Incompressibility of asymmetric nuclear matter
International Nuclear Information System (INIS)
Using an isospin- and momentum-dependent modified Gogny (MDI) interaction, the Skyrme-Hartree-Fock (SHF) approach, and a phenomenological modified Skyrme-like (MSL) model, we have studied the incompressibility Ksat(?) of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of Ksat(?) in powers of isospin asymmetry ?, i.e., Ksat(?) = K0 + Ksat,2?2 + Ksat,4?4 + O(?6), the magnitude of the 4th-order Ksat,4 parameter is generally small. The 2nd-order Ksat,2 parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matter at saturation density. Furthermore, the Ksat,2 can be expressed as Ksat,2 = Ksym – 6L – J0/K0 L in terms of the slope parameter L and the curvature parameter Ksym of the symmetry energy and the third-order derivative parameter J0 of the energy of symmetric nuclear matter at saturation density, and we find the higher order J0 contribution to Ksat,2 generally cannot be neglected. Also, we have found a linear correlation between Ksym and L as well as between J0/K0 and K0. Using these correlations together with the empirical constraints on K0 and L, the nuclear symmetry energy Esym(?0) at normal nuclear density, and the nucleon effective mass, we have obtained an estimated value of Ksat,2 = -370 ± 120 MeV for the 2nd-order parameter in the isospin asymmetry expansion of the incompressibility of asymmetric nuclear matter at its saturation density. (author)
Asymmetric nuclear matter equation of state
International Nuclear Information System (INIS)
Systematic calculations of asymmetric nuclear matter have been performed in the framework of the Brueckner-Bethe-Goldstone approach in a wide range of both density and asymmetry parameter. The empirical parabolic law fulfilled by the binding energy per nucleon is confirmed by the present results in all the range of the asymmetry parameter values. The predominant role of the 3S1-3D1 component of the NN interaction is elucidated. A linear variation of the proton and neutron single-particle potentials is found as increasing the neutron excess; a deviation from the phenomenological potentials occurs for highly asymmetric matter as an effect of the self-consistency. The present calculations of the incompressibility predict a strong softening of the equation of state going from symmetric to asymmetric nuclear matter. The proton fraction in equilibrium with neutron matter has been determined from the beta-stability condition and its relevance to the superfluidity of neutron stars has been investigated
Isospin-asymmetric nuclear matter
LóPez, J. A.; Ramírez-Homs, E.; González, R.; Ravelo, R
2013-01-01
This study uses classical molecular dynamics to simulate infinite nuclear matter and study the effect of isospin asymmetry on bulk properties such as energy per nucleon, pressure, saturation density, compressibility and symmetry energy. The simulations are performed on systems embedded in periodic boundary conditions with densities and temperatures in the ranges $\\rho$=0.02 to 0.2 fm$^{-3}$ and T = 1, 2, 3, 4 and 5 MeV, and with isospin content of $x=Z/A$=0.3, 0.4 and 0.5. T...
Medium polarization in asymmetric nuclear matter
Zhang, S S; Lombardo, U; Schuck, P
2016-01-01
The influence of the core polarization on the effective nuclear interaction of asymmetric nuclear matter is calculated in the framework of the induced interaction theory. The strong isospin dependence of the density and spin density fluctuations is studied along with the interplay between the neutron and proton core polarizations. Moving from symmetric nuclear matter to pure neutron matter the crossover of the induced interaction from attractive to repulsive in the spin singlet state is determined as a function of the isospin imbalance.The density range in which it occurs is also determined. For the spin triplet state the induced interaction turns out to be always repulsive. The implications of the results for the neutron star superfluid phases are shortly discussed.
Phase transitions in warm, asymmetric nuclear matter
International Nuclear Information System (INIS)
A relativistic mean-field model of nuclear matter with arbitrary proton fraction is studied at finite temperature. An analysis is performed of the liquid-gas phase transition in a system with two conserved charges (baryon number and isospin) using the stability conditions on the free energy, the conservation laws, and Gibbs' criteria for phase equilibrium. For a binary system with two phases, the coexistence surface (binodal) is two dimensional. The Maxwell construction through the phase-separation region is discussed, and it is shown that the stable configuration can be determined uniquely at every density. Moreover, because of the greater dimensionality of the binodal surface, the liquid-gas phase transition is continuous (second order by Ehrenfest's definition), rather than discontinuous (first order), as in familiar one-component systems. Using a mean-field equation of state calibrated to the properties of nuclear matter and finite nuclei, various phase-separation scenarios are considered. The model is then applied to the liquid-gas phase transition that may occur in the warm, dilute matter produced in energetic heavy-ion collisions. In asymmetric matter, instabilities that produce a liquid-gas phase separation arise from fluctuations in the proton concentration (chemical instability), rather than from fluctuations in the baryon density (mechanical instability)
Pseudo-Goldstone Modes in Isospin-Asymmetric Nuclear Matter
Cohen, Thomas. D.; Broniowski, Wojciech
1994-01-01
We 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.
G. H. Bordbar; M. Bigdeli
2008-01-01
In this paper, we calculate properties of the spin polarized asymmetrical nuclear matter and neutron star matter, using the lowest order constrained variational (LOCV) method with the $AV_{18}$, $Reid93$, $UV_{14}$ and $AV_{14}$ potentials. According to our results, the spontaneous phase transition to a ferromagnetic state in the asymmetrical nuclear matter as well as neutron star matter do not occur.
G. H. Bordbar
2003-01-01
We have studied the influences of isospin symmetry breaking of nucleon-nucleon interaction on the various properties of asymmetrical nuclear matter and $\\beta$-stable matter. For asymmetrical nuclear matter, it is found that by including this isospin symmetry breaking, the changes of bulk properties increase by increasing both density and asymmetry parameter. However, these effects on the total energy and equation of state of $\\beta$-stable matter are ignorable. For asymmetrical nuclear matte...
Pairing effects on spinodal decomposition of asymmetric nuclear matter
Directory of Open Access Journals (Sweden)
Burrello S.
2015-01-01
Full Text Available We present an analysis framed in the general context of two-component fermionic systems subjected to pairing correlations. The study is conducted for unstable asymmetric nuclear matter at low temperature, along the clusterization process driven by spinodal instabilities. It is shown that, especially around the transition temperature from the superfluid to the normal phase, pairing correlations may have non-negligible effects on the isotopic features of the clusterized low-density matter, which could be of interest also in the astrophysical context.
AMD study of the EOS of asymmetric nuclear matter in nuclear collisions
International Nuclear Information System (INIS)
The effects of the equation of state of asymmetric nuclear matter on the nuclear collisions are discussed based on the microscopic calculations by antisymmetrized molecular dynamics. In the calculations with the different effective interactions corresponding to different density dependence of the symmetry energy, the isospin effects in high and low density stages are seen in the collisions of neutron-rich unstable nuclei as well as in collisions of heavy stable nuclei with large N/Z. (author)
Effective Nucleon Masses in Symmetric and Asymmetric Nuclear Matter
Van Dalen, E N E; Faessler, A; Faessler, Amand
2005-01-01
The momentum and isospin dependence of the in-medium nucleon mass are studied. Two definitions of the effective mass, i.e. the Dirac mass $m^*_D$ and the nonrelativistic mass $m^*_{NR}$ which parameterizes the energy spectrum, are compared. Both masses are determined from relativistic Dirac-Brueckner-Hartree-Fock calculations. The nonrelativistic mass shows a distinct peak around the Fermi momentum. The proton-neutron mass splitting in isospin asymmetric matter is $m^*_{D,n} m^*_{NR,p}$, which is consistent with nonrelativistic approaches.
A study on the thermodynamics of liquid-gas phase transition for asymmetric polarized nuclear matter
International Nuclear Information System (INIS)
The equation of state, developed before, for asymmetric polarized nuclear matter revealed a liquid-gas phase transition behaviour. Such transition is typical to that described by Van der Waal equation of real gas. In the present work, the analogy between nuclear matter and real macroscopic gas is examined. The nuclear matter equation of state is compared to Van der Waal equation to find the corresponding values of the real gas constants. Results are analysed in terms of the physical meanings of such constants. The latent heat of vaporization and entropy of transformation are calculated for symmetric nuclear matter. The critical point data and Van der Waal constants are estimated for asymmetric polarized nuclear matter. (author). 17 refs, 9 figs, 4 tabs
International Nuclear Information System (INIS)
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.
Equation of State for Isospin Asymmetric Nuclear Matter Using Lane Potential
Basu, D. N.; Chowdhury, P. Roy; Samanta, C.
2006-10-01
A mean field calculation for obtaining the equation of state (EOS) for symmetric nuclear matter from a density dependent M3Y interaction supplemented by a zero-range potential is described. The energy per nucleon is minimized to obtain the ground state of symmetric nuclear matter. The saturation energy per nucleon used for nuclear matter calculations is determined from the co-efficient of the volume term of Bethe--Weizsäcker mass formula which is evaluated by fitting the recent experimental and estimated atomic mass excesses from Audi--Wapstra--Thibault atomic mass table by minimizing the mean square deviation. The constants of density dependence of the effective interaction are obtained by reproducing the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. The EOS of symmetric nuclear matter, thus obtained, provide reasonably good estimate of nuclear incompressibility. Once the constants of density dependence are determined, EOS for asymmetric nuclear matter is calculated by adding to the isoscalar part, the isovector component of the M3Y interaction that do not contribute to the EOS of symmetric nuclear matter. These EOS are then used to calculate the pressure, the energy density and the velocity of sound in symmetric as well as isospin asymmetric nuclear matter.
Equation of state for isospin asymmetric nuclear matter using Lane potential
Basu, D N; Samanta, C
2006-01-01
A variational method of obtaining equation of state (EOS) for symmetric nuclear matter from a density dependent M3Y interaction supplemented by a zero-range potential is described. The energy per nucleon is minimized to obtain the ground state of symmetric nuclear matter. The saturation energy per nucleon used for nuclear matter calculations is determined from the co-efficient of the volume term of Bethe-Weizs\\"acker mass formula which is evaluated by fitting the recent experimental and estimated atomic mass excesses from Audi-Wapstra-Thibault atomic mass table by minimizing the mean square deviation. The constants of density dependence of the effective interaction are obtained by reproducing the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. The EOS of symmetric nuclear matter, thus obtained, provide reasonably good estimate of nuclear incompressibility. Once the consants of density dependence are determined, EOS for asymmetric nuclear mat...
A Time Dependent Local Isospin Density Approximation Study of Asymmetric Nuclear Matter
Lipparini, Enrico; Pederiva, Francesco
2013-01-01
The dynamic response of asymmetric nuclear matter is studied by using a Time-Dependent Local Isospin Density (TDLIDA) approximation approach. Calculations are based on a local density energy functional derived by an Auxiliary Field Diffusion Monte Carlo (AFDMC) calculation of bulk nuclear matter. Three types of excited states emerge: collective states, a continuum of quasi-particle-quasi-hole excitations and unstable solutions. These states are analyzed and discussed for dif...
Symmetric and asymmetric nuclear matter in the Thomas-Fermi model at finite temperatures
Strobel, K; Weigel, M K; Strobel, Klaus; Weber, Fridolin; Weigel, Manfred 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 parametrization 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 was calculated.
Phase Transition Of Asymmetric Nuclear Matter Beyond The 4-Nucleon Model
International Nuclear Information System (INIS)
The contribution of the delta meson to asymmetric nuclear matter (ANM) in the four-nucleon model is considered within the Cornwall-Jackiw-Tomboulis (CJT) effective action approach. In the double-bubble approximation the theory provides the nuclear symmetry energy (NSE) consistent with the recent analysis of experimental data and, at the same time, leads to a softer incompressibility, K0 = 240 MeV, without invoking any additional term similar to the Boguta-Bodmer potential. (author)
Symmetric and asymmetric nuclear matter in the Thomas-Fermi model at finite temperatures
Strobel, Klaus; Weber, Fridolin; Weigel, Manfred K.
1998-01-01
The properties of warm symmetric and asymmetric nuclear matter are investigated in the frame of the Thomas-Fermi approximation using a recent modern parametrization 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 ...
Thermodynamic instabilities in warm and dense asymmetric nuclear matter and in compact stars
Lavagno, A.; Gervino, G.; Pigato, D.
2016-01-01
We investigate the possible thermodynamic instability in a warm and dense nuclear medium where a phase transition from nucleonic matter to resonance-dominated Î”-matter can take place. Such a phase transition is characterized by both mechanical instability (fluctuations on the baryon density) and by chemical-diffusive instability (fluctuations on the isospin concentration) in asymmetric nuclear matter. Similarly to the liquid-gas phase transition, the nucleonic and the Î”-matter phase have a different isospin density in the mixed phase. In the liquid-gas phase transition, the process of producing a larger neutron excess in the gas phase is referred to as isospin fractionation. A similar effects can occur in the nucleon- Î”matter phase transition due essentially to a Î”- excess in the Î”-matter phase in asymmetric nuclear matter. In this context we also discuss the relevance of Î”-isobar degrees of freedom in the bulk properties and in the maximum mass of compact stars.
Variational Calculation for the Equation of State of Hot Asymmetric Nuclear Matter
International Nuclear Information System (INIS)
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.
Graesser, Michael L.; Shoemaker, Ian M.; Vecchi, Luca
2011-01-01
In existing dark matter models with global symmetries the relic abundance of dark matter is either equal to that of anti-dark matter (thermal WIMP), or vastly larger, with essentially no remaining anti-dark matter (asymmetric dark matter). By exploring the consequences of a primordial asymmetry on the coupled dark matter and anti-dark matter Boltzmann equations we find large regions of parameter space that interpolate between these two extremes. Interestingly, this new asymm...
What can we learn from the instabilities of asymmetric nuclear matter?
International Nuclear Information System (INIS)
Based on a general approach to binary systems we show that in low density region asymmetric nuclear matter (ANM) is unstable only against isoscalarlike fluctuations. The physical meaning of the thermodynamical chemical and mechanical instabilities is related to the inequality relations verified by the strength of interaction among different components. Relevance of these results for bulk and neck fragmentation in the reaction 124 Sn + 124 Sn at 50 MeV/n is discussed. (authors)
Kouvaris, Chris; Nielsen, Niklas Grønlund
2015-09-01
We study the possibility of asymmetric dark matter with self-interactions forming compact stable objects. We solve the Tolman-Oppenheimer-Volkoff equation and find the mass-radius relation of such "dark stars," their density profile and their Chandrasekhar mass limit. We consider fermionic asymmetric dark matter with Yukawa-type self-interactions appropriate for solving the well-known problems of the collisionless dark matter paradigm. We find that in several cases the relativistic effects are significant.
Kouvaris, Chris
2015-01-01
We study the possibility of asymmetric dark matter with self-interactions forming compact stable objects. We solve the Tolman-Oppenheimer-Volkoff equation and find the mass-radius relation of such "dark stars", their density profile and their Chandrasekhar mass limit. We consider fermionic asymmetric dark matter with Yukawa-type self-interactions appropriate for solving the well known problems of the collisionless dark matter paradigm. We find that in several cases the relativistic effects are significant.
Kouvaris, Chris; Nielsen, Niklas Grønlund
2015-01-01
We study the possibility of asymmetric dark matter with self-interactions forming compact stable objects. We solve the Tolman-Oppenheimer-Volkoff equation and find the mass-radius relation of such "dark stars", their density profile and their Chandrasekhar mass limit. We consider fermionic asymmetric dark matter with Yukawa-type self-interactions appropriate for solving the well known problems of the collisionless dark matter paradigm. We find that in several cases the relat...
Asymmetric nuclear matter in a parity doublet model with hidden local symmetry
Motohiro, Yuichi; Harada, Masayasu
2015-01-01
We construct a model to describe dense hadronic matter at zero and finite temperature, based on the parity doublet model of DeTar and Kunihiro, with including the iso-singlet scalar meson $\\sigma$ as well as $\\rho$ and $\\omega$ mesons. We show that, by including a six-point interaction of $\\sigma$ meson, the model reasonably reproduces the properties of the normal nuclear matter with the chiral invariant nucleon mass $m_0$ in the range from $500~{\\rm MeV}$ to $900~{\\rm MeV}$. Furthermore, we study the phase diagram based on the model, which shows that the value of the chiral condensate drops at the liquid-gas phase transition point and at the chiral phase transition point. We also study asymmetric nuclear matter and find that the first order phase transition for the liquid-gas phase transition disappears in asymmetric matter and that the critical density for the chiral phase transition at non-zero density becomes smaller for larger asymmetry.
Asymmetric nuclear matter based on chiral two- and three-nucleon interactions
Drischler, Christian; Schwenk, Achim
2015-01-01
We calculate the properties of isospin-asymmetric nuclear matter based on chiral nucleon-nucleon (NN) and three-nucleon (3N) interactions. To this end, we develop an improved normal-ordering framework that allows to include general 3N interactions starting from a plane-wave partial-wave-decomposed form. We present results for the energy per particle for general isospin asymmetries based on a set of different Hamiltonians, study their saturation properties, the incompressibility, symmetry energy, and also provide an analytic parametrization for the energy per particle as a function of density and isospin asymmetry.
Studies of the equation of state of asymmetric nuclear matter with R3B at FAIR
Lemmon R.
2012-01-01
The R3B experiment at FAIR will offer unique opportunities worldwide to study the properties of bulk asymmetric nuclear matter, e.g. the phase diagram, equation of state, symmetry energy, transport coefficients and in-medium cross sections. The experiment will take advantage of the intense radioactive beams produced by the SuperFRS with energies up to 2 AGeV. We will outline this physics programme and describe the detector sub-systems of R3B which will enable these measurements. Some detector...
Studies of the equation of state of asymmetric nuclear matter with R3B at FAIR
Directory of Open Access Journals (Sweden)
Lemmon R.
2012-07-01
Full Text Available The R3B experiment at FAIR will offer unique opportunities worldwide to study the properties of bulk asymmetric nuclear matter, e.g. the phase diagram, equation of state, symmetry energy, transport coefficients and in-medium cross sections. The experiment will take advantage of the intense radioactive beams produced by the SuperFRS with energies up to 2 AGeV. We will outline this physics programme and describe the detector sub-systems of R3B which will enable these measurements. Some detectors are already under construction while others are at the planning/R&D stage.
Thermodynamic instabilities in dense asymmetric nuclear matter and in compact stars
International Nuclear Information System (INIS)
We investigate the presence of thermodynamic instabilities in compressed asymmetric baryonic matter, reachable in high energy heavy ion collisions, and in the cold ?-stable compact stars. To this end we study the relativistic nuclear equation of state with the inclusion of ?-isobars and require the global conservation of baryon and electric charge numbers. Similarly to the low density nuclear liquid-gas phase transition, we show that a phase transition can occur in dense asymmetric nuclear matter and it is characterized by both mechanical instability (fluctuations on the baryon density) and by chemical-diffusive instability (fluctuations on the electric charge concentration). Such thermodynamic instabilities can imply a very different electric charge fraction Z/A in the coexisting phases during the phase transition and favoring an early formation of ?? particles with relevant phenomenological consequences in the physics of the protoneutron stars and compact stars. Finally, we discuss the possible co-existence of very compact and very massive compact stars in terms of two separate families: compact hadronic stars and very massive quark stars.
Gandolfi, S.; Lovato, A.; Carlson, J; Schmidt, Kevin E.
2014-01-01
We present microscopic calculations of light and medium mass nuclei and the equation of state of symmetric and asymmetric nuclear matter using different nucleon-nucleon forces, including a new Argonne version that has the same spin/isospin structure as local chiral forces at next-to-next-to-leading order (N2LO). The calculations are performed using Auxiliary Field Diffusion Monte Carlo (AFDMC) combined with an improved variational wave function. We show that the AFDMC method...
Saturation properties of asymmetric nuclear matter to be obtained from unstable nuclei
International Nuclear Information System (INIS)
We examine relations among the parameters characterizing the phenomenological equation of state (EOS) of nearly symmetric, uniform nuclear matter near the saturation density from experimental data on radii and masses of stable nuclei. The EOS parameters of interest are the symmetry energy S0, the symmetry energy density-derivative coefficient L and the incompressibility K0 at the normal nuclear density. The calculations of the nuclear properties were performed with a simplified Thomas-Fermi model. We find a constraint on (K0, L) values from the slope of the saturation line (the line joining the saturation points of asymmetric matter EOS with fixed proton abundance). A strong correlation between S0 and L, which was discussed in the Skyrme Hartree-Fock theory for relatively small L values, is found to hold for such larger values as a relativistic mean field theory predicts. In the light of the uncertainties in the (K0, L) values, we calculate radii of unstable nuclei as expected to be produced in future facilities. We find that the matter radii depend strongly on L almost independently of K0, and that systematic detection of the radii of such nuclei will help to determine the L value. (author)
Variational study for the equation of state of asymmetric nuclear matter at finite temperatures
Togashi, H; 10.1016/j.nuclphysa.2013.02.014
2013-01-01
An equation of state (EOS) for uniform asymmetric nuclear matter (ANM) is constructed at zero and finite temperatures by the variational method starting from the nuclear Hamiltonian that is composed of the Argonne v18 and Urbana IX potentials. At zero temperature, the two-body energy is calculated with the Jastrow wave function in the two-body cluster approximation which is supplemented by Mayer's condition and the healing-distance condition so as to reproduce the result by Akmal, Pandharipande and Ravenhall. The energy caused by the three-body force is treated somewhat phenomenologically so that the total energy reproduces the empirical saturation conditions. The masses and radii of neutron stars obtained with the EOS are consistent with recent observational data. At finite temperatures, thermodynamic quantities such as free energy, internal energy, entropy, pressure and chemical potentials are calculated with an extension of the method by Schmidt and Pandharipande. The validity of the frozen-correlation app...
Behera, B.; Routray, T. R.; Pradhan, A.; Patra, S. K.; Sahu, P. K.
2005-05-01
Momentum and density dependence of the isospin part of nuclear mean field u(k,?) which is still, in part, the open problem of the old Lane potential is analysed using density dependent finite range effective interactions. The behaviour of u(k=k,?) around the Fermi momentum k is found to be related to the density dependence of nuclear symmetry energy J(?) and nucleon effective mass M(k=k,?)/M in symmetric nuclear matter. The momentum dependence of u(k,?) is separated out in terms of a simple functional u?ex(k,?) which vanishes at k=k and involves only the finite range parts of the exchange interactions between pairs of like and unlike nucleons. Depending on the choice of the parameters of these exchange interactions two conflicting trends of momentum dependence are noticed which lead to two opposite types of splitting of neutron and proton effective masses. The equation of state of asymmetric nuclear matter and the high density behaviour of nuclear symmetry energy J(?) are studied by constraining the additional parameters involved on the basis that pure neutron matter should not be predicted to be bound by any reasonable nuclear interaction. Emphasis is also given on the need of experimental data sensitive to the differences between neutron and proton transport properties in highly asymmetric dense nuclear matter and its analysis to constrain the high density behaviour of nuclear symmetry energy as well as to resolve the controversy on the two opposite types of splitting of neutron and proton effective masses.
Momentum, Density, and Isospin dependence of the Symmetric and Asymmetric Nuclear Matter Properties
Van Dalen, E N E; Fuchs, C; Faessler, Amand
2005-01-01
Properties of symmetric and asymmetric nuclear matter have been investigated in the relativistic Dirac-Brueckner-Hartree-Fock approach based on projection techniques using the Bonn A potential. The momentum, density, and isospin dependence of the optical potentials and nucleon effective masses are studied. It turns out that the isovector optical potential depends sensitively on density and momentum, but is almost insensitive to the isospin asymmetry. Furthermore, the Dirac mass $m^*_D$ and the nonrelativistic mass $m^*_{NR}$ which parametrizes the energy dependence of the single particle spectrum, are both determined from relativistic Dirac-Brueckner-Hartree-Fock calculations. The nonrelativistic mass shows a characteristic peak structure at momenta slightly above the Fermi momentum $\\kf$. The relativistic Dirac mass shows a proton-neutron mass splitting of $m^*_{D,n} m^*_{NR,p}$ which is in agreement with the results from nonrelativistic calculations.
Minimal asymmetric dark matter
Boucenna, Sofiane M.; Martin B. Krauss; Enrico Nardi
2016-01-01
In the early Universe, any particle carrying a conserved quantum number and in chemical equilibrium with the thermal bath will unavoidably inherit a particle-antiparticle asymmetry. A new particle of this type, if stable, would represent a candidate for asymmetric dark matter (DM) with an asymmetry directly related to the baryon asymmetry. We study this possibility for a minimal DM sector constituted by just one (generic) $SU(2)_L$ multiplet $\\chi$ carrying hypercharge, assuming that at tempe...
Variational study for the equation of state of asymmetric nuclear matter at finite temperatures
International Nuclear Information System (INIS)
An equation of state (EOS) for uniform asymmetric nuclear matter (ANM) is constructed at zero and finite temperatures by the variational method starting from the nuclear Hamiltonian that is composed of the Argonne v18 and Urbana IX potentials. At zero temperature, the two-body energy is calculated with the Jastrow wave function in the two-body cluster approximation which is supplemented by Mayer's condition and the healing-distance condition so as to reproduce the result by Akmal, Pandharipande and Ravenhall. The energy caused by the three-body force is treated somewhat phenomenologically so that the total energy reproduces the empirical saturation conditions. The masses and radii of neutron stars obtained with the EOS are consistent with recent observational data. At finite temperatures, thermodynamic quantities such as free energy, internal energy, entropy, pressure and chemical potentials are calculated with an extension of the method by Schmidt and Pandharipande. The validity of the frozen-correlation approximation employed in this work is confirmed as compared with the result of the fully minimized calculation. The quadratic proton-fraction-dependence of the energy of ANM is confirmed at zero temperature, whereas the free energy of ANM deviates from the quadratic proton-fraction-dependence markedly at finite temperatures. The obtained EOS of ANM will be an important ingredient of a new nuclear EOS for supernova numerical simulations
Variational study for the equation of state of asymmetric nuclear matter at finite temperatures
Energy Technology Data Exchange (ETDEWEB)
Togashi, H., E-mail: hajime_togashi@ruri.waseda.jp [Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555 (Japan); Takano, M. [Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555 (Japan); Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555 (Japan)
2013-03-15
An equation of state (EOS) for uniform asymmetric nuclear matter (ANM) is constructed at zero and finite temperatures by the variational method starting from the nuclear Hamiltonian that is composed of the Argonne v18 and Urbana IX potentials. At zero temperature, the two-body energy is calculated with the Jastrow wave function in the two-body cluster approximation which is supplemented by Mayer's condition and the healing-distance condition so as to reproduce the result by Akmal, Pandharipande and Ravenhall. The energy caused by the three-body force is treated somewhat phenomenologically so that the total energy reproduces the empirical saturation conditions. The masses and radii of neutron stars obtained with the EOS are consistent with recent observational data. At finite temperatures, thermodynamic quantities such as free energy, internal energy, entropy, pressure and chemical potentials are calculated with an extension of the method by Schmidt and Pandharipande. The validity of the frozen-correlation approximation employed in this work is confirmed as compared with the result of the fully minimized calculation. The quadratic proton-fraction-dependence of the energy of ANM is confirmed at zero temperature, whereas the free energy of ANM deviates from the quadratic proton-fraction-dependence markedly at finite temperatures. The obtained EOS of ANM will be an important ingredient of a new nuclear EOS for supernova numerical simulations.
Farina, Marco
2015-11-01
We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.
Equation of state for isospin asymmetric nuclear matter using Lane potential
D. N. Basu; Chowdhury, P. Roy; Samanta, C.
2006-01-01
A mean field calculation for obtaining the equation of state (EOS) for symmetric nuclear matter from a density dependent M3Y interaction supplemented by a zero-range potential is described. The energy per nucleon is minimized to obtain the ground state of symmetric nuclear matter. The saturation energy per nucleon used for nuclear matter calculations is determined from the co-efficient of the volume term of Bethe-Weizs\\"acker mass formula which is evaluated by fitting the re...
Asymmetric Dark Matter from Leptogenesis
Falkowski, Adam; Joshua T. Ruderman; Volansky, Tomer
2011-01-01
We present a new realization of asymmetric dark matter in which the dark matter and lepton asymmetries are generated simultaneously through two-sector leptogenesis. The right-handed neutrinos couple both to the Standard Model and to a hidden sector where the dark matter resides. This framework explains the lepton asymmetry, dark matter abundance and neutrino masses all at once. In contrast to previous realizations of asymmetric dark matter, the model allows for a wide range ...
Asymmetric dense matter in holographic QCD
Directory of Open Access Journals (Sweden)
Shin Ik Jae
2012-02-01
Full Text Available We study asymmetric dense matter in holographic QCD.We construct asymmetric dense matter by considering two quark flavor branes with dierent quark masses in a D4/D6/D6 model. To calculate the symmetry energy in nuclear matter, we consider two quarks with equal masses and observe that the symmetry energy increases with the total charge showing the stiff dependence. This behavior is universal in the sense that the result is independent of parameters in the model. We also study strange (or hyperon matter with one light and one intermediate mass quarks. In addition to the vacuum properties of asymmetric matter, we calculate meson masses in asymmetric dense matter and discuss our results in the light of in-medium kaon masses.
Minimal asymmetric dark matter
Boucenna, Sofiane M.; Krauss, Martin B.; Nardi, Enrico
2015-09-01
In the early Universe, any particle carrying a conserved quantum number and in chemical equilibrium with the thermal bath will unavoidably inherit a particle-antiparticle asymmetry. A new particle of this type, if stable, would represent a candidate for asymmetric dark matter (DM) with an asymmetry directly related to the baryon asymmetry. We study this possibility for a minimal DM sector constituted by just one (generic) SU (2)L multiplet ? carrying hypercharge, assuming that at temperatures above the electroweak phase transition an effective operator enforces chemical equilibrium between ? and the Higgs boson. We argue that limits from DM direct detection searches severely constrain this scenario, leaving as the only possibilities scalar or fermion multiplets with hypercharge y = 1, preferentially quintuplets or larger SU (2) representations, and with a mass in the few TeV range.
Originally Asymmetric Dark Matter
Okada, Nobuchika; Seto, Osamu
2012-01-01
We propose a scenario with a fermion dark matter, where the dark matter particle used to be the Dirac fermion, but it takes the form of the Majorana fermion at a late time. The relic number density of the dark matter is determined by the dark matter asymmetry generated through the same mechanism as leptogenesis when the dark matter was the Dirac fermion. After efficient dark matter annihilation processes have frozen out, a phase transition of a scalar field takes place and g...
Cluster formation in asymmetric nuclear matter: Semi-classical and quantal approaches
Energy Technology Data Exchange (ETDEWEB)
Ducoin, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Via Santa Sofia 64, I-95123 Catania (Italy); LPC - IN2P3-CNRS/Ensicaen et Universite, F-14050 Caen cedex (France); GANIL (DSM-CEA/IN2P3-CNRS), B.P. 5027, F-14076 Caen cedex 5 (France)], E-mail: camille.ducoin@ct.infn.it; Margueron, J. [Institut de Physique Nucleaire, IN2P3-CNRS and Universite Paris-Sud, F-91406 Orsay cedex (France); Center for Mathematical Sciences, University of Aizu, Aizu-Wakamatsu, 965-8580 Fukushima (Japan); Chomaz, Ph. [GANIL (DSM-CEA/IN2P3-CNRS), B.P. 5027, F-14076 Caen cedex 5 (France)
2008-08-15
The nuclear-matter liquid-gas phase transition induces instabilities against finite-size density fluctuations. This has implications for both heavy-ion-collision and compact-star physics. In this paper, we study the clusterization properties of nuclear matter in a scenario of spinodal decomposition, comparing three different approaches: the quantal RPA, its semi-classical limit (Vlasov method), and a hydrodynamical framework. The predictions related to clusterization are qualitatively in good agreement varying the approach and the nuclear interaction. Nevertheless, it is shown that (i) the quantum effects reduce the instability zone, and disfavor short-wavelength fluctuations; (ii) large differences appear between the two semi-classical approaches, which correspond respectively to a collisionless (Vlasov) and local equilibrium description (hydrodynamics); (iii) the isospin-distillation effect is stronger in the local equilibrium framework; (iv) important variations between the predicted time-scales of cluster formation appear near the borders of the instability region.
Asymmetric condensed dark matter
Aguirre, Anthony
2015-01-01
We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate can be very light, $10^{-22}\\,{\\rm eV} \\lesssim m \\lesssim 10^2\\,{\\rm eV}$; the lower limit arises from constraints on small-scale structure formation, while the upper bound ensures that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of deco...
