleus thus allowing to extend dark matter searches beyond the neutrino floor. Exploiting directionality would also give a proof of the galactic origin of dark matter making it possible to have a clear and unambiguous signal to background separation. The angular distribution of WIPM-scattered nuclei is indeed expected to be peaked in the direction of the motion of the Solar System in the Galaxy, i.e. toward the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on the use of gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we show the potentiality in terms of exclusion limit of a directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching sub-micrometric resolution.

Neutron matter within QCD sum rules

Science.gov (United States)

Cai, Bao-Jun; Chen, Lie-Wen

2018-05-01

The equation of state (EOS) of pure neutron matter (PNM) is studied in QCD sum rules (QCDSRs ). It is found that the QCDSR results on the EOS of PNM are in good agreement with predictions by current advanced microscopic many-body theories. Moreover, the higher-order density terms in quark condensates are shown to be important to describe the empirical EOS of PNM in the density region around and above nuclear saturation density although they play a minor role at subsaturation densities. The chiral condensates in PNM are also studied, and our results indicate that the higher-order density terms in quark condensates, which are introduced to reasonably describe the empirical EOS of PNM at suprasaturation densities, tend to hinder the appearance of chiral symmetry restoration in PNM at high densities.

A study of nuclear recoil backgrounds in dark matter detectors

Science.gov (United States)

Westerdale, Shawn S.

Despite the great success of the Standard Model of particle physics, a preponderance of astrophysical evidence suggests that it cannot explain most of the matter in the universe. This so-called dark matter has eluded direct detection, though many theoretical extensions to the Standard Model predict the existence of particles with a mass on the 1-1000 GeV scale that interact only via the weak nuclear force. Particles in this class are referred to as Weakly Interacting Massive Particles (WIMPs), and their high masses and low scattering cross sections make them viable dark matter candidates. The rarity of WIMP-nucleus interactions makes them challenging to detect: any background can mask the signal they produce. Background rejection is therefore a major problem in dark matter detection. Many experiments greatly reduce their backgrounds by employing techniques to reject electron recoils. However, nuclear recoil backgrounds, which produce signals similar to what we expect from WIMPs, remain problematic. There are two primary sources of such backgrounds: surface backgrounds and neutron recoils. Surface backgrounds result from radioactivity on the inner surfaces of the detector sending recoiling nuclei into the detector. These backgrounds can be removed with fiducial cuts, at some cost to the experiment's exposure. In this dissertation we briefly discuss a novel technique for rejecting these events based on signals they make in the wavelength shifter coating on the inner surfaces of some detectors. Neutron recoils result from neutrons scattering off of nuclei in the detector. These backgrounds may produce a signal identical to what we expect from WIMPs and are extensively discussed here. We additionally present a new tool for calculating (alpha, n) yields in various materials. We introduce the concept of a neutron veto system designed to shield against, measure, and provide an anti-coincidence veto signal for background neutrons. We discuss the research and development

A Study of Nuclear Recoil Backgrounds in Dark Matter Detectors

Energy Technology Data Exchange (ETDEWEB)

Westerdale, Shawn S. [Princeton Univ., NJ (United States)

2016-01-01

Despite the great success of the Standard Model of particle physics, a preponderance of astrophysical evidence suggests that it cannot explain most of the matter in the universe. This so-called dark matter has eluded direct detection, though many theoretical extensions to the Standard Model predict the existence of particles with a mass on the $1-1000$ GeV scale that interact only via the weak nuclear force. Particles in this class are referred to as Weakly Interacting Massive Particles (WIMPs), and their high masses and low scattering cross sections make them viable dark matter candidates. The rarity of WIMP-nucleus interactions makes them challenging to detect: any background can mask the signal they produce. Background rejection is therefore a major problem in dark matter detection. Many experiments greatly reduce their backgrounds by employing techniques to reject electron recoils. However, nuclear recoil backgrounds, which produce signals similar to what we expect from WIMPs, remain problematic. There are two primary sources of such backgrounds: surface backgrounds and neutron recoils. Surface backgrounds result from radioactivity on the inner surfaces of the detector sending recoiling nuclei into the detector. These backgrounds can be removed with fiducial cuts, at some cost to the experiment's exposure. In this dissertation we briefly discuss a novel technique for rejecting these events based on signals they make in the wavelength shifter coating on the inner surfaces of some detectors. Neutron recoils result from neutrons scattering from nuclei in the detector. These backgrounds may produce a signal identical to what we expect from WIMPs and are extensively discussed here. We additionally present a new tool for calculating ($\\alpha$, n)yields in various materials. We introduce the concept of a neutron veto system designed to shield against, measure, and provide an anti-coincidence veto signal for background neutrons. We discuss the research and

Bose-Einstein correlations and the equation of state of nuclear matter in relativistic heavy-ion collisions

International Nuclear Information System (INIS)

Schlei, B.R.

1998-01-01

Experimental spectra of the CERN/SPS experiments NA44 and NA49 are fitted while using four different equations of state of nuclear matter within a relativistic hydrodynamic framework. For the freeze-out temperatures, T f = 139 MeV and T f = 116 MeV, respectively, the corresponding freeze-out hypersurfaces and Bose-Einstein correlation functions for identical pion pairs are discussed. It is concluded, that the Bose-Einstein interferometry measures the relation between the temperature and the energy density in the equation of state of nuclear matter at the late hadronic stage of the fireball expansion. It is necessary, to use the detailed detector acceptances in the calculations for the Bose-Einstein correlations

Towards Dense Nuclear Matter in A Modified Sakai-Sugimoto Model

Directory of Open Access Journals (Sweden)

Rho Mannque

2012-02-01

Full Text Available As a part of the attempt to address dense baryonic matter, we first review holographic approaches to QCD. The big advantage of the holographic approaches is that they render strongly coupled 4D gauge theories as duals of certain weakly coupled string/supergravity that are well understood. Its relevance to real QCD is one of the central problems in hadron/nuclear physics as well as in the context of applied string theory. None of the models based on these holographic approaches presently available can adequately describe the system we are interested in, namely dense baryonic matter. Nevertheless, some aspects of the holographic approach are found to describe certain processes both in vacuum and in medium. In this talk we only present the structure of a model that appears to be closest to QCD, and has the potential to address the problem.

Single Particle Potential of a Σ Hyperon in Nuclear Matter. II Rearrangement Effects

International Nuclear Information System (INIS)

Dabrowski, J.

2000-01-01

The rearrangement contribution to the real part of the single particle potential of a Σ hyperon in nuclear matter, U Σ , is investigated. The isospin and spin dependent parts of U Σ are considered. Results obtained for four models of the Nijmegen baryon-baryon interaction are presented and discussed. (author)

Nucleonics, and nuclear matter in 10{sup {minus}20} secs. before the close of {open_quotes}Big Bang{close_quotes}

Energy Technology Data Exchange (ETDEWEB)

Ayub, S.M.

1995-10-01

The Nuclear picture 10{sup -20} secs. after the thermonuclear creation of the Universe {approximately}8 Billion years ago (as also evidenced by Hubble Telescope) was published. Relativity concepts predict the Nuclear picture l0{sup -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 {approximately} <13Km.> 10Km., {open_quote}r{close_quote}, P=10{sup 15}-10{sup 18} Temp. > 10{sup 10} Deg. C. P> 10{sup 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!

Upper-bound nature of the Brueckner energy of nuclear matter

International Nuclear Information System (INIS)

Harada, M.

1993-01-01

A trial wavefunction is constructed for nuclear matter in terms of the reaction matrix. The trial function includes only two-particle excitations and the resulting energy expectation value for two-nucleon forces with a state-independent repulsive core of Yukawa shape approaches in the thermodynamic limit the energy given by the lowest order Brueckner theory with standard dispersion. Evaluation of the energy expectation value is carried out in a systematic way by use of an identity that holds between the Hamiltonians and reaction matrix. (Author)

Many body effects in nuclear matter QCD sum rules

Science.gov (United States)

Drukarev, E. G.; Ryskin, M. G.; Sadovnikova, V. A.

2017-12-01

We calculate the single-particle nucleon characteristics in symmetric nuclear matter with inclusion of the 3N and 4N interactions. We calculated the contribution of the 3N interactions earlier, now we add that of the 4N ones. The contribution of the 4N forces to nucleon self energies is expressed in terms of the nonlocal scalar condensate (d = 3) and of the configurations of the vector-scalar and the scalar-scalar quark condensates (d = 6) in which two diquark operators act on two different nucleons of the matter.These four-quark condensates are obtained in the model-independent way. The density dependence of the nucleon effective mass, of the vector self energy and of the single-particle potential energy are obtained. We traced the dependence of the nucleon characteristics on the actual value of the pion-nucleon sigma term. We obtained also the nucleon characteristics in terms of the quasifree nucleons, with the noninteracting nucleons surrounded by their pion clouds as the starting point. This approach leads to strict hierarchy of the many body forces.

Nuclear and Condensed Matter Physics: VI Regional CRRNSM Conference. AIP Conference Proceedings, No. 513 [APCPCS

International Nuclear Information System (INIS)

Messina, A.

2000-01-01

This book contains 102 scientific contributions in the areas of nuclear and condensed matter physics. The conference was attended by 144 physicists, most of them belonging to the Sicilian Universities of Palermo, Catania and Messina

75 FR 74750 - In the Matter of Toshiba America Nuclear Energy Corporation and All Other Persons Who Seek or...

Science.gov (United States)

2010-12-01

... NUCLEAR REGULATORY COMMISSION [EA-10-152; Project No. 52-0001; NRC-2010-0368] In the Matter of Toshiba America Nuclear Energy Corporation and All Other Persons Who Seek or Obtain Access to Safeguards... protect SGI (73 FR 63546). The NRC is issuing this Order to Toshiba America Nuclear Energy Corporation...

78 FR 14361 - In the Matter of Luminant Generation Company LLC, Comanche Peak Nuclear Power Plant, Units 1 and...

Science.gov (United States)

2013-03-05

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0310; Docket Nos. 50-445 and 50-446; License Nos. NPF-87 and NPF-89] In the Matter of Luminant Generation Company LLC, Comanche Peak Nuclear Power Plant, Units... Nuclear Power Plant, Units 1 and 2 (CPNPP), and its Independent Spent Fuel Storage Installation Facility...

Measurements of cold nuclear matter effects on J/ψ in the PHENIX experiment via deuteron-gold collisions

International Nuclear Information System (INIS)

Cianciolo, Vince

2008-01-01

A new calculation of R dAu has been performed using the 2003 d+Au data and the higher-statistics 2005 p+p data. These nuclear modification factors are compared to calculations using nuclear-modified PDFs and a J/ψ breakup cross section is extracted. These values are then used to project the cold nuclear matter effects in Au+Au collisions. Additionally, a more data-driven projection is performed

Nuclear Magnetic Resonance and Elastic Wave Velocity of Chalk Saturated with Brines Containing Divalent Ions

DEFF Research Database (Denmark)

Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

divided into groups of three and each group was saturated either with deionized water, calcite equilibrated water, or sodium chloride, magnesium chloride and calcium chloride solutions of the same ionic strength. Saturation with solutions that contain divalent ions caused major shifts in the distribution...... of the relaxation time. Core samples saturated with calcium chloride solution relaxed slower and those saturated with magnesium chloride solution relaxed faster than the rest of the samples. Along with the changes in relaxation the samples experienced smaller velocities of elastic waves when saturated with MgCl2...

Role of isospin in nuclear-matter liquid-gas phase transition; Role de l'isospin dans la transition de phase liquide-gaz de la matiere nucleaire

Energy Technology Data Exchange (ETDEWEB)

Ducoin, C

2006-10-15

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)

Stars of strange matter

International Nuclear Information System (INIS)

Bethe, H.A.; Brown, G.E.; Cooperstein, J.

1987-01-01

We investigate suggestions that quark matter with strangeness per baryon of order unity may be stable. We model this matter at nuclear matter densities as a gas of close packed Λ-particles. From the known mass of the Λ-particle we obtain an estimate of the energy and chemical potential of strange matter at nuclear densities. These are sufficiently high to preclude any phase transition from neutron matter to strange matter in the region near nucleon matter density. Including effects from gluon exchange phenomenologically, we investigate higher densities, consistently making approximations which underestimate the density of transition. In this way we find a transition density ρ tr > or approx.7ρ 0 , where ρ 0 is nuclear matter density. This is not far from the maximum density in the center of the most massive neutron stars that can be constructed. Since we have underestimated ρ tr and still find it to be ∝7ρ 0 , we do not believe that the transition from neutron to quark matter is likely in neutron stars. Moreover, measured masses of observed neutron stars are ≅1.4 M sun , where M sun is the solar mass. For such masses, the central (maximum) density is ρ c 0 . Transition to quark matter is certainly excluded for these densities. (orig.)

Exploring the Quark-Gluon Content of Hadrons: From Mesons to Nuclear Matter

International Nuclear Information System (INIS)

Hrayr Matevosyan

2007-01-01

Even though Quantum Chromodynamics (QCD) was formulated over three decades ago, it poses enormous challenges for describing the properties of hadrons from the underlying quark-gluon degrees of freedom. Moreover, the problem of describing the nuclear force from its quark-gluon origin is still open. While a direct solution of QCD to describe the hadrons and nuclear force is not possible at this time, we explore a variety of developed approaches ranging from phenomenology to first principle calculations at one or other level of approximation in linking the nuclear force to QCD. The Dyson Schwinger formulation (DSE) of coupled integral equations for the QCD Green's functions allows a non-perturbative approach to describe hadronic properties, starting from the level of QCD n-point functions. A significant approximation in this method is the employment of a finite truncation of the system of DSEs, that might distort the physical picture. In this work we explore the effects of including a more complete truncation of the quark-gluon vertex function on the resulting solutions for the quark 2-point functions as well as the pseudoscalar and vector meson masses. The exploration showed strong indications of possibly large contributions from the explicit inclusion of the gluon 3- and 4-point functions that are omitted in this and previous analyses. We then explore the possibility of extrapolating state of the art lattice QCD calculations of nucleon form factors to the physical regime using phenomenological models of nucleon structure. Finally, we further developed the Quark Meson Coupling model for describing atomic nuclei and nuclear matter, where the quark-gluon structure of nucleons is modeled by the MIT bag model and the nucleon many body interaction is mediated by the exchange of scalar and vector mesons. This approach allows us to formulate a fully relativistic theory, which can be expanded in the nonrelativistic limit to reproduce the well known phenomenological Skyrme

Water hammer phenomena occurring in nuclear power installations while filling horizontal pipe containing saturated steam with liquid

Energy Technology Data Exchange (ETDEWEB)

Selivanov, Y.F.; Kirillov, P.L.; Yefanov, A.D. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

1995-09-01

The potentiality of the water hammer occurrence in nuclear reactor loop components has been considered under the conditions of filling a steam-containing pipeline leg involving horizontal and vertical sections with liquid subcooled to the saturation temperature. As a result of free discharging from the tank, the liquid enters the horizontal pipeline. When the liquid slug formation in the pipeline is fulfilled. The pressure drop being occurred in steam flowing along the pipelines causes the liquid slug to move to the pipeline inlet. When the liquid slug decelerates, a water hammer occurs. This mechanism of water hammer occurrence is tested by experiments. The regimes of the occurrence of multiple considerable water hammers were identified.

Water hammer phenomena occurring in nuclear power installations while filling horizontal pipe containing saturated steam with liquid

International Nuclear Information System (INIS)

Selivanov, Y.F.; Kirillov, P.L.; Yefanov, A.D.

1995-01-01

The potentiality of the water hammer occurrence in nuclear reactor loop components has been considered under the conditions of filling a steam-containing pipeline leg involving horizontal and vertical sections with liquid subcooled to the saturation temperature. As a result of free discharging from the tank, the liquid enters the horizontal pipeline. When the liquid slug formation in the pipeline is fulfilled. The pressure drop being occurred in steam flowing along the pipelines causes the liquid slug to move to the pipeline inlet. When the liquid slug decelerates, a water hammer occurs. This mechanism of water hammer occurrence is tested by experiments. The regimes of the occurrence of multiple considerable water hammers were identified

Effects of soil water saturation on sampling equilibrium and kinetics of selected polycyclic aromatic hydrocarbons.

Science.gov (United States)

Kim, Pil-Gon; Roh, Ji-Yeon; Hong, Yongseok; Kwon, Jung-Hwan

2017-10-01

Passive sampling can be applied for measuring the freely dissolved concentration of hydrophobic organic chemicals (HOCs) in soil pore water. When using passive samplers under field conditions, however, there are factors that might affect passive sampling equilibrium and kinetics, such as soil water saturation. To determine the effects of soil water saturation on passive sampling, the equilibrium and kinetics of passive sampling were evaluated by observing changes in the distribution coefficient between sampler and soil (K sampler/soil ) and the uptake rate constant (k u ) at various soil water saturations. Polydimethylsiloxane (PDMS) passive samplers were deployed into artificial soils spiked with seven selected polycyclic aromatic hydrocarbons (PAHs). In dry soil (0% water saturation), both K sampler/soil and k u values were much lower than those in wet soils likely due to the contribution of adsorption of PAHs onto soil mineral surfaces and the conformational changes in soil organic matter. For high molecular weight PAHs (chrysene, benzo[a]pyrene, and dibenzo[a,h]anthracene), both K sampler/soil and k u values increased with increasing soil water saturation, whereas they decreased with increasing soil water saturation for low molecular weight PAHs (phenanthrene, anthracene, fluoranthene, and pyrene). Changes in the sorption capacity of soil organic matter with soil water content would be the main cause of the changes in passive sampling equilibrium. Henry's law constant could explain the different behaviors in uptake kinetics of the selected PAHs. The results of this study would be helpful when passive samplers are deployed under various soil water saturations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nuclear incompressibility: from finite nuclei to nuclear matter

International Nuclear Information System (INIS)

Treiner, J.; Krivine, H.; Bohigas, O.

1981-01-01

The recent increase of experimental data concerning the Giant Monopole Resonance Energy Esub(M) gives information on the incompressibility modulus of nuclear matter, provided one can extrapolate the incompressibility of a nucleus Ksub(A) defined by Esub(M)=[h 2 /m KA/ 2 >]sup(1/2), to the infinite medium. We discuss the theoretical interpretation of the coefficients of an Asup(-1/3) - expansion of Ksub(A) by studying the asymptotic behaviour of two RPA sum rules (corresponding to the scaling and the constrained model), evaluated using self-consistent Thomas-Fermi calculations. We show that the scaling model is the most suitable one as it leads to a rapidly converging Asup(-1/3)-expansion of the corresponding incompressibility Ksub(A)sup(S), whereas this is not the case with the constrained model. Some semi-empirical relations between the coefficients of the expansion of Ksub(A)sup(S) are established, which reduce to one the number of free-parameters in a best fit analysis of the experimental data. This reduction is essential due to the still limited number and accuracy of experimental data. We then show the compatibility of the data given by the various experimental groups with this parametrization and obtain a value of Ksub(nm)=220+-20 MeV, in good agreement with more microscopic analysis

Hyperon interaction in free space and nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Dhar, Madhumita; Lenske, Horst [Institute for Theoretical Physics, Justus- Liebig-University Giessen (Germany)

2015-07-01

Baryon-baryon interactions within the SU(3)-octet are investigated in free space and nuclear matter.A meson exchange model based on SU(3) symmetry is used for determining the interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. In-medium effect has been incorporated by including a two particle Pauli projector operator in the scattering equation. The coupling of the various channels of total strangeness S and conserved total charge is studied in detail. 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.

Two-body tensor interactions in the nuclear matter response function

International Nuclear Information System (INIS)

Besprosvany, J.

1997-01-01

The inclusive scattering response of nuclear matter is studied in the regime of large momentum transfer q, and around the quasielastic peak. We review interaction corrections to free propagation as embodied in the impulse approximation. Calculations of the two-body and many-body corrections within an eikonal approach are presented. These use an approximated two-body density matrix which takes account of spin and isospin degrees of freedom. Both calculations give similar and sizable corrections at q = 550 MeV and reproduce data extrapolated from finite nuclei; this indicates the relevance of two-body tensor contributions in this regime. (Author)

Experimental effects of dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4 π detector

Energy Technology Data Exchange (ETDEWEB)

De Filippo, E.; Pagano, A. [INFN, Catania (Italy)

2014-02-15

Heavy-ion collisions have been widely used in the last decade to constrain the parameterizations of the symmetry energy term of the nuclear equation of state (EOS) for asymmetric nuclear matter as a function of baryonic density. In the Fermi energy domain one is faced with variations of the density within a narrow range of values around the saturation density ρ{sub 0}=0.16 fm{sup -3} down towards sub-saturation densities. The experimental observables which are sensitive to the symmetry energy are constructed starting from the detected light particles, clusters and heavy fragments that, in heavy-ion collisions, are generally produced by different emission mechanisms at different stages and time scales of the reaction. In this review the effects of dynamics and thermodynamics on the symmetry energy in nuclear reactions are discussed and characterized using an overview of the data taken so far with the CHIMERA multi detector array. (orig.)