Stable Bound States of Asymmetric Dark Matter
Wise, Mark B.; Zhang, Yue
2014-01-01
The simplest renormalizable effective field theories with asymmetric dark matter bound states contain two additional gauge singlet fields one being the dark matter and the other a mediator particle that the dark matter annihilates into. We examine the physics of one such model with a Dirac fermion as the dark matter and a real scalar mediator. For a range of parameters the Yukawa coupling of the dark matter to the mediator gives rise to stable asymmetric dark matter bound st...
Sammarruca, Francesca
2013-01-01
After reviewing our microscopic approach to nuclear and neutron-rich matter, we focus on how nucleon-nucleon scattering is impacted by the presence of a dense hadronic medium, with special emphasis on the case where neutron and proton densities are different. We discuss in detail medium and isospin asymmetry effects on the total elastic cross section and the mean free path of a neutron or a proton in isospin-asymmetric nuclear matter. We point out that in-medium cross sections play an importa...
Solar Constraints on Asymmetric Dark Matter
Lopes, I.; Silk, J
2012-01-01
The dark matter content of the Universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the Universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freeze-out depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels). In these \\eta-parametrised asymmetric dark ma...
The deconfinement phase transition in asymmetric matter
International Nuclear Information System (INIS)
We study the phase transition of asymmetric hadronic matter to a quark-gluon plasma within the framework of a simple two-phase model. The analysis is performed in a system with two conserved charges (baryon number and isospin) using the stability conditions on the free energy, the conservation laws and Gibbs' criteria for phase equilibrium. The EOS is obtained in a separate description for the hadronic phase and for the quark-gluon plasma. For the hadrons, a relativistic mean-field model calibrated to the properties of nuclear matter is used, and a bag-model type EOS is used for the quarks and gluons. The model is applied to the deconfinement phase transition that may occur in matter created in ultra-relativistic collisions of heavy ions. Based on the two-dimensional coexistence surface (binodal), various phase separation scenarios and the Maxwell construction through the mixed phase are discussed. In the framework of the two-phase model the phase transition in asymmetric matter is continuous (second-order by Ehrenfest's definition) in contrast to the discontinuous (first-order) transition of symmetric systems. (orig.)
Twin Higgs Asymmetric Dark Matter.
GarcÃa GarcÃa, Isabel; Lasenby, Robert; March-Russell, John
2015-09-18
We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}Ã—SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Î›_{QCD}^{'}â‰ƒ0.5-20â€‰â€‰GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}â‰²Î›_{QCD}^{'}, where QCD^{'} is characterized by a single scale Î›_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Î”^{'}âˆ¼b^{'}b^{'}b^{'}, with a dynamically determined mass (âˆ¼5Î›_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Î©_{DM}/Î©_{baryon}â‰ƒ5. Gauging the U(1)^{'} group leads to twin atoms (Î”^{'}-Ï„^{'}[over Â¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors. PMID:26430985
Twin Higgs Asymmetric Dark Matter
García, Isabel García; March-Russell, John
2015-01-01
We study Asymmetric Dark Matter (ADM) in the context of the minimal (Fraternal) Twin Higgs solution to the little hierarchy problem, with a twin sector with gauged $SU(3)' \\times SU(2)'$, a twin Higgs, and only third generation twin fermions. Naturalness requires the QCD$^\\prime$ scale $\\Lambda'_{\\rm QCD} \\simeq 0.5 - 20 \\ {\\rm GeV}$, and $t'$ to be heavy. We focus on the light $b'$ quark regime, $m_{b'} \\lesssim \\Lambda'_{\\rm QCD}$, where QCD$^\\prime$ is characterised by a single scale $\\Lambda'_{\\rm QCD}$ with no light pions. A twin baryon number asymmetry leads to a successful DM candidate: the spin-3/2 twin baryon, $\\Delta' \\sim b'b'b'$, with a dynamically determined mass ($\\sim 5 \\Lambda'_{\\rm QCD}$) in the preferred range for the DM-to-baryon ratio $\\Omega_{\\rm DM}/\\Omega_{\\rm baryon} \\simeq 5$. Gauging the $U(1)'$ group leads to twin atoms ($\\Delta'$ - $\\bar {\\tau'}$ bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo ...
Asymmetric dark matter in braneworld cosmology
Energy Technology Data Exchange (ETDEWEB)
Meehan, Michael T.; Whittingham, Ian B., E-mail: Michael.Meehan@my.jcu.edu.au, E-mail: Ian.Whittingham@jcu.edu.au [School of Engineering and Physical Sciences, James Cook University, Townsville, 4811 Australia (Australia)
2014-06-01
We investigate the effect of a braneworld expansion era on the relic density of asymmetric dark matter. We find that the enhanced expansion rate in the early universe predicted by the Randall-Sundrum II (RSII) model leads to earlier particle freeze-out and an enhanced relic density. This effect has been observed previously by Okada and Seto (2004) for symmetric dark matter models and here we extend their results to the case of asymmetric dark matter. We also discuss the enhanced asymmetric annihilation rate in the braneworld scenario and its implications for indirect detection experiments.
Nuclear matter effects on J /? production in asymmetric Cu + Au collisions at ?{sNN}=200 GeV
Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Alexander, J.; Alfred, M.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bai, X.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bathe, S.; Baublis, V.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Bing, X.; Black, D.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Christiansen, P.; Chujo, T.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Cronin, N.; Crossette, N.; Csanád, M.; Csörg?, T.; Datta, A.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Ding, L.; Dion, A.; Do, J. H.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; D'Orazio, L.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Hashimoto, K.; Hayano, R.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Hoshino, T.; Huang, J.; Huang, S.; Ichihara, T.; Ikeda, Y.; Imai, K.; Imazu, Y.; Inaba, M.; Iordanova, A.; Isenhower, D.; Isinhue, A.; Ivanishchev, D.; Jacak, B. V.; Jeon, S. J.; Jezghani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, E.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kamin, J.; Kanda, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Kawall, D.; Kazantsev, A. V.; Key, J. A.; Khachatryan, V.; Khandai, P. K.; Khanzadeev, A.; Kihara, K.; Kijima, K. M.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.-J.; Kim, H.-J.; Kim, M.; Kim, Y.-J.; Kim, Y. K.; Kistenev, E.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kofarago, M.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Krizek, F.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, G. H.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S. H.; Leitch, M. J.; Leitgab, M.; Lewis, B.; Li, X.; Lim, S. H.; Liu, M. X.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Maruyama, T.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Miller, A. J.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Montuenga, P.; Moon, T.; Morrison, D. P.; Moskowitz, M.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Netrakanti, P. K.; Nihashi, M.; Niida, T.; Nouicer, R.; Novak, T.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Oide, H.; Okada, K.; Orjuela Koop, J. D.; Oskarsson, A.; Ozaki, H.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, S.; Park, S. K.; Pate, S. F.; Patel, L.; Patel, M.; Peng, J.-C.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Purschke, M. L.; Qu, H.; Rak, J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Riveli, N.; Roach, D.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Rubin, J. G.; Ryu, M. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, S.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Sekiguchi, Y.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shaver, A.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Slune?ka, M.; Solano, S.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Soumya, M.; Sourikova, I. V.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Stone, M. R.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Takahara, A.; Taketani, A.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Torii, H.; Towell, M.; Towell, R.; Towell, R. S.; Tserruya, I.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Vrba, V.
2014-12-01
We report on J /? production from asymmetric Cu + Au heavy-ion collisions at ?{sNN}=200 GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J /? yields in Cu + Au collisions in the Au-going direction is found to be comparable to that in Au + Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J /? production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-x gluon suppression in the larger Au nucleus.
Aidala, C; Akiba, Y; Akimoto, R; Alexander, J; Aoki, K; Apadula, N; Asano, H; Atomssa, E T; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Bai, X; Bannier, B; Barish, K N; Bathe, S; Baublis, V; Baumann, C; Baumgart, S; Bazilevsky, A; Beaumier, M; Belmont, R; Berdnikov, A; Berdnikov, Y; Bing, X; Black, D; Blau, D S; Bok, J; Boyle, K; Brooks, M L; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Butsyk, S; Campbell, S; Chen, C -H; Chi, C Y; Chiu, M; Choi, I J; Choi, J B; Choi, S; Christiansen, P; Chujo, T; Cianciolo, V; Cole, B A; Cronin, N; Crossette, N; Csanád, M; Csörg?, T; Datta, A; Daugherity, M S; David, G; Dehmelt, K; Denisov, A; Deshpande, A; Desmond, E J; Ding, L; Do, J H; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; D'Orazio, L; Engelmore, T; Enokizono, A; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Finger,, M; Fleuret, F; Fokin, S L; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Gainey, K; Gal, C; Garg, P; Garishvili, A; Garishvili, I; Giordano, F; Glenn, A; Gong, X; Gonin, M; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guragain, H; Haggerty, J S; Hahn, K I; Hamagaki, H; Hanks, J; Hashimoto, K; Hayano, R; He, X; Hemmick, T K; Hester, T; Hill, J C; Hollis, R S; Homma, K; Hong, B; Hoshino, T; Huang, J; Huang, S; Ichihara, T; Ikeda, Y; Imai, K; Imazu, Y; Inaba, M; Iordanova, A; Isenhower, D; Isinhue, A; Ivanishchev, D; Jacak, B V; Jeon, S J; Jezghani, M; Jia, J; Jiang, X; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kamin, J; Kanda, S; Kang, B H; Kang, J H; Kang, J S; Kapustinsky, J; Kawall, D; Kazantsev, A V; Key, J A; Khachatryan, V; Khandai, P K; Khanzadeev, A; Kijima, K M; Kim, C; Kim, D J; Kim, E -J; Kim, Y -J; Kim, Y K; Kistenev, E; Klatsky, J; Kleinjan, D; Kline, P; Koblesky, T; Kofarago, M; Komkov, B; Koster, J; Kotchetkov, D; Kotov, D; Krizek, F; Kurita, K; Kurosawa, M; Kwon, Y; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, G H; Lee, J; Lee, K B; Lee, K S; Lee, S H; Leitch, M J; Leitgab, M; Lewis, B; Li, X; Lim, S H; Liu, M X; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Manion, A; Manko, V I; Mannel, E; Maruyama, T; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Milov, A; Mishra, D K; Mitchell, J T; Miyasaka, S; Mizuno, S; Mohanty, A K; Morrison, D P; Moskowitz, M; Moukhanova, T V; Murakami, T; Murata, J; Nagae, T; Nagamiya, S; Nagle, J L; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nattrass, C; Netrakanti, P K; Nihashi, M; Niida, T; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; O'Brien, E; Ogilvie, C A; Oide, H; Okada, K; Oskarsson, A; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, S; Park, S K; Pate, S F; Patel, L; Peng, J -C; Perepelitsa, D; Perera, G D N; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pisani, R P; Purschke, M L; Qu, H; Rak, J; Ravinovich, I; Read, K F; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Riveli, N; Roach, D; Rolnick, S D; Rosati, M; Ryu, M S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sako, H; Samsonov, V; Sarsour, M; Sato, S; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Sekiguchi, Y; Sen, A; Seto, R; Sett, P; Sharma, D; Shaver, A; Shein, I; Shibata, T -A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Singh, B K; Singh, C P; Singh, V; Skolnik, M; Slune?ka, M; Solano, S; Soltz, R A; Sondheim, W E; Sorensen, S P; Soumya, M; Sourikova, I V; Stankus, P W; Steinberg, P; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Stone, M R; Sugitate, T; Sukhanov, A; Sun, J; Takahara, A; Taketani, A; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tennant, E; Timilsina, A; Todoroki, T; Tomášek, M; Torii, H; Towell, R S; Tserruya, I; van Hecke, H W; Vargyas, M; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Whitaker, S; Wolin, S; Woody, C L; Wysocki, M; Yamaguchi, Y L; Yanovich, A; Yokkaichi, S; Yoon, I; You, Z; Younus, I; Yushmanov, I E; Zajc, W A; Zelenski, A; Zhou, S
2014-01-01
We report on $J/\\psi$ production from asymmetric Cu+Au heavy-ion collisions at $\\sqrt{s_{_{NN}}}$=200 GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of $J/\\psi$ yields in Cu$+$Au collisions in the Au-going direction is found to be comparable to that in Au$+$Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, $J/\\psi$ production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-$x$ gluon suppression in the larger Au nucleus. The relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.
Asymmetric Inert Scalar Dark Matter
Dhen, Mikael
2015-01-01
In the quite minimal inert scalar doublet dark matter framework, we analyze what would be the effect of a $B-L$ asymmetry that could have been produced in the Universe thermal bath at high temperature. We show that, unless the "$\\lambda_5$" scalar interaction is tiny, this asymmetry is automatically reprocessed in part into a DM asymmetry that can easily dominate the DM relic density today. This scenario requires the inert DM mass scale to lie in the few-TeV range. Two types of relic density suppressions render this scenario viable: thermalization, from the same "$\\lambda_5$" interaction, of the asymmetries at temperature below the dark matter particle threshold, and DM particle-antiparticle oscillations.
Baryon destruction by asymmetric dark matter
International Nuclear Information System (INIS)
We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause induced nucleon decay by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 1029-1032 yrs in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter-induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.
Baryon Destruction by Asymmetric Dark Matter
Davoudiasl, Hooman; Sigurdson, Kris; Tulin, Sean
2011-01-01
We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause {\\it induced nucleon decay} by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10^{29}-10^{32} years in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter--induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.
International Nuclear Information System (INIS)
Realistic versions of the M3Y effective nucleon-nucleon interaction have been used to calculate the basic properties of asymmetric nuclear matter within a non-relativistic Hartree-Fock scheme. Special attention was devoted to the dependence of the binding energy, pressure and incompressibility upon the neutron-proton asymmetry. Our results reproduce reasonably well the empirical value of the symmetry energy and the softening of the equation of state for neutron-rich nuclear matter, as suggested in several supernova studies. The same effective interaction has been further used to calculate the interaction potential between neutron-rich nuclei within an extended version of the double-folding model, where the knock-on exchange and the isospin dependence of the nucleon-nucleon interaction are treated explicitly. The symmetry (isospin-dependent) term of the central nucleus-nucleus potential was found to be negligible compared to the isoscalar term. An exploratory study of the elastic 8He,11Li+14C scattering was performed using the new folded potentials, and possible signatures of the 8He,11Li neutron halos in these processes have been discussed. (orig.)
SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER
International Nuclear Information System (INIS)
The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these ?-parameterized asymmetric dark matter (?ADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry ? close to the baryon asymmetry ?B. Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain ?ADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an ?-asymmetry with a value in the interval 10–12-10–10, would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological ?ADM scenarios that we discuss have a relic dark matter density ?h 2 and baryon asymmetry ?B in agreement with the current WMAP measured values, ?DM h 2 = 0.1109 ± 0.0056 and ?B = 0.88 × 10–10.
DAMA annual modulation effect and asymmetric mirror matter
Energy Technology Data Exchange (ETDEWEB)
Addazi, A.; Berezhiani, Z. [Universita di L' Aquila, Dipartimento di Scienze Fisiche e Chimiche, Coppito, AQ (Italy); INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Bernabei, R.; Belli, P. [Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); INFN, Tor Vergata, Rome (Italy); Cappella, F.; Cerulli, R. [INFN, Laboratori Nazionali del Gran Sasso, Assergi, AQ (Italy); Incicchitti, A. [Universita di Roma ' ' La Sapienza' ' , Roma, Dipartimento di Fisica, Rome (Italy); INFN, Roma (Italy)
2015-08-15
The long-standing model-independent annual modulation effect measured by DAMA Collaboration is examined in the context of asymmetric mirror dark matter, assuming that dark atoms interact with target nuclei in the detector via kinetic mixing between mirror and ordinary photons, both being massless. The relevant ranges for the kinetic mixing parameter are obtained taking into account various existing uncertainties in nuclear and particle physics quantities as well as characteristic density and velocity distributions of dark matter in different halo models. (orig.)
Indirect Detection of Self-Interacting Asymmetric Dark Matter
Pearce, Lauren(Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547, U.S.A.); Kusenko, Alexander
2013-01-01
Self-interacting dark matter resolves the issue of cuspy profiles that appear in non-interacting cold dark matter simluations; it may additionally resolve the so-called "too big to fail" problem in structure formation. Asymmetric dark matter provides a natural explanation of the comparable densities of baryonic matter and dark matter. In this paper, we discuss unique indirect detection signals produced by a minimal model of self-interacting asymmetric scalar dark matter. Thr...
Yong, Gao-Chan
2016-01-01
It is generally considered that an atomic nucleus is always compact. Based on the isospin-dependent Boltzmann nuclear transport model, here I show that large block nuclear matter or excited nuclear matter may both be hollow. The size of the inner bubble in these matter is affected by the charge number of nuclear matter. The existence of hollow nuclear matter may have many implications in nuclear or atomic physics or astrophysics as well as some practical applications.
Yong, Gao-Chan
2015-01-01
It is generally considered that an atomic nucleus is always compact. Based on the isospin-dependent Boltzmann nuclear transport model, here I show that large block nuclear matter or excited nuclear matter may both be hollow. And the size of inner bubble in these matter is affected by the charge number of nuclear matter. Existence of hollow nuclear matter may have many implications in nuclear or atomic physics or astrophysics as well as some practical applications.
ADMonium: Asymmetric Dark Matter Bound State
Bi, Xiao-Jun; Kang, Zhaofeng; Ko, P; Li, Jinmian; Li, Tianjun
2016-01-01
We propose a novel framework for asymmetric scalar dark matter (ADM), which has interesting collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local $U(1)_d$ symmetry which is broken at a low scale and provides a light gauge boson $X$. The dark gauge coupling is strong and then ADM can annihilate away into $X$-pair effectively. The...
Asymmetric Dark Matter and Dark Radiation
International Nuclear Information System (INIS)
Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry, similar to the one observed in the Baryon sector, to account for the Dark Matter (DM) abundance. Both asymmetries are usually generated by the same mechanism and generally related, thus predicting DM masses around 5 GeV in order to obtain the correct density. The main challenge for successful models is to ensure efficient annihilation of the thermally produced symmetric component of such a light DM candidate without violating constraints from collider or direct searches. A common way to overcome this involves a light mediator, into which DM can efficiently annihilate and which subsequently decays into Standard Model particles. Here we explore the scenario where the light mediator decays instead into lighter degrees of freedom in the dark sector that act as radiation in the early Universe. While this assumption makes indirect DM searches challenging, it leads to signals of extra radiation at BBN and CMB. Under certain conditions, precise measurements of the number of relativistic species, such as those expected from the Planck satellite, can provide information on the structure of the dark sector. We also discuss the constraints of the interactions between DM and Dark Radiation from their imprint in the matter power spectrum
Asymmetric dark matter and effective number of neutrinos
Kitabayashi, Teruyuki
2015-01-01
We study the effect of the MeV-scale asymmetric dark matter annihilation on the effective number of neutrinos $N_{\\rm eff}$ at the epoch of the big bang nucleosynthesis. If the asymmetric dark matter $\\chi$ couples more strongly to the neutrinos $\
Continuous flavor symmetries and the stability of asymmetric dark matter
Bishara, Fady; Zupan, Jure
2015-01-01
Generically, the asymmetric interactions in asymmetric dark matter (ADM) models could lead to decaying DM. We show that, for ADM that carries nonzero baryon number, the continuous flavor symmetries that generate the flavor structure in the quark sector also imply a looser lower bound on the mass scale of the asymmetric mediators between the dark and visible sectors. The mediators for B = 2 ADM that can produce a signal in the future indirect dark matter searches can thus also be searched for ...
The phases of isospin asymmetric matter in the two flavor NJL model
Lawley, S.; Bentz, W.; Thomas, A.W.
2005-01-01
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 is discussed.
ADMonium: Asymmetric Dark Matter Bound State
Bi, Xiao-Jun; Ko, P; Li, Jinmian; Li, Tianjun
2016-01-01
We propose a novel framework for asymmetric scalar dark matter (ADM), which has interesting collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local $U(1)_d$ symmetry which is broken at a low scale and provides a light gauge boson $X$. The dark gauge coupling is strong and then ADM can annihilate away into $X$-pair effectively. Therefore, the ADM can form bound state due to its large self-interaction via $X$ mediation. To explore the collider signature of ADMonium, we propose that ADM has a two-Higgs doublet portal. The ADMonium can have a sizable mixing with the heavier Higgs boson, which admits a large cross section of ADMonium production associated with $b\\bar b$. Of particular interest, our setup nicely explains the recent di-photon anomaly at 750 GeV via the events from ${\\rm ADMonium}\\ra 2X(\\ra e^+e^-)$, where the electrons are identified as ...
Asymmetric dark matter and effective number of neutrinos
Kitabayashi, Teruyuki; Kurosawa, Yoshihiro
2016-02-01
We study the effect of the MeV-scale asymmetric dark matter annihilation on the effective number of neutrinos Neff at the epoch of the big bang nucleosynthesis. If the asymmetric dark matter Ï‡ couples more strongly to the neutrinos Î½ than to the photons Î³ and electrons e-, Î“Ï‡ Î³ ,Ï‡ eâ‰ªÎ“Ï‡ Î½ , or Î“Ï‡ Î³ ,Ï‡ eâ‰«Î“Ï‡ Î½, the lower mass limit on the asymmetric dark matter is about 18 MeV for Neffâ‰ƒ3.0 .
Charge Asymmetric Cosmic Rays as a probe of Flavor Violating Asymmetric Dark Matter
DEFF Research Database (Denmark)
Masina, Isabella; Sannino, Francesco
2011-01-01
The recently introduced cosmic sum rules combine the data from PAMELA and Fermi-LAT cosmic ray experiments in a way that permits to neatly investigate whether the experimentally observed lepton excesses violate charge symmetry. One can in a simple way determine universal properties of the unknown component of the cosmic rays. Here we attribute a potential charge asymmetry to the dark sector. In particular we provide models of asymmetric dark matter able to produce charge asymmetric cosmic rays. We consider spin zero, spin one and spin one-half decaying dark matter candidates. We show that lepton flavor violation and asymmetric dark matter are both required to have a charge asymmetry in the cosmic ray lepton excesses. Therefore, an experimental evidence of charge asymmetry in the cosmic ray lepton excesses implies that dark matter is asymmetric.
Charge asymmetric cosmic rays as a probe of flavor violating asymmetric dark matter
International Nuclear Information System (INIS)
The recently introduced cosmic sum rules combine the data from PAMELA and Fermi-LAT cosmic ray experiments in a way that permits to neatly investigate whether the experimentally observed lepton excesses violate charge symmetry. One can in a simple way determine universal properties of the unknown component of the cosmic rays. Here we attribute a potential charge asymmetry to the dark sector. In particular we provide models of asymmetric dark matter able to produce charge asymmetric cosmic rays. We consider spin zero, spin one and spin one-half decaying dark matter candidates. We show that lepton flavor violation and asymmetric dark matter are both required to have a charge asymmetry in the cosmic ray lepton excesses. Therefore, an experimental evidence of charge asymmetry in the cosmic ray lepton excesses implies that dark matter is asymmetric
Abundance of Asymmetric Dark Matter in Brane World Cosmology
Iminniyaz, Hoernisa
2015-01-01
Relic abundance of asymmetric Dark Matter particles in brane world cosmological scenario is investigated in this article. Hubble expansion rate is enhanced in brane world cosmology and it affects the relic abundance of asymmetric Dark Matter particles. We analyze how the relic abundance of asymmetric Dark Matter is changed in this model. We show that in such kind of nonstandard cosmological scenario, indirect detection of asymmetric Dark Matter is possible if the cross section is small enough which let the anti--particle abundance kept in the same amount with the particle. We show the indirect detection signal like Fermi--LAT constraints can be used to such model only when the cross section and the 5 dimensional Planck mass scale are in appropriate values.
Upper Bounds on Asymmetric Dark Matter Self Annihilation Cross Sections
ELLWANGER, Ulrich; Mitropoulos, Pantelis
2012-01-01
Most models for asymmetric dark matter allow for dark matter self annihilation processes, which can wash out the asymmetry at temperatures near and below the dark matter mass. We study the coupled set of Boltzmann equations for the symmetric and antisymmetric dark matter number densities, and derive conditions applicable to a large class of models for the absence of a significant wash-out of an asymmetry. These constraints are applied to various existing scenarios. In the ca...
Charge Asymmetric Cosmic Rays as a probe of Flavor Violating Asymmetric Dark Matter
DEFF Research Database (Denmark)
Masina, Isabella; Sannino, Francesco
2011-01-01
The recently introduced cosmic sum rules combine the data from PAMELA and Fermi-LAT cosmic ray experiments in a way that permits to neatly investigate whether the experimentally observed lepton excesses violate charge symmetry. One can in a simple way determine universal properties of the unknown component of the cosmic rays. Here we attribute a potential charge asymmetry to the dark sector. In particular we provide models of asymmetric dark matter able to produce charge asymmetric cosmic rays. ...
Exotic States of Nuclear Matter
Lombardo, Umberto; Baldo, Marcello; Burgio, Fiorella; Schulze, Hans-Josef
2008-02-01
pt. A. Theory of nuclear matter EOS and symmetry energy. Constraining the nuclear equation of state from astrophysics and heavy ion reactions / C. Fuchs. In-medium hadronic interactions and the nuclear equation of state / F. Sammarruca. EOS and single-particle properties of isospin-asymmetric nuclear matter within the Brueckner theory / W. Zuo, U. Lombardo & H.-J. Schulze. Thermodynamics of correlated nuclear matter / A. Polls ... [et al.]. The validity of the LOCV formalism and neutron star properties / H. R. Moshfegh ... [et al.]. Ferromagnetic instabilities of neutron matter: microscopic versus phenomenological approaches / I. VidaÃ£. Sigma meson and nuclear matter saturation / A. B. Santra & U. Lombardo. Ramifications of the nuclear symmetry energy for neutron stars, nuclei and heavy-ion collisions / A. W. Steiner, B.-A. Li & M. Prakash. The symmetry energy in nuclei and nuclear matter / A. E. L. Dieperink. Probing the symmetry energy at supra-saturation densities / M. Di Toro et al. Investigation of low-density symmetry energy via nucleon and fragment observables / H. H. Wolter et al. Instability against cluster formation in nuclear and compact-star matter / C. Ducoin ... [et al.]. Microscopic optical potentials of nucleon-nucleus and nucleus-nucleus scattering / Z.-Y. Ma, J. Rong & Y.-Q. Ma -- pt. B. The neutron star crust: structure, formation and dynamics. Neutron star crust beyond the Wigner-Seitz approximation / N. Chamel. The inner crust of a neutron star within the Wigner-Seitz method with pairing: from drip point to the bottom / E. E. Saperstein, M. Baldo & S. V. Tolokonnikov. Nuclear superfluidity and thermal properties of neutron stars / N. Sandulescu. Collective excitations: from exotic nuclei to the crust of neutron stars / E. Khan, M. Grasso & J. Margueron. Monte Carlo simulation of the nuclear medium: fermi gases, nuclei and the role of Pauli potentials / M. A. PÃ©rez-GarcÃa. Low-density instabilities in relativistic hadronic models / C. ProvidÃªncia et al. Quartetting in nuclear matter and [symbol] particle condensation in nuclear systems / G. RÃ¶pke & P. Schuck et al. -- pt. C. Neutron star structure and dynamics. Shear viscosity of neutron matter from realistic nuclear interactions / O. Benhar & M. Valli. Protoneutron star dynamo: theory and observations / A. Bonanno & V. Urpin. Magnetic field dissipation in neutron stars: from magnetars to isolated neutron stars / J. A. Pons. Gravitational radiation and equations of state in super-dense cores of core-collapse supernovae / K. Kotake. Joule heating in the cooling of magnetized neutron stars / D. N. Aguilera, J. A. Pons & J. A. Miralles. Exotic fermi surface of dense neutron matter / M. V. Zverev, V. A. Khodel & J. W. Clark. Coupling of nuclear and electron modes in relativistic stellar matter / A. M. S. Santos et al. Neutron stars in the relativistic Hartree-Fock theory and hadron-quark phase transition / B. Y. Sun ... [et al.] -- pt. D. Prospects of present and future observations. Measurements of neutron star masses / D. G. Yakovlev. Dense nuclear matter: constraints from neutron stars / J. M. Lattimer. Neutron star versus heavy-ion data: is the nuclear equation of state hard or soft? / J. Schaffner-Bielich ... [et al.]. Surface emission from x-ray dim isolated neutron stars / R. Turolla. High energy neutrino astronomy / E. Migneco. What gravitational waves say about the inner structure of neutron stars / V. Ferrari. Reconciling 2 M[symbol] pulsars and SN1987A: two branches of neutron stars / P. Haensel, M. Bejger & J. L. Zdunik. EOS of dense matter and fast rotation of neutron stars / J. L. Zdunik ... [et al.] -- pt. E. Quark and strange matter in neutron stars. Bulk viscosity of color-superconducting quark matter / M. Alford. Chiral symmetry restoration and quark deconfinement at large densities and temperature / A. Drago, L. Bonanno & A. Lavagno. Color superconducting quark matter in compact stars / D. B. Blaschke, T. KlÃ¤hn & F. Sandin. Thermal hadronization, Hawking-Unruh radiation and event horizon in QCD / P. Castorina. Ferromagnetism in the QCD phase diagram / T. Tatsumi. Asymmetric neutrino emission in quark matter and pulsar kicks / I. Sagert & J. Schaffner-Bielich. Effects of the transition of neutron stars to quark stars on the cooling / T. Noda ... [et al.]. The energy release - stellar angular momentum independence in rotating compact stars undergoing first-order phase transitions / M. Bejger ... [et al.]. Hyperon-quark mixed phase in dense matter / T. Maruyama ... [et al.]. Nucleation of quark matter in neutron stars: role of color superconductivity / I. Bombaci, G. Lugones & I. VidaÃ±a. The bulk viscosity and r-mode instability of strange quark matter / B. A. Sa'd. Neutrino trapping in neutron stars in the presence of Kaon condensation / A. Li ... [et al.]. P. Auger Observatory: status and preliminary results / A. Insolia -- pt. F. Nuclear structure from laboratory to stars. Recent advances in the theory of nuclear forces and its impact on microscopic nuclear structure / R. Machleidt. Kohn-Sham density functional approach to nuclear binding / X. ViÃ±as ... [et al.]. Structure and decay of Kaon-condensed hypernuclei / T. Muto. Isoscalar and isovector nuclear matter properties and giant resonances / H. Sagawa & S. Yoshida. The Skyrme interaction and its tensor component / G. Col, P. F. Bortignon & H. Sagawa. Spin-isospin physics and ICHOR project / H. Sakai for the ICHOR collaboration. Neutron skin thickness of [symbol]Zr determined by (p, n) and (n, p) reactions / K. Yako, H. Sakai & H. Sagawa. Synthesis of super-heavy nuclei in a modified di-nuclear system model / E. G. Zhao et al. -- pt. G. Nuclear superfluidity. Mesoscopic treatment of superfluid neutron current in solid star crust / B. Carter. Equation of state in the inner crust of neutron stars: discussion of the unbound neutrons states / J. Margueron, N. Van Giai & N. Sandulescu. Pairing and bound states in nuclear matter / J. W. Clark & A. Sedrakian. Pairing in BCS theory and beyond / L. G. Cao, U. Lombardo & P. Schuck. Pinning and binding energies for vortices in neutron stars: comments on recent results / P. M. Pizzochero. Structure of a vortex in the inner crust of neutron stars / P. Avogadro ... [et al.]. The dynamics of vortex pinning in the neutron star crust / B. Link -- pt. H. Poster session. Microscopic data and supernovae evolution / P. Blottiau, Ph. Mellor & J. Margueron. Parity doublet model applied to neutron star / V. Dexheimer, S. Schramm & H. Stoecker. Structure of hybrid stars / D. Jaccarino, U. Lombardo & G. X. Peng. Nuclear three-body force from the Nijmegen potential / Z. H. Li ... [et al.]. Monopole excitations in QRPA on top of HFB / J. Li, G. ColÃ² & J. Meng. The influence of the [symbol]-field on neutron stars / A. J. Mi, W. Zuo & A. Li. Magnetization of color-flavor locked matter / J. Noronha & I. A. Shovkovy. Ab initio pairing gap calculation for a slab of nuclear matter with Paris and Argonne V18 bare NN-potentials / S. S. Pankratov et al. Hybrid neutron stars within the Nambu-Jona-Lasinio model and confinement / S. Plumari et al. A study of pairing interaction in a separable form / Y. Tian, Z. Ma & P. Ring. Isospin dependence of nuclear matter / E. N. E Van Dalen ... [et al.]. Ejected elements from the envelope of compact stars by QCD phase transition / N. Yasutake et al. Microscopic three-body force effect on nucleon-nucleon cross sections / H. F. Zhang et al. Tensor correlations and single-particle states in medium-mass nuclei / W. Zou et al.