Strange quark matter in the Universe and accelerator nuclear beams

International Nuclear Information System (INIS)

Okonov, Eh.

1995-01-01

An almost symmetric mixture of u, d and s-quarks - Strange Quark Matter (SQM) is strongly argued to be the ground and absolutely stable of the matter. Astrophysical objects, supposed to be the SQM states, could be formed as the result of the Big Bang (in the early Universe) and the conversion of neutron stars into strange ones. Such objects are considered to be favourable candidates as black holes. The unique possibility to produce the SQM under terrestrial conditions (at accelerator laboratories) are violent relativistic nucleus-nucleus collisions so called 'little big bang'. The expected singulares of SQM are reviewed which could be revealed from astrophysical observations of peculiarities of large SQM objects as well as from accelerator experiments with searching smaller SQM states including the simplest one - metastable six-quark H dihyperon. The first results of the Dubna search experiments, with considerable heating of matter and formation a dense strangeness abundant fireball (mixed phase?) in central nuclear collisions, is presented. Under these favourable conditions a candidate for H dihyperon is observed and an upper limit of production cross sections of this SQM state is estimated. Some prospects and advantages of further searches for light SQM states, using the JINR new superconducting accelerator - Nuclotron with energy 5-6 GeV per nucleon, are briefly outlined. 19 refs., 7 figs

Compressed Baryonic Matter of Astrophysics

OpenAIRE

Guo, Yanjun; Xu, Renxin

2013-01-01

Baryonic matter in the core of a massive and evolved star is compressed significantly to form a supra-nuclear object, and compressed baryonic matter (CBM) is then produced after supernova. The state of cold matter at a few nuclear density is pedagogically reviewed, with significant attention paid to a possible quark-cluster state conjectured from an astrophysical point of view.

Searching saturation effects in inclusive and exclusive eA processes

International Nuclear Information System (INIS)

Goncalves, V.P.

2016-01-01

In this contribution we have discussed the search of saturation effects in inclusive and exclusive eA processes. In particular, we present a comparison between the linear and non-linear predictions for the nuclear structure functions as well as for the Deep Virtual Compton Scattering (DVCS) and vector meson production in future eA colliders. These results demonstrated that although the inclusive observables are sensitive to saturation effects, it is not yet possible to draw any firm conclusion concerning the QCD dynamics from inclusive quantities due to the large uncertainty present in the collinear predictions. In contrast, exclusive processes are promising observables to search saturation effects, due to the quadratic dependence on the forward scattering amplitude. In particular, the analysis of the nuclear DVCS and vector meson production demonstrated that the energy dependence of the differential cross sections are strongly modified with the increasing of the atomic mass number and that coherent cross section dominates at small t and the incoherent one at large t. Moreover, the number of dips at small t increases with the atomic number, with the position of the dips being almost independent of the model used to treat the dipole - proton interaction

Density slope of the nuclear symmetry energy from the neutron skin thickness of heavy nuclei

International Nuclear Information System (INIS)

Chen Liewen; Ko Che Ming; Xu Jun; Li Baoan

2010-01-01

Expressing explicitly the parameters of the standard Skyrme interaction in terms of the macroscopic properties of asymmetric nuclear matter, we show in the Skyrme-Hartree-Fock approach that unambiguous correlations exist between observables of finite nuclei and nuclear matter properties. We find that existing data on neutron skin thickness Δr np of Sn isotopes give an important constraint on the symmetry energy E sym (ρ 0 ) and its density slope L at saturation density ρ 0 . Combining these constraints with those from recent analyses of isospin diffusion and the double neutron/proton ratio in heavy-ion collisions at intermediate energies leads to a more stringent limit on L approximately independent of E sym (ρ 0 ). The implication of these new constraints on the Δr np of 208 Pb as well as the core-crust transition density and pressure in neutron stars is discussed.

Minimal nuclear energy density functional

Science.gov (United States)

Bulgac, Aurel; Forbes, Michael McNeil; Jin, Shi; Perez, Rodrigo Navarro; Schunck, Nicolas

2018-04-01

We present a minimal nuclear energy density functional (NEDF) called "SeaLL1" that has the smallest number of possible phenomenological parameters to date. SeaLL1 is defined by seven significant phenomenological parameters, each related to a specific nuclear property. It describes the nuclear masses of even-even nuclei with a mean energy error of 0.97 MeV and a standard deviation of 1.46 MeV , two-neutron and two-proton separation energies with rms errors of 0.69 MeV and 0.59 MeV respectively, and the charge radii of 345 even-even nuclei with a mean error ɛr=0.022 fm and a standard deviation σr=0.025 fm . SeaLL1 incorporates constraints on the equation of state (EoS) of pure neutron matter from quantum Monte Carlo calculations with chiral effective field theory two-body (NN ) interactions at the next-to-next-to-next-to leading order (N3LO) level and three-body (NNN ) interactions at the next-to-next-to leading order (N2LO) level. Two of the seven parameters are related to the saturation density and the energy per particle of the homogeneous symmetric nuclear matter, one is related to the nuclear surface tension, two are related to the symmetry energy and its density dependence, one is related to the strength of the spin-orbit interaction, and one is the coupling constant of the pairing interaction. We identify additional phenomenological parameters that have little effect on ground-state properties but can be used to fine-tune features such as the Thomas-Reiche-Kuhn sum rule, the excitation energy of the giant dipole and Gamow-Teller resonances, the static dipole electric polarizability, and the neutron skin thickness.

Study of nuclear matter in hard proton-nuclei and nuclei-nuclei collisions at the U70 accelerator (FLUKTON project proposal)

Science.gov (United States)

Antonov, N. N.; Baldin, A. A.; Viktorov, V. A.; Gapienko, V. A.; Gapienko, G. S.; Gres, V. N.; Ilyushin, M. A.; Korotkov, V. A.; Mysnik, A. I.; Prudkoglyad, A. F.; Pryanikov, D. S.; Semak, A. A.; Stavinsky, A. V.; Terekhov, V. I.; Uglekov, V. Ya.; Ukhanov, M. N.; Chuiko, B. V.; Shimansky, S. S.

2017-11-01

A two-arm spectrometer FLUKTON for investigations in the field of relativistic nuclear physics at U70 energies is proposed to be constructed on base of the existing detector SPIN (IHEP, Protvino). The main objective is to obtain new data on clusters of cold superdense nuclear matter. Interaction of a high intensity proton beam with nuclear targets and an ion beam with liquid hydrogen and nuclear targets will be studied.

Considerations concerning the physics of nuclear matter under extreme conditions and an accelerator for relativistic heavy ions

International Nuclear Information System (INIS)

Blasche, K.; Bock, R.; Franzke, B.; Greiner, W.; Gutbrod, H.H.; Povh, B.; Schmelzer, C.; Stock, R.

1977-01-01

The future problems of heavy-ion physics in the 10 GeV/U range are dealt with: the dynamics of relativistic nuclear collisions, phase transitions, nuclear matter, quantum electrodynamics of extremely strong fields, and astrophysical aspects. In the second part, the project of a heavy-ion accelerator in the 10 GeV/U range to be coupled to the present GSI UNILAC accelerator is discussed. (WL) [de

Nuclear recoil energy scale in liquid xenon with application to the direct detection of dark matter

International Nuclear Information System (INIS)

Sorensen, Peter; Dahl, Carl Eric

2011-01-01

We show for the first time that the quenching of electronic excitation from nuclear recoils in liquid xenon is well-described by Lindhard theory, if the nuclear recoil energy is reconstructed using the combined (scintillation and ionization) energy scale proposed by Shutt et al. We argue for the adoption of this perspective in favor of the existing preference for reconstructing nuclear recoil energy solely from primary scintillation. We show that signal partitioning into scintillation and ionization is well described by the Thomas-Imel box model. We discuss the implications for liquid xenon detectors aimed at the direct detection of dark matter.

Liquid-gas phase transition in asymmetric nuclear matter at finite temperature

Science.gov (United States)

Maruyama, Toshiki; Tatsumi, Toshitaka; Chiba, Satoshi

2010-03-01

Liquid-gas phase transition is discussed in warm asymmetric nuclear matter. Some peculiar features are figured out from the viewpoint of the basic thermodynamics about the phase equilibrium. We treat the mixed phase of the binary system based on the Gibbs conditions. When the Coulomb interaction is included, the mixed phase is no more uniform and the sequence of the pasta structures appears. Comparing the results with those given by the simple bulk calculation without the Coulomb interaction, we extract specific features of the pasta structures at finite temperature.

Liquid-gas phase transition in asymmetric nuclear matter at finite temperature

International Nuclear Information System (INIS)

Maruyama, Toshiki; Tatsumi, Toshitaka; Chiba, Satoshi

2010-01-01

Liquid-gas phase transition is discussed in warm asymmetric nuclear matter. Some peculiar features are figured out from the viewpoint of the basic thermodynamics about the phase equilibrium. We treat the mixed phase of the binary system based on the Gibbs conditions. When the Coulomb interaction is included, the mixed phase is no more uniform and the sequence of the pasta structures appears. Comparing the results with those given by the simple bulk calculation without the Coulomb interaction, we extract specific features of the pasta structures at finite temperature.