International Nuclear Information System (INIS)
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.)
Fixed-velocity chiral sum rules for nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Cohen, T.D. [Dept. of Physics, Univ. of Maryland, College Park, MD (United States); Broniowski, W. [The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)
1997-02-01
Infinite sets of sum rules involving the excitations of infinite nuclear matter are derived using only completeness, the current algebra implicit in QCD, and relativistic covariance. The sum rules can be used for isospin-asymmetric nuclear matter, including neutron matter. They relate the chiral condensate and the isospin density to weighted sums over states with fixed velocity relative to the nuclear matter ground state. (author) 16 refs, 2 figs
Fixed-Velocity Chiral Sum Rules for Nuclear Matter
Cohen, Thomas D.; Broniowski, Wojciech
1997-01-01
Infinite sets of sum rules involving the excitations of infinite nuclear matter are derived using only completeness, the current algebra implicit in QCD, and relativistic covariance. The sum rules can be used for isospin-asymmetric nuclear matter, including neutron matter. They relate the chiral condensate and the isospin density to weighted sums over states with fixed velocity relative to the nuclear matter ground state.
Upper Bounds on Asymmetric Dark Matter Self Annihilation Cross Sections
Ellwanger, Ulrich
2012-01-01
Most models for asymmetric dark matter allow for dark matter self annihilation processes, which can wash out the asymmetry at temperatures near and below the dark matter mass. We study the coupled set of Boltzmann equations for the symmetric and antisymmetric dark matter number densities, and derive conditions applicable to a large class of models for the absence of a significant wash-out of an asymmetry. These constraints are applied to various existing scenarios. In the case of left- or right-handed sneutrinos, very large electroweak gaugino masses, or very small mixing angles are required.
Upper bounds on asymmetric dark matter self annihilation cross sections
International Nuclear Information System (INIS)
Most models for asymmetric dark matter allow for dark matter self annihilation processes, which can wash out the asymmetry at temperatures near and below the dark matter mass. We study the coupled set of Boltzmann equations for the symmetric and antisymmetric dark matter number densities, and derive conditions applicable to a large class of models for the absence of a significant wash-out of an asymmetry. These constraints are applied to various existing scenarios. In the case of left- or right-handed sneutrinos, very large electroweak gaugino masses, or very small mixing angles are required
Upper bounds on asymmetric dark matter self annihilation cross sections
Energy Technology Data Exchange (ETDEWEB)
Ellwanger, Ulrich; Mitropoulos, Pantelis, E-mail: ulrich.ellwanger@th.u-psud.fr, E-mail: pantelis.mitropoulos@th.u-psud.fr [LPT, UMR 8627, CNRS, Université de Paris-Sud, Bât. 210, 91405 Campus d' Orsay (France)
2012-07-01
Most models for asymmetric dark matter allow for dark matter self annihilation processes, which can wash out the asymmetry at temperatures near and below the dark matter mass. We study the coupled set of Boltzmann equations for the symmetric and antisymmetric dark matter number densities, and derive conditions applicable to a large class of models for the absence of a significant wash-out of an asymmetry. These constraints are applied to various existing scenarios. In the case of left- or right-handed sneutrinos, very large electroweak gaugino masses, or very small mixing angles are required.
Continuous flavor symmetries and the stability of asymmetric dark matter
Bishara, Fady; Zupan, Jure
2015-01-01
Generically, the asymmetric interactions in asymmetric dark matter (ADM) models could lead to decaying DM. We show that, for ADM that carries nonzero baryon number, the continuous flavor symmetries that generate the flavor structure in the quark sector also imply a looser lower bound on the mass scale of the asymmetric mediators between the dark and visible sectors. The mediators for B = 2 ADM that can produce a signal in the future indirect dark matter searches can thus also be searched for at the LHC. For two examples of the mediator models, with either the MFV or Froggatt-Nielsen flavor breaking pattern, we derive the FCNC constraints and discuss the search strategies at the LHC.
Continuous Flavor Symmetries and the Stability of Asymmetric Dark Matter
Bishara, Fady
2014-01-01
Generically, the asymmetric interactions in asymmetric dark matter (ADM) models lead to decaying DM. We show that, for ADM that carries nonzero baryon number, the continuous flavor symmetries that generate the flavor structure in the quark sector also imply a looser lower bound on the mass scale of the asymmetric mediators between the dark and visible sectors. The mediators for $B=2$ ADM that can produce a signal in the future indirect dark matter searches can thus also be searched for at the LHC. For two examples of the mediator models, with either the MFV or Froggatt-Nielsen flavor breaking pattern, we derive the FCNC constraints and discuss the search strategies at the LHC.
Asymmetric dark matter and the Sun
DEFF Research Database (Denmark)
Frandsen, Mads Toudal; Sarkar, Subir
2010-01-01
Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure...... formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particles can solve the `solar composition problem'. The predicted small decrease in the low energy neutrino...
Asymmetric dark matter and the Sun
DEFF Research Database (Denmark)
Frandsen, Mads Toudal; Sarkar, Subir
2010-01-01
Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particl...
Asymmetric dark matter and the Sun
DEFF Research Database (Denmark)
Frandsen, Mads Toudal; Sarkar, Subir
2010-01-01
Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particles can solve the `solar composition problem'. The predicted small decrease in the low energy neutrino fluxes may be measurable by the Borexino and SNO+ experiments.
Directory of Open Access Journals (Sweden)
Lenske H.
2016-01-01
Full Text Available Recent developments of nuclear structure theory for exotic nuclei are addressed. The inclusion of hyperons and nucleon resonances is discussed. Nuclear multipole response functions, hyperon interactions in infinite matter and in neutron stars and theoretical aspects of excitations of nucleon resonances in nuclei are discussed.
Gamma ray constraints on flavor violating asymmetric dark matter
DEFF Research Database (Denmark)
Masina, I.; Panci, P.
2012-01-01
We show how cosmic gamma rays can be used to constrain models of asymmetric Dark Matter decaying into lepton pairs by violating flavor. First of all we require the models to explain the anomalies in the charged cosmic rays measured by PAMELA, Fermi and H.E.S.S.; performing combined fits we determine the allowed values of the Dark Matter mass and lifetime. For these models, we then determine the constraints coming from the measurement of the isotropic gamma-ray background by Fermi for a complete set of lepton flavor violating primary modes and over a range of DM masses from 100 GeV to 10 TeV. We find that the Fermi constraints rule out the flavor violating asymmetric Dark Matter interpretation of the charged cosmic ray anomalies.
Gamma ray constraints on flavor violating asymmetric dark matter
DEFF Research Database (Denmark)
Masina, I.; Panci, P.; Sannino, F.
We show how cosmic gamma rays can be used to constrain models of asymmetric Dark Matter decaying into lepton pairs by violating flavor. First of all we require the models to explain the anomalies in the charged cosmic rays measured by PAMELA, Fermi and H.E.S.S.; performing combined fits we...... determine the allowed values of the Dark Matter mass and lifetime. For these models, we then determine the constraints coming from the measurement of the isotropic gamma-ray background by Fermi for a complete set of lepton flavor violating primary modes and over a range of DM masses from 100 GeV to 10 Te......V. We find that the Fermi constraints rule out the flavor violating asymmetric Dark Matter interpretation of the charged cosmic ray anomalies....
Gamma ray constraints on flavor violating asymmetric dark matter
International Nuclear Information System (INIS)
We show how cosmic gamma rays can be used to constrain models of asymmetric Dark Matter decaying into lepton pairs by violating flavor. First of all we require the models to explain the anomalies in the charged cosmic rays measured by PAMELA, Fermi and HESS performing combined fits we determine the allowed values of the Dark Matter mass and lifetime. For these models, we then determine the constraints coming from the measurement of the isotropic ?-ray background by Fermi for a complete set of lepton flavor violating primary modes and over a range of DM masses from 100 GeV to 10 TeV. We find that the Fermi constraints rule out the flavor violating asymmetric Dark Matter interpretation of the charged cosmic ray anomalies
Decaying asymmetric dark matter relaxes the AMS-Fermi tension
International Nuclear Information System (INIS)
The first result of AMS-02 confirms the positron fraction excess observed by PAMELA, but the spectrum is somewhat softer than that of PAMELA. In the dark matter (DM) interpretation it brings a tension between AMS-02 and Fermi-LAT, which reported an excess of the electron plus positron flux. In this work we point out that the asymmetric cosmic ray from asymmetric dark matter (ADM) decay relaxes the tension. It is found that in the case of two-body decay a bosonic ADM around 2.4 TeV and decaying into ???+ can significantly improve the fits. Based on the R?parity-violating supersymmetry with operators LLEc, we propose a minimal model to realize that ADM. The model introduces only a pair of singlets (X, X-bar ) with a tiny coupling LHuX, which makes the ADM share the lepton asymmetry and decay into ???+ along the operator LLEc
Chromomagnetism in nuclear matter
Ranjan, Akhilesh; Raina, P. K.
2011-01-01
Quarks are color charged particles. Due to their motion there is a strong possibility of generation of color magnetic field. It is shown that however hadrons are color singlet particles they may have non-zero color magnetic moment. Due to this color magnetic moment hadrons can show color interaction. In this paper we have studied the chromomagnetic properties of nuclear matter.
Asymmetric capture of Dirac dark matter by the Sun
International Nuclear Information System (INIS)
Current problems with the solar model may be alleviated if a significant amount of dark matter from the galactic halo is captured in the Sun. We discuss the capture process in the case where the dark matter is a Dirac fermion and the background halo consists of equal amounts of dark matter and anti-dark matter. By considering the case where dark matter and anti-dark matter have different cross sections on solar nuclei as well as the case where the capture process is considered to be a Poisson process, we find that a significant asymmetry between the captured dark particles and anti-particles is possible even for an annihilation cross section in the range expected for thermal relic dark matter. Since the captured number of particles are competitive with asymmetric dark matter models in a large range of parameter space, one may expect solar physics to be altered by the capture of Dirac dark matter. It is thus possible that solutions to the solar composition problem may be searched for in these type of models
Asymmetric capture of Dirac dark matter by the Sun
Blennow, Mattias; Clementz, Stefan
2015-08-01
Current problems with the solar model may be alleviated if a significant amount of dark matter from the galactic halo is captured in the Sun. We discuss the capture process in the case where the dark matter is a Dirac fermion and the background halo consists of equal amounts of dark matter and anti-dark matter. By considering the case where dark matter and anti-dark matter have different cross sections on solar nuclei as well as the case where the capture process is considered to be a Poisson process, we find that a significant asymmetry between the captured dark particles and anti-particles is possible even for an annihilation cross section in the range expected for thermal relic dark matter. Since the captured number of particles are competitive with asymmetric dark matter models in a large range of parameter space, one may expect solar physics to be altered by the capture of Dirac dark matter. It is thus possible that solutions to the solar composition problem may be searched for in these type of models.
Constraining Asymmetric Dark Matter through observations of compact stars
DEFF Research Database (Denmark)
Kouvaris, Christoforos; Tinyakov, Peter
2011-01-01
We put constraints on asymmetric dark matter candidates with spin-dependent interactions based on the simple existence of white dwarfs and neutron stars in globular clusters. For a wide range of the parameters (WIMP mass and WIMP-nucleon cross section), WIMPs can be trapped in progenitors in large...... numbers and once the original star collapses to a white dwarf or a neutron star, these WIMPs might self-gravitate and eventually collapse forming a mini-black hole that eventually destroys the star. We impose constraints competitive to direct dark matter search experiments, for WIMPs with masses down to...
Gamma ray constraints on flavor violating asymmetric dark matter
DEFF Research Database (Denmark)
Masina, I.; Panci, P.; Sannino, F.
2012-01-01
We show how cosmic gamma rays can be used to constrain models of asymmetric Dark Matter decaying into lepton pairs by violating flavor. First of all we require the models to explain the anomalies in the charged cosmic rays measured by PAMELA, Fermi and H.E.S.S.; performing combined fits we determine the allowed values of the Dark Matter mass and lifetime. For these models, we then determine the constraints coming from the measurement of the isotropic gamma-ray background by Fermi for a complete ...
Constraining asymmetric dark matter through observations of compact stars
International Nuclear Information System (INIS)
We put constraints on asymmetric dark matter candidates with spin-dependent interactions based on the simple existence of white dwarfs and neutron stars in globular clusters. For a wide range of the parameters (WIMP mass and WIMP-nucleon cross section), weakly interacting massive particles (WIMPs) can be trapped in progenitors in large numbers and once the original star collapses to a white dwarf or a neutron star, these WIMPs might self-gravitate and eventually collapse forming a mini-black hole that eventually destroys the star. We impose constraints competitive to direct dark matter search experiments, for WIMPs with masses down to the TeV scale.
Constraining Asymmetric Dark Matter through observations of compact stars
DEFF Research Database (Denmark)
Kouvaris, Christoforos; Tinyakov, Peter
2011-01-01
We put constraints on asymmetric dark matter candidates with spin-dependent interactions based on the simple existence of white dwarfs and neutron stars in globular clusters. For a wide range of the parameters (WIMP mass and WIMP-nucleon cross section), WIMPs can be trapped in progenitors in large numbers and once the original star collapses to a white dwarf or a neutron star, these WIMPs might self-gravitate and eventually collapse forming a mini-black hole that eventually destroys the star. We impose constraints competitive to direct dark matter search experiments, for WIMPs with masses down to the TeV scale.
Kaon polarization in nuclear matter
International Nuclear Information System (INIS)
The kaon-nucleon interaction in nuclear matter is considered by taking into account tree graphs, p-wave interaction, pionic intermediate states and some residual interaction constrained by Adler's consistency condition. The kaon spectra in nuclear matter are discussed as well as the possibility of K- and anti K0 condensation in dense nuclear matter. (orig.)
A Model of Asymmetric Hadronic Dark Matter and Leptogenesis
Yang, Wei-Min
2015-01-01
The paper suggests a model to account for the common origins of the asymmetric dark matter (ADM) and matter-antimatter asymmetry. The ADM nature is a stable hadronic particle consisting of a heavy color scalar and a light $u$ quark, which is formed after the QCD phase transition. At the early stage the ADM are in thermal equilibrium through collisions with the nucleons, moreover, they can emit the $\\gamma$ photons with $0.32$ MeV energy. However they are decoupling and become the dark matter at the temperature about $130$ MeV. The mass upper limit of the ADM is predicted as $M_{D}<1207$ GeV. It is feasible and promising to test the model in future experiments.
Possible implications of asymmetric fermionic dark matter for neutron stars
International Nuclear Information System (INIS)
We consider the implications of fermionic asymmetric dark matter (ADM) for a “mixed neutron star” composed of ordinary baryons and dark fermions. We find examples, where for a certain range of dark fermion mass – when it is less than that of ordinary baryons – such systems can reach higher masses than the maximal values allowed for ordinary (“pure”) neutron stars. This is shown both within a simplified, heuristic Newtonian analytic framework with non-interacting particles and via a general relativistic numerical calculation, under certain assumptions for the dark matter equation of state. Our work applies to various dark fermion models such as mirror matter models and to other models where the dark fermions have self-interactions
Bulk matters on symmetric and asymmetric de Sitter thick branes
Energy Technology Data Exchange (ETDEWEB)
Liu, Yu-Xiao; Zhao, Zhen-Hua; Wei, Shao-Wen; Duan, Yi-Shi, E-mail: liuyx@lzu.edu.cn, E-mail: zhaozhenhua@impcas.ac.cn, E-mail: weishaow06@lzu.cn, E-mail: ysduan@lzu.edu.cn [Institute of Theoretical Physics, Lanzhou University, Tianshui South Road 222, Lanzhou 730000 (China)
2009-02-15
An asymmetric thick domain wall solution with de Sitter (dS) expansion in five dimensions can be constructed from a symmetric one by using a same scalar (kink) with different potentials. In this paper, by presenting the mass-independent potentials of Kaluza-Klein (KK) modes in the corresponding Schroedinger equations, we investigate the localization and mass spectra of various bulk matter fields on the symmetric and asymmetric dS thick branes. For spin 0 scalars and spin 1 vectors, the potentials of KK modes in the corresponding Schroedinger equations are the modified Poeschl-Teller potentials, and there exist a mass gap and a series of continuous spectrum. It is shown that the spectrum of scalar KK modes on the symmetric dS brane contains only one bound mode (the massless mode). However, for the asymmetric dS brane with a large asymmetric factor, there are two bound scalar KK modes: a zero mode and a massive mode. For spin 1 vectors, the spectra of KK modes on both dS branes consist of a bound massless mode and a set of continuous ones, i.e., the asymmetric factor does not change the number of the bound vector KK modes. For spin 1/2 fermions, two types of kink-fermion couplings are investigated in detail. For the usual Yukawa coupling {eta}barPsi{phi}{Psi}, there exists no mass gap but a continuous gapless spectrum of KK states. For the scalar-fermion coupling {eta}barPsisin({phi}/{phi}{sub 0})cos{sup -{delta}}({phi}/{phi}{sub 0}){Psi} with a positive coupling constant {eta}, there exist some discrete bound KK modes and a series of continuous ones. The total number of bound states increases with the coupling constant {eta}. For the case of the symmetric dS brane and positive {eta}, there are N{sub L}(N{sub L} {>=} 1) left chiral fermion bound states (including zero mode and massive KK modes) and N{sub L}-1 right chiral fermion bound states (including only massive KK modes). For the asymmetric dS brane scenario, the asymmetric factor a reduces the number of the bound fermion KK modes. For large enough a, there would not be any right chiral fermion bound mode, but at least one left chiral fermion zero mode.
Constraining Asymmetric Dark Matter through observations of compact stars
DEFF Research Database (Denmark)
Kouvaris, Christoforos; Tinyakov, Peter
2011-01-01
We put constraints on asymmetric dark matter candidates with spin-dependent interactions based on the simple existence of white dwarfs and neutron stars in globular clusters. For a wide range of the parameters (WIMP mass and WIMP-nucleon cross section), WIMPs can be trapped in progenitors in large numbers and once the original star collapses to a white dwarf or a neutron star, these WIMPs might self-gravitate and eventually collapse forming a mini-black hole that eventually destroys the star. We...
Exposing asymmetric gray matter vulnerability in amyotrophic lateral sclerosis
Directory of Open Access Journals (Sweden)
Matthew S. Devine
2015-01-01
Full Text Available Limb weakness in amyotrophic lateral sclerosis (ALS is typically asymmetric. Previous studies have identified an effect of limb dominance on onset and spread of weakness, however relative atrophy of dominant and non-dominant brain regions has not been investigated. Our objective was to use voxel-based morphometry (VBM to explore gray matter (GM asymmetry in ALS, in the context of limb dominance. 30 ALS subjects were matched with 17 healthy controls. All subjects were right-handed. Each underwent a structural MRI sequence, from which GM segmentations were generated. Patterns of GM atrophy were assessed in ALS subjects with first weakness in a right-sided limb (n = 15 or left-sided limb (n = 15. Within each group, a voxelwise comparison was also performed between native and mirror GM images, to identify regions of hemispheric GM asymmetry. Subjects with ALS showed disproportionate atrophy of the dominant (left motor cortex hand area, irrespective of the side of first limb weakness (p < 0.01. Asymmetric atrophy of the left somatosensory cortex and temporal gyri was only observed in ALS subjects with right-sided onset of limb weakness. Our VBM protocol, contrasting native and mirror images, was able to more sensitively detect asymmetric GM pathology in a small cohort, compared with standard methods. These findings indicate particular vulnerability of dominant upper limb representation in ALS, supporting previous clinical studies, and with implications for cortical organisation and selective vulnerability.
International Nuclear Information System (INIS)
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)
Condensed Matter Nuclear Science
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 into characteristics of X-ray emission laser beams from solidstate cathode medium of high-current glow discharge / A. B. Karabut. Charged particles from Ti and Pd foils / L. Kowalski ... [et al.]. Cr-39 track detectors in cold fusion experiments: review and perspectives / A. S. Roussetski. Energetic particle shower in the vapor from electrolysis / R. A. Oriani and J. C. Fisher. Nuclear reactions produced in an operating electrolysis cell / R. A. Oriani and J. C. Fisher. Evidence of microscopic ball lightning in cold fusion experiments / E. H. Lewis. Neutron emission from D[symbol] gas in magnetic fields under low temperature / T. Mizuno ... [et al.]. Energetic charged particle emission from hydrogen-loaded Pd and Ti cathodes and its enhancement by He-4 implantation / A. G. Lipson ... [et al.]. H-D permeation. Observation of nuclear transmutation reactions induced by D[symbol] gas permeation through Pd complexes / Y. Iwamura ... [et al.]. Deuterium (hydrogen) flux permeating through palladium and condensed matter nuclear science / Q. M. Wei ... [et al.]. Triggering. Precursors and the fusion reactions in polarized Pd/D-D[symbol]O system: effect of an external electric field / S. Szpak, P. A. Mosier-Boss, and F. E. Gordon. Calorimetric and neutron diagnostics of liquids during laser irradiation / Yu. N. Bazhutov ... [et al.]. Anomalous neutron capture and plastic deformation of Cu and Pd cathodes during electrolysis in a weak thermalized neutron field: evidence of nuclei-lattice exchange / A. G. Lipson and G. H. Miley. H-D loading. An overview of experimental studies on H/Pd over-loading with thin Pd wires and different electrolytic solutions / A. Spallone ... [et al.] -- 3. Transmutations. Photon and particle emission, heat production, and surface transformation in Ni-H system / E. Campari ... [et al.]. Surface analysis of hydrogen-loaded nickel alloys / E. Campari ... [et al.]. Low-energy nuclear reactions and the leptonic monopole / G. Lochak and L. Urutskoev. Results of analysis of Ti foil after glow discharge with deuterium / I. B. Savvatimova and D. V. Gavritenkov. Enhancement mechanisms of low-energy nuclear reactions / F. A. Gareev, I. E. Zhidkova, and Y. L. Ratis. Co-deposition of palladium with hydrogen isotopes / J. Dash and A. Ambadkar. Variation of the concentration of isotopes copper and zinc in human plasmas of patients affected by cancer / A. Triassi. Transmutation of metal at low energy in a confined plasma in water / D. Cirillo and V. Iorio. The conditions and realization of self-similar Coulomb collapse of condensed target and low-energy laboratory nucleosynthesis / S. V. Adamenko and V. I. Vysotskii. The spatial structure of water and the problem of controlled low-energy nuclear reactions in water matrix / V. I. Vysotskii and A. A. Kornilova. Experiments on controlled decontamination of water mixture of longlived active isotopes in biological cells / V. I. Vysotskii. Assessment of the biological effects of "strange" radiation / E. A. Pryakhin ... [et al.]. Possible nuclear transmutation of nitrogen in the earth's atmosphere / M. Fukuhara. Evidences on the occurrence of LENR-type processes in alchemical transmutations / J. PÃ©rez-Pariente. History of the discovery of transmutation at Texas A&M University / J. O.-M. Bockris -- 4. Theory. Quantum electrodynamics. Concerning the modeling of systems in terms of quantum electro dynamics: the special case of "cold fusion" / M. Abyaneh ... [et al.]. Screening. Theoretical model of the probability of fusion between deuterons within deformed lattices with microcracks at room temperature / F. Fulvio. Resonant tunnelling. Effective interaction potential in the deuterium plasma and multiple resonance scattering / T. Toimela. Multiple scattering theory and condensed matter nuclear science - "super-absorption" in a crystal latice / X. Z. Li ... [et al.]. Ion band states. Framework for understanding LENR processes, using conventional condensed matter physics / S. R. Chubb. I. Bloch ions / T. A. Chubb. II. Inhibited diffusion driven surface transmutations / T. A. Chubb. III. Bloch nuclides, Iwamura transmutations, and Oriani showers / T. A. Chubb. Bose-Einstein condensate. Theoretical study of nuclear reactions induced by Bose-Einstein condensation in Pd / K.-I. Tsuchiya and H. Okumura. Proposal for new experimental tests of the Bose-Einstein condensation mechanism for low-energy nuclear reaction and transmutation processes in deuterium loaded micro- and nano-scale cavities / Y. E. Kim ... [et al.]. Mixtures of charged bosons confined in harmonic traps and Bose-Einstein condensation mechanism for low-energy nuclear reactions and transmutation processes in condensed matters / Y. E. Kim and A. L. Zubarev. Alternative interpretation of low-energy nuclear reaction processes with deuterated metals based on the Bose-Einstein condensation mechanism / Y. E. Kim and T. O. Passell. Multi-body fusion. [symbol]He/[symbol]He production ratios by tetrahedral symmetric condensation / A. Takahashi. Phonon coupling. Phonon-exchange models: some new results / P. L. Hagelstein. Neutron clusters. Cold fusion phenomenon and solid state nuclear physics / H. Kozima. Neutrinos, magnetic monopoles. Neutrino-driven nuclear reactions of cold fusion and transmutation / V. Filimonov. Light monopoles theory: an overview of their effects in physics, chemistry, biology, and nuclear science (weak interactions) / G. Lochak. Electrons clusters and magnetic monopoles / M. Rambaut. Others. Effects of atomic electrons on nuclear stability and radioactive decay / D. V. Filippov, L. I. Urutskoev, and A. A. Rukhadze. Search for erzion nuclear catalysis chains from cosmic ray erzions stopping in organic scintillator / Yu. N. Bazhutov and E. V. Pletnikov. Low-energy nuclear reactions resulting as picometer interactions with similarity to K-shell electron capture / H. Hora ... [et al.] -- 5. Other topics. On the possible magnetic mechanism of shortening the runaway of RBMK-1000 reactor at Chernobyl Nuclear Power Plant / D. V. Filippov ... [et al.]. Cold fusion in the context of a scientific revolution in physics: history and economic ramifications / E. Lewis. The nucleovoltaic cell / D. D. Moon. Introducing the book "Cold Fusion and the Future" / J. Rothwell. Recent cold fusion claims: are they valid? / L. Kowalski. History of attempts to publish a paper / L. Kowalski.
Discovering asymmetric dark matter with anti-neutrinos
International Nuclear Information System (INIS)
We discuss possible signatures of Asymmetric Dark Matter (ADM) through dark matter decays to neutrinos. We specifically focus on scenarios in which the Standard Model (SM) baryon asymmetry is transferred to the dark sector (DS) through higher dimensional operators in chemical equilibrium. In such cases, the dark matter (DM) carries lepton and/or baryon number, and we point out that for a wide range of quantum number assignments, by far the strongest constraints on dark matter decays come from decays to neutrinos through the ''neutrino portal'' operator HL. Together with the facts that ADM favors lighter DM masses ? a few GeV and that the decays would lead only to anti-neutrinos and no neutrinos (or vice versa), the detection of such decays at neutrino telescopes would provide compelling evidence for ADM. We discuss current and future bounds on models where the DM decays to neutrinos through operators of dimension ? 6. For dimension 6 operators, the scale suppressing the decay is bounded to be ?>1012–1013 GeV
Muller, H. -M.; Koonin, S. E.; Seki, R.; van Kolck, U.
1999-01-01
We investigate nuclear matter on a cubic lattice. An exact thermal formalism is applied to nucleons with a Hamiltonian that accommodates on-site and next-neighbor parts of the central, spin- and isospin-exchange interactions. We describe the nuclear matter Monte Carlo methods which contain elements from shell model Monte Carlo methods and from numerical simulations of the Hubbard model. We show that energy and basic saturation properties of nuclear matter can be reproduced. ...
Nuclear Matter Equation of State and Three body Forces
Mansour, Hesham M. M.; Gamoudi, Abdelsalam
2011-01-01
The energy per particle, symmetry energy, pressure, Free energy are calculated for asymmetric nuclear matter using BHF approach and modern nucleon-nucleon CD-Bonn, Nijm1, Argonnev18 and Reid93 potentials. To obtain saturation in nuclear matter we add three-body interaction terms which are equivalent a la Skyrme to a density-dependent two-nucleon interaction. Good agreement is obtained in comparison with previous theoretical estimates and experimental data.
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.)
Nuclear matter and electron scattering
International Nuclear Information System (INIS)
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.)
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.)
Propagation of neutrinos in nuclear matter
International Nuclear Information System (INIS)
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??'0 (where ?, ?' = 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)
Covariant density functional theory for nuclear matter
International Nuclear Information System (INIS)
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.)
Limits on momentum-dependent asymmetric dark matter with CRESST-II
Angloher, G; Bucci, C; Canonica, L; Defay, X; Erb, A; Feilitzsch, F v; Iachellini, N Ferreiro; Gorla, P; Gütlein, A; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J -C; Loebell, J; Münster, A; Pagliarone, C; Petricca, F; Potzel, W; Pröbst, F; Reindl, F; Schäffner, K; Schieck, J; Schönert, S; Seidel, W; Stodolsky, L; Strandhagen, C; Strauss, R; Tanzke, A; Thi, H H Trinh; Türko?lu, C; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wüstrich, M; Zöller, A
2016-01-01
The usual assumption in direct dark matter searches is to only consider the spin-dependent or spin-independent scattering of dark matter particles. However, especially in models with light dark matter particles $\\mathcal{O}(\\mathrm{GeV/c^2})$, operators which carry additional powers of the momentum transfer $q^2$ can become dominant. One such model based on asymmetric dark matter has been invoked to overcome discrepancies in helioseismology and an indication was found for a particle with preferred mass of 3 $\\mathrm{GeV/c^2}$ and cross section of $10^{-37} \\mathrm{cm^2}$. Recent data from the CRESST-II experiment, which uses cryogenic detectors based on $\\mathrm{CaWO_4}$ to search for nuclear recoils induced by dark matter particles, are used to constrain these momentum-dependent models. The low energy threshold of 307 eV for nuclear recoils of the detector used, allows us to rule out the proposed best fit value above.
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.
Chiral thermodynamics of nuclear matter
International Nuclear Information System (INIS)
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.
Flavor and collider signatures of asymmetric dark matter
Kim, Ian-Woo; Zurek, Kathryn M.
2014-02-01
We consider flavor constraints on, and collider signatures of, asymmetric dark matter (ADM) via higher dimension operators. In the supersymmetric models we consider, R-parity-violating (RPV) operators carrying B -L interact with n dark matter particles X through an interaction of the form W =XnOB -L, where OB-L=q?dc, ucdcdc, ??ec. This interaction ensures that the lightest ordinary supersymmetric particle is unstable to decay into the X sector, leading to a higher multiplicity of final state particles and reduced missing energy at a collider. Flavor-violating processes place constraints on the scale of the higher dimension operator, impacting whether the LOSP decays promptly. While the strongest limitations on RPV from n -n¯ oscillations and proton decay do not apply to ADM, we analyze the constraints from meson mixing, ?-e conversion, ??3e and b?s?+?-. We show that these flavor constraints, even in the absence of flavor symmetries, allow parameter space for prompt decay to the X sector, with additional jets and leptons in exotic flavor combinations. We study the constraints from existing 8 TeV LHC Supersymmetry (SUSY) searches with (i) 2-6 jets plus missing energy and (ii) 1-2 leptons, 3-6 jets plus missing energy, comparing the constraints on ADM-extended supersymmetry with the usual supersymmetric simplified models.
Flavor and Collider Signatures of Asymmetric Dark Matter
Kim, Ian-Woo
2014-01-01
We consider flavor constraints on, and collider signatures of, Asymmetric Dark Matter (ADM) via higher dimension operators. In the supersymmetric models we consider, R-parity violating (RPV) operators carrying B-L interact with n dark matter (DM) particles X through an interaction of the form W = X^n O_{B-L}, where O_{B-L} = q l d^c, u^c d^c d^c, l l e^c. This interaction ensures that the lightest ordinary supersymmetric particle (LOSP) is unstable to decay into the X sector, leading to a higher multiplicity of final state particles and reduced missing energy at a collider. Flavor-violating processes place constraints on the scale of the higher dimension operator, impacting whether the LOSP decays promptly. While the strongest limitations on RPV from n-\\bar{n} oscillations and proton decay do not apply to ADM, we analyze the constraints from meson mixing, mu-e conversion, mu -> 3 e and b -> s l^+ l^-. We show that these flavor constraints, even in the absence of flavor symmetries, allow parameter space for pr...