NDM06: 2. symposium on neutrinos and dark matter in nuclear physics

Energy Technology Data Exchange (ETDEWEB)

Akerib, D; Arnold, R; Balantekin, A; Barabash, A; Barnabe, H; Baroni, S; Baussan, E; Bellini, F; Bobisut, F; Bongrand, M; Brofferio, Ch; Capolupo, A; Enrico, Carrara; Caurier, E; Cermak, P; Chardin, G; Civitarese, O; Couchot, F; Kerret, H de; Heros, C de los; Detwiler, J; Dracos, M; Drexlin, G; Efremenko, Y; Ejiri, H; Falchini, E; Fatemi-Ghomi, N; Finger, M Ch; Finger Miroslav, Ch; Fiorillo, G; Fiorini, E; Fracasso, S; Frekers, D; Fushimi, K I; Gascon, J; Genest, M H; Georgadze, A; Giuliani, A; Goeger-Neff, M; Gomez-Cadenas, J J; Greenfield, M; H de Jesus, J; Hallin, A; Hannestad, St; Hirai, Sh; Hoessl, J; Ianni, A; Ieva, M B; Ishihara, N; Jullian, S; Kaim, S; Kajino, T; Kayser, B; Kochetov, O; Kopylov, A; Kortelainen, M; Kroeninger, K; Lachenmaier, T; Lalanne, D; Lanfranchi, J C; Lazauskas, R; Lemrani, A R; Li, J; Mansoulie, B; Marquet, Ch; Martinez, J; Mirizzi, A; Morfin Jorge, G; Motz, H; Murphy, A; Navas, S; Niedermeier, L; Nishiura, H; Nomachi, M; Nones, C.; Ogawa, H; Ogawa, I; Ohsumi, H; Palladino, V; Paniccia, M; Perotto, L; Petcov, S; Pfister, S; Piquemal, F; Poves, A; Praet, Ch; Raffelt, G; Ramberg, E; Rashba, T; Regnault, N; Ricol, J St; Rodejohann, W; Rodin, V; Ruz, J; Sander, Ch; Sarazin, X; Scholberg, K; Sigl, G; Simkovic, F; Sousa, A; Stanev, T; Strolger, L; Suekane, F; Thomas, J; Titov, N; Toivanen, J; Torrente-Lujan, E; Tytler, D; Vala, L; Vignaud, D; Vitiello, G; Vogel, P; Volkov, G; Volpe, C; Wong, H; Yilmazer, A

2006-07-01

This second symposium on neutrinos and dark matter is aimed at discussing research frontiers and perspectives on currently developing subjects. It has been organized around 6 topics: 1) double beta decays, theory and experiments (particularly: GERDA, MOON, SuperNEMO, CUORE, CANDLES, EXO, and DCBA), 2) neutrinos and nuclear physics, 3) single beta decays and nu-responses, 4) neutrino astrophysics, 5) solar neutrino review, and 6) neutrino oscillations. This document is made up of the slides of the presentations.

NDM06: 2. symposium on neutrinos and dark matter in nuclear physics

International Nuclear Information System (INIS)

Akerib, D.; Arnold, R.; Balantekin, A.; Barabash, A.; Barnabe, H.; Baroni, S.; Baussan, E.; Bellini, F.; Bobisut, F.; Bongrand, M.; Brofferio, Ch.; Capolupo, A.; Carrara Enrico; Caurier, E.; Cermak, P.; Chardin, G.; Civitarese, O.; Couchot, F.; Kerret, H. de; Heros, C. de los; Detwiler, J.; Dracos, M.; Drexlin, G.; Efremenko, Y.; Ejiri, H.; Falchini, E.; Fatemi-Ghomi, N.; Finger, M.Ch.; Finger Miroslav, Ch.; Fiorillo, G.; Fiorini, E.; Fracasso, S.; Frekers, D.; Fushimi, K.I.; Gascon, J.; Genest, M.H.; Georgadze, A.; Giuliani, A.; Goeger-Neff, M.; Gomez-Cadenas, J.J.; Greenfield, M.; H de Jesus, J.; Hallin, A.; Hannestad, St.; Hirai, Sh.; Hoessl, J.; Ianni, A.; Ieva, M.B.; Ishihara, N.; Jullian, S.; Kaim, S.; Kajino, T.; Kayser, B.; Kochetov, O.; Kopylov, A.; Kortelainen, M.; Kroeninger, K.; Lachenmaier, T.; Lalanne, D.; Lanfranchi, J.C.; Lazauskas, R.; Lemrani, A.R.; Li, J.; Mansoulie, B.; Marquet, Ch.; Martinez, J.; Mirizzi, A.; Morfin Jorge, G.; Motz, H.; Murphy, A.; Navas, S.; Niedermeier, L.; Nishiura, H.; Nomachi, M.; Nones, C.; Ogawa, H.; Ogawa, I.; Ohsumi, H.; Palladino, V.; Paniccia, M.; Perotto, L.; Petcov, S.; Pfister, S.; Piquemal, F.; Poves, A.; Praet, Ch.; Raffelt, G.; Ramberg, E.; Rashba, T.; Regnault, N.; Ricol, J.St.; Rodejohann, W.; Rodin, V.; Ruz, J.; Sander, Ch.; Sarazin, X.; Scholberg, K.; Sigl, G.; Simkovic, F.; Sousa, A.; Stanev, T.; Strolger, L.; Suekane, F.; Thomas, J.; Titov, N.; Toivanen, J.; Torrente-Lujan, E.; Tytler, D.; Vala, L.; Vignaud, D.; Vitiello, G.; Vogel, P.; Volkov, G.; Volpe, C.; Wong, H.; Yilmazer, A.

2006-01-01

This second symposium on neutrinos and dark matter is aimed at discussing research frontiers and perspectives on currently developing subjects. It has been organized around 6 topics: 1) double beta decays, theory and experiments (particularly: GERDA, MOON, SuperNEMO, CUORE, CANDLES, EXO, and DCBA), 2) neutrinos and nuclear physics, 3) single beta decays and nu-responses, 4) neutrino astrophysics, 5) solar neutrino review, and 6) neutrino oscillations. This document is made up of the slides of the presentations

Premature saturation in backpropagation networks: Mechanism and necessary conditions

International Nuclear Information System (INIS)

Vitela, J.E.; Reifman, J.

1997-01-01

The mechanism that gives rise to the phenomenon of premature saturation of the output units of feedforward multilayer neural networks during training with the standard backpropagation algorithm is described. The entire process of premature saturation is characterized by three distinct stages and it is concluded that the momentum term plays the leading role in the occurrence of the phenomenon. The necessary conditions for the occurrence of premature saturation are presented and a new method is proposed, based on these conditions, that eliminates the occurrence of the phenomenon. Validity of the conditions and the proposed method are illustrated through simulation results. Three case studies are presented. The first two came from a training session for classification of three component failures in a nuclear power plant. The last case, comes from a training session for classification of welded fuel elements

Quark matter droplets in neutron stars

Science.gov (United States)

Heiselberg, H.; Pethick, C. J.; Staubo, E. F.

1993-01-01

We show that, for physically reasonable bulk and surface properties, the lowest energy state of dense matter consists of quark matter coexisting with nuclear matter in the presence of an essentially uniform background of electrons. We estimate the size and nature of spatial structure in this phase, and show that at the lowest densities the quark matter forms droplets embedded in nuclear matter, whereas at higher densities it can exhibit a variety of different topologies. A finite fraction of the interior of neutron stars could consist of matter in this new phase, which would provide new mechanisms for glitches and cooling.

Research on evaluation method for water saturation of tight sandstone in Suxi region

Science.gov (United States)

Lv, Hong; Lai, Fuqiang; Chen, Liang; Li, Chao; Li, Jie; Yi, Heping

2017-05-01

The evaluation of irreducible water saturation is important for qualitative and quantitative prediction of residual oil distribution. However, it is to be improved for the accuracy of experimental measuring the irreducible water saturation and logging evaluation. In this paper, firstly the multi-functional core flooding experiment and the nuclear magnetic resonance centrifugation experiment are carried out in the west of Sulige gas field. Then, the influence was discussed about particle size, porosity and permeability on the water saturation. Finally, the evaluation model was established about irreducible water saturation and the evaluation of irreducible water saturation was carried out. The results show that the results of two experiments are both reliable. It is inversely proportional to the median particle size, porosity and permeability, and is most affected by the median particle size. The water saturation of the dry layer is higher than that of the general reservoir. The worse the reservoir property, the greater the water saturation. The test results show that the irreducible water saturation model can be used to evaluate the water floor.

The breathing mode and the nuclear surface

International Nuclear Information System (INIS)

Blaizot, J.P.; Grammaticos, B.

1981-01-01

The role of nuclear surface in the breathing mode of nuclei is analyzed. We discuss a simple model in which the density varies according to a scaling of the coordinates. We show that this model reproduces accurately the results of microscopic calculations in heavy nuclei, and we use it to estimate the contribution of the surface to the effective compression modulus of semi-infinite nuclear matter. The calculation is performed in the framework of an extended Thomas-Fermi approximation and using several effective interactions. It is shown that the surface energy is maximum with respect to variations of the density around saturation density. The reduction of the effective compression modulus due to the surface turns to be proportional to the bulk compression modulus. The magnitude of the effect is compared with results of RPA calculations. Other contributions to the effective compressions modulus of finite nuclei are also discussed. (orig.)

Nucleons, Nuclear Matter and Quark Matter: A unified NJL approach

Energy Technology Data Exchange (ETDEWEB)

S. Lawley; W. Bentz; A.W. Thomas

2006-02-10

We use an effective quark model to describe both hadronic matter and deconfined quark matter. By calculating the equations of state and the corresponding neutron star properties, we show that the internal properties of the nucleon have important implications for the properties of these systems.

Nucleons, nuclear matter and quark matter: a unified NJL approach

Energy Technology Data Exchange (ETDEWEB)

Lawley, S [Special Research Centre for the Subatomic Structure of Matter, University of Adelaide, Adelaide SA 5005 (Australia); Bentz, W [Department of Physics, School of Science, Tokai University Hiratsuka-shi, Kanagawa 259-1292 (Japan); Thomas, A W [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2006-05-01

We use an effective quark model to describe both hadronic matter and deconfined quark matter. By calculating the equations of state and the corresponding neutron star properties, we show that the internal properties of the nucleon have important implications for the properties of these systems.

Neutron star properties and the relativistic nuclear equation of state of many-baryon matter

International Nuclear Information System (INIS)

Weber, F.; Weigel, M.K.

1989-01-01

A relativistic model of baryons interacting via the exchange of σ-, ω-, π- and ρ-mesons (scalar-vector-isovector (SVI) theory) is used to describe the properties of both dense and superdense matter. For the theoretical frame, we used the temperature-dependent Green's function formalism. The equation of state (EOS) is calculated for nuclear as well as neutron matter in the Hartree (H) and Hartree-Fock (HF) approximation. The existence of phase transitions has been investigated. The isotherms of pressure as a function of density show for nuclear matter a critical temperature of about T c HF =16.6 MeV. (As in the usual scalar-vector (SV) theory, the phase transition is absent for neutron matter. A phase transition of both many-baryon systems in the high-pressure and high-density region, which has been found within the SV many-baryon theory, appears in the SVI theory too. The calculated maximum stable masses of neutron stars depend on 1. the underlying parameter set and/or 2. on the chosen approximation (i.e., H, HF; SV-, SVI theory, respectively). Hartree calculations lead to a mass stability limit of M max H ≤2.87 M sun (M max H ≤2.44 M sun when hyperons are taken into account). For the HF calculations we obtained M max HF ≤3.00 M sun (M max HF ≤2.85 M sun ). The corresponding maximum radii are (same notation as above) R H ≤13.2 km (R H ≤11.8 km), R HF ≤14.0 km (R HF ≤13.94 km).) The influence of the approximations, parameter sets and hyperons on the neutron star's moment of inertia is exhibited. (orig.)

Compact bifluid hybrid stars: hadronic matter mixed with self-interacting fermionic asymmetric dark matter

Energy Technology Data Exchange (ETDEWEB)

Mukhopadhyay, Somnath; Basu, D.N. [HBNI, Variable Energy Cyclotron Centre, Kolkata (India); Atta, Debasis [HBNI, Variable Energy Cyclotron Centre, Kolkata (India); Government General Degree College, West Bengal (India); Imam, Kouser [HBNI, Variable Energy Cyclotron Centre, Kolkata (India); Aliah University, Department of Physics, Kolkata (India); Samanta, C. [Virginia Military Institute, Department of Physics and Astronomy, Lexington, VA (United States)

2017-07-15

The masses and radii of non-rotating and rotating configurations of pure hadronic stars mixed with self-interacting fermionic asymmetric dark matter are calculated within the two-fluid formalism of stellar structure equations in general relativity. The Equation of State (EoS) of nuclear matter is obtained from the density dependent M3Y effective nucleon-nucleon interaction. We consider the dark matter particle mass of 1 GeV. The EoS of self-interacting dark matter is taken from two-body repulsive interactions of the scale of strong interactions. We explore the conditions of equal and different rotational frequencies of nuclear matter and dark matter and find that the maximum mass of differentially rotating stars with self-interacting dark matter to be ∝1.94 M {sub CircleDot} with radius ∝10.4 km. (orig.)

KIDS Nuclear Energy Density Functional: 1st Application in Nuclei

Science.gov (United States)

Gil, Hana; Papakonstantinou, Panagiota; Hyun, Chang Ho; Oh, Yongseok

We apply the KIDS (Korea: IBS-Daegu-Sungkyunkwan) nuclear energy density functional model, which is based on the Fermi momentum expansion, to the study of properties of lj-closed nuclei. The parameters of the model are determined by the nuclear properties at the saturation density and theoretical calculations on pure neutron matter. For applying the model to the study of nuclei, we rely on the Skyrme force model, where the Skyrme force parameters are determined through the KIDS energy density functional. Solving Hartree-Fock equations, we obtain the energies per particle and charge radii of closed magic nuclei, namely, 16O, 28O, 40Ca, 48Ca, 60Ca, 90Zr, 132Sn, and 208Pb. The results are compared with the observed data and further improvement of the model is shortly mentioned.

Influence of the nuclear matter equation of state on the r-mode instability using the finite-range simple effective interaction

Science.gov (United States)

Pattnaik, S. P.; Routray, T. R.; Viñas, X.; Basu, D. N.; Centelles, M.; Madhuri, K.; Behera, B.

2018-05-01

The characteristic physical properties of rotating neutron stars under the r-mode oscillation are evaluated using the finite-range simple effective interaction. Emphasis is given on examining the influence of the stiffness of both the symmetric and asymmetric parts of the nuclear equation of state on these properties. The amplitude of the r-mode at saturation is calculated using the data of particular neutron stars from the considerations of ‘spin equilibrium’ and ‘thermal equilibrium’. The upper limit of the r-mode saturation amplitude is found to lie in the range 10‑8–10‑6, in agreement with the predictions of earlier work.

Two-body correlation functions in dilute nuclear matter

International Nuclear Information System (INIS)

Isayev, A A

2006-01-01

Finding the distinct features of the crossover from the regime of large overlapping Cooper pairs to the limit of non-overlapping pairs of fermions (Shafroth pairs) in multicomponent Fermi systems remains one of the actual problems in a quantum many-body theory. Here this transition is studied by calculating the two-body density, spin and isospin correlation functions in dilute asymmetric nuclear matter. It is shown that criterion of the crossover (Phys. Rev. Lett. 95, 090402 (2005)), consisting in the change of the sign of the density correlation function at low momentum transfer, fails to describe correctly the density-driven BEC-BCS transition at finite isospin asymmetry or finite temperature. As an unambiguous signature of the BEC-BCS transition, there can be used the presence (BCS regime) or absence (BEC regime) of the singularity in the momentum distribution of the quasiparticle density of states

Detailed Characterization of Nuclear Recoil Pulse Shape Discrimination in the Darkside-50 Direct Dark Matter Experiment

Science.gov (United States)

Ludert, Erin Edkins

While evidence of non-baryonic dark matter has been accumulating for decades, its exact nature continues to remain a mystery. Weakly Interacting Massive Particles (WIMPs) are a well motivated candidate which appear in certain extensions of the Standard Model, independently of dark matter theory. If such particles exist, they should occasionally interact with particles of normal matter, producing a signal which may be detected. The DarkSide-50 direct dark matter experiment aims to detect the energy of recoiling argon atoms due to the elastic scattering of postulated WIMPs. In order to make such a discovery, a clear understanding of both the background and signal region is essential. This understanding requires a careful study of the detector's response to radioactive sources, which in turn requires such sources may be safely introduced into or near the detector volume and reliably removed. The CALibration Insertaion System (CALIS) was designed and built for this purpose in a joint effort between Fermi National Laboratory and the University of Hawaii. This work describes the design and testing of CALIS, its installation and commissioning at the Laboratori Nazionali del Gran Sasso (LNGS) and the multiple calibration campaigns which have successfully employed it. As nuclear recoils produced by WIMPs are indistinguishable from those produced by neutrons, radiogenic neutrons are both the most dangerous class of background and a vital calibration source for the study of the potential WIMP signal. Prior to the calibration of DarkSide-50 with radioactive neutron sources, the acceptance region was determined by the extrapolation of nuclear recoil data from a separate, dedicated experiment, ScENE, which measured the distribution of the pulse shape discrimination parameter, f 90, for nuclear recoils of known energies. This work demonstrates the validity of the extrapolation of ScENE values to DarkSide-50, by direct comparison of the f90 distribution of nuclear recoils from Sc

Detailed Characterization of Nuclear Recoil Pulse Shape Discrimination in the DarkSide-50 Direct Dark Matter Experiment

Energy Technology Data Exchange (ETDEWEB)

Edkins, Erin Elisabeth [Univ. of Hawaii, Honolulu, HI (United States)

2017-05-01

While evidence of non-baryonic dark matter has been accumulating for decades, its exact nature continues to remain a mystery. Weakly Interacting Massive Particles (WIMPs) are a well motivated candidate which appear in certain extensions of the Standard Model, independently of dark matter theory. If such particles exist, they should occasionally interact with particles of normal matter, producing a signal which may be detected. The DarkSide-50 direct dark matter experiment aims to detect the energy of recoiling argon atoms due to the elastic scattering of postulated WIMPs. In order to make such a discovery, a clear understanding of both the background and signal region is essential. This understanding requires a careful study of the detector's response to radioactive sources, which in turn requires such sources may be safely introduced into or near the detector volume and reliably removed. The CALibration Insertaion System (CALIS) was designed and built for this purpose in a j oint effort between Fermi National Laboratory and the University of Hawaii. This work describes the design and testing of CALIS, its installation and commissioning at the Laboratori Nazionali del Gran Sasso (LNGS) and the multiple calibration campaigns which have successfully employed it. As nuclear recoils produced by WIMPs are indistinguishable from those produced by neutrons, radiogenic neutrons are both the most dangerous class of background and a vital calibration source for the study of the potential WIMP signal. Prior to the calibration of DarkSide-50 with radioactive neutron sources, the acceptance region was determined by the extrapolation of nuclear recoil data from a separate, dedicated experiment, ScENE, which measured the distribution of the pulse shape discrimination parameter, $f_{90}$, for nuclear recoils of known energies. This work demonstrates the validity of the extrapolation of ScENE values to DarkSide-50, by direct comparison of the $f_{90}$ distributio n of nuclear

Mutual boosting of the saturation scales in colliding nuclei

Energy Technology Data Exchange (ETDEWEB)

Kopeliovich, B.Z., E-mail: bzk@mpi-hd.mpg.d [Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Instituto de Estudios Avanzados en Ciencias e Ingenieria, Centro Cientifico-Tecnologico de Valparaiso, Casilla 110-V, Valparaiso (Chile); Institut fuer Theoretische Physik der Universitaet, Philosophenweg 19, 69120 Heidelberg (Germany); Pirner, H.J. [Institut fuer Theoretische Physik der Universitaet, Philosophenweg 19, 69120 Heidelberg (Germany); Potashnikova, I.K.; Schmidt, Ivan [Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Instituto de Estudios Avanzados en Ciencias e Ingenieria, Centro Cientifico-Tecnologico de Valparaiso, Casilla 110-V, Valparaiso (Chile)

2011-03-14

Saturation of small-x gluons in a nucleus, which has the form of transverse momentum broadening of projectile gluons in pA collisions in the nuclear rest frame, leads to a modification of the parton distribution functions in the beam compared with pp collisions. The DGLAP driven gluon distribution turns out to be suppressed at large x, but significantly enhanced at x<<1. This is a high twist effect. In the case of nucleus-nucleus collisions all participating nucleons on both sides get enriched in gluon density at small x, which leads to a further boosting of the saturation scale. We derive reciprocity equations for the saturation scales corresponding to a collision of two nuclei. The solution of these equations for central collisions of two heavy nuclei demonstrate a significant, up to several times, enhancement of Q{sub sA}{sup 2}, in AA compared with pA collisions.

Neutron-Proton Mass Difference in Nuclear Matter and in Finite Nuclei and the Nolen-Schiffer Anomaly

Directory of Open Access Journals (Sweden)

Yakhshiev U.T.