Nuclear physics and dense matter
International Nuclear Information System (INIS)
Crucial to understanding the properties of dense matter in supernova explosions and neutron stars is determining the role of the nuclei present in such matter. Because many of the properties of the matter do not depend strongly on the fine details of nuclear structure, the liquid drop model of the nucleus provides a convenient starting point. The influence of the matter outside the nuclei on the properties of the nuclei must, however, be taken into account. One studies several aspects of the liquid drop model and its applications. In particular one first studies the theory of surface tension as used in the liquid drop model. Then a refined version of the compressible liquid drop model was developed which enables a redetermination semi-empirically of the properties of bulk nuclear matter. Finally, resultant nuclear mass formula is applied to the equation of state of hot, dense matter
Takeshita, Hisako; Sawa, Hitoshi
2005-01-01
?-Catenin can promote adhesion at the cell cortex and mediate Wnt signaling in the nucleus. We show that, in Caenorhabditis elegans, both WRM-1/?-catenin and LIT-1 kinase localize to the anterior cell cortex during asymmetric cell division but to the nucleus of the posterior daughter afterward. Both the cortical and nuclear localizations are regulated by Wnts and are apparently coupled. We also found that the daughters show different nuclear export rates for LIT-1. Our results indicate that W...
What can we learn from nuclear matter instabilities
International Nuclear Information System (INIS)
We discuss the features of instabilities in binary systems, in particular for asymmetric nuclear matter. We show the relevance for the interpretation of results obtained in experiments and in 'ab initio' simulations of the reaction 124 Sn + nat Sn at 50 MeV/n (authors)
Monte Carlo approach to nuclei and nuclear matter
Fantoni, Stefano; Gandolfi, Stefano; Illarionov, Alexey Yu.; Schmidt, Kevin E.; Pederiva, Francesco
2008-01-01
We report on the most recent applications of the Auxiliary Field Diffusion Monte Carlo (AFDMC) method. The equation of state (EOS) for pure neutron matter in both normal and BCS phase and the superfluid gap in the low--density regime are computed, using a realistic Hamiltonian containing the Argonne AV8' plus Urbana IX three--nucleon interaction. Preliminary results for the EOS of isospin--asymmetric nuclear matter are also presented.
Phase transitions in nuclear matter
International Nuclear Information System (INIS)
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
Shear viscosity of nuclear matter
Xu, Jun
2013-01-01
In this talk I report my recent study on the shear viscosity of neutron-rich nuclear matter from a relaxation time approach. An isospin- and momentum-dependent interaction is used in the study. Effects of density, temperature, and isospin asymmetry of nuclear matter on its shear viscosity have been discussed. Similar to the symmetry energy, the symmetry shear viscosity is defined and its density and temperature dependence are studied.
The phase diagram of bulk nuclear matter
International Nuclear Information System (INIS)
Recent analyses of nuclear multifragmentation and compound nuclear data determined the pressure-density-temperature phase diagram of bulk nuclear matter. A condensation model, modified to account for nuclear energies, was used to describe the fragment yields and finite size scaling techniques were used to determine the bulk property of nuclear matter from finite, charged samples of nuclear matter, i.e. nuclei. (orig.)
Anatomy of nuclear matter fundamentals
Patra, S . K.; Biswal, S. K.; Singh, S.K.; M Bhuyan
2014-01-01
The bridge between finite and infinite nuclear system is analyzed for the fundamental quantities like binding energy, density, compressibility, giant monopole excitation energy and effective mass of both nuclear matter and finite nuclei systems. It is shown quantitatively that by knowing one of the fundamental property of one system one can estimate the same in its counter part, only approximately
Bosonic variables in nuclear matters
International Nuclear Information System (INIS)
It is shown that the boson theoretical interpretation of nuclear forces nessecitates the introduction of bosonic variables within the state function of nuclear matter. In this framework the 2-boson exchange plays a decisive role and calls for the introduction of special selfenergy diagrams. This generalized scheme is discussed with the help of a solvable field theoretical model. (orig.)
More on nucleon-nucleon cross sections in symmetric and asymmetric matter
Sammarruca, F.; Krastev, P.
2005-01-01
Following a recent work, we present numerical results for total two-nucleon effective cross sections in isospin symmetric and asymmetric matter. The present calculations include the additional effect of Pauli blocking of the final states.
Linear response of homogeneous nuclear matter with energy density functionals
Pastore, A.; Davesne, D.; Navarro, J.
2015-03-01
Response functions of infinite nuclear matter with arbitrary isospin asymmetry are studied in the framework of the random phase approximation. The residual interaction is derived from a general nuclear Skyrme energy density functional. Besides the usual central, spin-orbit and tensor terms it could also include other components as new density-dependent terms or three-body terms. Algebraic expressions for the response functions are obtained from the Bethe-Salpeter equation for the particle-hole propagator. Applications to symmetric nuclear matter, pure neutron matter and asymmetric nuclear matter are presented and discussed. Spin-isospin strength functions are analyzed for varying conditions of density, momentum transfer, isospin asymmetry, and temperature for some representative Skyrme functionals. Particular attention is paid to the discussion of instabilities, either real or unphysical, which could manifest in finite nuclei.
Linear response of homogeneous nuclear matter with energy density functionals
International Nuclear Information System (INIS)
Response functions of infinite nuclear matter with arbitrary isospin asymmetry are studied in the framework of the random phase approximation. The residual interaction is derived from a general nuclear Skyrme energy density functional. Besides the usual central, spin–orbit and tensor terms it could also include other components as new density-dependent terms or three-body terms. Algebraic expressions for the response functions are obtained from the Bethe–Salpeter equation for the particle–hole propagator. Applications to symmetric nuclear matter, pure neutron matter and asymmetric nuclear matter are presented and discussed. Spin–isospin strength functions are analyzed for varying conditions of density, momentum transfer, isospin asymmetry, and temperature for some representative Skyrme functionals. Particular attention is paid to the discussion of instabilities, either real or unphysical, which could manifest in finite nuclei
Energy Technology Data Exchange (ETDEWEB)
Chapman, S.
1992-11-01
The goal in this thesis is thus twofold: The first is to investigate the feasibility of using heavy ion collisions to create conditions in the laboratory which are ripe for the formation of a quark-gluon plasma. The second is to develop a technique for studying some of the many non-perturbative features of this novel phase of matter.
International Nuclear Information System (INIS)
The goal in this thesis is thus twofold: The first is to investigate the feasibility of using heavy ion collisions to create conditions in the laboratory which are ripe for the formation of a quark-gluon plasma. The second is to develop a technique for studying some of the many non-perturbative features of this novel phase of matter
Limits on momentum-dependent asymmetric dark matter with CRESST-II
Angloher, G.(Max-Planck-Institut für Physik, 80805 , Munich, Germany); Bento, A.; Bucci, C.; Canonica, L.; Defay, X.; Erb, A.(Physik-Department, Technische Universität München, 85747, Garching, Germany); Feilitzsch, F. v.; Iachellini, N. Ferreiro(Max-Planck-Institut für Physik, 80805, Munich, Germany); Gorla, P.; Gütlein, A.; Hauff, D.; Jochum, J.; Kiefer, M; Kluck, H.(Institut für Hochenergiephysik der Österreichischen Akademie der Wissenschaften, 1050, Wien, Austria); Kraus, H.
2016-01-01
The usual assumption in direct dark matter searches is to only consider the spin-dependent or spin-independent scattering of dark matter particles. However, especially in models with light dark matter particles $\\mathcal{O}(\\mathrm{GeV/c^2})$, operators which carry additional powers of the momentum transfer $q^2$ can become dominant. One such model based on asymmetric dark matter has been invoked to overcome discrepancies in helioseismology and an indication was found for a particle with pref...
International Nuclear Information System (INIS)
We present a phenomenological theory of nuclei that incorporates clustering at the nuclear surface in a general form. The theory explains the recently extracted large symmetry energy by Natowitz et al., at low densities of nuclear matter and is fully consistent with the static properties of nuclei. In a phenomenological way, clusters of all sizes and shapes along with medium modifications are included. Symmetric nuclear matter properties are discussed in detail. Arguments are given that lead to an equation of state of nuclear matter consistent with clustering in the low-density region. We also discuss properties of asymmetric nuclear matter. Because of clustering, an interesting interpretation of the equation of state of asymmetric nuclear matter emerges. As a framework, an extended version of Thomas-Fermi theory is adopted for nuclei which also contain phenomenological pairing and Wigner contributions. This theory connects the nuclear matter equation of state, which incorporates clustering at low densities, with clustering in nuclei at the nuclear surface. Calculations are performed for various equations of state of nuclear matter. We consider measured binding energies of 2149 nuclei for N, Z? 8. The importance of the quartic term in symmetry energy is demonstrated at and below the saturation density of nuclear matter. It is shown that it is largely related to the use of, ab initio, a realistic equation of state of neutron matter, particularly the contribution arising from the three neutron interactions and somewhat to clustering. Reasons for these are discussed. Because of clustering the neutron skin thickness in nuclei is found to reduce significantly. The developed theory predicts situations and regimes to be explored both theoretically and experimentally.
International Nuclear Information System (INIS)
Full text: High energy collisions of Hadrons or finite Nuclei with nuclei can generate locally high density and temperature. In such a case there will be copious production of mesons and baryons with strange, charm and bottom quarks. This will allow a study of their behaviour in nuclei, thus opening a vast range of new nuclear physics that complements the usual nuclear physics. The propagation and decay of these tagged particles will help us to understand the role of high density and temperature. There is also a large probability of producing double hypernuclei, thus allowing a study of interaction among hyperons. At present Japan Hadron Facility is focussed on such studies. However colliders like RHIC, that is able to study the deconfinement transition, and LHCb, the b meson facility at LHC, will add a great deal of new information. (author)
Energy Technology Data Exchange (ETDEWEB)
Heiselberg, H. [NORDITA, Copenhagen (Denmark)
1998-06-01
The kaon energy in a nuclear medium and its dependence on kaon-nucleon and nucleon-nucleon correlations is discussed. The transition from the Lenz potential at low densities to the Hartree potential at high densities can be calculated analytically by making a Wigner-Seitz cell approximation and employing a square well potential. As the Hartree potential is less attractive than the Lenz one, kaon condensation inside cores of neutron stars appears to be less likely than previously estimated. (orig.)
Moments of ? meson spectral functions in vacuum and nuclear matter
Gubler, Philipp; Weise, Wolfram
2015-12-01
Moments of the ? meson spectral function in vacuum and in nuclear matter are analyzed, combining a model based on chiral SU (3) effective field theory (with kaonic degrees of freedom) and finite-energy QCD sum rules. For the vacuum we show that the spectral density is strongly constrained by a recent accurate measurement of the e+e- ?K+K- cross section. In nuclear matter the ? spectrum is modified by interactions of the decay kaons with the surrounding nuclear medium, leading to a significant broadening and an asymmetric deformation of the ? meson peak. We demonstrate that both in vacuum and nuclear matter, the first two moments of the spectral function are compatible with finite-energy QCD sum rules. A brief discussion of the next-higher spectral moment involving strange four-quark condensates is also presented.
Nuclear matter: new states of dense matter
International Nuclear Information System (INIS)
Heavy ion collisions when involving incident ion velocity of about a quarter of light speed are powerful tools for understanding the behaviour of nuclear matter. Hot nuclei produced in such collisions decay either by evaporation (emission of particles) or by multifragmentation (production of smaller nuclei) or by vaporization (production of particles and light nuclei). These decay processes show strong analogies with liquid-gas transition. 2 new experimental facts support this interpretation: energy fluctuations and abnormal correlations. In the first case fluctuations show the existence of negative heat capacity and in the second case correlations show the possibility of a spinodal decomposition that was, till now only speculated for liquid-gas transitions. (A.C.)
Kaon polarization in nuclear matter
International Nuclear Information System (INIS)
The kaon-nucleon interaction in nuclear matter is considered by taking into account tree graphs, p-wave interaction, pionic intermediate states, kaon fluctuations and some residual interaction. The latter one is constrained by Adler's consistency condition. The K-, K+, K0, anti K0 polarization operators are calculated in cold nuclear matter with arbitrary isotopic composition. An extra s-wave repulsion is found, which probably shifts the critical point of a K- condensation with vanishing kaon momentum to large nucleon densities. Oppositely, an extra p-wave attraction is obtained, which may lead to a K- condensation at vanishing temperatures and densities Ïâ‰¥Ïc-âˆ¼(4-6)Ï0. The spectrum of the kaonic excitations in nuclear matter is analyzed and a new low-lying branch in the K- (and also anti K0) spectrum is found. Its presence may lead to interesting observable consequences, such as the enhancement of the K- yields in heavy-ion reactions. At Ïâ‰¥Ïc- the frequency of this low-lying branch becomes negative at non-vanishing momentum; that signals the onset of inhomogeneous K-condensation. The K- condensate energy is calculated in the approximation of a small KK coupling constant. Accordingly, neutron matter may undergo a first-order phase transition to proton matter with K- condensate at Ï>Ïc-. The temperature dependence of the most important terms of the K- polarization operator is discussed. In a rather wide temperature region 0Ï€/2 a growing temperature enlarges the K-N attraction and promotes the kaon condensation. The possibility of anti K0 condensation is also considered. The question is qualitatively discussed whether proton matter with K- condensate or neutron matter with anti K0 condensate is energetically more favorable. (orig.)
Asymmetric capture of Dirac dark matter by the Sun
Blennow, Mattias; Clementz, Stefan
2015-01-01
Current problems with the solar model may be alleviated if a significant amount of dark matter from the galactic halo is captured in the Sun. We discuss the capture process in the case where the dark matter is a Dirac fermion and the background halo consists of equal amounts of dark matter and anti-dark matter. By considering the case where dark matter and anti-dark matter have different cross sections on solar nuclei as well as the case where the capture process is consider...
Big Bang synthesis of nuclear dark matter
Hardy, Edward; Lasenby, Robert; March-Russell, John; West, Stephen M.
2015-06-01
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. ? 108, 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 ? 108, 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.
Nuclear and neutron matters at low density
International Nuclear Information System (INIS)
In this study, symmetric and asymmetric nuclear matter, as well as pure neutron matter in the low-density regime, where the density ranges 0.01 fm-3 ? 0.13 fm-3, have been investigated. Two different realistic and accurate two-body forces are considered. These include Argonne V18 and the CD-Bonn, which give quite different equations of state. The binding energy per nucleon as a function of the density is calculated using the Brueckner-Hartree-Fock approximation. Both the conventional (gap) and continuous choice of single-particle energies are utilized. For the sake of comparison, the equation of state within the self-consistent Green's function approach is calculated using the CD-Bonn potential. The contribution of the hole-hole terms leads to a repulsive contribution to the energy per nucleon which increases with the nuclear density. Significantly, very good agreement between the experimental symmetry energy values and those calculated in the self-consistent Green's function and BHF approaches especially at low density, has been accomplished. Finally, The results are compared with those from various many-body approaches, such as variational and relativistic mean field approaches. (orig.)
Nuclear and neutron matters at low density
Energy Technology Data Exchange (ETDEWEB)
Gad, Kh. [Sohag University, Physics Department, Faculty of Science, Sohag (Egypt)
2015-08-15
In this study, symmetric and asymmetric nuclear matter, as well as pure neutron matter in the low-density regime, where the density ranges 0.01 fm{sup -3} ? 0.13 fm{sup -3}, have been investigated. Two different realistic and accurate two-body forces are considered. These include Argonne V18 and the CD-Bonn, which give quite different equations of state. The binding energy per nucleon as a function of the density is calculated using the Brueckner-Hartree-Fock approximation. Both the conventional (gap) and continuous choice of single-particle energies are utilized. For the sake of comparison, the equation of state within the self-consistent Green's function approach is calculated using the CD-Bonn potential. The contribution of the hole-hole terms leads to a repulsive contribution to the energy per nucleon which increases with the nuclear density. Significantly, very good agreement between the experimental symmetry energy values and those calculated in the self-consistent Green's function and BHF approaches especially at low density, has been accomplished. Finally, The results are compared with those from various many-body approaches, such as variational and relativistic mean field approaches. (orig.)
Symmetry energy: from nuclear matter to finite nuclei
Kolomietz, V M
2014-01-01
We suggest a particular procedure of derivation of the beta-stability line and isotopic symmetry energy. The behavior of the symmetry energy coefficient $b(A,N-Z)$ is analyzed. We redefine the surface tension coefficient and the surface symmetry energy for an asymmetric nuclear Fermi-liquid drop with a finite diffuse layer. Following Gibbs-Tolman concept, we introduce the equimolar radius at which the surface tension is applied. The relation of the nuclear macroscopic characteristics like surface and symmetry energies, Tolman length, etc. to the bulk properties of nuclear matter is considered. The surface-to-volume symmetry energy ratio for several Skyrme-force parametrizations is obtained.
Asymmetric capture of Dirac dark matter by the Sun
Blennow, Mattias
2015-01-01
Current problems with the solar model may be alleviated if a significant amount of dark matter from the galactic halo is captured in the Sun. We discuss the capture process in the case where the dark matter is a Dirac fermion and the background halo consists of equal amounts of dark matter and anti-dark matter. By considering the case where dark matter and anti-dark matter have different cross sections on solar nuclei as well as the case where the capture process is considered to be a Poisson process, we find that a significant asymmetry between the captured dark particles and anti-particles is possible. Such an asymmetry puts a lower bound on the total amount of captured dark matter and could be a possible solution to the solar composition problem.
Nuclear fluxes during coherent tunnelling in asymmetric double well potentials
Liu, ChunMei; Manz, Jörn; Yang, Yonggang
2015-08-01
Previous results for nuclear fluxes during coherent tunnelling of molecules with symmetric double well potentials are extended to fluxes in asymmetric double well potentials. The theory is derived using the two-state approximation (TSA). The symmetric system serves as a reference. As an example, we consider the one-dimensional model of the tunnelling inversion of oriented ammonia, with semiclassical dipole coupling to an electric field. The tunnelling splitting increases with the dipole coupling by a factor f?slant 1. The tunnelling time decreases by 1/f. The nuclear density appears as the sum of two parts: The tunnelling part decreases as {1/f}2 times the density of the symmetric reference, whereas the non-tunnelling part is the initial density times ?ft({{1-1}/f}2\\right). Likewise, the nuclear flux decreases by 1/f, with essentially the same shape as for the symmetric reference, with maximum value at the potential barrier. Coherent nuclear tunnellings starting from the upper or lower wells of the asymmetric potential are equivalent. The results are universal, in the frame of the TSA, hence they allow straightforward extrapolations from one system to others. This is demonstrated by the prediction of isotope effects for five isotopomers of ammonia.
Periodic structure in nuclear matter
International Nuclear Information System (INIS)
The properties of nuclear matter are studied in the framework of the quantumhadrodynamics. Assuming an ?-meson field, periodic in space, a self-consistent set of equations is derived in mean field approximation for the description of nucleons interacting via ?-meson and ?-meson fields. Solutins of these self-consistent equations have been found: the baryon density is constant in space, however the baryon current density is periodic. This high density phase of nuclear matter can be produced by anisotropic external pressure, occurring e.g. in relativistic heavy ion reactions. The self-consistent fields developing beyond the instability limit have a special screw symmetry. In the presence of such an ? field the energy spectrum of the relativistic nucleons exhibits allowed and forbidden bands similarly to the energy spectrum of the electrons in solids. (author) 15 refs.; 8 figs.; 1 tab
Asymmetric sneutrino dark matter and the ?b/?DM puzzle
International Nuclear Information System (INIS)
The inferred values of the cosmological baryon and dark matter densities are strikingly similar, but in most theories of the early universe there is no true explanation of this fact; in particular, the baryon asymmetry and thus density depends upon unknown, and a priori unknown and possibly small, CP-violating phases which are independent of all parameters determining the dark matter density. We consider models of dark matter possessing a particle-antiparticle asymmetry where this asymmetry determines both the baryon asymmetry and strongly effects the dark matter density, thus naturally linking ?b and ?dm. We show that sneutrinos can play the role of such dark matter in a previously studied variant of the MSSM in which the light neutrino masses result from higher-dimensional supersymmetry-breaking terms
Nuclear Matter Equations of State and the Neutron Stars
International Nuclear Information System (INIS)
The equations of state (EoS) of relativistic asymmetric nuclear matter are obtainable from assumed form of the interaction Lagrangian. They are one of important inputs to describe the neutron stars. The structure of the neutron stars, i.e. the density of matter and the pressure as functions of radial distance starting from their values at the center of a star, is straightforwardly dependent on EoS. Similarly, a limitation on the total mass of the neutron star can be obtained therefrom. Thus, EoS and the underlying nucleon interactions can be tested also by the means of astronomical observations
Role of isospin in nuclear-matter liquid-gas phase transition
International Nuclear Information System (INIS)
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)
Takeshita, Hisako; Sawa, Hitoshi
2005-08-01
beta-Catenin can promote adhesion at the cell cortex and mediate Wnt signaling in the nucleus. We show that, in Caenorhabditis elegans, both WRM-1/beta-catenin and LIT-1 kinase localize to the anterior cell cortex during asymmetric cell division but to the nucleus of the posterior daughter afterward. Both the cortical and nuclear localizations are regulated by Wnts and are apparently coupled. We also found that the daughters show different nuclear export rates for LIT-1. Our results indicate that Wnt signals release cortical WRM-1 from the posterior cortex to generate cortical asymmetry that may control WRM-1 asymmetric nuclear localization by regulating cell polarity. PMID:16077003
Baryogenesis and asymmetric dark matter from the leftâ€“right mirror symmetric model
International Nuclear Information System (INIS)
The paper suggests a leftâ€“right mirror symmetric model to account for the baryogenesis and asymmetric dark matter. The model can simultaneously accommodate the standard model, neutrino physics, matterâ€“antimatter asymmetry and dark matter. In particular, it naturally and elegantly explains the origin of the baryon and dark matter asymmetries, and clearly gives the close interrelations of them. In addition, the model predicts a number of interesting results, e.g. that the cold dark matter neutrino mass is 3.1 times the proton mass. It is also feasible and promising to test the model in future experiments
Odundo, Magdalene
2009-01-01
Asymmetrical brings together a series of ceramic works exploring the effects of burnishing, glazes and firing processes on the final manifestation of the form and its surface qualities. The elements of this series of hand built forms came into life almost simultaneously over a period of several weeks. Each dried form was laboriously burnished, covered with slip and burnished again. When dry, the pots were fired in a gas kiln, first in an oxidizing atmosphere, which turned them a natural re...
Quasiparticle interaction in nuclear matter
International Nuclear Information System (INIS)
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)
Light asymmetric dark matter from new strong dynamics
DEFF Research Database (Denmark)
Frandsen, Mads Toudal; Sarkar, Subir; Schmidt-Hoberg, Kai
2011-01-01
A ~5 GeV `dark baryon' with a cosmic asymmetry similar to that of baryons is a natural candidate for the dark matter. We study the possibility of generating such a state through dynamical electroweak symmetry breaking, and show that it can share the relic baryon asymmetry via sphaleron interactions...
Phase transition from nuclear matter to color superconducting quark matter
Bentz, W.; Horikawa, T.; Ishii, N.; Thomas, A.W.
2002-01-01
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.
BCS-BEC crossovers and unconventional phases in dilute nuclear matter. II
Stein, Martin; Huang, Xu-Guang; Clark, John W
2014-01-01
We study the phase diagram of isospin-asymmetrical nuclear matter in the density-temperature plane, allowing for four competing phases of nuclear matter: (i) the unpaired phase, (ii) the translationally and rotationally symmetric, but isospin-asymmetrical BCS condensate, (iii) the current-carrying Larkin-Ovchinnikov-Fulde-Ferrell phase, and (iv) the heterogeneous phase-separated phase. The phase diagram of nuclear matter composed of these phases features two tri-critical points in general, as well as crossovers from the asymmetrical BCS phase to a BEC of deuterons plus a neutron gas, both for the homogeneous superfluid phase (at high temperatures) and for the heterogeneous phase (at low temperatures). The BCS-BEC type crossover in the condensate occurs as the density is reduced. We analyze in detail some intrinsic properties of these phases, including the Cooper-pair wave function, the coherence length, the occupation numbers of majority and minority nucleonic components, and the dispersion relations of quasi...
Light clusters in nuclear matter
International Nuclear Information System (INIS)
Within a quantum statistical approach, a in-medium Schroedinger equation is derived for a few-nucleon system embedded in nuclear matter. Medium modifications of the cluster quasiparticles are described by self-energy and Pauli blocking effects. Benchmarks such as the nuclear statistical equilibrium, virial expansion and the relativistic mean field approximation are considered. An interesting effect is the formation of a four- or two-nucleon quantum condensate, showing the crossover from Cooper pairing to Bose-Einstein condensation. The resulting thermodynamic properties are of interest for heavy-ion collisions and astrophysical applications. Quantum condensates and the Mott effect are also of relevance for the structure of finite nuclei, specially dilute excited states like the Hoyle state of 12C. (author)
Asymmetric nuclear reprogramming in somatic cell nuclear transfer?
Loi, Pasqualino; Beaujean, Nathalie; Khochbin, Saadi; Fulka, Josef; Ptak, Grazyna
2008-01-01
Despite the progress achieved over the last decade after the birth of the first cloned mammal, the efficiency of reproductive cloning remains invariably low. However, research aiming at the use of nuclear transfer for the production of patient-tailored stem cells for cell/tissue therapy is progressing rapidly. Yet, reproductive cloning has many potential implications for animal breeding, transgenic research and the conservation of endangered species. In this article we suggest that the changes in the epi-/genotype observed in cloned embryos arise from unbalanced nuclear reprogramming between parental chromosomes. It is probable that the oocyte reprogramming machinery, devised for resident chromosomes, cannot target the paternal alleles of somatic cells. We, therefore, suggest that a reasonable approach to balance this asymmetry in nuclear reprogramming might involve the transient expression in donor cells of chromatin remodelling proteins, which are physiologically expressed during spermatogenesis, in order to induce a male-specific chromatin organisation in the somatic cells before nuclear transfer. PMID:18081016
Asymmetric dark matter from spontaneous cogenesis in the supersymmetric standard model
Energy Technology Data Exchange (ETDEWEB)
Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yamaguchi, Masahide [Tokyo Institute of Technology (Japan). Dept. of Physics
2012-01-15
The observational relation between the density of baryon and dark matter in the Universe, {omega}{sub DM}/{omega}{sub B}{approx_equal}5, is one of the most difficult problems to solve in modern cosmology. We discuss a scenario that explains this relation by combining the asymmetric dark matter scenario and the spontaneous baryogenesis associated with the flat direction in the supersymmetric standard model. A part of baryon asymmetry is transferred to charge asymmetry D that dark matter carries, if a symmetry violating interaction that works at high temperature breaks not only B-L but also D symmetries simultaneously. In this case, the present number density of baryon and dark matter can be same order if the symmetric part of dark matter annihilates sufficiently. Moreover, the baryon number density can be enhanced as compared to that of dark matter if another B-L violating interaction is still in thermal equilibrium after the spontaneous genesis of dark matter, which accommodates a TeV scale asymmetric dark matter model. (orig.)
Light asymmetric dark matter from new strong dynamics
DEFF Research Database (Denmark)
Frandsen, Mads Toudal; Sarkar, Subir; Schmidt-Hoberg, Kai
2011-01-01
A ~5 GeV `dark baryon' with a cosmic asymmetry similar to that of baryons is a natural candidate for the dark matter. We study the possibility of generating such a state through dynamical electroweak symmetry breaking, and show that it can share the relic baryon asymmetry via sphaleron interactions, even though it has no electroweak interactions. The scattering cross-section on nucleons, estimated in analogy to QCD, is within reach of underground direct detection experiments.
Quartic isospin asymmetry energy of nuclear matter from chiral pion-nucleon dynamics
Kaiser, N.
2015-06-01
Based on a chiral approach to nuclear matter, the quartic term in the expansion of the equation of state of isospin-asymmetric nuclear matter is calculated. The contributions to the quartic isospin asymmetry energy A4(kf) arising from 1 ? exchange and chiral 2 ? exchange in nuclear matter are calculated analytically together with three-body terms involving virtual ? (1232 ) isobars. From these interaction terms one obtains at saturation density ?0=0.16 fm-3 the value A4(kf 0) =1.5 MeV , more than three times as large as the kinetic energy part. Moreover, iterated 1 ? exchange exhibits components for which the fourth derivative with the respect to the isospin asymmetry parameter ? becomes singular at ? =0 . The genuine presence of a nonanalytical term ?4ln|? | in the expansion of the energy per particle of isospin-asymmetric nuclear matter is demonstrated by evaluating an s -wave contact interaction at second order.
Hot Nuclear Matter : A Variational Approach
Mishra, H.; Misra, S. P.; P.K. Panda; Parida, B. K.
1992-01-01
We develop a nonperturbative technique in field theory to study properties of infinite nuclear matter at zero temperature as well as at finite temperatures. Here we dress the nuclear matter with off-mass shell pions. The techniques of thermofield dynamics are used for finite temperature calculations. Equation of state is derived from the dynamics of the interacting system in a self consistent manner. The transition temperature for nuclear matter appears to be around 15 MeV.
Unifying Asymmetric Inert Fermion Doublet Dark Matter and Leptogenesis with Neutrino Mass
Sahu, Narendra
2012-01-01
We propose a scalar Triplet extension of the standard model (SM) to unify the origin of neutrino mass with the visible and dark matter component of the Universe. We assume that the scalar triplet is super heavy, so that its CP-violating out-of-equilibrium decay in the early Universe not only produce asymmetric dark matter which is the neutral component of an additional vector like fermion doublet, but also give rise to lepton asymmetry. The latter gets converted to observed baryon asymmetry via B+L violating sphaleron processes. Below electroweak phase transition the scalar triplet acquires a vacuum expectation value and give rise to sub-eV Majorana masses to three flavors of active neutrinos. Thus an unification of the origin of neutrino mass, lepton asymmetry and asymmetric dark matter is achieved within a scalar triplet extension of the SM.
Asymmetric dark matter and CP violating scatterings in a UV complete model
Baldes, Iason; Bell, Nicole F.; Millar, Alexander J.; Volkas, Raymond R.
2015-10-01
We explore possible asymmetric dark matter models using CP violating scatterings to generate an asymmetry. In particular, we introduce a new model, based on DM fields coupling to the SM Higgs and lepton doublets, a neutrino portal, and explore its UV completions. We study the CP violation and asymmetry formation of this model, to demonstrate that it is capable of producing the correct abundance of dark matter and the observed matter-antimatter asymmetry. Crucial to achieving this is the introduction of interactions which violate CP with a T2 dependence.
Asymmetric Dark Matter and CP Violating Scatterings in a UV Complete Model
Baldes, Iason; Millar, Alexander J; Volkas, Raymond R
2015-01-01
We explore possible asymmetric dark matter models using CP violating scatterings to generate an asymmetry. In particular, we introduce a new model, based on DM fields coupling to the SM Higgs and lepton doublets, $\\overline{L}H$, and explore its UV completions. We study the CP violation and asymmetry formation of this model, to demonstrate that it is capable of producing the correct abundance of dark matter and the observed matter-antimatter asymmetry. Crucial to achieving this is the introduction of interactions which violate CP with a $T^{2}$ dependence.
Asymmetric dark matter and CP violating scatterings in a UV complete model
Energy Technology Data Exchange (ETDEWEB)
Baldes, Iason; Bell, Nicole F.; Millar, Alexander J.; Volkas, Raymond R. [ARC Centre of Excellence for Particle Physics at the Terascale,School of Physics, The University of Melbourne, Victoria, 3010 (Australia)
2015-10-21
We explore possible asymmetric dark matter models using CP violating scatterings to generate an asymmetry. In particular, we introduce a new model, based on DM fields coupling to the SM Higgs and lepton doublets, a neutrino portal, and explore its UV completions. We study the CP violation and asymmetry formation of this model, to demonstrate that it is capable of producing the correct abundance of dark matter and the observed matter-antimatter asymmetry. Crucial to achieving this is the introduction of interactions which violate CP with a T{sup 2} dependence.
Nuclear charge and neutron radii and nuclear matter: trend analysis
Reinhard, P -G
2016-01-01
Radii of charge and neutron distributions are fundamental nuclear properties. They depend on both nuclear interaction parameters related to the equation of state of infinite nuclear matter and on quantal shell effects, which are strongly impacted by the presence of nuclear surface. In this work, by studying the dependence of charge and neutron radii, and neutron skin, on nuclear matter parameters, we assess different mechanisms that drive nuclear sizes. We apply nuclear density functional theory using a family of Skyrme functionals obtained by means of different optimization protocols targeting specific nuclear properties. By performing the Monte-Carlo sampling of reasonable functionals around the optimal parametrization, we study correlations between nuclear matter paramaters and observables characterizing charge and neutron distributions. We demonstrate the existence of the strong converse relation between the nuclear charge radii and the saturation density of symmetric nuclear matter and also between the n...
Collective modes in strange and isospin asymmetric hadronic matter
Aguirre, R M
2004-01-01
We study the propagation of non-strange and strange meson modes in hadronic matter considering isospin and/or strangeness mixing induced by quantum fluctuations in the medium. Baryons are described using the Quark Meson Coupling model extended to include couplings with strange quarks. In particular we evaluate the dependence of the meson masses on the baryonic density, the strangeness fraction and the isospin asymmetry of the medium. We have found a considerable admixture of strangeness and isospin in the sigma mode at the high density regime.