2010-04-01

Full Text Available The neutron-proton mass difference in (isospin asymmetric nuclear matter and finite nuclei is studied in the framework of a medium-modified Skyrme model. The proposed effective Lagrangian incorporates both the medium influence of the surrounding nuclear environment on the single nucleon properties and an explicit isospin-breaking effect in the mesonic sector. Energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels are included as well. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it markedly decreases in neutron matter. Furthermore, the possible interplay between the effective nucleon mass in finite nuclei and the Nolen-Schiffer anomaly is discussed. In particular, we find that a correct description of the properties of mirror nuclei leads to a stringent restriction of possible modifications of the nucleon’s effective mass in nuclei.

Uranium (VI) transport in saturated heterogeneous media: Influence of kaolinite and humic acid.

Science.gov (United States)

Chen, Chong; Zhao, Kang; Shang, Jianying; Liu, Chongxuan; Wang, Jin; Yan, Zhifeng; Liu, Kesi; Wu, Wenliang

2018-05-07

Natural aquifers typically exhibit a variety of structural heterogeneities. However, the effect of mineral colloids and natural organic matter on the transport behavior of uranium (U) in saturated heterogeneous media are not totally understood. In this study, heterogeneous column experiments were conducted, and the constructed columns contained a fast-flow domain (FFD) and a slow-flow domain (SFD). The effect of kaolinite, humic acid (HA), and kaolinite/HA mixture on U(VI) retention and release in saturated heterogeneous media was examined. Media heterogeneity significantly influenced U fate and transport behavior in saturated subsurface environment. The presence of kaolinite, HA, and kaolinite/HA enhanced the mobility of U in heterogeneous media, and the mobility of U was the highest in the presence of kaolinite/HA and the lowest in the presence of kaolinite. In the presence of kaolinite, there was no difference in the amount of U released from the FFD and SFD. However, in the presence of HA and kaolinite/HA, a higher amount of U was released from the FFD. The findings in this study showed that medium structure and mineral colloids, as well as natural organic matter in the aqueous phase had significant effects on U transport and fate in subsurface environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Temperature and density of nuclear matter in central CC interactions at P=4.2 GeV/c per nucleon

International Nuclear Information System (INIS)

Didenko, L.A.; Grishin, V.G.; Kowalski, M.; Kuznetsov, A.A.

1984-01-01

An estimation of the temperature and density of nuclear matter in central carbon-carbon interactions at P/A=4.2 GeV/c is presented. It is shown that at energies of about 4 GeV per nucleon it is possible to reach the transitional region between hadronic matter and quark-gluon plasma. The results could be however more convincing if one uses heavier ions than carbon

Estimating pore-space gas hydrate saturations from well log acoustic data

Science.gov (United States)

Lee, Myung W.; Waite, William F.

2008-07-01

Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate-bearing sands are modeled using a three-phase Biot-type theory in which sand, gas hydrate, and pore fluid form three homogeneous, interwoven frameworks. This theory is developed using well log compressional and shear wave velocity data from the Mallik 5L-38 permafrost gas hydrate research well in Canada and applied to well log data from hydrate-bearing sands in the Alaskan permafrost, Gulf of Mexico, and northern Cascadia margin. Velocity-based gas hydrate saturation estimates are in good agreement with Nuclear Magneto Resonance and resistivity log estimates over the complete range of observed gas hydrate saturations.

Measurement of Nuclear Recoils in the CDMS II Dark Matter Search

Energy Technology Data Exchange (ETDEWEB)

Fallows, Scott Mathew [Univ. of Minnesota, Minneapolis, MN (United States)

2014-12-01

The Cryogenic Dark Matter Search (CDMS) experiment is designed to directly detect elastic scatters of weakly-interacting massive dark matter particles (WIMPs), on target nuclei in semiconductor crystals composed of Si and Ge. These scatters would occur very rarely, in an overwhelming background composed primarily of electron recoils from photons and electrons, as well as a smaller but non-negligible background of WIMP-like nuclear recoils from neutrons. The CDMS II generation of detectors simultaneously measure ionization and athermal phonon signals from each scatter, allowing discrimination against virtually all electron recoils in the detector bulk. Pulse-shape timing analysis allows discrimination against nearly all remaining electron recoils taking place near detector surfaces. Along with carefully limited neutron backgrounds, this experimental program allowed for \\background- free" operation of CDMS II at Soudan, with less than one background event expected in each WIMP-search analysis. As a result, exclusionary upper-limits on WIMP-nucleon interaction cross section were placed over a wide range of candidate WIMP masses, ruling out large new regions of parameter space.

Measurement of Nuclear Recoils in the CDMS II Dark Matter Search

Science.gov (United States)

Fallows, Scott M.

The Cryogenic Dark Matter Search (CDMS) experiment is designed to directly detect elastic scatters of weakly-interacting massive dark matter particles (WIMPs), on target nuclei in semiconductor crystals composed of Si and Ge. These scatters would occur very rarely, in an overwhelming background composed primarily of electron recoils from photons and electrons, as well as a smaller but non-negligible background of WIMP-like nuclear recoils from neutrons. The CDMS~II generation of detectors simultaneously measure ionization and athermal phonon signals from each scatter, allowing discrimination against virtually all electron recoils in the detector bulk. Pulse-shape timing analysis allows discrimination against nearly all remaining electron recoils taking place near detector surfaces. Along with carefully limited neutron backgrounds, this experimental program allowed for "background-free'' operation of CDMS~II at Soudan, with less than one background event expected in each WIMP-search analysis. As a result, exclusionary upper-limits on WIMP-nucleon interaction cross section were placed over a wide range of candidate WIMP masses, ruling out large new regions of parameter space. These results, like any others, are subject to a variety of systematic effects that may alter their final interpretations. A primary focus of this dissertation will be difficulties in precisely calibrating the energy scale for nuclear recoil events like those from WIMPs. Nuclear recoils have suppressed ionization signals relative to electron recoils of the same recoil energy, so the response of the detectors is calibrated differently for each recoil type. The overall normalization and linearity of the energy scale for electron recoils in CDMS~II detectors is clearly established by peaks of known gamma energy in the ionization spectrum of calibration data from a 133Ba source. This electron-equivalent keVee) energy scale enables calibration of the total phonon signal (keVt) by enforcing unity

Suprathermal viscosity of dense matter

International Nuclear Information System (INIS)

Alford, Mark; Mahmoodifar, Simin; Schwenzer, Kai

2010-01-01

Motivated by the existence of unstable modes of compact stars that eventually grow large, we study the bulk viscosity of dense matter, taking into account non-linear effects arising in the large amplitude regime, where the deviation μ Δ of the chemical potentials from chemical equilibrium fulfills μ Δ > or approx. T. We find that this supra-thermal bulk viscosity can provide a potential mechanism for saturating unstable modes in compact stars since the viscosity is strongly enhanced. Our study confirms previous results on strange quark matter and shows that the suprathermal enhancement is even stronger in the case of hadronic matter. We also comment on the competition of different weak channels and the presence of suprathermal effects in various color superconducting phases of dense quark matter.

Nanoscale Titanium Dioxide (nTiO2) Transport in Water-Saturated Natural Sediments: Influence of Soil Organic Matter and Fe/Al Oxyhydroxides

Science.gov (United States)

Fisher-Power, L.; Cheng, T.

2017-12-01

Transport of engineered nanoparticles (ENP) in subsurface environments has important implications to water quality and soil contamination. Although extensive research has been conducted to understand the effects of water chemistry on ENP transport, less attention has been paid to influences from the transport medium/matrix. The objective of this research is to investigate the effects of natural organic matter (NOM) and Fe/Al oxyhydroxides in a natural sediment on ENP transport. A sediment was collected and separated into four portions, one of which was unmodified, and the others treated to remove specific components (organic matter, Fe/Al oxyhydroxides, or both organic matter and Fe/Al oxyhydroxides). Transport of nanoscale titanium dioxide (nTiO2) in columns packed with quartz sand and each of the four types of the sediment under water-saturated conditions was studied. Our results showed that nTiO2 transport was strongly influenced by pH and sediment composition. When influent pH = 5, nTiO2 transport in all the sediments was low, as positively-charged nTiO2 was attracted to negatively charged NOM, quartz, and other minerals. nTiO2 transport was slightly enhanced in columns packed with untreated sediment or Fe/Al oxyhydroxides removed sediment due to dissolved organic matter generated by the partial dissolution of NOM, which adsorbed onto nTiO2 surface and reversed its zeta potential to negative. When influent pH = 9, nTiO2 transport was generally high since negatively-charged nTiO2 was repelled by negatively charged transport medium. However, in columns packed with the organic matter removed sediment or the Fe/Al oxyhydroxides removed sediment, nTiO2 transport was low. This was attributable to pH buffering by the sediment, which decreased pore water pH in the column, resulting in zeta potential change and electrostatic attraction between Fe/Al oxyhydroxides and nTiO2. This research demonstrates that electrostatic forces between nTiO2 and mineral/organic components

Kearns-Sayre syndrome with facial and white matter extensive involvement: a (mitochondrial and nuclear gene related? neurocristopathy?

Directory of Open Access Journals (Sweden)

Agostino Berio

2017-12-01

Full Text Available The Authors report on a patient with Kearns-Sayre syndrome, large mtDNA deletion (7/kb, facial abnormalities and severe central nervous system (CNS white matter radiological features, commonly attributed to spongy alterations. The common origin from neural crest cell (NCC of facial structures (cartilagineous, osseous, vascular and of the peripheral nervous system and of peripheral glia and partially of the CNS white matter are underlined and the facial and glial abnormalities are attributed to the abnormal reproduction/migration of NCC. In this view, the CNS spongy alterations in KSS may be not only a dystrophic process (leukodystrophy but also a dysplastic condition (leukodysplasia. The Authors hypothesize that the symptoms may be related to mtDNA mutations associated to NCC nuclear gene abnormality. SOX 10 gene may be a nuclear candidate gene, as reported in some case of Waardenburg IV syndrome.

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

Soil Organic Matter Stabilization via Mineral Interactions in Forest Soils with Varying Saturation Frequency

Science.gov (United States)

Possinger, A. R.; Inagaki, T.; Bailey, S. W.; Kogel-Knabner, I.; Lehmann, J.