Inhomogeneous chiral symmetry breaking phases in isospin-asymmetric matter
Nowakowski, Daniel; Carignano, Stefano; Wambach, Jochen
2015-01-01
We investigate the effects of isospin asymmetry on inhomogeneous chiral symmetry breaking phases within the two-flavor NJL model. After introducing a plane-wave ansatz for each quark-flavor condensate, we find that, as long as their periodicities are enforced to be equal, a non-zero isospin chemical potential shrinks the size of the inhomogeneous phase. The asymmetry reached in charge neutral matter is nevertheless not excessively large, so that an inhomogeneous window is still present in the phase diagram. Lifting the constraint of equal periodicities alters the picture significantly, as the inhomogeneous phase survives in a much larger region of the phase diagram.
Anomalous pseudorapidity correlations in asymmetrical nucleus-nuclear interactions
International Nuclear Information System (INIS)
By the method of normalized amplitude the analysis of pseudorapidity correlations in 315 interaction of 197Au nuclei with energy 10.7 GeV/nucleon and 264 interactions of 32S nuclei with energy 200 GeV/nucleon with photoemulsion nuclei was carried out. The events with anomalous multi-particle correlations have been revealed. At that the most effect in interaction of asymmetrical nuclei has been exhibited namely in Au nuclei and nuclei of CNO group in which the complete target nucleus decay is taking place. For clarification anomalous events a nucleus-nuclear interactions with pseudo-rapidity distributions were simulated. From simulation calculation it was revealed, that behavior of experimental correlation curve of anomalous events is similarly to correlation curve, corresponding to processes of blowing up character with generation of some interim system of great size, from which of the 40 % secondary particles in rather narrow pseudo-rapidities range ??<1 have being born
Asymmetrical sabotage tactics, nuclear facilities/materials, and vulnerability analysis
International Nuclear Information System (INIS)
Full text: The emerging paradigm of a global community wherein post-modern political violence is a fact of life that must be dealt with by safety and security planners is discussed. This paradigm shift in the philosophy of terrorism is documented by analysis of the emerging pattern of asymmetrical tactics being employed by terrorists. Such philosophical developments in violent political movements suggest a shift in the risks that security and safety personnel must account for in their planning for physical protection of fixed site nuclear source facilities like power generation stations and the eventual storage and transportation of the by-products of these facilities like spent nuclear fuel and other high level wastes. This paper presents a framework for identifying these new political realities and related threat profiles, suggests ways in which security planners and administrators can design physical protection practices to meet these emerging threats, and argues for global adoption of standards for the protection of nuclear facilities that could be used as a source site from which terrorists could inflict a mass contamination event and for standards related to the protection of the waste materials that can be used in the production of radiological weapons of mass victimization. (author)
Nuclear matter between gas and liquid
International Nuclear Information System (INIS)
Heavy ion collisions on target nuclei can create very hot and very dense nuclear systems. The way back to equilibrium that follows the nuclear matter is not very well known. To observe its condensation would be a spectacular show of nuclear matter liquid-gas phase transition. This article presents the nuclear matter-real gas analogy and recalls notions of critical points, around which droplets are forming. Nuclear fragment research near the critical point at GANIL, SARA or at the Michigan State University cyclotron is then evoked in relation to the condensation phenomenon
Asymmetric WIMP Dark Matter in the presence of DM/anti-DM oscillations
International Nuclear Information System (INIS)
The general class of 'Asymmetric Dark Matter (DM)' scenarios assumes the existence of a primordial particle/anti-particle asymmetry in the dark matter sector related to the asymmetry in the baryonic one, as a way to achieve the observed similarity between the baryonic and dark matter energy densities today. Focusing on this framework we study the effect of oscillations between dark matter and its anti-particle on the re-equilibration of the initial asymmetry. We calculate the evolution of the dark matter relic abundance and show how oscillations re-open the parameter space of asymmetric dark matter models, in particular in the direction of allowing large (WIMP-scale) DM masses. We found in particular that a typical WIMP with a mass at the EW scale (about 1 TeV) having a primordial asymmetry of the same order as the baryon asymmetry, naturally gets the correct relic abundance if the ?m mass term is in the ? meV range. This turns out to be a natural value for fermionic DM arising from the higher dimensional operator H2DM2/? where H is the Higgs field and ? ? MPl. Finally, we constrain the parameter space in this framework by applying up-to-date bounds from indirect detection signals on annihilating DM
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)
Quasiparticle pole strength in nuclear matter
International Nuclear Information System (INIS)
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)
Cosmic ray-dark matter scattering: a new signature of (asymmetric) dark matter in the gamma ray sky
International Nuclear Information System (INIS)
We consider the process of scattering of Galactic cosmic-ray electrons and protons off of dark matter with the radiation of a final-state photon. This process provides a novel way to search for Galactic dark matter with gamma rays. We argue that for a generic weakly interacting massive particle, barring effects such as co-annihilation or a velocity-dependent cross section, the gamma-ray emission from cosmic-ray scattering off of dark matter is typically smaller than that from dark matter pair-annihilation. However, if dark matter particles cannot pair-annihilate, as is the case for example in asymmetric dark matter scenarios, cosmic-ray scattering with final state photon emission provides a unique window to detect a signal from dark matter with gamma rays. We estimate the expected flux level and its spectral features for a generic supersymmetric setup, and we also discuss dipolar and luminous dark matter. We show that in some cases the gamma-ray emission might be large enough to be detectable with the Fermi Large Area Telescope
Light Asymmetric Dark Matter on the Lattice: SU(2) Technicolor with Two Fundamental Flavors
Lewis, Randy; Sannino, Francesco
2012-01-01
The SU(2) gauge theory with two massless Dirac flavors constitutes the building block of several models of Technicolor. Furthermore it has also been used as a template for the construction of a natural light asymmetric, or mixed type, dark matter candidate. We use explicit lattice simulations to confirm the pattern of chiral symmetry breaking by determining the Goldstone spectrum and therefore show that the dark matter candidate can, de facto, be constituted by a complex Goldstone boson. We also determine the phenomenologically relevant spin one and spin zero isovector spectrum and demonstrate that it is well separated from the Goldstone spectrum.
Mizumoto, Kota; Sawa, Hitoshi
2007-02-01
In C. elegans, Wnt signaling regulates a number of asymmetric cell divisions. During telophase, WRM-1/beta-catenin localizes asymmetrically to the anterior cortex and the posterior daughter's nucleus. However, cortical WRM-1's functions are not known. Here, we use a membrane-targeted form of WRM-1 to show that cortical WRM-1 inhibits Wnt signaling and the nuclear localization of WRM-1. These functions are mediated by APR-1/APC, which regulates WRM-1 nuclear export. We also show that APR-1 as well as PRY-1/Axin and Dishevelled homologs localize asymmetrically to the cortex. Our results suggest a model in which cortical WRM-1 recruits APR-1 to the anterior cortex before and during division, and the cortical APR-1 stimulates WRM-1 export from the anterior nucleus at telophase. Because beta-catenin and APC are localized to the cortex in many cell types in different species, our results suggest that these cortical proteins may regulate asymmetric divisions or Wnt signaling in other organisms as well. PMID:17276345
Interaction of nuclear radiation with matter
International Nuclear Information System (INIS)
This chapter of a textbook presents an overview of an important aspect of nuclear physics and nuclear chemistry. The effects of the interaction of nuclear radiation with substances are classified according to the acting particle, and the reacting constituents of the substance. The interactions of alpha radiation with matter (slowing down, scattering), of electron radiation with matter (slowing down, Cherenkov radiation, backscattering, absorption, annihilation), and of gamma radiation with matter (Compton effect, photoelectric effect, pair formation, absorption) are discussed. The reacting constituents are categorized as shell electrons, atomic nuclei, the Coulomb field of nuclei. In the complex interactions, the Auger effect and the photoelectron-induced bremsstrahlung is discussed. (R.P.)
Phi meson spectral moments and QCD condensates in nuclear matter
Gubler, Philipp
2016-01-01
A detailed analysis of the lowest two moments of the $\\phi$ meson spectral function in vacuum and nuclear matter is performed. The consistency is examined between the constraints derived from finite energy QCD sum rules and the spectra computed within an improved vector dominance model, incorporating the coupling of kanonic degrees of freedom with the bare $\\phi$ meson. In the vacuum, recent accurate measurements of the $e^+ e^- \\to K^+ K^-$ cross section allow us to determine the spectral function with high precision. In nuclear matter, the modification of the spectral function can be described by the interactions of the kaons from $\\phi \\rightarrow K\\bar{K}$ with the surrounding nuclear medium. This leads primarily to a strong broadening and an asymmetric deformation of the $\\phi$ meson peak structure. We confirm that, both in vacuum and nuclear matter, the zeroth and first moments of the corresponding spectral functions satisfy the requirements of the finite energy sum rules to a remarkable degree of accur...
Nuclear matter, nuclear and subnuclear degrees of freedom
Alberico, Wanda M.
1999-01-01
We report here theoretical investigations on the complexity of nuclear structure, which have been carried out in the framework of different many-body approaches, typically applied to nuclear matter and quark matter studies. The variational, functional and perturbative scheme are illustrated in their latest developments. The effect of various nucleon-nucleon interactions are tested, particularly in the context of the nuclear response functions, against a large body of experim...
Nuclear matter with JISP16 NN interaction
Shirokov, A M; Vary, J P; Bogner, S K; Mazur, A I; Mazur, E A; Gogny, D
2014-01-01
Saturation properties of the JISP16 NN interaction are studied in symmetric nuclear matter calculations, with special attention paid to the convergence properties with respect to the number of partial waves. We also present results of pure neutron matter calculations with the JISP16 interaction.
Heavy Mesons in Nuclear Matter and Nuclei
Tolos, Laura; Garcia-Recio, Carmen; Molina, Raquel; Nieves, Juan; Oset, Eulogio; Ramos, Angels; Romanets, Olena; Salcedo, Lorenzo Luis; Torres-Rincon, Juan M
2014-01-01
Heavy mesons in nuclear matter and nuclei are analyzed within different frameworks, paying a special attention to unitarized coupled-channel approaches. Possible experimental signatures of the properties of these mesons in matter are addressed, in particular in connection with the future FAIR facility at GSI.
Nuclear shock waves and quark matter
International Nuclear Information System (INIS)
Atomic nuclei colliding with each other in a particle accelerator at extremely high velocities undergo interactions which lead to novel states of matter. The equation of state of this hot, dense nuclear matter reveals information on the processes occurring in a supernova, and on the big bang at the origin of the universe. (orig.)
Sigma meson and properties of nuclear matter
International Nuclear Information System (INIS)
We have calculated the saturation observables of symmetric nuclear matter and nuclear symmetry energy in the framework of Brueckner-Hartree-Fock (BHF) formalism with Bonn-B potential as two-body interaction, including modification of hadronic parameter inside nuclear medium. We have found that it is possible to understand all the saturation observables of symmetric nuclear matter by incorporating in-medium modification of the parameters of sigma meson alone. Linear density dependent reduction of ?-nucleon coupling constant by about 6.8% and density independent reduction ?-meson mass by about 3.5% is sufficient to understand nuclear matter saturation observables. We find with the calculated symmetry energy that neutron skin thickness of 208Pb is 0.20 fm and the radius of 1.4 solar mass neutron stars as 11.98 ± 0.75 km. (author)
Properties of nuclear matter from macroscopic-microscopic mass formulas
Wang, Ning; Ou, Li; Zhang, Yingxun
2015-01-01
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 Weizs\\"acker-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 $K_\\infty=230 \\pm 11$ MeV and $235\\pm 11$ MeV, respectively. The slope parameter of symmetry energy at saturation density is $L=41.6\\pm 7.6$ MeV for LSD and $51.5\\pm 9.6$ MeV for WS*, respectively, which is compatible with the liquid-drop analysis of Lattimer and Lim [ApJ. \\textbf{771}, 51 (2013)]. 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 Skyrm...
Properties of nuclear matter from macroscopic-microscopic mass formulas
Wang, Ning; Liu, Min; Ou, Li; Zhang, Yingxun
2015-12-01
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.
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.
Clusters in nuclear matter and Mott points
Röpke, G
2015-01-01
Light clusters (mass number $A \\leq 4$) in nuclear matter at subsaturation densities are described using a quantum statistical approach. In addition to self-energy and Pauli-blocking, effects of continuum correlations are taken into account to calculate the quasiparticle properties and abundances of light elements. Medium-modified quasiparticle properties are important ingredients to derive a nuclear matter equation of state applicable in the entire region of warm dense matter below saturation density. The influence of the nucleon-nucleon interaction on the quasiparticle shift is discussed.
Past and present of nuclear matter
International Nuclear Information System (INIS)
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 ? 10-22sec, 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
Describing Nuclear Matter with Effective Field Theories
Steele, James V.; Furnstahl, R. J.
1999-01-01
An accurate description of nuclear matter starting from free-space nuclear forces has been an elusive goal. The complexity of the system makes approximations inevitable, so the challenge is to find a consistent truncation scheme with controlled errors. The virtues of an effective field theory approach to this problem are discussed.
Relativity damps OPEP in nuclear matter
International Nuclear Information System (INIS)
Using a relativistic Dirac-Brueckner analysis the OPEP contribution to the ground state energy of nuclear matter is studied. In the study the pion is derivative-coupled. The author finds that the role of the tensor force in the saturation mechanism is substantially reduced compared to its dominant role in a usual nonrelativistic treatment. He shows that the damping of derivative-coupled OPEP is actually due to the decrease of M*/M with increasing density. He points out that if derivative-coupled OPEP is the preferred form of nuclear effective lagrangian nonrelativistic treatment of nuclear matter is in trouble. Lacking the notion of M* it cannot replicate the damping. He suggests an examination of the feasibility of using pseudoscalar coupled ?N interaction before reaching a final conclusion about nonrelativistic treatment of nuclear matter
Physics of nuclear matter at high density
International Nuclear Information System (INIS)
Relativistic nuclear collisions should cause shockwaves of high densities. The conditions for their generation are discussed. The angular distributions of the reaction products in central relativistic collision between a light projectile and a heavier target nucleus were analysed. Significant energy-dependent peaks were found which may be interpreted in a quasi-hydrodynamic model as Mach shockwaves of high density. Theoretically, the occurrence of density variations due to pion condensation ought to facilitate the hydrodynamic behaviour of the nuclear matter even at very high energies. The vanishing of the peak at energies between 1 and 2 GeV per nucleon might be interpreted as an indication of a phase transition in nuclear matter, i.e. of the formation of a density isomer. According to this interpretation, the binding energy per nucleon for higher densities of nuclear matter may be derived from the data. (orig/BJ.)
Nuclear matter in all its states
International Nuclear Information System (INIS)
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
Wnt regulates spindle asymmetry to generate asymmetric nuclear ?-catenin in C. elegans.
Sugioka, Kenji; Mizumoto, Kota; Sawa, Hitoshi
2011-09-16
Extrinsic signals received by a cell can induce remodeling of the cytoskeleton, but the downstream effects of cytoskeletal changes on gene expression have not been well studied. Here, we show that during telophase of an asymmetric division in C. elegans, extrinsic Wnt signaling modulates spindle structures through APR-1/APC, which in turn promotes asymmetrical nuclear localization of WRM-1/?-catenin and POP-1/TCF. APR-1 that localized asymmetrically along the cortex established asymmetric distribution of astral microtubules, with more microtubules found on the anterior side. Perturbation of the Wnt signaling pathway altered this microtubule asymmetry and led to changes in nuclear WRM-1 asymmetry, gene expression, and cell-fate determination. Direct manipulation of spindle asymmetry by laser irradiation altered the asymmetric distribution of nuclear WRM-1. Moreover, laser manipulation of the spindles rescued defects in nuclear POP-1 asymmetry in wnt mutants. Our results reveal a mechanism in which the nuclear localization of proteins is regulated through the modulation of microtubules. PMID:21925317
Phase transitions in high density nuclear matter
International Nuclear Information System (INIS)
A method for the description of spin-isospin phase transitions in nuclear matter is developed. It allows a complete description of the pion condensation phase transition in the framework of the Landau-Migdal Fermi liquid theory. The equation of the order parameters is derived and the condensation energy is calculated. We study the influence of pion condensation on the nuclear equation of state and the temperature dependence of pion condensation. Finally the phase transition from nucleon to quark matter is investigated. The relevance of the color degree of freedom is discussed. (orig.)
Maruyama, Tomoyuki; Yasutake, Nobutoshi; Cheoun, Myung-Ki; Ryu, Chung-Yeol
2010-01-01
We calculate asymmetric neutrino absorption and scattering cross sections on hot and dense magnetized neutron-star matter including hyperons in fully relativistic mean field theory. The absorption/scattering cross sections are suppressed/enhanced incoherently in the direction of the magnetic fielld, B. The asymmetry is 2-4% at the matter density \\rho_0 < \\rho_B < 3\\rho_0 and temperature T < 40 MeV for B=2 X 10^{17} G. This asymmetry is comparable to the effects owing to parity violation or asymmetric magnetic field topology proposed for the origin of pulsar kicks.
Femtotechnology: Nuclear Matter with Fantastic Properties
Directory of Open Access Journals (Sweden)
A. A. Bolonkin
2009-01-01
Full Text Available Problem statement: At present the term 'nanotechnology' is well known-in its' ideal form, the flawless and completely controlled design of conventional molecular matter from molecules or atoms. Such a power over nature would offer routine achievement of remarkable properties in conventional matter and creation of metamaterials where the structure not the composition brings forth new powers of matter. But even this yet unachieved goal is not the end of material science possibilities. The author herein offers the idea of design of new forms of nuclear matter from nucleons (neutrons, protons, electrons and other nuclear particles. Approach: The researcher researches the nuclear forces. He shows these force may be used for design the new nuclear matter from protons, neutrons, electrons and other nuclear particles. Results: Author shows this new 'AB-Matter' has extraordinary properties (for example, tensile strength, stiffness, hardness, critical temperature, superconductivity, supertransparency and zero friction., which are up to millions of times better than corresponding properties of conventional molecular matter. He shows concepts of design for aircraft, ships, transportation, thermonuclear reactors, constructions and so on from nuclear matter. These vehicles will have unbelievable possibilities (e.g., invisibility, ghost-like penetration through any walls and armor, protection from nuclear bomb explosions and any radiation flux. Conclusion: People may think this fantasy. But fifteen years ago most people and many scientists thought-nanotechnology is fantasy. Now many groups and industrial labs, even startups, spend hundreds of millions of dollars for development of nanotechnological-range products (precise chemistry, patterned atoms, catalysts and meta-materials and we have nanotubes (a new material which does not exist in Nature! and other achievements beginning to come out of the pipeline in prospect. Nanotubes are stronger than steel by a hundred times-surely an amazement to a 19th Century observer if he could behold them. Nanotechnology, in near term prospect, operates with objects (molecules and atoms having the size in nanometer (10-9 m. The researcher here outlines perhaps more distant operations with objects (nuclei having size in the femtometer range, (10-15m, millions of times less smaller than the nanometer scale. The name of this new technology is femtotechnology.
QMC calculations of symmetric nuclear matter
Gandolfi, S.; Pederiva, F.; Fantoni, S.; Schmidt, K E
2006-01-01
We present an accurate numerical study of the equation of state of nuclear matter based on realistic nucleon--nucleon interactions by means of Auxiliary Field Diffusion Monte Carlo (AFDMC) calculations. The AFDMC method samples the spin and isospin degrees of freedom allowing for quantum simulations of large nucleonic systems and represents an important step forward towards a quantitative understanding of problems in nuclear structure and astrophysics.
Nuclear matter theory. [Realistic forces, review
Energy Technology Data Exchange (ETDEWEB)
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.
Moments of $\\phi$ meson spectral functions in vacuum and nuclear matter
Gubler, Philipp
2015-01-01
Moments of the $\\phi$ meson spectral function in vacuum and in nuclear matter are analyzed, combining a model based on chiral SU(3) effective field theory (with kaonic degrees of freedom) and finite-energy QCD sum rules. For the vacuum we show that the spectral density is strongly constrained by a recent accurate measurement of the $e^+ e^- \\to K^+ K^-$ cross section. In nuclear matter the $\\phi$ spectrum is modified by interactions of the decay kaons with the surrounding nuclear medium, leading to a significant broadening and an asymmetric deformation of the $\\phi$ meson peak. We demonstrate that both in vacuum and nuclear matter, the first two moments of the spectral function are compatible with finite-energy QCD sum rules. A brief discussion of the next-higher spectral moment involving strange four-quark condensates is also presented.
Controllable Asymmetric Matter-wave Beam Splitter and Ring Potential on an Atom Chip
Kim, S J; Gang, S T; Anderson, D; Kim, J B
2015-01-01
We have constructed an asymmetric matter-wave beam splitter and a ring potential on an atom chip with Bose-Einstein condensates using radio-frequency dressing. By applying rf-field parallel to the quantization axis in the vicinity of the static trap minima added to perpendicular rf-fields, versatile controllability on the potentials is realized. Asymmetry of the rf-induced double well is manipulated without discernible displacement of the each well along horizontal and vertical direction. Formation of an isotropic ring potential on an atom chip is achieved by compensating the gradient due to gravity and inhomogeneous coupling strength. In addition, position and rotation velocity of a BEC along the ring geometry are controlled by the relative phase and the frequency difference between the rf-fields, respectively.
Chen, Shao-Long
2015-01-01
The inverse seesaw mechanism provides an attractive approach to generate small neutrino mass, which origins from a tiny $U(1)_L$ breaking. In this paper, we work in the supersymmetric version of this mechanism, where the singlet-like sneutrino could be an asymmetric dark matter (ADM) candidate in the maximally $U(1)_{L}$ symmetric limit. However, even a tiny $\\delta m$, the mass splitting between sneutrino and anti-sneutrino as a result of the tiny $U(1)_{L}$ breaking effect, could lead to fast oscillation between sneutrino and anti-sneutrino and thus spoils the ADM scenario. We study the evolution of this oscillation and find that a weak scale sneutrino, which tolerates a relatively larger $\\delta m\\sim 10^{-5}$ eV, is strongly favored. We also investigate possible natural ways to realize that small $\\delta m$ in the model.
Nuclear matter in heavy ion collisions
International Nuclear Information System (INIS)
In this report the measurement of the inclusive production of negative pions and protons in reactions of 40Ar with KCl at 1.8 GeV/nucleon is described. The measured energy spectra and multiplicities are presented and discussed regarding the stopping power of nuclear matter. (HSI)
Cold nuclear matter in holographic QCD
International Nuclear Information System (INIS)
We study the Sakai-Sugimoto model of holographic QCD at zero temperature and finite chemical potential. We find that as the baryon chemical potential is increased above a critical value, there is a phase transition to a nuclear matter phase characterized by a condensate of instantons on the probe D-branes in the string theory dual. As a result of electrostatic interactions between the instantons, this condensate expands towards the UV when the chemical potential is increased, giving a holographic version of the expansion of the Fermi surface. We argue based on properties of instantons that the nuclear matter phase is necessarily inhomogeneous to arbitrarily high density. This suggests an explanation of the 'chiral density wave' instability of the quark Fermi surface in large Nc QCD at asymptotically large chemical potential. We study properties of the nuclear matter phase as a function of chemical potential beyond the transition and argue in particular that the model can be used to make a semi-quantitative prediction of the binding energy per nucleon for nuclear matter in ordinary QCD
Condensed matter studies by nuclear methods
International Nuclear Information System (INIS)
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.)
Probing cold dense nuclear matter.
Energy Technology Data Exchange (ETDEWEB)
Subedi, R.; Monaghan, P.; Shneor, R.; Anderson, B. D.; Aniol, K.; Arrington, J.; Physics; Kent State Univ.; Tel Aviv Univ.; California State Univ. Los Angeles
2008-06-13
The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.
Probing Cold Dense Nuclear Matter
Energy Technology Data Exchange (ETDEWEB)
Subedi, Ramesh; Shneor, R.; Monaghan, Peter; Anderson, Bryon; Aniol, Konrad; Annand, John; Arrington, John; Benaoum, Hachemi; Benmokhtar, Fatiha; Bertozzi, William; Boeglin, Werner; Chen, Jian-Ping; Choi, Seonho; Cisbani, Evaristo; Craver, Brandon; Frullani, Salvatore; Garibaldi, Franco; Gilad, Shalev; Gilman, Ronald; Glamazdin, Oleksandr; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Ibrahim, Hassan; Igarashi, Ryuichi; De Jager, Cornelis; Jans, Eddy; Jiang, Xiaodong; Kaufman, Lisa; Kelleher, Aidan; Kolarkar, Ameya; Kumbartzki, Gerfried; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; Mazouz, Malek; Meekins, David; Michaels, Robert; Moffit, Bryan; Perdrisat, Charles; Piasetzky, Eliazer; Potokar, Milan; Punjabi, Vina; Qiang, Yi; Reinhold, Joerg; Ron, Guy; Rosner, Guenther; Saha, Arunava; Sawatzky, Bradley; Shahinyan, Albert; Sirca, Simon; Slifer, Karl; Solvignon, Patricia; Sulkosky, Vince; Sulkosky, Vincent; Sulkosky, Vince; Sulkosky, Vincent; Urciuoli, Guido; Voutier, Eric; Watson, John; Weinstein, Lawrence; Wojtsekhowski, Bogdan; Wood, Stephen; Zheng, Xiaochao; Zhu, Lingyan
2008-06-01
The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.
The public and nuclear matters
International Nuclear Information System (INIS)
The nuclear industry has an image problem and is facing a major crisis of public confidence. The solution lies not merely in better public relations and advertising campaigns, but in a fundamental reassessment of electricity management, a comprehensive re-examination of the economics of electricity use and generation and, in all probability, a shift towards more public-friendly reactor designs. Over the next decade the industry faces two great forces: the power of public opinion and the momentum of inherent technological advance. Somehow these two elements have to be guided so that they complement each other. This article aims to show how this might be achieved. (author)
Chiral density wave in nuclear matter
International Nuclear Information System (INIS)
Inspired by recent work on inhomogeneous chiral condensation in cold, dense quark matter within models featuring quark degrees of freedom, we investigate the chiral density-wave solution in nuclear matter at zero temperature and nonvanishing baryon number density in the framework of the so-called extended linear sigma model (eLSM). The eLSM is an effective model for the strong interaction based on the global chiral symmetry of quantum chromodynamics (QCD). It contains scalar, pseudoscalar, vector, and axial-vector mesons as well as baryons. In the latter sector, the nucleon and its chiral partner are introduced as parity doublets in the mirror assignment. The eLSM simultaneously provides a good description of hadrons in vacuum as well as nuclear matter ground-state properties. We find that an inhomogeneous phase in the form of a chiral density wave is realized, but only for densities larger than 2.4?0, where ?0 is the nuclear matter ground-state density
Chiral density wave in nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Heinz, Achim [Institute for Theoretical Physics, Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Giacosa, Francesco [Institute for Theoretical Physics, Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Rischke, Dirk H. [Institute for Theoretical Physics, Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany)
2015-01-15
Inspired by recent work on inhomogeneous chiral condensation in cold, dense quark matter within models featuring quark degrees of freedom, we investigate the chiral density-wave solution in nuclear matter at zero temperature and nonvanishing baryon number density in the framework of the so-called extended linear sigma model (eLSM). The eLSM is an effective model for the strong interaction based on the global chiral symmetry of quantum chromodynamics (QCD). It contains scalar, pseudoscalar, vector, and axial-vector mesons as well as baryons. In the latter sector, the nucleon and its chiral partner are introduced as parity doublets in the mirror assignment. The eLSM simultaneously provides a good description of hadrons in vacuum as well as nuclear matter ground-state properties. We find that an inhomogeneous phase in the form of a chiral density wave is realized, but only for densities larger than 2.4?{sub 0}, where ?{sub 0} is the nuclear matter ground-state density.
Consequences of DM/antiDM oscillations for asymmetric WIMP dark matter
International Nuclear Information System (INIS)
Assuming the existence of a primordial asymmetry in the dark sector, a scenario usually dubbed Asymmetric Dark Matter (aDM), we study the effect of oscillations between dark matter and its antiparticle on the re-equilibration of the initial asymmetry before freeze-out, which enable efficient annihilations to recouple. We calculate the evolution of the DM relic abundance and show how oscillations re-open the parameter space of aDM models, in particular in the direction of allowing large (WIMP-scale) DM masses. A typical WIMP with a mass at the EW scale ( ? 100 GeV – 1 TeV) presenting a primordial asymmetry of the same order as the baryon asymmetry naturally gets the correct relic abundance if the DM-number-violating ?(DM) = 2 mass term is in the ? meV range. The re-establishment of annihilations implies that constraints from the accumulation of aDM in astrophysical bodies are evaded. On the other hand, the ordinary bounds from BBN, CMB and indirect detection signals on annihilating DM have to be considered
From QCD to nuclear matter saturation
International Nuclear Information System (INIS)
We discuss a relativistic chiral theory of nuclear matter with ? and ? exchange using a formulation of the ? model in which all the chiral constraints are automatically fulfilled. We establish a relation between the nuclear response to the scalar field and the QCD one which includes the nucleonic parts. It allows a comparison between nuclear and QCD information. Going beyond the mean field approach we introduce the effects of the pion loops supplemented by the short-range interaction. The corresponding Landau-Migdal parameters are taken from spin-isospin physics results. The parameters linked to the scalar meson exchange are extracted from lattice QCD results. These inputs lead to a reasonable description of the saturation properties, illustrating the link between QCD and nuclear physics. We also derive from the corresponding equation of state the density dependence of the quark condensate and of the QCD susceptibilities. (authors)
From QCD to nuclear matter saturation
Energy Technology Data Exchange (ETDEWEB)
Ericson, Magda [Universite de Lyon, Univ. Lyon 1, CNRS/IN2P3, IPN Lyon, F-69622 Villeurbanne Cedex (France)]|[Theory division, CERN, CH-12111 Geneva (Switzerland); Chanfray, Guy [Universite de Lyon, Univ. Lyon 1, CNRS/IN2P3, IPN Lyon, F-69622 Villeurbanne Cedex (France)
2007-03-15
We discuss a relativistic chiral theory of nuclear matter with {sigma} and {omega} exchange using a formulation of the {sigma} model in which all the chiral constraints are automatically fulfilled. We establish a relation between the nuclear response to the scalar field and the QCD one which includes the nucleonic parts. It allows a comparison between nuclear and QCD information. Going beyond the mean field approach we introduce the effects of the pion loops supplemented by the short-range interaction. The corresponding Landau-Migdal parameters are taken from spin-isospin physics results. The parameters linked to the scalar meson exchange are extracted from lattice QCD results. These inputs lead to a reasonable description of the saturation properties, illustrating the link between QCD and nuclear physics. We also derive from the corresponding equation of state the density dependence of the quark condensate and of the QCD susceptibilities. (authors)
Nuclear dynamics of mass asymmetric systems at balance energy
International Nuclear Information System (INIS)
In the search of nuclear equation of state as well as of nuclear interactions and forces, collective transverse flow has been found to be of immense importance. At low incident energies, the collective transverse flow is dominated by attractive interactions and the flow is expected to be negative, while at high incident energies, the flow is dominated by nucleon-nucleon repulsive interactions and is expected to be positive. While going from low to high incident energies, collective transverse flow vanishes at a particular value of energy, which is termed as Balance Energy (Ebal). The Ebal has been reported to be of significance toward the understanding of nuclear interactions and related dynamics
A variational theory of nuclear matter. III
International Nuclear Information System (INIS)
Developments in a variational theory of nuclear matter for treating v6 homework potentials that include central, spin, isospin and tensor operators are reported. The central, spin, isospin and tensor correlations are parametrized by their range d, and the magnitudes of the non-central correlations. Integral equations are used to sum Fermi hypernetted chain, and single operator chain diagrams. All commutators required to evaluate the energy from the operator chain functions are treated exactly, and the energy is found to have a minimum with respect to variations in all parameters. Results of calculations with v6 models based on the Reid and Bethe-Johnson potentials are reported. A crude estimate of the effect of the spin-orbit potentials on nuclear matter binding energy indicates that it could be significant. (Auth.)
Two-nucleon forces and nuclear matter
International Nuclear Information System (INIS)
Recent nuclear matter calculations have shown that (a) a precise knowledge of the tensor force in the nucleon-nucleon interaction, and (b) an explicit description of the intermediate-range attraction, are absolutely essential to aobtain saturation at empirical density. This article describes the progress made recently with respect to these two topics. Concerning the tensor force, we discuss the influence of ?- and rho-exchange and show the importance of a precise knowledge of the ?NN-form factor. As to the second point, we demonstrate the outstanding role of the ?-isobar. We emphasize the importance of a consistent treatment of the two-body and the many-body problem, starting from a field-theoretical Hamiltonian. We present an explicit boson-exchange model for the NN-interaction including the ?, and show results for NN-scattering, the deuteron and nuclear matter. (orig.)