2017-12-01

Soil carbon (C) interaction with minerals and metals through surface adsorption and co-precipitation processes is important for soil organic C (SOC) stabilization. Co-precipitation (i.e., the incorporation of C as an "impurity" in metal precipitates as they form) may increase the potential quantity of mineral-associated C per unit mineral surface compared to surface adsorption: a potentially important and as yet unaccounted for mechanism of C stabilization in soil. However, chemical, physical, and biological characterization of co-precipitated SOM as such in natural soils is limited, and the relative persistence of co-precipitated C is unknown, particularly under dynamic environmental conditions. To better understand the relationships between SOM stabilization via organometallic co-precipitation and environmental variables, this study compares mineral-SOM characteristics across a forest soil (Spodosol) hydrological gradient with expected differences in co-precipitation of SOM with iron (Fe) and aluminum (Al) due to variable saturation frequency. Soils were collected from a steep, well-drained forest soil transect with low, medium, and high frequency of water table intrusion into surface soils (Hubbard Brook Experimental Forest, Woodstock, NH). Lower saturation frequency soils generally had higher C content, C/Fe, C/Al, and other indicators of co-precipitation interactions resulting from SOM complexation, transport, and precipitation, an important process of Spodosol formation. Preliminary Fe X-ray Absorption Spectroscopic (XAS) characterization of SOM and metal chemistry in low frequency profiles suggest co-precipitation of SOM in the fine fraction (soils showed greater SOC mineralization per unit soil C for low saturation frequency (i.e., higher co-precipitation) soils; however, increased mineralization may be attributed to non-mineral associated fractions of SOM. Further work to identify the component of SOM contributing to rapid mineralization using 13C

Equation of state of dense baryonic matter

International Nuclear Information System (INIS)

Weber, F.; Weigel, M.K.

1989-01-01

In a previous investigation we treated nuclear matter as well as neutron matter at zero and finite temperatures in the frame of different relativistic field theoretical models, but with the restriction to nucleons as the only present baryons. This approach is extended by including a larger fraction of baryons and mesons, necessary for a description of baryon matter under extreme conditions. The equation of state (EOS) is calculated in both the Hartree and Hartree-Fock (HF) approximations for dense nuclear as well as neutron matter. Self-interactions of the σ field up to fourth order have been taken into account. For the treatment of many-baryon matter in the HF approach the parameters of the theory had to be readjusted. A phase transition of both many-baryon systems (neutron as well as nuclear matter) in the high-pressure and high-energy-density region has been found. (author)

31P nuclear magnetic resonance spectroscopy studies of tumor energy metabolism and its relationship to intracapillary oxyhemoglobin saturation status and tumor hypoxia.

Science.gov (United States)

Rofstad, E K; DeMuth, P; Fenton, B M; Sutherland, R M

1988-10-01

Relationships between tumor bioenergetic status on the one hand and intracapillary oxyhemoglobin (HbO2) saturation status and fraction of radiobiologically hypoxic cells on the other were studied using two murine sarcoma lines (KHT, RIF-1) and two human ovarian carcinoma xenograft lines (MLS, OWI). Tumor energy metabolism was studied in vivo by 31P nuclear magnetic resonance (NMR) spectroscopy and the resonance area ratio (PCr + NTP beta)/Pi was used as parameter for bioenergetic status. Intracapillary HbO2 saturation status reflects the oxygen supply conditions in tumors and was measured in vitro using a cryospectrophotometric method. The KHT, RIF-1, and MLS lines showed decreasing bioenergetic status, i.e., decreasing PCr and NTP beta resonances and an increasing Pi resonance, with increasing tumor volume, whereas the OWI line showed no changes in these resonances during tumor growth. The volume-dependence of the HbO2 saturation status differed similarly among the tumor lines; HbO2 saturation status decreased with increasing tumor volume for the KHT, RIF-1, and MLS lines and was independent of tumor volume for the OWI line. Moreover, linear correlations were found between bioenergetic status and HbO2 saturation status for individual tumors of the KHT, RIF-1, and MLS lines. These observations together indicated a direct relationship between 31P-NMR spectral parameters and tumor oxygen supply conditions. However, this relationship was not identical for the different tumor lines, suggesting that it was influenced by intrinsic properties of the tumor cells such as rate of respiration and ability to survive under hypoxia. Similarly, there was no correlation between bioenergetic status and fraction of radiobiologically hypoxic cells across the four tumor lines. This indicates that 31P-NMR spectroscopy data have to be supplemented with other data, e.g., rate of oxygen consumption, cell survival time under hypoxic stress, and/or fraction of metabolically active

Saturated Adaptive Output-Feedback Power-Level Control for Modular High Temperature Gas-Cooled Reactors

Directory of Open Access Journals (Sweden)

Zhe Dong

2014-11-01

Full Text Available Small modular reactors (SMRs are those nuclear fission reactors with electrical output powers of less than 300 MWe. Due to its inherent safety features, the modular high temperature gas-cooled reactor (MHTGR has been seen as one of the best candidates for building SMR-based nuclear plants with high safety-level and economical competitive power. Power-level control is crucial in providing grid-appropriation for all types of SMRs. Usually, there exists nonlinearity, parameter uncertainty and control input saturation in the SMR-based plant dynamics. Motivated by this, a novel saturated adaptive output-feedback power-level control of the MHTGR is proposed in this paper. This newly-built control law has the virtues of having relatively neat form, of being strong adaptive to parameter uncertainty and of being able to compensate control input saturation, which are given by constructing Lyapunov functions based upon the shifted-ectropies of neutron kinetics and reactor thermal-hydraulics, giving an online tuning algorithm for the controller parameters and proposing a control input saturation compensator respectively. It is proved theoretically that input-to-state stability (ISS can be guaranteed for the corresponding closed-loop system. In order to verify the theoretical results, this new control strategy is then applied to the large-range power maneuvering control for the MHTGR of the HTR-PM plant. Numerical simulation results show not only the relationship between regulating performance and control input saturation bound but also the feasibility of applying this saturated adaptive control law practically.

Dark matter directional detection in non-relativistic effective theories

International Nuclear Information System (INIS)

Catena, Riccardo

2015-01-01

We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF 4 , CS 2 and 3 He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments

Evidences for a new state of the nuclear matter: quark gluon plasma in liquid phase

International Nuclear Information System (INIS)

Jipa, Alexandru

2005-01-01

The experimental results obtained in the last years at the RHIC BNL (USA) allowed to obtain an important experimental result, namely the observation of the quark gluon plasma formation in nucleus-nucleus collisions at 200 A GeV in CMS. Evidences for this new state of nuclear matter are presented in this work. The results of the BRAHMS Experiment are detailed. (author)

Quark matter

Energy Technology Data Exchange (ETDEWEB)

Csernai, L.; Kampert, K. H.

1994-10-15

Precisely one decade ago the GSI (Darmstadt)/LBL (Berkeley) Collaboration at the Berkeley Bevalac reported clear evidence for collective sidewards flow in high energy heavy ion collisions. This milestone observation clearly displayed the compression and heating up of nuclear matter, providing new insights into how the behaviour of nuclear matter changes under very different conditions. This year, evidence for azimuthally asymmetric transverse flow at ten times higher projectile energy (11 GeV per nucleon gold on gold collisions) was presented by the Brookhaven E877 collaboration at the recent European Research Conference on ''Physics of High Energy Heavy Ion Collisions'', held in Helsinki from 17-22 June.

Quark matter

International Nuclear Information System (INIS)

Csernai, L.; Kampert, K.H.

1994-01-01

Precisely one decade ago the GSI (Darmstadt)/LBL (Berkeley) Collaboration at the Berkeley Bevalac reported clear evidence for collective sidewards flow in high energy heavy ion collisions. This milestone observation clearly displayed the compression and heating up of nuclear matter, providing new insights into how the behaviour of nuclear matter changes under very different conditions. This year, evidence for azimuthally asymmetric transverse flow at ten times higher projectile energy (11 GeV per nucleon gold on gold collisions) was presented by the Brookhaven E877 collaboration at the recent European Research Conference on ''Physics of High Energy Heavy Ion Collisions'', held in Helsinki from 17-22 June

Nuclear PDF studies with proton-lead measurements with the ALICE detector

CERN Document Server

Mischke, André

2018-01-01

The proton-lead programme at CERN’s Large Hadron Collider allowed the study of cold-nuclear matter effects from the initial state, such as Cronin enhancement, nuclear shadowing and gluon saturation. They result in a modification of the production cross section and thus provide crucial tests of predictions from perturbative Quantum-Chromodynamics. Furthermore, these control measurements are needed to characterise the extent to which initial-state effects can be differentiated from effects due to final-state interactions in the so-called quark-gluon plasma, produced in high-energy collisions of heavy atomic nuclei. In this contribution, recent results from the ALICE experiment on the measurements of lightflavour production and jets will be presented. Especially, the multi-strange baryon yields allow the study of the canonical suppression in small systems, whereas jets have been studied in term of the acoplanarity between full and charged jets and the nuclear modification factor as a function of collision cent...

Nuclear PDF studies with proton-lead measurements with the ALICE detector

CERN Document Server

Mischke, André

2017-01-01

The proton-lead programme at CERN’s Large Hadron Collider allowed the study of cold-nuclear matter effects from the initial state, such as Cronin enhancement, nuclear shadowing and gluon saturation. They result in a modification of the production cross section and thus provide crucial tests of predictions from perturbative Quantum-Chromodynamics. Furthermore, these control measurements are needed to characterise the extent to which initial-state effects can be differentiated from effects due to final-state interactions in the so-called quark-gluon plasma, produced in high-energy collisions of heavy atomic nuclei. In this contribution, recent results from the ALICE experiment on the measurements of lightflavour production and jets will be presented. Especially, the multi-strange baryon yields allow the study of the canonical suppression in small systems, whereas jets have been studied in term of the acoplanarity between full and charged jets and the nuclear modification factor as a function of collision cent...

Kaons in nuclear matter; Kaonen in Kernmaterie

Energy Technology Data Exchange (ETDEWEB)

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) [Deutsch] Die Arbeit befasst sich mit der Untersuchung der Eigenschaften von Kao nen in Kernmaterie. Zu diesem Zweck wurde ein Verfahren entwickelt, di e Kaon- Nukleon- Wechselwirkung und Kaon- Nukleon- Streuung im Vakuumzu beschreiben. Die Hauptherausforderung bestand darin, dass die abgel eiteten Relationen ausserhalb der Kaonen- Massenschale anwendbar werde n. Eine Nebenforderung war, dass die vorgeschlagenen Verfahren moeglic hst modell- unabhaengig sind. Um dieses Ziel zu erreichen, wurden Redu ktionsformeln, Stromalgebra- Relationen und die PCAC- Hypothese angewe ndet.