Anatomy of symmetry energy of dilute nuclear matter
De, J N; Agrawal, B K
2010-01-01
The symmetry energy coefficients of dilute clusterized nuclear matter are evaluated in the $S$-matrix framework. Employing a few different definitions commonly used in the literature for uniform nuclear matter, it is seen that the different definitions lead to perceptibly different results for the symmetry coefficients for dilute nuclear matter. They are found to be higher compared to those obtained for uniform matter in the low density domain. The calculated results are in reasonable consonance with those extracted recently from experimental data.
Asymmetric Dark Matter in the Sun and the Diphoton Excess at the LHC
Dev, P S Bhupal
2015-01-01
Recently, ATLAS and CMS have observed an excess in the diphoton channel with respect to the Standard Model background, with resonance at an invariant mass of about 750 GeV. At the same time, it has been recently pointed out that a momentum-dependent cross section for asymmetric Dark Matter (DM) interacting with nucleons can explain the disagreement between helioseismological observables and the predictions of solar models. In this letter we consider the minimal model for generating such momentum-dependent cross section, which consists of a scalar and a pseudoscalar mediator, in addition to the DM Dirac fermion. Remarkably, the pseudoscalar can be taken at a mass of 750 GeV, explaining quantitatively at the same time the observed diphoton excess and the solar anomaly. In this framework, the total width of the resonance is naturally large, as suggested by the ATLAS experiment. The model predicts the existence of a new scalar in the GeV range, interacting with quarks, and observable t-tbar and dijet signals in t...
Heavy Vector and Axial-Vector Mesons in Hot and Dense Asymmetric Strange Hadronic Matter
Kumar, Arvind
2015-01-01
We calculate the effects of finite density and temperature of isospin asymmetric strange hadronic matter, for different strangeness fractions, on the in-medium properties of vector $\\left( D^{\\ast}, D_{s}^{\\ast}, B^{\\ast}, B_{s}^{\\ast}\\right)$ and axial-vector $\\left( D_{1}, D_{1s}, B_{1}, B_{1s}\\right)$ mesons, using chiral hadronic SU(3) model and QCD sum rules. We focus on the evaluation of in-medium mass-shift and shift in decay constant of above vector and axial-vector mesons. In QCD sum rule approach, the properties, e.g., the masses and decay constants of vector and axial-vector mesons are written in terms of quark and gluon condensates. These quark and gluon condensates are evaluated in the present work within chiral SU(3) model, through the medium modification of, scalar-isoscalar fields $\\sigma$ and $\\zeta$, the scalar-isovector field $\\delta$ and scalar dilaton field $\\chi$, in the strange hadronic medium which includes both nucleons as well as hyperons. As we shall see in detail, the masses and de...
Stellar properties and nuclear matter constraints
Dutra, Mariana; Menezes, Débora P
2015-01-01
We have analyzed stellar properties of the relativistic mean-field (RMF) parametrizations shown to be consistent with the recently studied constraints related to nuclear matter, pure neutron matter, symmetry energy and its derivatives [Dutra et al., Phys. Rev. C 90, 055203 (2014)]. Our results show that only two RMF parametrizations do not allow the emergence of the direct Urca process, important aspect regarding the evolution of a neutron star. Moreover, among all approved RMF models, fourteen of them produce neutron stars with maximum masses inside the range $1.93\\leqslant M/M_\\odot\\leqslant 2.05$, with $M_\\odot$ being the solar mass. Only three models yield maximum masses above this range and a discussion on the inclusion of hyperons is presented. Finally, we have verified that the models satisfying the neutron star maximum mass constraint do not observe the squared sound velocity bound, namely, $v_s^2 < 1/3$, corroborating recent findings.
Elementary diagrams in nuclear and neutron matter
International Nuclear Information System (INIS)
Variational calculations of nuclear and neutron matter are currently performed using a diagrammatic cluster expansion with the aid of nonlinear integral equations for evaluating expectation values. These are the Fermi hypernetted chain (FHNC) and single-operator chain (SOC) equations, which are a way of doing partial diagram summations to infinite order. A more complete summation can be made by adding elementary diagrams to the procedure. The simplest elementary diagrams appear at the four-body cluster level; there is one such E4 diagram in Bose systems, but 35 diagrams in Fermi systems, which gives a level of approximation called FHNC/4. We developed a novel technique for evaluating these diagrams, by computing and storing 6 three-point functions, Sxyz(r12, r13, r23), where xyz (= ccd, cce, ddd, dde, dee, or eee) denotes the exchange character at the vertices 1, 2, and 3. All 35 Fermi E4 diagrams can be constructed from these 6 functions and other two-point functions that are already calculated. The elementary diagrams are known to be important in some systems like liquid 3He. We expect them to be small in nuclear matter at normal density, but they might become significant at higher densities appropriate for neutron star calculations. This year we programmed the FHNC/4 contributions to the energy and tested them in a number of simple model cases, including liquid 3He and Bethe's homework problem. We get reasonable, but not exact agreement with earlier published work. In nuclear and neutron matter with the Argonne v14 interaction these contributions are indeed small corrections at normal density and grow to only 5-10 MeV/nucleon at 5 times normal density
Nuclear target effect on dark matter detection rate
Bednyakov, V. A.; Simkovic, F.
2005-01-01
Expected event rates for a number of dark matter nuclear targets were calculated in the effective low-energy minimal supersymmetric standard model, provided the lightest neutralino is the dark matter Weakly Interacting Massive Particle (WIMP). These calculations allow direct comparison of sensitivities of different dark matter detectors to intermediate mass WIMPs expected from the measurements of the DArk MAtter (DAMA) experiment.
Mass shift of -meson in nuclear matter
Indian Academy of Sciences (India)
J R Morones-Ibarra; Mónica Menchaca Maciel; Ayax Santos-Guevara; Felipe Robledo Padilla
2013-03-01
The propagation of -meson in nuclear matter is studied in the Walecka model, by assuming that the sigma couples to a pair of nucleon–antinucleon states and to particle–hole states. The in-medium effect of $\\sigma -\\omega$ mixing is also studied. For completeness, the coupling of sigma to two virtual pions was also considered. It is found that the -meson mass decreases with respect to its value in vacuum and that the contribution of the $\\sigma -\\omega$ mixing effect on the mass shift is relatively small.
Mass shift of ?-meson in nuclear matter
International Nuclear Information System (INIS)
The propagation of ?-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 ?-? mixing is also studied. For completeness, the coupling of sigma to two virtual pions was also considered. It is found that the ?-meson mass decreases with respect to its value in vacuum and that the contribution of the ?-? mixing effect on the mass shift is relatively small. (author)
Hadronization measurements in cold nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Dupre, Raphael [Inst. de Physique Nucleaire (IPN), Orsay (France). et al.
2015-05-01
Hadronization is the non-perturbative process of QCD by which partons become hadrons. It has been studied at high energies through various processes, we focus here on the experiments of lepto-production of hadrons in cold nuclear matter. By studying the dependence of observables to the atomic number of the target, these experimentscan give information on the dynamic of the hadronization at the femtometer scale. In particular, we will present preliminary results from JLab Hall B (CLAS collaboration), which give unprecedented statistical precision. Then, we will present results of a phenomenological study showing how HERMES data can be described with pure energyloss models.
Nuclear interaction rates for dark matter detectors
International Nuclear Information System (INIS)
I describe nuclear shell model calculations of the spin-dependent elastic cross sections of supersymmetric particles on the nuclei 73Ge and 29Si, which are being used in the construction of dark matter detectors. To check the accuracy of the wave functions I have calculated excited state energy spectra, magnetic moments, and spectroscopic factors for each of the nuclei. Our results differ significantly from previous estimates based upon the independent single particle shell model and the odd group model. I at% discuss the modifications that occur when finite momentum transfer between the neutralino and nucleus is included
Self-interacting asymmetric dark matter coupled to a light massive dark photon
International Nuclear Information System (INIS)
Dark matter (DM) with sizeable self-interactions mediated by a light species offers a compelling explanation of the observed galactic substructure; furthermore, the direct coupling between DM and a light particle contributes to the DM annihilation in the early universe. If the DM abundance is due to a dark particle-antiparticle asymmetry, the DM annihilation cross-section can be arbitrarily large, and the coupling of DM to the light species can be significant. We consider the case of asymmetric DM interacting via a light (but not necessarily massless) Abelian gauge vector boson, a dark photon. In the massless dark photon limit, gauge invariance mandates that DM be multicomponent, consisting of positive and negative dark ions of different species which partially bind in neutral dark atoms. We argue that a similar conclusion holds for light dark photons; in particular, we establish that the multi-component and atomic character of DM persists in much of the parameter space where the dark photon is sufficiently light to mediate sizeable DM self-interactions. We discuss the cosmological sequence of events in this scenario, including the dark asymmetry generation, the freeze-out of annihilations, the dark recombination and the phase transition which gives mass to the dark photon. We estimate the effect of self-interactions in DM haloes, taking into account this cosmological history. We place constraints based on the observed ellipticity of large haloes, and identify the regimes where DM self-scattering can affect the dynamics of smaller haloes, bringing theory in better agreement with observations. Moreover, we estimate the cosmological abundance of dark photons in various regimes, and derive pertinent bounds
Dark Matter Particle Spectroscopy at the LHC: Generalizing M(T2) to Asymmetric Event Topologies
Energy Technology Data Exchange (ETDEWEB)
Konar, Partha; /Florida U.; Kong, Kyoungchul; /SLAC; Matchev, Konstantin T.; Park, Myeonghun; /Florida U.
2012-04-03
We consider SUSY-like missing energy events at hadron colliders and critically examine the common assumption that the missing energy is the result of two identical missing particles. In order to experimentally test this hypothesis, we generalize the subsystem M{sub T2} variable to the case of asymmetric event topologies, where the two SUSY decay chains terminate in different 'children' particles. In this more general approach, the endpoint M{sub T2(max)} of the M{sub T2} distribution now gives the mass {tilde M}p({tilde M}{sub c}{sup (a)}, {tilde M}{sub c}{sup (b)}) of the parent particles as a function of two input children masses {tilde M}{sub c}{sup (a)} and {tilde M}{sub c}{sup (b)}. We propose two methods for an independent determination of the individual children masses M{sub c}{sup (a)} and M{sub c}{sup (b)}. First, in the presence of upstream transverse momentum PUTM the corresponding function {tilde M}p({tilde M}{sub c}{sup (a)}, {tilde M}{sub c}{sup (b)}, P{sub UTM}) is independent of P{sub UTM} at precisely the right values of the children masses. Second, the previously discussed MT2 'kink' is now generalized to a 'ridge' on the 2-dimensional surface {tilde M}p({tilde M}{sub c}{sup (a)}, {tilde M}{sub c}{sup (b)}). As we show in several examples, quite often there is a special point along that ridge which marks the true values of the children masses. Our results allow collider experiments to probe a multi-component dark matter sector directly and without any theoretical prejudice.
Self-interacting asymmetric dark matter coupled to a light massive dark photon
Energy Technology Data Exchange (ETDEWEB)
Petraki, Kalliopi [Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Pearce, Lauren; Kusenko, Alexander, E-mail: kpetraki@nikhef.nl, E-mail: lpearce@ucla.edu, E-mail: kusenko@ucla.edu [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States)
2014-07-01
Dark matter (DM) with sizeable self-interactions mediated by a light species offers a compelling explanation of the observed galactic substructure; furthermore, the direct coupling between DM and a light particle contributes to the DM annihilation in the early universe. If the DM abundance is due to a dark particle-antiparticle asymmetry, the DM annihilation cross-section can be arbitrarily large, and the coupling of DM to the light species can be significant. We consider the case of asymmetric DM interacting via a light (but not necessarily massless) Abelian gauge vector boson, a dark photon. In the massless dark photon limit, gauge invariance mandates that DM be multicomponent, consisting of positive and negative dark ions of different species which partially bind in neutral dark atoms. We argue that a similar conclusion holds for light dark photons; in particular, we establish that the multi-component and atomic character of DM persists in much of the parameter space where the dark photon is sufficiently light to mediate sizeable DM self-interactions. We discuss the cosmological sequence of events in this scenario, including the dark asymmetry generation, the freeze-out of annihilations, the dark recombination and the phase transition which gives mass to the dark photon. We estimate the effect of self-interactions in DM haloes, taking into account this cosmological history. We place constraints based on the observed ellipticity of large haloes, and identify the regimes where DM self-scattering can affect the dynamics of smaller haloes, bringing theory in better agreement with observations. Moreover, we estimate the cosmological abundance of dark photons in various regimes, and derive pertinent bounds.
Unmasking the nuclear matter equation of state
Piekarewicz, J
2004-01-01
Accurately calibrated (or ``best fit'') relativistic mean-field models are used to compute the distribution of isoscalar monopole strength in 90Zr and 208Pb, and the isovector dipole strength in 208Pb using a continuum random-phase-approximation approach. It is shown that the distribution of isoscalar monopole strength in 208Pb--but not in 90Zr--is sensitive to the density dependence of the symmetry energy. This sensitivity hinders the extraction of the compression modulus of symmetric nuclear matter from the isoscalar giant monopole resonance (ISGMR) in 208Pb. Thus, one relies on 90Zr, a nucleus with both a small neutron-proton asymmetry and a well developed ISGMR peak, to constrain the compression modulus of symmetric nuclear matter to the range K=(248 +/- 6) MeV. In turn, the sensitivity of the ISGMR in 208Pb to the density dependence of the symmetry energy is used to constrain its neutron skin to the range Rn-Rp<=0.22 fm. The impact of this result on the enhanced cooling of neutron stars is briefly add...
The few scales of nuclei and nuclear matter
Delfino, A.; Frederico, T.; Timoteo, V. S.; Tomio, Lauro
2007-01-01
The well-known correlations of low-energy three and four-nucleon observables with a typical three-nucleon scale (e.g., the Tjon line) is extended to light nuclei and nuclear matter. Evidence for the scaling between light nuclei binding energies and the triton one are pointed out. We argue that the saturation energy and density of nuclear matter are correlated to the triton binding energy. The available systematic nuclear matter calculations indicate a possible band structure representing thes...
Chiral Fermi liquid description of nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Holt, Jeremy; Kaiser, Norbert; Weise, Wolfram [Technische Universitaet Muenchen (Germany)
2012-07-01
We employ Landau's theory of normal Fermi liquids to study the bulk properties of nuclear matter with high-precision two- and three-nucleon interactions derived within the framework of chiral effective field theory. The L=0,1 Landau parameters, characterizing the isotropic and p-wave interaction between two quasiparticles on the Fermi surface, are computed to second order in many-body perturbation theory (MBPT) with chiral and low-momentum two-nucleon forces. Already at this order a number of observables are well described in the theory, including the nuclear isospin asymmetry energy, the quasiparticle effective mass and the spin-isospin response. An adequate description of the nuclear compression modulus (encoded in the Landau parameter F{sub 0}) requires the inclusion of the leading-order (N{sup 2}LO) chiral three-nucleon force, which we include to first order in MBPT. The remaining L=0 Landau parameters receive only small corrections from the chiral three-nucleon force, and the L=1 parameters are all reduced, resulting in an effective interaction of apparent short range. We then employ renormalization group techniques to study the scale dependence of the quasiparticle interaction, which allows for an estimation of theoretical uncertainties.
Chiral Fermi liquid description of nuclear matter
International Nuclear Information System (INIS)
We employ Landau's theory of normal Fermi liquids to study the bulk properties of nuclear matter with high-precision two- and three-nucleon interactions derived within the framework of chiral effective field theory. The L=0,1 Landau parameters, characterizing the isotropic and p-wave interaction between two quasiparticles on the Fermi surface, are computed to second order in many-body perturbation theory (MBPT) with chiral and low-momentum two-nucleon forces. Already at this order a number of observables are well described in the theory, including the nuclear isospin asymmetry energy, the quasiparticle effective mass and the spin-isospin response. An adequate description of the nuclear compression modulus (encoded in the Landau parameter F0) requires the inclusion of the leading-order (N2LO) chiral three-nucleon force, which we include to first order in MBPT. The remaining L=0 Landau parameters receive only small corrections from the chiral three-nucleon force, and the L=1 parameters are all reduced, resulting in an effective interaction of apparent short range. We then employ renormalization group techniques to study the scale dependence of the quasiparticle interaction, which allows for an estimation of theoretical uncertainties.
Hirschegg '95: Dynamical properties of hadrons in nuclear matter. Proceedings
International Nuclear Information System (INIS)
The following topics were dealt with: Chiral symmetry, chiral condensates, in-medium effective chiral Lagrangians, Î”'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)LxSU(3)R sigma model, nonequilibrium dense nuclear matter, pion pair production at finite temperature. (HSI)
Recent Advances in Microscopic Approaches to Nuclear Matter and Symmetry Energy
Directory of Open Access Journals (Sweden)
Francesca Sammarruca
2014-10-01
Full Text Available Nuclear matter is a convenient theoretical laboratory to test many-body theories. When neutron and proton densities are different, the isospin dependence of the nuclear force gives rise to the symmetry energy term in the equation of state. This quantity is a crucial mechanism in the formation of the neutron skin in nuclei, as well as in other systems and phenomena involved in the dynamics of neutrons and protons in neutron-rich systems, such as isospin-asymmetric heavy-ion collisions. In this article, we will review phenomenological facts about the symmetry energy and recent experimental efforts to constrain its density dependence and related quantities. We will then review our microscopic approach to the equation of state of symmetric and asymmetric nuclear matter and present a corresponding set of predictions. Our calculations utilize the Dirac–Brueckner–Hartree–Fock method and realistic meson-theoretic nucleon-nucleon potentials. Chiral perturbation theory is an alternative approach, based on a well-defined scheme, which allows one to develop nuclear forces at each order of the chiral expansion. We will present and discuss predictions based on chiral perturbation theory, where we employ consistent two- and three-body chiral interactions. Throughout the article, one of the focal points is the importance of pursuing ab initio methods towards a deeper understanding of the many-body system.
Relativistic calculation of polarized nuclear matter
International Nuclear Information System (INIS)
The binding energy of nuclear matter with excess of neutrons, of spin-up neutrons, and spin-up protons (characterized by the corresponding parameters, ?sub(tau) = (N - Z)/A, ?sub(N) = (N - N )/A, and ?sub(p) = (Z - Z)/A)), contains three symmetry energies: the isospin symmetry energy epsilon sub(?), the spin symmetry energy epsilon sub(?), and the spin-isospin symmetry energy epsilon sub(?tau). The relativistic corrections to epsilon sub(tau), epsilon sub(?) and epsilon sub(?tau) are found to be -2.06, -2.6 and -0.89 MeV respectively. The relativistic correction to the compression modulus is -10.8 MeV. (author)
Attenuation of ? mesons in cold nuclear matter
International Nuclear Information System (INIS)
The attenuation of ? mesons in cold nuclear matter has been investigated via the time-dependent multiple-scattering Monte Carlo multicollisional (MCMC) intranuclear cascade model. The inelastic ? width deduced from CBELSA/TAPS Collaboration data of meson transparency in complex nuclei (?*?30 MeV/c2) is approximately 5 times lower than the value obtained with recent theoretical models and consistent with an in-medium total ?N cross section within 25-30 mb for an average meson momentum of 1.1 GeV/c . The momentum-dependent transparency ratios suggest an elastic/total cross-section ratio around 40%. For the case of CLAS Collaboration data a much higher width is deduced (?* > or approx. 120 MeV/c2), with the MCMC model providing a consistent interpretation of the data, assuming a much higher meson absorption (??N* > or approx. 100 mb) for p??1.7 GeV/c.
On the Density Dependent Nuclear Matter Compressibility
Dexheimer, V A; Bodmann, B E J
2007-01-01
In the present work we apply a quantum hadrodynamic effective model in the mean-field approximation to the description of neutron stars. We consider an adjustable derivative-coupling model and study the parameter influence on the dynamics of the system by analyzing the full range of values they can take. We establish a set of parameters which define a specific model that is able to describe phenomenological properties such as the effective nucleon mass at saturation as well as global static properties of neutron stars (mass and radius). If one uses observational data to fix the maximum mass for neutron stars by a specific model, we are able to predict the compression modulus of nuclear matter K = 257,2MeV.
Phase transitions in nuclear matter and consequences for neutron stars
International Nuclear Information System (INIS)
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)
On the thermal properties of polarised nuclear matter
International Nuclear Information System (INIS)
The thermal properties of polarised nuclear matter are calculated using the Skyrme-III interaction as modified by Dabrowski (Nukleonika;21:143 (1977)) for polarised nuclear matter. The temperature dependences of the volume, isospin, spin and spin-isospin pressure and energies are determined. The temperature, isospin, spin and spin-isospin dependences of the equilibrium Fermi momentum are also discussed. (author)
On the spin saturation and thermal properties of nuclear matter
International Nuclear Information System (INIS)
The binding energy and the incompressibility of nuclear matter with degree of spin saturation D is calculated using the Skyrme interaction and two forms of a velocity dependent effective potential. The effect of the degree of spin saturation D on the thermal properties of nuclear matter is also discussed. It is found that generally the pressure decreases with increasing D. (author)
On the thermal properties of polarized nuclear matter
International Nuclear Information System (INIS)
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)
On the thermal properties of nuclear matter with neutron excess
International Nuclear Information System (INIS)
The schematic model of nuclear matter proposed by Gomes, Walecka and Weisskopf which was generalized to finite temperatures including interacting Fermi particle aspects is extended here to include nuclear matter with neutron excess. The level density parameter as a function of neutron excess is calculated. Also the temperature dependence of the equilibrium Fermi momentum is calculated. (author)
Equation of state for ?-stable hot nuclear matter
International Nuclear Information System (INIS)
We provide an equation of state for hot nuclear matter in ? equilibrium by applying a momentum-dependent effective interaction. We focus on the study of the equation of state of high-density and high-temperature nuclear matter, containing leptons (electrons and muons) under the chemical equilibrium condition in which neutrinos have left the system. The conditions of charge neutrality and equilibrium under the ?-decay process lead first to the evaluation of proton and lepton fractions and then to the evaluation of internal energy, free energy, and pressure, and in total to the equation of state of hot nuclear matter. Thermal effects on the properties and equation of state of nuclear matter are assessed and analyzed in the framework of the proposed effective interaction model. Special attention is given to the study of the contribution of the components of ?-stable nuclear matter to the entropy per particle, a quantity of great interest in the study of structure and collapse of supernova.
Nucleons, Nuclear Matter and Quark Matter: A unified NJL approach
Lawley, S.; Bentz, W.; Thomas, A.W.
2006-01-01
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.
Cherenkov and Fano effects at the origin of asymmetric vector mesons in nuclear media
Dremin, I M
2015-01-01
It is argued that the experimentally observed phenomenon of asymmetric vector mesons produced in nuclear media during high energy nucleus-nucleus collisions can be explained as Cherenkov and Fano effects. The mass distributions of lepton pairs created at meson decays decline from the traditional Breit-Wigner shape in the low-mass wing of the resonance. That is explained by the positive real part of the amplitude in this wing for classic Cherenkov treatment and further detalized in quantum mechanics as the interference of direct and continuum states in Fano effect. The corresponding parameters are found from the comparison with rho-meson data and admit reasonable explanation.
Studies for the equation of state in the isospin asymmetrical nuclear interactions
International Nuclear Information System (INIS)
In order to determine the equation of state in the isospin asymmetrical nuclear interactions, we have found the observables for extracting the information of them within the isospin-dependent quantum molecular dynamics in recent years. The several sensitive probes for extracting the information of the in-medium nucleon–nucleon cross section and the symmetry potential have found; meanwhile, their mechanisms are investigated in more details. The main point in this paper gives the summary for above probes and their outlook in the future. (author)
Strangeness and charm in nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Tolos, Laura, E-mail: tolos@ice.csic.es [Instituto de Ciencias del Espacio (IEEC/CSIC), Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193 Bellaterra (Barcelona) (Spain); Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Cabrera, Daniel [Departamento de Física Teórica II, Universidad Complutense, 28040 Madrid (Spain); Garcia-Recio, Carmen [Departamento de Física Atómica, Molecular y Nuclear, and Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, E-18071 Granada (Spain); Molina, Raquel [Research Center for Nuclear Physics (RCNP), Mihogaoka 10-1, Ibaraki 567-0047 (Japan); Nieves, Juan; Oset, Eulogio [Instituto de Física Corpuscular (Centro Mixto CSIC-UV), Institutos de Investigación de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Ramos, Angels [Departament d' Estructura i Constituents de la Matèria, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Romanets, Olena [Theory Group, KVI, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Salcedo, Lorenzo Luis [Departamento de Física Atómica, Molecular y Nuclear, and Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, E-18071 Granada (Spain)
2013-09-20
The properties of strange (K, K{sup ¯} and K{sup ¯?}) and open-charm (D, D{sup ¯} and D{sup ?}) mesons in dense matter are studied using a unitary approach in coupled channels for meson–baryon scattering. In the strangeness sector, the interaction with nucleons always comes through vector-meson exchange, which is evaluated by chiral and hidden gauge Lagrangians. For the interaction of charmed mesons with nucleons we extend the SU(3) Weinberg–Tomozawa Lagrangian to incorporate spin–flavor symmetry and implement a suitable flavor symmetry breaking. The in-medium solution for the scattering amplitude accounts for Pauli blocking effects and meson self-energies. On one hand, we obtain the K, K{sup ¯} and K{sup ¯?} spectral functions in the nuclear medium and study their behaviour at finite density, temperature and momentum. We also make an estimate of the transparency ratio of the ?A?K{sup +}K{sup ??}A{sup ?} reaction, which we propose as a tool to detect in-medium modifications of the K{sup ¯?} meson. On the other hand, in the charm sector, several resonances with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with 1/2{sup +} and 3/2{sup +} baryons. The properties of these states in matter are analyzed and their influence on the open-charm meson spectral functions is studied. We finally discuss the possible formation of D-mesic nuclei at FAIR energies.
The curvature dependence of the surface tension of nuclear matter
International Nuclear Information System (INIS)
It is shown that the curvature dependence of the surface tension of nuclear matter is analogous to that of normal liquids. This can be described quantitatively by the modified Tolman equation. The surface tension of plane nuclear matter is 2.4 x 1017 Nm-1. According to its physical meaning the delta-parameter has been interpreted as the half-width of the nuclear surface. (author)
Nuclear matter burning induced by strange matter into protoneutron star
International Nuclear Information System (INIS)
Full text: In this work we present a schematic description of the dynamical evolution of a protoneutron star which begins to burn neutron matter into strange matter inside the core. We have used a simple two-shell model where the inner shell medium is initially composed of a small lump of strange quark matter surrounded by an outer shell composed of free neutron matter. In a first attempt, we have utilized a polytropic equation of state (EOS) for the outer hadronic medium description and the MIT bag model EOS describing for the strange quark matter. We investigate, as was suggested by Lugones et al (1994), if the combustion mode can actually become a detonation process. The main purpose of the work is to study the formation and propagation of the shock front generated by the detonation process. An effective description for the thermodynamic global evolution of the burning shell is developed and we also investigate the possibility of matter ejection as a consequence of the process of detonation, which could produce a pure quark star as a remnant or even a hybrid neutron star. The mass and radii values obtained for the final equilibrium configurations are compared with the observational data of compact stars. (author)
Nuclear matter burning induced by strange matter into protoneutron star
Energy Technology Data Exchange (ETDEWEB)
Almeida, Luis Gustavo de [Universidade Federal do Acre (UFAC), AC (Brazil). Campus Floresta; Duarte, Sergio Barbosa [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Goncalves, Hilario A. Rodrigues [Centro Federal de Educacao Tecnologica (CEFET-RJ), Rio de Janeiro, RJ (Brazil)
2011-07-01
Full text: In this work we present a schematic description of the dynamical evolution of a protoneutron star which begins to burn neutron matter into strange matter inside the core. We have used a simple two-shell model where the inner shell medium is initially composed of a small lump of strange quark matter surrounded by an outer shell composed of free neutron matter. In a first attempt, we have utilized a polytropic equation of state (EOS) for the outer hadronic medium description and the MIT bag model EOS describing for the strange quark matter. We investigate, as was suggested by Lugones et al (1994), if the combustion mode can actually become a detonation process. The main purpose of the work is to study the formation and propagation of the shock front generated by the detonation process. An effective description for the thermodynamic global evolution of the burning shell is developed and we also investigate the possibility of matter ejection as a consequence of the process of detonation, which could produce a pure quark star as a remnant or even a hybrid neutron star. The mass and radii values obtained for the final equilibrium configurations are compared with the observational data of compact stars. (author)
Antikaons in infinite nuclear matter and nuclei
Energy Technology Data Exchange (ETDEWEB)
Moeller, M.
2007-12-10
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.)
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.
Track theory and nuclear photographic emulsions for Dark Matter searches
International Nuclear Information System (INIS)
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.Body - Highlights: â–º Specific features of Dark Matter Search in nuclear photographic emulsions. â–º Track theory for WIMP search in nuclear emulsions. â–º Primary efficiency for single WIMP registration. â–º Properties of primary WIMP registration efficiency. â–º Primary registration efficiency of WIMP flow
Berec, V.
2016-02-01
We study the coupling and control adaptation of a hybrid electron-nuclear spin system using the laser mediated proton beam in MeV energy regime. The asymmetric control mechanism is based on exact optimization of both: the measure of exchange interaction and anisotropy of the hyperfine interaction induced in the resonance with optimal channeled protons (CP) superfocused field, allowing manipulation over arbitrary localized spatial centers while addressing only the electron spin. Using highly precise and coherent proton channeling regime we have obtained efficient pulse shaping separator technique aimed for spatio-temporal engineering of quantum states, introducing a method for control of nuclear spins, which are coupled via anisotropic hyperfine interactions in isolated electron spin manifold, without radio wave (RW) pulses. The presented method can be efficiently implemented in synchronized spin networks with the purpose to facilitate preservation and efficient transfer of experimentally observed quantum particle states, contributing to the overall background noise reduction.
Dielectron spectroscopy in cold nuclear matter
International Nuclear Information System (INIS)
The subject of this thesis is the production of light mesons and baryonic resonances in p+Nb collisions at Ekin=3.5 GeV via their decay in e+e- pairs and their kinematic observables. This reaction system in particular allows for the production of vector mesons in approximately cold nuclear matter and the study of expected in-medium effects. The experiment was conducted at the dielectron spectrometer HADES at GSI Helmholtzzentrum fuer Schwerionenforschung GmbH. In total, 64827±294 signal pairs with an pair opening angle ?ee>9 and e+/e- momenta 80e(MeV/c)ee(MeV/c2)ee> 550 MeV/c2). Inclusive e+e- production cross sections inside the HADES acceptance were calculated by analyzing the simultaneously measured charged pions and by comparing the obtained ?- yields to an independent data set. For the vector mesons one obtains ??,acc=(65.8±4.6(stat)±18.4(sys)) nb and ??,acc=(7.8±1.7(stat)±2.2 (sys)) nb. A comparison with cross sections in free p+p collisions at Ekin=3.5 GeV results in the nuclear modification factors RpA as well as their scaling ? with the nuclear mass number A and their dependence on the pair lab momenta pee. While absorption is not important for the ? meson (?? ?1), scaling factors ? ?0.7 are established for the quasi free decay (pee>800 MeV/c) of all other hadrons. From an adapted Glauber model calculation a minimal absorption >or similar 35% of all contributing hadrons in nuclei can be deduced. At smaller pair momenta different scaling factors are obtained. The ? meson is absorbed with a higher probability (??=0.62), but for all other sources above the ?0 mass, dominantly ?, ?, and ? with ?=0.82-0.86, production in secondary reactions exceeds the absorption inside the nucleus. Measured e+e- distributions were compared with different transport model calculations. Within the uncertainties the cross section of the ?0 Dalitz decay is reproduced in all models. However differences arise in the high mass region and the distributions of transverse momenta and rapidities. Additionally the GiBUU calculations describe the behaviour of slow and fast e+e- sources due to a momentum dependent in medium decay width. In the experiment no signal of the direct decay ??e+e- was measured. The existing upper level for the branching ratio BR=2.7 x 10-5 has to be reduced by at least a factor of 3. (orig.)
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.)
Properties of the ?-meson in dense nuclear matter
International Nuclear Information System (INIS)
The properties of ?-mesons in dense nuclear matter are studied in a model which satisfies unitarity and current conservation. The important coupling of the ?-meson to two pions as well as the strong mixing of pions and delta-nucleon-hole states in nuclear matter are included. The ?-meson self energy in nuclear matter is evaluated with in-medium pion propagators and the corresponding vertex corrections required by current conservation. We find that the ?-meson width grows drastically with increasing density while its mass remains almost unchanged. (orig.)
Transverse charge densities in the nucleon in nuclear matter
Yakhshiev, Ulugbek
2013-01-01
We investigated the transverse charge densities in the nucleon in nuclear matter within the framework of the in-medium modified Skyrme model. The medium modification of the nucleon electromagnetic form factors are first discussed. The results show that the form factors in nuclear matter fall off faster than those in free space, as the momentum transfer increases. As a result, the charge radii of the nucleon become larger, as the nuclear matter density increases. The transverse charge densities in the nucleon indicate that the size of the nucleon tends to bulge out in nuclear matter. This salient feature of the swelling is more clearly observed in the neutron case. When the proton is transversely polarized, the transverse charge densities exhibit the distortion due to the effects of the magnetization.
The response function of a slab of noninteracting nuclear matter
International Nuclear Information System (INIS)
Analytic expressions of the density and of the particle-hole polarization propagator are derived for a slab of noninteracting nuclear matter. The nondiagonal behaviour of the polarization propagator in the momentum components perpendicular to the slab is explored
K meson-nucleus interactions: strangeness and nuclear matter
International Nuclear Information System (INIS)
A brief review is provided of some straightforward K-nuclear and Î›-hypernuclear systems. A discussion of less straightforward speculations on H-dibaryons and strange quark matter by many authors, is also given. 28 refs., 6 figs
Reflection on penal policy in nuclear matters
International Nuclear Information System (INIS)
This document expresses ethical reflexions as far as nuclear energy development is concerned. The potential diversion of the peaceful use of nuclear energy results in the necessity of a criminal policy which would control the nuclear regulations. For each potential nuclear infringement, systems of laws are established either to prevent damages or to penalize them. (TEC)
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)
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.)
Surface Tension between Kaon Condensate and Normal Nuclear Matter Phase
Christiansen, Michael B.; Glendenning, Norman K.; Schaffner-Bielich, Jurgen
2000-01-01
We calculate for the first time the surface tension and curvature coefficient of a first order phase transition between two possible phases of cold nuclear matter, a normal nuclear matter phase in equilibrium with a kaon condensed phase, at densities a few times the saturation density. We find the surface tension is proportional to the difference in energy density between the two phases squared. Furthermore, we show the consequences for the geometrical structures of the mixe...
Improved nuclear matter calculations from chiral low-momentum interactions
Hebeler, K; Furnstahl, R J; Nogga, A; Schwenk, A
2010-01-01
We present new nuclear matter calculations based on low-momentum interactions derived from chiral effective field theory potentials. The current calculations use an improved treatment of the three-nucleon force contribution that includes a corrected combinatorial factor beyond Hartree-Fock that was omitted in previous nuclear matter calculations. We find realistic saturation properties using parameters fit only to few-body data, but with larger uncertainty estimates from cutoff dependence and the 3NF parametrization than in previous calculations.
Improved nuclear matter calculations from chiral low-momentum interactions
International Nuclear Information System (INIS)
We present nuclear matter calculations based on low-momentum interactions derived from chiral effective field theory potentials. The current calculations use an improved treatment of the three-nucleon force (3NF) contribution that includes a corrected combinatorial factor beyond Hartree-Fock that was omitted in previous nuclear matter calculations. We find realistic saturation properties using parameters fit only to few-body data, but with larger uncertainty estimates from cutoff dependence and the 3NF parametrization than in previous calculations.
A contribution to phenomenology of phase transitions in nuclear matter
International Nuclear Information System (INIS)
A review is given on the phenomenology of phase transitions in nuclear matter and neutron matter. We deal with (1) the liquid-gas transition in expanding nuclear systems and collapsing stellar cores, (2) the pion condensation in neutron stars and the direct pion emission in relativistic heavy ion collisions and (3) the deconfinement transition in neutron stars, in the early universe and in the compression/expansion stage of heavy ion reactions. (author)
Equation of state for $\\beta$-stable hot nuclear matter
Moustakidis, Ch. C.; Panos, C. P.
2008-01-01
We provide an equation of state for hot nuclear matter in $\\beta$-equilibrium by applying a momentum-dependent effective interaction. We focus on the study of the equation of state of high-density and high-temperature nuclear matter, containing leptons (electrons and muons) under the chemical equilibrium condition in which neutrinos have left the system. The conditions of charge neutrality and equilibrium under $\\beta$-decay process lead first to the evaluation of proton and...
Nuclear matter equation of state and three-body forces
Energy Technology Data Exchange (ETDEWEB)
Mansour, H. M. M.; Algamoudi, A. M. A. [Cairo University, Physics Department, Faculty of Science (Egypt)
2012-04-15
The energy per particle, symmetry energy, pressure, and free energy are calculated for symmetric nuclear matter using BHF approach with modern nucleon-nucleon CD-Bonn, Nijm1, Argonne v{sub 18}, and Reid 93 potentials. To obtain saturation in nuclear matter we add three-body interaction terms which are equivalent to a density-dependent two-nucleon interaction a la Skyrme force. Good agreement is obtained in comparison with previous theoretical estimates and experimental data.
Dense nuclear matter in a strong magnetic field
Chakrabarty, Somenath; Bandyopadhyay, Debades; Pal, Subrata
1997-01-01
We investigate in a relativistic Hartree theory the gross properties of cold symmetric nuclear matter and nuclear matter in beta equilibrium under the influence of strong magnetic fields. If the field strengths are above the critical values for electrons and protons, the respective phase spaces are strongly modified. This results in additional binding of the systems with distinctively softer equations of state compared to the field free cases. For magnetic field $\\sim 10^{20}$ Gauss and beyon...
Nuclear and neutron matter calculations with different model spaces
International Nuclear Information System (INIS)
In this work we investigate the so-called model-space Brueckner-Hartree-Fock (MBHF) approach for nuclear matter as well as for neutron matter and the extension of this which includes the particle-particle and hole-hole (PPHH) diagrams. A central ingredient in the model-space approach for nuclear matter is the boundary momentum kM beyond which the single-particle potential energy is set equal to zero. This is also the boundary of the model space within which the PPHH diagrams are calculated. It has been rather uncertain which value should be used for kM. We have carried out model-space nuclear matter and neutron matter calculations with and without PPHH diagrams for various choices of kM and using several modern nucleon-nucleon potentials. Our results exhibit a saturation region where the nuclear and neutron matter energies are quite stable as kM varies. The location of this region may serve to determine an ''optimum'' choice for kM. However, we find that the strength of the tensor force has a significant influence on the variations of binding energy with kM. The implications for nuclear and neutron matter calculations are discussed. (orig.)
Higher-order symmetry energy of nuclear matter and the inner edge of neutron star crusts
Seif, W M
2014-01-01
The parabolic approximation to the equation of state of the isospin asymmetric nuclear matter (ANM) is widely used in the literature to make predictions for the nuclear structure and the neutron star properties. Based on the realistic M3Y-Paris and M3Y-Reid nucleon-nucleon interactions, we investigate the effects of the higher-order symmetry energy on the proton fraction in neutron stars and the location of the inner edge of their crusts and their core-crust transition density and pressure, thermodynamically. Analytical expressions for different-order symmetry energy coefficients of ANM are derived using the realistic interactions mentioned above. It is found that the higher-order terms of the symmetry energy coefficients up to its eighth-order (E$_{sym8}$) contributes substantially to the proton fraction in $\\beta$ stable neutron star matter at different nuclear matter densities, the core-crust transition density and pressure. Even by considering the symmetry energy coefficients up to E$_{sym8}$, we obtain a...
Effects of Brown-Rho scalings in nuclear matter, neutron stars and finite nuclei
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 ~ 5?0, 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 ? below ?0, 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 ?-decay.
Quantum Monte Carlo calculations of symmetric nuclear matter
Gandolfi, Stefano; Pederiva, Francesco; Fantoni, Stefano; Schmidt, Kevin E.
2006-01-01
We present an accurate numerical study of the equation of state of nuclear matter based on realistic nucleon--nucleon interactions by means of Auxiliary Field Diffusion Monte Carlo (AFDMC) calculations. The AFDMC method samples the spin and isospin degrees of freedom allowing for quantum simulations of large nucleonic systems and can provide quantitative understanding of problems in nuclear structure and astrophysics.
National control of nuclear matters. Protection against malicious intent
International Nuclear Information System (INIS)
This talk deals with, at first, the regulatory dispositions taken to guarantee the protection and the control of nuclear matters in installations and during transportation, and then with the general principles kept to evaluate the nuclear installations protection against malicious intent. (TEC)
From holography towards real-world nuclear matter
Li, Si-wen; Schmitt, Andreas; Wang, Qun
2015-07-01
Quantum chromodynamics is notoriously difficult to solve at nonzero baryon density, and most models or effective theories of dense quark or nuclear matter are restricted to a particular density regime and/or a particular form of matter. Here we study dense (and mostly cold) matter within the holographic Sakai-Sugimoto model, aiming at a strong-coupling framework in the wide density range between nuclear saturation density and ultrahigh quark matter densities. The model contains only three parameters, and we ask whether it fulfills two basic requirements of real-world cold and dense matter, a first-order onset of nuclear matter and a chiral phase transition at high density to quark matter. Such a model would be extremely useful for astrophysical applications because it would provide a single equation of state for all densities relevant in a compact star. Our calculations are based on two approximations for baryonic matter—first, an instanton gas and, second, a homogeneous ansatz for the non-Abelian gauge fields on the flavor branes of the model. While the instanton gas shows chiral restoration at high densities but an unrealistic second-order baryon onset, the homogeneous ansatz behaves exactly the other way around. Our study, thus, provides all ingredients that are necessary for a more realistic model and allows for systematic improvements of the applied approximations.
From holography towards real-world nuclear matter
Li, Si-wen; Wang, Qun
2015-01-01
Quantum chromodynamics is notoriously difficult to solve at nonzero baryon density, and most models or effective theories of dense quark or nuclear matter are restricted to a particular density regime and/or a particular form of matter. Here we study dense (and mostly cold) matter within the holographic Sakai-Sugimoto model, aiming at a strong-coupling framework in the wide density range between nuclear saturation density and ultra-high quark matter densities. The model contains only three parameters, and we ask whether it fulfills two basic requirements of real-world cold and dense matter, a first-order onset of nuclear matter and a chiral phase transition at high density to quark matter. Such a model would be extremely useful for astrophysical applications because it would provide a single equation of state for all densities relevant in a compact star. Our calculations are based on two approximations for baryonic matter, firstly an instanton gas and secondly a homogeneous ansatz for the non-abelian gauge fi...
Effects of the momentum dependence of potential on the nuclear matter flow
International Nuclear Information System (INIS)
A flow analysis on symmetric and asymmetric reactions from 100 to 400 MeV/n is performed in the framework of the semi-classical Landau-Vlasov approach. Two different trends are presented: at lower energies the flow is governed by the momentum dependence of the nuclear optical potential, whereas at higher energies its density dependence plays a crucial role leading to a rather pronounced sensitivity to the incompressibility modulus. The ingredients of our model are the one-body potential and the nucleon-nucleon collision cross section in the nuclear environment. In the computations the free nucleon nucleon cross section was used. The study of the symmetric system Nb + Nb, for which numerous experimental studies exist, made evident the effect of momentum dependence of the potential. It was found that the experimental data can be reproduced either with a local force having a incompressibility module Kâˆž = 380 MeV or with a momentum dependent force of Kâˆž = 228 MeV. To solve this ambiguity, the asymmetric system Ar + Pb at 400 A.MeV was considered. From the dependence of flow parameter on impact parameter one can deduce that only the momentum dependent forces are able to reproduce the experimental data over the entire range of impact parameter while the local forces underestimate systematically the values of the flow parameter. To conclude, a simultaneous study of a symmetric and asymmetrical system shows that only a momentum dependent interaction is able to reproduce the assembly of experimental data related to the nuclear matter flow. From these considerations it results that the incompressibility module is around 230 MeV
Light Asymmetric Dark Matter on the Lattice: SU(2) Technicolor with Two Fundamental Flavors
DEFF Research Database (Denmark)
Lewis, Randy; Pica, Claudio; Sannino, Francesco
2012-01-01
confirm the pattern of chiral symmetry breaking by determining the Goldstone spectrum and therefore show that the dark matter candidate can, de facto, be constituted by a complex Goldstone boson. We also determine the phenomenologically relevant spin one and spin zero isovector spectrum and demonstrate...
Simulations of cold nuclear matter at sub-saturation densities
International Nuclear Information System (INIS)
Ideal nuclear matter is expected to undergo a first order phase transition at the thermodynamic limit. At such phase transitions the size of density fluctuations (bubbles or droplets) scale with the size of the system. This means that simulations of nuclear matter at sub-saturation densities will inexorably suffer from what is vaguely referred to as “finite size effects”. It is usually thought that these finite size effects can be diminished by imposing periodic boundary conditions and making the system large enough, but as we show in this work, that is actually not the case at sub-saturation densities. In this paper we analyze the equilibrium configurations of molecular dynamics simulations of a classical model for symmetric ideal (uncharged) nuclear matter at sub-saturation densities and low temperatures, where phase coexistence is expected at the thermodynamic limit. We show that the most stable configurations in this density range are almost completely determined by artificial aspects of the simulations (i.e. boundary conditions) and can be predicted analytically by surface minimization. This result is very general and is shown to hold true for several well known semi-classical models of nuclear interaction and even for a simple Lennard-Jones potential. Also, in the limit of very large systems, when “small size” effects can be neglected, those equilibrium configurations seem to be restricted to a few structures reminiscent to the “Pasta Phases” expected in Neutron Star matter, but arising from a completely different origin: In Neutron Star matter, the non-homogeneous structures arise from a competition between nuclear and Coulomb interactions while for ideal nuclear matter they emerge from finite (yet not “small”) size effects. The role of periodic boundary conditions and finite size effects in Neutron Star matter simulations are reexamined
Simulations of cold nuclear matter at sub-saturation densities
Energy Technology Data Exchange (ETDEWEB)
Giménez Molinelli, P.A., E-mail: pagm@df.uba.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina); Nichols, J.I. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina); López, J.A. [Department of Physics, University of Texas at El Paso, El Paso, TX 79968 (United States); Dorso, C.O. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina)
2014-03-01
Ideal nuclear matter is expected to undergo a first order phase transition at the thermodynamic limit. At such phase transitions the size of density fluctuations (bubbles or droplets) scale with the size of the system. This means that simulations of nuclear matter at sub-saturation densities will inexorably suffer from what is vaguely referred to as “finite size effects”. It is usually thought that these finite size effects can be diminished by imposing periodic boundary conditions and making the system large enough, but as we show in this work, that is actually not the case at sub-saturation densities. In this paper we analyze the equilibrium configurations of molecular dynamics simulations of a classical model for symmetric ideal (uncharged) nuclear matter at sub-saturation densities and low temperatures, where phase coexistence is expected at the thermodynamic limit. We show that the most stable configurations in this density range are almost completely determined by artificial aspects of the simulations (i.e. boundary conditions) and can be predicted analytically by surface minimization. This result is very general and is shown to hold true for several well known semi-classical models of nuclear interaction and even for a simple Lennard-Jones potential. Also, in the limit of very large systems, when “small size” effects can be neglected, those equilibrium configurations seem to be restricted to a few structures reminiscent to the “Pasta Phases” expected in Neutron Star matter, but arising from a completely different origin: In Neutron Star matter, the non-homogeneous structures arise from a competition between nuclear and Coulomb interactions while for ideal nuclear matter they emerge from finite (yet not “small”) size effects. The role of periodic boundary conditions and finite size effects in Neutron Star matter simulations are reexamined.
Extended Skyrme interactions for nuclear matter, finite nuclei and neutron stars
Zhang, Zhen
2015-01-01
Recent progress in theory, experiment and observation challenges the mean field models using the conventional Skyrme interaction, suggesting that the extension of the conventional Skyrme interaction is necessary. In this work, we construct three Skyrme interaction parameter sets, namely, eMSL07, eMSL08 and eMSL09, based on an extended Skyrme interaction which includes additional momentum and density dependent two-body forces to effectively simulate the momentum dependence of the three-body force. The three new interactions can well reproduce both the ground-state properties and isoscalar giant monopole resonance energy of finite nuclei, nicely conform to the current knowledge on the equation of state of asymmetric nuclear matter around and below saturation density $\\rho_0$, eliminate the notorious unphysical instabilities of symmetric nuclear matter and pure neutron matter at densities up to about $7.5\\rho_0$, and simultaneously support heavier neutron stars with mass larger than two times solar mass. The new...
Dark Matter Particle Spectroscopy at the LHC: Generalizing MT2 to Asymmetric Event Topologies
Konar, Partha; Matchev, Konstantin T; Park, Myeonghun
2009-01-01
We consider SUSY-like missing energy events at hadron colliders and critically examine the common assumption that the missing energy is the result of two identical missing particles. In order to experimentally test this hypothesis, we generalize the subsystem MT2 variable to the case of asymmetric event topologies, where the two SUSY decay chains terminate in different "children" particles. In this more general approach, the endpoint MT2max of the MT2 distribution now gives the mass Mp(Mc(a),Mc(b)) of the parent particle as a function of two input children masses Mc(a) and Mc(b). We propose two methods for an independent determination of the individual children masses Mc(a) and Mc(b). First, in the presence of upstream transverse momentum P(UTM) the corresponding function Mp(Mc(a),Mc(b),P(UTM)) is independent of P(UTM) at precisely the right values of the children masses. Second, the previously discussed MT2 "kink" is now generalized to a "ridge" on the 2-dimensional surface Mp(Mc(a),Mc(b)). As we show in sev...
Pion absorption in excited nuclear matter
International Nuclear Information System (INIS)
The target dependence and azimuthal correlations of protons and plons are investigated for pA reactions at 4.9, 60 and 200 GeV. The experimental observations can be understood qualitatively under the assumption that pions are absorbed in excited target spectator matter. (orig.)
Holographic cold nuclear matter as dilute instanton gas
Ghoroku, Kazuo; Tachibana, Motoi; Taminato, Tomoki; Toyoda, Fumihiko
2012-01-01
We study cold nuclear matter based on the holographic gauge theory, where baryons are introduced as the instantons in the probe D8/$\\bar{\\rm D8}$ branes according to the Sakai-Sugimoto model. Within a dilute gas approximation of instantons, we seek for the stable states via the variational method and fix the instanton size. We find the first order phase transition from the vacuum to the nuclear matter phase as we increase the chemical potential. At the critical chemical potential, we could see a jump of the baryon density from zero to a finite definite value. While the size of the baryon in the nuclear matter is rather small compared to the nucleus near the transition point, where the charge density is also small, it increases with the baryon density. Those behaviors obtained here are discussed by relating to the force between baryons.
Valid QCD sum rules for vector mesons in nuclear matter
Jin, X; Jin, Xuemin; Leinweber, Derek B
1995-01-01
QCD sum rules for vector mesons (rho, omega, phi) in nuclear matter are reexamined with an emphasis on the reliability of various sum rules. Monitoring the continuum contribution and the convergence of the operator product expansion plays a crucial role in determining the validity of a sum rule. The uncertainties arising from less than precise knowledge of the condensate values and other input parameters are analyzed via a Monte-Carlo error analysis. Our analysis leaves no doubt that vector-meson masses decrease with increasing density. This resolves the current debate over the behavior of the vector-meson masses and the sum rules to be used in extracting vector meson properties in nuclear matter. We find a ratio of rho-meson masses of m_{\\rho^*}/m_\\rho = 0.78\\pm0.08 at nuclear matter saturation density.
Nowakowski, Daniel
2016-01-01
We investigate the effects of isospin asymmetry on the competition between color-superconductivity and inhomogeneous chiral symmetry breaking in dense two-flavor quark matter using an extended Nambu--Jona-Lasinio model. We confirm the appearance of a coexistence window where chiral symmetry is inhomogeneously broken and a nonzero spatially homogeneous diquark gap is present, consistently with previous works, and show that such a phase survives at nonzero isospin chemical potentials. We also discuss how the model phase structure becomes modified as large isospin asymmetries are considered.
On the influence of the nuclear medium on the new nuclear matter states
International Nuclear Information System (INIS)
In many nucleus-nucleus collisions at high energies an increase of the particle production below the free nucleon-nucleon threshold has been observed. This increase can be related to the effects of the nuclear medium on the properties of the elementary particles, as well as on the new states of the nuclear matter, as resonance matter, for example. The present work takes into account the previous predictions on the rest mass particle modifications and resonance matter formation to discuss the influences of the nuclear medium on this new nuclear matter state. Experimental results on neutron-proton collisions at momenta between 1.25 GeV/c and 5.1 GeV/c, as well as on nucleus-nucleus collisions at energies between 1 A GeV and 15 A GeV are considered. Nuclear density and temperature determinations mainly at the pion emission, and the effective mass are used to establish the rest mass modification and the resonance weights in the considered collisions. A significant increase of the resonance matter formation is observed in nucleus-nucleus collisions, as compared with nucleon-nucleon collisions, at the same energy. The behaviour of the resonance matter formation in nucleus-nucleus collisions is also discussed. A like-saturation behaviour with energy increase can be considered. The major conclusion is that the nuclear medium has an important influence on the new states of nuclear matter. (authors)
Condensates and correlations in nuclear matter
Directory of Open Access Journals (Sweden)
Röpke G.
2010-10-01
Full Text Available Nuclei in dense matter are in?uenced by the medium. Solving an A-particle Schroedinger equation including the e?ects of self-energy and Pauli blocking, a quasiparticle description is introduced. Deriving thermodynamic properties, this approach contains the NSE at low densities as well as mean-?eld approaches at high densities. Consequences for the symmetry energy, the phase transition, the determination of thermodynamic parameters from cluster yields and astrophysical applications are discussed.
Energy-range relations for hadrons in nuclear matter
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.
Lectures notes on phase transformations in nuclear matter
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
The ?? cloud contribution to the ? width in nuclear matter
Cabrera, D.Institute for Theoretical Physics, Frankfurt University, 60438 Frankfurt am Main, Germany; Rapp, R.
2014-01-01
The width of the ? meson in cold nuclear matter is computed in a hadronic many-body approach, focusing on a detailed treatment of the medium modifications of intermediate ?? states. The ? and ? propagators are dressed by their self-energies in nuclear matter taken from previously constrained many-body calculations. The pion self-energy includes Nh and ?h excitations with short-range correlations, while the ? self-energy incorporates the same dressing of its 2? cloud with a full 3-momentum dep...
Consistent treatment of isobar degrees of freedom in nuclear matter
International Nuclear Information System (INIS)
It is argued that the present situation in nuclear matter requires an explicit description of the 2? exchange contribution to the NN interaction providing the intermediate-range attraction. Especially, a realistic treatment of isobar degrees of freedom is strongly suggested. A suitable scheme is described, which starts from a field-theoretic Hamiltonian and uses old-fashioned perturbation theory consistently in the two- and the many-body problem. Numerical results (for NN scattering data and nuclear matter binding) emerging from such an approach are briefly outlined. (Auth.)
Thermal properties of nuclear matter under the periodic boundary condition
Energy Technology Data Exchange (ETDEWEB)
Otuka, Naohiko; Ohnishi, Akira [Division of Physics, Graduate School of Science, Hokkaido Univ., Sapporo, Hokkaido (Japan)
1999-08-01
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 {rho}{sub b} = 0.77 fm{sup 3} at some energy densities. Time evolution of particle abundance and temperature are shown. (author)
Nuclear physics: the core of matter, the fuel of stars
International Nuclear Information System (INIS)
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 quantitatively the properties of nuclei, which are at the centers of all atoms in our world, in terms of models derived from the properties of the strong interaction. These properties include the nuclear processes that fuel the stars and produce the chemical elements. A third active frontier addresses fundamental symmetries of nature that manifest themselves in the nuclear processes in the cosmos, such as the behavior of neutrinos from the Sun and cosmic rays, and in low-energy laboratory tests of these symmetries. With recent developments on the rapidly changing frontiers of nuclear physics the Committee on Nuclear Physics is greatly optimistic about the next ten years. Important steps have been taken in a program to understand the structure of matter in terms of quarks and gluons
The modification of the scalar field in dense nuclear matter
International Nuclear Information System (INIS)
We show the possible evolution of the nuclear deep inelastic structure function with nuclear density ?. The nucleon deep inelastic structure function represents distribution of quarks as a function of Bjorken variable x, which measures the longitudinal fraction of the momentum carried by them during deep inelastic scattering (DIS) of electrons on nuclear targets. The quark localization is proportional to 1/x and this relation introduces the dependence of the nucleon structure function on the nuclear medium. Starting with small density and negative pressure in nuclear matter (NM), we have relatively large inter-nucleon distances and increasing role of nuclear interaction mediated by virtual mesons. When the density approaches the saturation point, ? = ?0, we have no longer separate mesons and nucleons but eventually modified nucleon structure function (SF) in the medium. The ratio of the nuclear to the nucleon SF measured at the saturation point is well known as the "EMC effect". For larger density, ? > ?0, when the localization of quarks is smaller than 0.3 fm, the nucleons overlap. We argue that nucleon mass should start to decrease in order to satisfy the momentum sum rule (MSR) of DIS. These modifications of the nucleon structure function are calculated in the frame of the nuclear relativistic mean field (RMF) convolution model. The correction to the Fermi energy from a term proportional to the pressure is very important and its inclusion modifies the equation of state (EoS) for the nuclear matter. (author)
Experimental signals of the first phase transition of nuclear matter
International Nuclear Information System (INIS)
Vaporized and multi-fragmenting sources produced in heavy ion collisions at intermediate energies are good candidates to investigate the phase diagram of nuclear matter. The properties of highly excited nuclear sources which undergo a simultaneous disassembly into particles are found to sign the presence of a gas phase. For heavy nuclear sources produced in the Fermi energy domain, which undergo a simultaneous disassembly into particles and fragments, a fossil signal (fragment size correlations) reveals the origin of multifragmentation: spinodal instabilities which develop in the unstable coexistence region of the phase diagram of nuclear matter. Studies of fluctuations give a direct signature of a first order phase transition through measurements of a negative microcanonical heat capacity. (author)
Supernovae and high density nuclear matter
International Nuclear Information System (INIS)
The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs
Supernovae and high density nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Kahana, S.
1986-01-01
The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs.
Final state interactions and hadron quenching in cold nuclear matter
Accardi, Alberto
2007-01-01
I examine the role of final state interactions in cold nuclear matter in modifying hadron production on nuclear targets with leptonic or hadronic beams. I demonstrate the extent to which available experimental data in electron-nucleus collisions can give direct information on final state effects in hadron-nucleus and nucleus-nucleus collisions. For hadron-nucleus collisions, a theoretical estimate based on a parton energy loss model tested in lepton-nucleus collisions shows ...
Exponential enhancement of nuclear reactions in condensed matter environment
Kuchiev, M . Yu.; Altshuler, B.L.; Flambaum., V. V.
2003-01-01
A mechanism that uses the environment to enhance the probability of the nuclear reaction when a beam of accelerated nuclei collides with a target nucleus implanted in condensed matter is suggested. The effect considered is exponentially large for low collision energies. For t + p collision the mechanism becomes effective when the energy of the projectile tritium is below $\\sim$ 1 Kev per nucleon. The gain in probability of the nuclear reaction is due to a redistribution of energy and momentum...
Asymmetric Arginine dimethylation of Epstein-Barr virus nuclear antigen 2 promotes DNA targeting
International Nuclear Information System (INIS)
The Epstein-Barr virus (EBV) growth-transforms B-lymphocytes. The virus-encoded nuclear antigen 2 (EBNA2) is essential for transformation and activates gene expression by association with DNA-bound transcription factors such as RBPJ? (CSL/CBF1). We have previously shown that EBNA2 contains symmetrically dimethylated Arginine (sDMA) residues. Deletion of the RG-repeat results in a reduced ability of the virus to immortalise B-cells. We now show that the RG repeat also contains asymmetrically dimethylated Arginines (aDMA) but neither non-methylated (NMA) Arginines nor citrulline residues. We demonstrate that only aDMA-containing EBNA2 is found in a complex with DNA-bound RBPJ? in vitro and preferentially associates with the EBNA2-responsive EBV C, LMP1 and LMP2A promoters in vivo. Inhibition of methylation in EBV-infected cells results in reduced expression of the EBNA2-regulated viral gene LMP1, providing additional evidence that methylation is a prerequisite for DNA-binding by EBNA2 via association with the transcription factor RBPJ?.
The Modification of the Scalar Field in dense Nuclear Matter
Directory of Open Access Journals (Sweden)
RoÅ¼ynek J.
2011-04-01
Full Text Available We show the possible evolution of the nuclear deep inelastic structure function with nuclear density Ï. The nucleon deep inelastic structure function represents distribution of quarks as function of BjÃ¶rken variable x which measures the longitudinal fraction of momentum carried by them during the Deep Inelastic Scattering (DIS of electrons on nuclear targets. Starting with small density and negative pressure in Nuclear Matter (NM we have relatively large inter-nucleon distances and increasing role of nuclear interaction mediated by virtual mesons.When the density approaches the saturation point, Ï = Ï0, we have no longer separate mesons and nucleons but eventually modified nucleon Structure Function (SF in medium. The ratio of nuclear to nucleon SF measured at saturation point is well known as â€œEMC effectâ€. For larger density, Ï > Ï0, when the localization of quarks is smaller then 0.3 fm, the nucleons overlap. We argue that nucleon mass should start to decrease in order to satisfy the Momentum Sum Rule (MSR of DIS. These modifications of the nucleon Structure Function (SF are calculated in the frame of the nuclear Relativistic Mean Field (RMF convolution model. The correction to the Fermi energy from term proportional to the pressure is very important and its inclusion modifies the Equation of State (EoS for nuclear matter.
From atomic helium to nuclear matter
Fantoni, S; Schmidt, K E
1999-01-01
Differences between the quasiparticle and the bare particle, as constituents of Fermi systems, mainly result from the effects of correlations. Comparative studies performed in liquid helium and indicating interesting similarities in the single particle properties of Bose and Fermi liquids will be discussed, also in connection with the theoretical and experimental quasihole strength in nuclei. A new Quantum Monte Carlo method for nuclear systems is also outlined.
Nuclear matter from chiral low-momentum interactions
Bogner, S K; Nogga, A; Schwenk, A
2009-01-01
Nuclear matter calculations based on low-momentum interactions derived from chiral nucleon-nucleon and three-nucleon effective field theory interactions and fit only to few-body data predict realistic saturation properties with controlled uncertainties. This is promising for a unified description of nuclei and to develop a universal density functional based on low-momentum interactions.
Radiative energy loss of jets in hot / cold nuclear matter
International Nuclear Information System (INIS)
The radiative energy loss encountered by a high energy quark or gluon propagating in a nuclear medium is estimated. Under reasonable assumptions it is found to be larger by at least an order of magnitude in hot compared to cold matter. (author)
Cluster formation and the nuclear matter equation of state
International Nuclear Information System (INIS)
Bound state formation is considered in nuclear matter within the frame of many-particle theory. Medium effects such as self-energy and Pauli blocking will modify the single-particle properties as well as the cluster properties. Consequences for the composition, the formation of quantum condensates and the symmetry energy are given. (author)
The coexistence curve of finite charged nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Elliott, J.B.; Moretto, L.G.; Phair, L.; Wozniak, G.J.; Beaulieu, L.; Breuer, H.; Korteling, R.G.; Kwiatkowski, K.; Lefort, T.; Pienkowski, L.; Ruangma, A.; Viola, V.E.; Yennello, S.J.; Albergo, S.; Bieser, F.; Brady, F.P.; Caccia, Z.; Cebra, D.A.; Chacon, A.D.; Chance, J.L.; Choi, Y.; Costa, S.; Gilkes, M.L.; Hauger, J.A.; Hirsch, A.S.; Hjort, E.L.; Insolia, A.; Justice, M.; Keane, D.; Kintner, J.C.; Lindenstruth, V.; Lisa, M.A.; Matis, H.S.; McMahan, M.; McParland, C.; Muller, W.F.J.; Olson, D.L.; Partlan, M.D.; Porile, N.T.; Potenza, R.; Rai, G.; Rasmussen, J.; Ritter, H.G.; Romanski, J.; Romero, J.L.; Russo, G.V.; Sann, H.; Scharenberg, R.P.; Scott, A.; Shao, Y.; Srivastava, B.K.; Symons, T.J.M.; Tincknell, M.; Tuve, C.; Wang , S.; Warren, P.; Wieman, H.H.; Wienold, T.; Wolf, K.