Risk assessment model for nuclear accident emergency protection countermeasure based on fuzzy matter-element analysis

International Nuclear Information System (INIS)

Xin Jing; Tang Huaqing; Zhang Yinghua; Zhang Limin

2009-01-01

A risk assessment model of nuclear accident emergency protection countermeasure based on fuzzy matter-element analysis and Euclid approach degree is proposed in the paper. The weight of assessed index is determined by information entropy and the scoring by experts, which could not only make full use of the inherent information of the indexes adequately, but reduce subjective assumption in the course of assessment effectively. The applied result shows that it is reasonable that the model is adopted to make risk assessment for nuclear accident emergency protective countermeasure,and it could be a kind of effective analytical method and decision making basis to choose the optimum protection countermeasure. (authors)

Phases of kinky holographic nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Elliot-Ripley, Matthew; Sutcliffe, Paul; Zamaklar, Marija [Department of Mathematical Sciences, Durham University,South Road, Durham (United Kingdom)

2016-10-17

Holographic QCD at finite baryon number density and zero temperature is studied within the five-dimensional Sakai-Sugimoto model. We introduce a new approximation that models a smeared crystal of solitonic baryons by assuming spatial homogeneity to obtain an effective kink theory in the holographic direction. The kink theory correctly reproduces a first order phase transition to lightly bound nuclear matter. As the density is further increased the kink splits into a pair of half-kink constituents, providing a concrete realization of the previously suggested dyonic salt phase, where the bulk soliton splits into constituents at high density. The kink model also captures the phenomenon of baryonic popcorn, in which a first order phase transition generates an additional soliton layer in the holographic direction. We find that this popcorn transition takes place at a density below the dyonic salt phase, making the latter energetically unfavourable. However, the kink model predicts only one pop, rather than the sequence of pops suggested by previous approximations. In the kink model the two layers produced by the single pop form the surface of a soliton bag that increases in size as the baryon chemical potential is increased. The interior of the bag is filled with abelian electric potential and the instanton charge density is localized on the surface of the bag. The soliton bag may provide a holographic description of a quarkyonic phase.

Strange Hadronic Matter in a Chiral Model

Institute of Scientific and Technical Information of China (English)

ZHANG Li-Liang; SONG Hong-Qiu; WANG Ping; SU Ru-Keng

2000-01-01

The strange hadronic matter with nucleon, Λ-hyperon and E-hyperon is studied by using a chiral symmetry model in a mean-field approximation. The saturation properties and stabilities of the strange hadronic matter are discussed. The result indicates a quite large strangeness fraction (fs) region where the strange hadronic matter is stable against particle emission. In the large fs region, the component dominates, resulting in a deep minimum in the curve of the binding energy per baryon EB versus the strangeness fraction fs with (EB, fs) -～ (-26.0MeV, 1.23).

Critical temperature of liquid-gas phase transition for hot nuclear matter and three-body force effect

International Nuclear Information System (INIS)

Zuo Wei; Lu Guangcheng; Li Zenghua; Luo Peiyan; Chinese Academy of Sciences, Beijing

2005-01-01

The finite temperature Brueckner-Hartree-Fock (FTBHF) approach is extended by introducing a microscopic three-body force. Within the extended approach, the three-body force effects on the equation of state of hot nuclear matter and its temperature dependence have been investigated. The critical properties of the liquid-gas phase transition of hot nuclear matter have been calculated. It is shown that the three-body force provides a repulsive contribution to the equation of state of hot nuclear matter. The repulsive effect of the three-body force becomes more pronounced as the density and temperature increase and consequently inclusion of the three-body force contribution in the calculation reduces the predicted critical temperature from about 16 MeV to about 13 MeV. By separating the contribution originated from the 2σ-exchange process coupled to the virtual excitation of a nucleon-antinucleon pair from the full three-body force, the connection between the three-body force effect and the relativistic correction from the Dirac-Brueckner-Hartree-Fock has been explored. It turns out that the contribution of the 2σ-N(N-bar) part is more repulsive than that of the full three-body force and the calculated critical temperature is about 11 MeV if only the 2σ-N(N-bar) component of the three-body force is included which is lower than the value obtained in the case of including the full three-body force and is close to the value predicted by the Dirac-Brueckner-Hartree-Fock (DBHF) approach. Our result provides a reasonable explanation for the discrepancy between the values of critical temperature predicted from the FTBHF approach including the three-body force and the DBHF approach. (authors)

The Physical Protection of Nuclear Material and Nuclear Facilities

International Nuclear Information System (INIS)

1999-08-01

Physical protection against the theft or unauthorized diversion of nuclear materials and against the sabotage of nuclear facilities by individuals or groups has long been a matter of national and international concern. Although responsibility for establishing and operating a comprehensive physical protection system for nuclear materials and facilities within a State rests entirely with the Government of that State, it is not a matter of indifference to other States whether and to what extent that responsibility is fulfilled. Physical protection has therefore become a matter of international concern and co-operation. The need for international co-operation becomes evident in situations where the effectiveness of physical protection in one State depends on the taking by other States also of adequate measures to deter or defeat hostile actions against nuclear facilities and nuclear materials, particularly when such materials are transported across national frontiers

The Physical Protection of Nuclear Material and Nuclear Facilities

International Nuclear Information System (INIS)

1999-06-01

Physical protection against the theft or unauthorized diversion of nuclear materials and against the sabotage of nuclear facilities by individuals or groups has long been a matter of national and international concern. Although responsibility for establishing and operating a comprehensive physical protection system for nuclear materials and facilities within a State rests entirely with the Government of that State, it is not a matter of indifference to other States whether and to what extent that responsibility is fulfilled. Physical protection has therefore become a matter of international concern and co-operation. The need for international co-operation becomes evident in situations where the effectiveness of physical protection in one State depends on the taking by other States also of adequate measures to deter or defeat hostile actions against nuclear facilities and nuclear materials, particularly when such materials are transported across national frontiers [es

The Physical Protection of Nuclear Material and Nuclear Facilities

International Nuclear Information System (INIS)

1999-06-01

Physical protection against the theft or unauthorized diversion of nuclear materials and against the sabotage of nuclear facilities by individuals or groups has long been a matter of national and international concern. Although responsibility for establishing and operating a comprehensive physical protection system for nuclear materials and facilities within a State rests entirely with the Government of that State, it is not a matter of indifference to other States whether and to what extent that responsibility is fulfilled. Physical protection has therefore become a matter of international concern and co-operation. The need for international co-operation becomes evident in situations where the effectiveness of physical protection in one State depends on the taking by other States also of adequate measures to deter or defeat hostile actions against nuclear facilities and nuclear materials, particularly when such materials are transported across national frontiers

Nuclear theory progress report

International Nuclear Information System (INIS)

1991-01-01

This report discusses research performed at University of Washington in nuclear theory. Some of the topics discussed are: nuclear astrophysics; symmetry; time reversal invariance; quark matter; superallowed beta decay; exclusive reactions; nuclear probes; soliton model; relativistic heavy ion collisions; supernova explosions; neutrino processes in dense matter; field theories; weak interaction physics; and nuclear structure

Trends concerning description of radiation and nuclear-related matters in current textbooks used at junior and senior high schools in Japan

International Nuclear Information System (INIS)

Matsuura, Tatsuo; Sekimoto, Junko; Takagi, Shinji; Iiri, Yuichi

2005-01-01

Descriptions on topics concerning radiation and nuclear energy in textbooks currently used in junior and senior high schools in Japan have been examined and summarized. As for the textbooks used in junior high schools, both in science studies and in social (geography/society) studies, the description is unsatisfactory for the reviewers in the following points: the space describing the radiation and nuclear-related problems has become considerably reduced than before, and as a general tendency the demerits of nuclear-related matters are stressed than the merits, while the renewable energies are much more favorably treated than the actual role. As for the textbooks of senior high schools on science studies written based on the new education guidelines, the present reviewers acknowledge the description has considerably been improved than before. However, as for those in the fields of social studies, geography/history, etc., the situation is similar to the cases of junior high schools described above. That is, the description on radiation and nuclear-related matters are generally not sufficient, and incorrect or unfair views on the value of nuclear energy are sometimes seen, in such a manner that the demerits of nuclear energy production or anxiety for radiation/radioactivity and for waste disposal are treated in much space than the merits, in special reference to the cases of nuclear accidents. (author)

From nuclear reactions to neutron stars

Indian Academy of Sciences (India)

2014-04-30

Apr 30, 2014 ... An equation of state (EoS) for symmetric nuclear matter is constructed using the density-dependent M3Y effective interaction and extended for isospin asymmetric nuclear matter. Theoretically obtained values of symmetric nuclear matter incompressibility, isobaric incompressibility, symmetry energy and its ...

Implications of the DAMA and CRESST experiments for mirror matter-type dark matter

International Nuclear Information System (INIS)

Foot, R.

2004-01-01

Mirror atoms are expected to be a significant component of the galactic dark matter halo if mirror matter is identified with the nonbaryonic dark matter in the Universe. Mirror matter can interact with ordinary matter via gravity and via the photon-mirror photon kinetic mixing interaction--causing mirror charged particles to couple to ordinary photons with an effective electric charge εe. This means that the nuclei of mirror atoms can elastically scatter off the nuclei of ordinary atoms, leading to nuclear recoils, which can be detected in existing dark matter experiments. We show that the dark matter experiments most sensitive to this type of dark matter candidate (via the nuclear recoil signature) are the DAMA/NaI and CRESST/Sapphire experiments. Furthermore, we show that the impressive annual modulation signal obtained by the DAMA/NaI experiment can be explained by mirror matter-type dark matter for vertical bar ε vertical bar ∼5x10 -9 and is supported by DAMA's absolute rate measurement as well as the CRESST/Sapphire data. This value of vertical bar ε vertical bar is consistent with the value obtained from various solar system anomalies including the Pioneer spacecraft anomaly, anomalous meteorite events and lack of small craters on the asteroid Eros. It is also consistent with standard big bang nucleosynthesis

Toward the Limits of Matter: Ultra-relativistic nuclear collisions at CERN