2001-01-01
The multifragmentation data of the ISiS Collaboration and the EOS Collaboration are examined. Fisher's droplet formalism, modified to account for Coulomb energy, is used to determine the critical exponents {tau} and {sigma}, the surface energy coefficient c{sub 0}, the pressure-temperature-density coexistence curve of finite nuclear matter and the location of the critical point.
The coexistence curve of finite charged nuclear matter
International Nuclear Information System (INIS)
The multifragmentation data of the ISiS Collaboration and the EOS Collaboration are examined. Fisher's droplet formalism, modified to account for Coulomb energy, is used to determine the critical exponents ? and ?, the surface energy coefficient c0, the pressure-temperature-density coexistence curve of finite nuclear matter and the location of the critical point
Thermodynamic properties of nuclear matter at finite temperature
Soma, V.; Bozek, P.
2006-01-01
A self-consistent approach based on finite temperature Green's functions is used to investigate thermodynamic properties of nuclear matter. The internal energy is derived from the diagrams associated to the interaction energy. Pressure and entropy up to T=20 MeV are obtained from the generating functional form of the thermodynamic potential.
Condensed matter nuclear reactions with metal particles in gases
International Nuclear Information System (INIS)
Various metals have been used by a number of researchers to study the condensed matter nuclear reactions occurring within the metal lattice when exposed to gases containing hydrogen, its deuterium isotope and various mixes. This article will give a brief overview of such studies. (author)
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)
Stieltjes, Frederik Bernd Laun Wolfhard Semmler Bram
2010-01-01
Temporally asymmetric gradient profiles in nuclear magnetic resonance diffusion experiments are investigated using modified Stejskal-Tanner gradients. Three novel findings are presented. 1. The phase of the diffusion-weighted signal contains information about the confining geometry. This information can be extracted from the 'diffusion-weighted phase'. 2. In the motional narrowing regime, it is possible to exactly determine the confining boundary in closed domains. 3. Diffusion-weighting gradients can act like imaging gradients.
Relativistic Mean-Field Models and Nuclear Matter Constraints
Dutra, M; Carlson, B V; Delfino, A; Menezes, D P; Avancini, S S; Stone, J R; Providência, C; Typel, S
2013-01-01
This work presents a preliminary study of 147 relativistic mean-field (RMF) hadronic models used in the literature, regarding their behavior in the nuclear matter regime. We analyze here different kinds of such models, namely: (i) linear models, (ii) nonlinear \\sigma^3+\\sigma^4 models, (iii) \\sigma^3+\\sigma^4+\\omega^4 models, (iv) models containing mixing terms in the fields \\sigma and \\omega, (v) density dependent models, and (vi) point-coupling ones. In the finite range models, the attractive (repulsive) interaction is described in the Lagrangian density by the \\sigma (\\omega) field. The isospin dependence of the interaction is modeled by the \\rho meson field. We submit these sets of RMF models to eleven macroscopic (experimental and empirical) constraints, used in a recent study in which 240 Skyrme parametrizations were analyzed. Such constraints cover a wide range of properties related to symmetric nuclear matter (SNM), pure neutron matter (PNM), and both SNM and PNM.
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
Jacobs, Peter; 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 sqrt{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 the early onset of thermalization and ideal hydrodynamic expansion, with a Quark-Gluon Plasma equation of state.
Matter in extremis: ultrarelativistic nuclear collisions at RHIC
Jacobs, Peter; Wang, Xin-Nian
2005-04-01
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.
Matter in extremis: Ultrarelativistic nuclear collisions at RHIC
International Nuclear Information System (INIS)
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
Pairing in bulk nuclear matter beyond BCS
Ding, D; Dickhoff, W H; Dussan, H; Rios, A; Polls, A
2014-01-01
The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the ${}^3P_2-{}^3F_2$ coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the ${}^3P_2-{}^3F_2$ coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive.
Nuclear condensation and symmetry energy of dilute nuclear matter: an S-matrix approach
J.N.; Samaddar, S. K.
2008-01-01
Based on the general analysis of the grand canonical partition function in the S-matrix framework, the calculated results on symmetry energy, free energy and entropy of dilute warm nuclear matter are presented. At a given temperature and density, the symmetry energy or symmetry free energy of the clusterized nuclear matter in the S-matrix formulation deviates, particularly at low temperature and relatively higher density, in a subtle way, from the linear dependence on the sq...
$D_S$ Mesons in Asymmetric Hot and Dense Hadronic Matter
Pathak, Divakar
2014-01-01
The in-medium properties of $D_S$ mesons are investigated within the framework of a chiral effective model. These are observed to experience net attractive interactions in a dense hadronic medium, hence reducing the masses of the $D_S^+$ and $D_S^-$ mesons from the vacuum values. While this conclusion holds in both nuclear and hyperonic media, the magnitude of the mass drop is observed to intensify with the inclusion of strangeness in the medium. Additionally, in hyperonic medium, the mass degeneracy of the $D_S$ mesons is observed to be broken, due to opposite signs of the Weinberg-Tomozawa interaction term in the Lagrangian density. Along with the magnitude of the mass drops, the mass splitting between $D_S^+$ and $D_S^-$ mesons is also observed to grow with an increase in baryonic density and strangeness content of the medium. However, all medium effects analyzed are found to be weakly dependent on isospin asymmetry and temperature. We discuss the possible implications emanating from this analysis, which a...
International Nuclear Information System (INIS)
The properties of nuclear matter and nuclear scattering reactions were studied from the same effective nucleon-nucleon interactions. In this project, we used CDM3Y and M3Y-Pn interaction version as the input to build the nuclear interaction potential (nuclear optical potential). After that, nuclear scattering reactions were studied by coupled channel formalism and folding model for scattering potential. The theoretical calculated cross sections of (alpha, nucleus) and (nucleon, nucleus) scattering system have been compared with the experimental values. Using the above interactions, the properties of nuclear matter: (i) biding energy, (ii) pressure and (iii) Compressibility were deduced in the Hartree-Fock calculation frame work. From the consistence between theory and experiment, the information of nuclear structure has been extracted. (author)
Pairing in bulk nuclear matter beyond BCS
Energy Technology Data Exchange (ETDEWEB)
Ding, D.; Dickhoff, W. H.; Dussan, H. [Department of Physics, Washington University, St. Louis, Missouri 63130 (United States); Witte, S. J. [Department of Physics, Washington University, St. Louis, Missouri 63130, USA and Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Rios, A. [Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Polls, A. [Departament d' Estructura i Constituents de la Matèria, Universitat de Barcelona, E-08028 Barcelona (Spain)
2014-10-15
The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the {sup 3}P{sub 2}?{sup 3}F{sub 2} coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the {sup 3}P{sub 2}?{sup 3}F{sub 2} coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive.
Nonlinear mean field theory for nuclear matter and surface properties
International Nuclear Information System (INIS)
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 F0 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.)
Enhancement of nuclear reactions in matter
International Nuclear Information System (INIS)
Full text: We analyze enhancement of the nuclear fusion initiated by low-energy projectile deuterons, though we do not aim at interpreting particular experiments reported previously. The nuclear fusion processes at low energies are exponentially suppressed due to the Coulomb repulsion. We consider several factors which can enhance the fusion. The most powerful among them is the 'carambole' mechanism of enhancement. It needs that a projectile deuteron and a target deuteron undergo a chain of preliminary elastic collisions between themselves and nuclei of Environment. These collisions effectively convert the fixed-target process into a fusion reaction with colliding beams. This reduces the exponent of the factor that describes penetration through the Coulomb barrier by a factor 21/2, thus drastically, by many orders of magnitude (1011,) increasing the probability. We also calculate increase of the fusion probability given by two other mechanisms by the motion of a bound target deuteron in a solid and by stimulation of this motion by the Coulomb field of a projectile. The later effect we call the 'ping-pong' mechanism. The factor which gives increase for the fusion probability for the three considered mechanisms is illustrated. For low energies the 'carambole' mechanism dominates, producing very strong effect. We expect it to be most efficient in compounds with target deuterons localized in the vicinity of heavy atoms. The electric fields in non-equilibrium processes (like chemical reactions, where cracks in solids or cavities in liquids) or in ferroelectric materials may accelerate deuterons creating the beam-like situation. The beam-like problem may also arise in laser-induced fusion where ions are accelerated due to the laser field and the interaction with electrons
Phase transitions in high excited nuclear matter
International Nuclear Information System (INIS)
This work is a study of the mechanism of thermal multifragmentation, which takes place in collisions of light relativistic projectiles with heavy targets. This is a new multibody decay process of very hot nuclei (target spectator) with emission of a number of intermediate mass fragments (IMF, 2 4He and 12C with Au. The main results are the following: - The mean IMF multiplicity () saturates at 2.2 ± 0.2.This fact cannot be rendered by the traditional approach with the intranuclear cascade (INC) followed by Statistical Multifragmentation Models (SMM). Considering the expansion phase between two parts of the calculations, the excitation energies and the residual masses are empirically modified to obtain agreement with the measured IMF- multiplicities. The mean excitation energy is found to be around 500 MeV for the beam energies above 5 GeV. This modified model is denoted as INC + ? + SMM where ? indicates the preequilibrium processes. - The expansion is driven by the thermal pressure. It is larger for 4He and 12C induced collisions because of higher initial temperature. The kinetic energy spectra of IMF become harder and the expansion flow is visible. The total flow energy of the system is estimated to be around 115 MeV both for the He and the carbon beams. - The analysis of the data reveals very interesting information on the fragment space distribution inside the break-up volume. Heavier IMF are formed predominately in the interior of the fragmenting nucleus possibly due to a density gradient. This conclusion is in contrast to the predictions of the Statistical Multifragmentation Model (SMM). - This study of the multifragmentation using a range of projectiles demonstrates a transition from pure '' thermal decay '' (for p + Au collisions) to disintegration '' completed by '' the onset of a collective flow for the heavier projectiles. Nevertheless, in case of reaction caused by fast protons the decay mechanism should be considered as a thermal multifragmentation. - The time scale of the thermal multifragmentation in p + Au collision at 8.1 GeV has been measured for the first time (by the analysis of IMF-IMF angular correlations). The mean decay time of the fragmenting system was found to be ? = (50 ± 18) fm/c in accordance with the scenario of a '' simultaneous '' multibody decay of a hot and expanded nuclear system. The measured time-scale is close to that for the density fluctuation in the diluted nuclear system. Hence, the thermal multifragmentation can be interpreted as the first order nuclear liquid-fog phase transition in the spinodal region. - Characteristic temperature Tf is less than Tc - critical temperature for the liquid-gas phase transition. Tc -critical temperature for the liquid-gas phase transition is found to be (17 ± 2) MeV, which is significantly larger than the temperature of fragmenting system (5 - 6 MeV). This is a very important observation in favour of the mechanism of spinodal disintegration. - It is concluded that the decay process of hot nuclei is characterized by two size parameters: transition state and freeze-out volumes. The IMF emission time is related to the mean rupture time at the multi-scission point, which corresponds to the kinetic freeze-out configuration. (author)
Matter in extremis: ultrarelativistic nuclear collisions at RHIC
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 $\\sqrt{s}=200$ GeV. Jet quenching and global measurements show that the initial energy density of the str...
Initial-state splitting kernels in cold nuclear matter
Ovanesyan, Grigory; Vitev, Ivan
2015-01-01
We derive medium-induced splitting kernels for energetic partons that undergo interactions in dense QCD matter before a hard-scattering event at large momentum transfer $Q^2$. Working in the framework of the effective theory ${\\rm SCET}_{\\rm G}\\,$, we compute the splitting kernels beyond the soft gluon approximation. We present numerical studies that compare our new results with previous findings. We expect the full medium-induced splitting kernels to be most relevant for the extension of initial-state cold nuclear matter energy loss phenomenology in both p+A and A+A collisions.
Rates for inelastic nuclear excitation by dark matter particles
International Nuclear Information System (INIS)
We calculate rates for the inelastic scattering of dark matter particles X on nuclei to produce low-lying excited nuclear states. Assuming a maxwellian velocity distribution for the dark matter particles X, the inelastic two-body phase space suppresses all rates by factors > 10 for mX ? 100 GeV unless the excitation energy ?E-4 events/kg.day, with the least unfavourable rates being for 69169Tm and 75187Os. Problems of natural radioactivity and expense disfavour these and many other materials, leaving 53127I, 74183W and 80201Hg as the least unpromising isotopes. (orig.)
Open charm tomography of cold nuclear matter
Vitev, I; Johnson, M B; Qiu, J W
2006-01-01
We study the relative contribution of partonic sub-processes to D meson production and D meson-triggered inclusive di-hadrons to lowest order in perturbative QCD. While gluon fusion dominates the creation of large angle DD-bar pairs, charm on light parton scattering determines the yield of single inclusive D mesons. The distinctly different non-perturbative fragmentation of c quarks into D mesons versus the fragmentation of quarks and gluons into light hadrons results in a strong transverse momentum dependence of anticharm content of the away-side charm-triggered jet. In p+A reactions, we calculate and resum the coherent nuclear-enhanced power corrections from the final state partonic scattering in the medium. We find that single and double inclusive open charm production can be suppressed as much as the yield of neutral pions from dynamical high-twist shadowing. Effects of energy loss in p+A collisions are also investigated phenomenologically and may lead to significantly weaker transverse momentum dependenc...
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
Energy Technology Data Exchange (ETDEWEB)
Robert J. Goldston
2010-03-03
Integrated energy, environment and economics modeling suggests electrical energy use will increase from 2.4 TWe today to 12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources. Thus nuclear power may be needed to provide ~30% by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century proliferation risks are much greater, and more resistant to mitigation. The risks of nuclear power should be compared with the risks of the estimated 0.64oC long-term global surface-average temperature rise predicted if nuclear power were replaced with coal-fired power plants without carbon sequestration. Fusion energy, if developed, would provide a source of nuclear power with much lower proliferation risks than fission.
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
International Nuclear Information System (INIS)
Integrated energy, environment and economics modeling suggests electrical energy use will increase from 2.4 TWe today to 12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources. Thus nuclear power may be needed to provide ?30% by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century proliferation risks are much greater, and more resistant to mitigation. The risks of nuclear power should be compared with the risks of the estimated 0.64 C long-term global surface-average temperature rise predicted if nuclear power were replaced with coal-fired power plants without carbon sequestration. Fusion energy, if developed, would provide a source of nuclear power with much lower proliferation risks than fission.
Nuclear matter descriptions including quark structure of the hadrons
International Nuclear Information System (INIS)
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)
Review of the theory of infinite nuclear matter
International Nuclear Information System (INIS)
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
A Modified Pion-Rho-Omega Mesonic Lagrangian in Nuclear Matter
International Nuclear Information System (INIS)
We present an in-medium modified effective Lagrangian which describes the pion, rho- and omega mesons and the corresponding soliton properties in nuclear matter. We discuss possible modifications of ?- and ?-meson properties in nuclear matter. In particular, the masses of vector mesons are shown to decrease about 30% at normal nuclear matter density within the present approach. (author)
Nuclear equation of state in the MIT bag crystal model for nuclear matter
International Nuclear Information System (INIS)
We developed the MIT bag crystal model for nuclear matter in two aspects. First, we proved a ??=4 selection rule in the harmonic expansion of quark wave function by group theory. It enables us to push the maximum Dirac quantum number ?m up from 7 to 15, therefore improving our calculation for the energy band and wave functions of quarks. Then, by a multipole expansion of the color fields we calculate the color interaction energy between quarks. These developments enable us to calculate the energy per nucleon in nuclear matter as done previously for a free nucleon. A nuclear equation of state is derived
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
Energy Technology Data Exchange (ETDEWEB)
Robert J. Goldston
2011-04-28
Integrated energy, environment and economics modeling suggests that worldwide electrical energy use will increase from 2.4 TWe today to ~12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources derived from natural energy flows. Thus nuclear power may be needed to provide ~30%, 3600 GWe, by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century global nuclear proliferation risks are much greater, and more resistant to mitigation. Fusion energy, if successfully demonstrated to be economically competitive, would provide a source of nuclear power with much lower proliferation risks than fission.
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
International Nuclear Information System (INIS)
Integrated energy, environment and economics modeling suggests that worldwide electrical energy use will increase from 2.4 TWe today to âˆ¼12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources derived from natural energy flows. Thus nuclear power may be needed to provide âˆ¼30%, 3600 GWe, by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century global nuclear proliferation risks are much greater, and more resistant to mitigation. Fusion energy, if successfully demonstrated to be economically competitive, would provide a source of nuclear power with much lower proliferation risks than fission.
Phase transitions in a saturating chiral theory of nuclear matter
International Nuclear Information System (INIS)
The formalism of a relativistically covariant saturating chiral field theory of nuclear matter is developed in the mean approximation, and some of the properties are studied. The theory possesses the normal saturated state of nuclear matter. The finite temperature properties are examined. A normal gas-liquid phase equilibrium region exists below T roughly-equal 23 MeV. The maximum mass for a neutron star is calculated, and it lies well above the lower bound set by observation. In the high-temperature regime, there is a second minimum in the free energy, on which branch the effective baryon mass is very small. However, this branch is everywhere mechanically unstable, and so is not a realizable state of the theory. Above a certain critical temperature there is in fact no stable state at low baryon density. There is no density or temperature regime where chiral symmetry is restored
Pure Neutron Matter Constraints and Nuclear Symmetry Energy
International Nuclear Information System (INIS)
In this review, we will discuss the results of our recent work [1] to study the general optimization of the pure isovector parameters of the popular relativistic mean-field (RMF) and Skyrme-Hartree-Fock (SHF) nuclear energy-density functionals (EDFs), using constraints on the pure neutron matter (PNM) equation of state (EoS) from recent ab initio calculations. By using RMF and SHF parameterizations that give equivalent predictions for ground-state properties of doubly magic nuclei and properties of symmetric nuclear matter (SNM) and PNM, we found that such optimization leads to broadly consistent symmetry energy J and its slope parameter L at saturation density within a tight range of ?(J) sym, (b) the symmetry energy at supra-saturation densities, and (c) the radius of neutron stars.
Strangeness in nuclear matter at DA?NE
International Nuclear Information System (INIS)
The low energy kaons from the ? meson produced at DA?NE offer a unique opportunity to study strangeness in nuclear matter. The interaction of kaons with hadronic matter can be investigated at DA?NE 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 DA?NE are FINUDA and DEAR. The physics topics of both experiments are illustrated together with a detailed descriptions of the two detectors
Strangeness in nuclear matter at DA{Phi}NE
Energy Technology Data Exchange (ETDEWEB)
Gianotti, P. [INFN, Laboratori Nazionali di Frascati, Rome (Italy)
1998-01-01
The low energy kaons from the {phi} meson produced at DA{Phi}NE offer a unique opportunity to study strangeness in nuclear matter. The interaction of kaons with hadronic matter can be investigated at DA{Phi}NE 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 DA{Phi}NE are FINUDA and DEAR. The physics topics of both experiments are illustrated together with a detailed descriptions of the two detectors.
Relativistic nuclear matter with alternative derivative coupling models
International Nuclear Information System (INIS)
Effective Lagrangians involving nucleons coupled to scalar and vector fields are investigated within the framework of relativistic mean-field theory. The study presents the traditional Walecka model and different kinds of scalar derivative coupling suggested by Zimanyi and Moszkowski. The incompressibility (presented in an analytical form), scalar potential, and vector potential at the saturation point of nuclear matter are compared for these models. The real optical potential for the models are calculated and one of the models fits well the experimental curve from-50 to 400 MeV while also gives a soft equation of state. By varying the coupling constants and keeping the saturation point of nuclear matter approximately fixed, only the Walecka model presents a first order phase transition of finite temperature at zero density. (author)
The Coester line in relativistic mean field nuclear matter
Scientific Electronic Library Online (English)
A., Delfino; M., Malheiro; V. S., Timóteo; J. S. Sá, Martins.
2005-03-01
Full Text Available The Walecka model contains essentially two parameters that are associated with the Lorentz scalar (S) and vector (V) interactions. These parameters are related to a two-body interaction consisting of S and V, imposing the condition that the two-body binding energy is fixed. We have obtained a set of [...] different values for the nuclear matter binding energies (B N) at equilibrium densities (rhoo). We investigated the existence of a linear correlation between B N and rhoo, claimed to be universal for nonrelativistic systems and usually known as the Coester line, and found an approximate linear correlation only if V - S remains constant. It is shown that the relativistic content of the model, which is related to the strength of V - S, is responsible for the shift of the Coester line to the empirical region of nuclear matter saturation.
Chiral symmetry and nuclear matter equation of state
Indian Academy of Sciences (India)
A B Santra
2001-08-01
We investigate the effect on the nuclear matter equation of state (EOS) due to modi?cation of meson and nucleon parameters in nuclear medium as a consequence of partial restoration of chiral symmetry. To get the EOS, we have used Brueckner–Bethe–Golstone formalism with Bonn- potential as two-body interaction and QCD sum rule and Brown–Rho scaling prescriptions for modi?cation of hadron parameters. We ?nd that EOS is very much sensitive to the meson parameters. We can ?t, with two body interaction alone, both the saturation density and the binding energy per nucleon.
Collective motion in nuclear matter at low and high energies
International Nuclear Information System (INIS)
A comparison of kinematic characteristics of the collective motions in nuclear matter at low and high energies has been performed. The experimental data used in analysis are comprised of the nuclear fission at low energies and the deep spallation of heavy nuclei induced by relativistic particles at high energies. The connection between the collective processes at low and high energies is dicussed. It is shown that final result of the collective intranuclear motion for both cases consists in forming of stable or unstable massive fragments. The existence of the latter is confirmed by the results of independent experimental investigations
Quark mean field theory and consistency with nuclear matter
International Nuclear Information System (INIS)
1/Nc expansion in QCD (with Nc the number of colours) suggests using a potential from meson sector (e.g. Richardson) for baryons. For light quarks a ? field has to be introduced to ensure chiral symmetry breaking (?SB). It is found that nuclear matter properties can be used to pin down the ?SB-modelling. All masses, M?, m?, m? are found to scale with density. The equations are solved self consistently. (author)
Pairing effects in low density domain of nuclear matter
Isayev, A. A.; Bastrukov, S. I.; Yang, J.
2004-01-01
Using equations, governing np pairing correlations in S=1, T=0 pairing channel (PRC 63 (2001) 021304(R)), it is shown that at low densities equations for the energy gap in the spectrum of quasiparticles and chemical potentials of protons and neutrons allow solutions with negative chemical potential. This corresponds to appearance of Bose--Einstein condensate (BEC) of deuterons in low density region of nuclear matter.
Competition of ferromagnetic and antiferromagnetic spin ordering in nuclear matter
Isayev, A. A.
2003-01-01
In the framework of a Fermi liquid theory it is considered the possibility of ferromagnetic and antiferromagnetic phase transitions in symmetric nuclear matter with Skyrme effective interaction. The zero temperature dependence of ferromagnetic and antiferromagnetic spin polarization parameters as functions of density is found for SkM$^*$, SGII effective forces. It is shown that in the density domain, where both type of solutions of self--consistent equations exist, ferromagn...
Heating of nuclear matter and multifragmentation: antiprotons vs. pions
International Nuclear Information System (INIS)
Heating of nuclear matter with 8 GeV/c bar p and ?- beams has been investigated in an experiment conducted at BNL AGS accelerator. All charged particles from protons to Z ? 16 were detected using the Indiana Silicon Sphere 4? array. Significant enhancement of energy deposition in high multiplicity events is observed for antiprotons compared to other hadron beams. The experimental trends are qualitatively consistent with predictions from an intranuclear cascade code
Heating of nuclear matter and multifragmentation : antiprotons vs. pions.
Energy Technology Data Exchange (ETDEWEB)
Back, B.; Beaulieu, L.; Breuer, H.; Gushue, S.; Hsi, W.-C.; Korteling, R. G.; Kwiatkowski, K.; Laforest, R.; Lefort, T.; Martin, E.; Pienkowski, L.; Ramakrishnan, E.; Remsberg, L. P.; Rowland, D.; Ruangma, A.; Viola, V. E.; Winchester, E.; Yennello, S. J.
1999-05-03
Heating of nuclear matter with 8 GeV/c {bar p} and {pi}{sup {minus}} beams has been investigated in an experiment conducted at BNL AGS accelerator. All charged particles from protons to Z {approx_equal} 16 were detected using the Indiana Silicon Sphere 4{pi} array. Significant enhancement of energy deposition in high multiplicity events is observed for antiprotons compared to other hadron beams. The experimental trends are qualitatively consistent with predictions from an intranuclear cascade code.
Probing the nuclear matter at the CERN super proton synchrotron
International Nuclear Information System (INIS)
Full text : A survey is given of signals probing the phase structure of nuclear matter created in the interactions of heavy atomic nuclei. The structures in the excitation functions of inclusive observables in 208Pb+208Pb collisions, measured by the NA49 experiment, are discussed. Seen in this light, the necessity for the differential study of event-by-event fluctuations in two dimensions is introduced. In this context, the dedicated program of the NA61/Shine experiment is discussed
Properties of the ? meson in dense nuclear matter
International Nuclear Information System (INIS)
In order to reach a description of the ? 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 ? meson in the vacuum is developed. Thereafter follows the calculation of the properties of the ? meson in nuclear matter. First the connection between the spectral function of the ? 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 ? meson in nuclear matter following from this description is formally derived from the requirement to couple the ? 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 ? 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)
High-density nuclear matter with nonlocal confining solitons
Johnson, C W; Johnson, Charles W.; Fai, George
1997-01-01
An infinite system of nonlocal, individually confining solitons is considered as a model of high-density nuclear matter. The soliton-lattice problem is discussed in the Wigner-Seitz approximation. The cell size is varied to study the density dependence of physical quantities of interest. A transition to a system where quarks can migrate between solitons is found. We argue that this signals quark deconfinement. The model is applied to the calculation of selected in-medium properties.
Investigation of the organic matter in inactive nuclear tank liquids
International Nuclear Information System (INIS)
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- and four-body correlations in nuclear matter
International Nuclear Information System (INIS)
Few-nucleon correlations in nuclear matter at finite densities and temperatures are explored. Using the Dyson-equation approach leads to effective few-body equations that include self-energy corrections and Pauli blocking factors in a systematic way. Examples given are the nucleon-deuteron in-medium reaction rates, few-body bound states including the Î±-particle, and Î±-particle condensation. Refs. 17 (author)
Coexisting single particle solutions in low density symmetric nuclear matter
International Nuclear Information System (INIS)
The only two nucleon bound state system occurring in free space is the deuteron, constituted by a proton neutron pair. Although the neutron neutron interaction is attractive, its strength is not deep enough to allow for a bound state in the form of a dineutron. However, this picture changes drastically when the interacting neutrons are submerged in nuclear matter. In this contribution we address di nucleon properties as implied by the Brueckner Hartree Fock approximation for infinite symmetric nuclear matter at zero temperature.Special emphasis is given to di nucleon formation in the search of self-consistent single-particle fields, leading to novel features for low-density nuclear matter, i.e. mass densities of the order of 1011-12 g cm-3. Searches have been carried out at Fermi momenta in the range 0 < k F 1.75 fm-1 using the Argonne vt8 bare nucleon-nucleon potential. As a result, two distinct solutions meeting self-consistency are found with overlapping domains in the interval 0.130 fm-1 k F 0.285 fm-1. Effective masses as high as three times the nucleon mass are found in the coexistence domain, in resemblance to heavy Fermions in strongly correlated systems. Properties of di nucleon bound state solutions and possible implications shall be discussed
Field theoretic treatment of pion-nuclear matter elastic scattering
International Nuclear Information System (INIS)
Pion-nucleon amplitudes of a field theoretical origin are constructed as a semi-phenomenological input into the pion-nuclear matter problem. The amplitudes are obtained from a scattering equation. The new scattering equation approximates the static one meson low equation as to its analytical structure and crossing symmetry, but differs from the Low equation in that a closed form solution is possible. The resulting t-matrices depend on an arbitrary form factor as do those of the one meson Low Equation, and the scattering amplitudes can therefore be fit to the experimental data by an extension of existing inverse problems. The resulting t-matrix is corrected for the effects of noninteracting nuclear matter by an appropriate extension of the new scattering equation presented, and then entered into a field theoretical pion-nuclear matter optical potential that employs Dyson's equation for the irreducible self energy of the pion. It is found that while the off shell extension of the two-body t-matrix is affected only slightly by the results of the new scattering equation, the optical potential thus obtained has some novel features
Theory of superfluid states with singlet and triplet types of pairing in nuclear matter
International Nuclear Information System (INIS)
The paper presents the results of investigation of superfluid states in a two-component Fermi liquid in the framework of the Fermi liquid approach. Particular attention is paid to superfluid states in nuclear matter which are characterized by the superposition of singlet and triplet types of pairing in spin and isospin spaces. The authors have formulated the basic points of the Fermi liquid approach which are used in the study of superfluidity in nuclear matter with the superposition of singlet and triplet types of pairing. Derivation of the system of self-consistency equations and their solution are presented. For concrete calculations the interaction in the Skyrme model is taken. Using this model the conditions for the existence of the considered states are determined. These conditions impose certain constraints on the potential of interaction and on the density of particles in the system. It is shown that the states with a complete set of nonzero order parameters are realized only in a narrow density range, whose width and position in the density scale depend on the choice of a particular Skyrme force. Considered are 18 different parameterizations, and indicated is for which of them the studied types of superfluid states may appear The problem of stability of the states with superposition of singlet and triplet types of pairing is studied. It is shown that the lowest value of the thermodynamic potential corresponds to purely triplet states, then in order of increasing there are the thermodynamic potential of purely singlet states, and mixed singlet-triplet states. The case of unitary states is considered separately. For these states the solutions of the self-consistency equations are analyzed too. The density range for these states is defined and it is shown that this range is different than from that which corresponds to the nonunitary states. In addition, studied is the problem of the existence of unitary superfluid states with the superposition of singlet and triplet superfluidity in the case of asymmetrical nuclear matter. It is shown that the appearance of asymmetry causes the unitarity of superfluid states in nuclear matter to be broken.
Nuclear spin resonances in double beta decays and dark matters
International Nuclear Information System (INIS)
In this paper, as the experiment using the spin in atomic nuclei as the experimental means, the double data decay and the experiment for searching for dark matters by Ejiri group of Osaka University are reported. Double beta decay is the phenomenon in which beta decay occurs twice successively in atomic nuclei, and theoretically a number of decay modes are considered. In double beta decay, two beta rays (electrons) and two neutrinos are emitted, therefore, the energy spectra of beta ray become continuous. The probability of decay, the effect of neutrino emission and others are discussed. The detector (ELEGANTS V) that the group of Osaka University uses for the measurement is introduced. The thin film specimens of Mo are used. The spectrum is shown, and the half life was obtained. The results are reported. The existence of space dark matters was predicted, but it has not been found. The application of NaI detector to the search for dark matters has been investigated. NaI consists of the nuclei having finite nuclear spin, and is suitable to the search for the dark matters of spin coupling type. The limit for the existence of dark matters was determined. (K.I.)
Application of effective field theory on nuclear matter and neutron matter
International Nuclear Information System (INIS)
In the thesis the effective field theory in NLO and NNLO order is applied. The order NLO still knows no three-particle forces. The theory yields however already in this order the saturation behaviour of nuclear matter. This is due to the fact that in the NLO order the scattering phases are qualitatively correctly reproduced, especially the scattering phases 1S0 and 3S1 are for energies above 200 MeV negative, which is in all potentials by a so called hard core represented. In the NNLO orde three-particle forces occur, which lead to a larger improvement of the saturation curve, however the saturation point lies still at too high densities. A correction of the low-energy constants by scarcely three percent of the value in the vacuum generates however a saturation curve, which reproduces the empirical binding energy per particle, the density and the compressibility of nuclear matter. About the equation of state of neutron matter is empirically few known. At small densities of neutron matter (kf-1) the NLO and NNLO orders scarcely differ, but indeed from the free Fermi gas. For applications in finite nuclei a simplified parametrization of the nucleon-nucleon interactions was developed, which reproduces both the known scattering phases with an NLO-comparable accuracy and the empirical saturation behaviour
The effective action approach applied to nuclear matter (1)
International Nuclear Information System (INIS)
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
Nuclear Transparency Effect in the Strongly Interacting Matter
Ajaz, M; Abdinov, O B; Zaman, Ali; Khan, K H; Wazir, Z; Khalilova, Sh
2012-01-01
We discuss that the results of study of the nuclear transparency effect in nuclear-nuclear collisions at relativistic and ultrarelativistic energies could help to extract the information on new phases of the strongly interacting matter as well as the QCD critical point. The results could provide further confirmation of the existence of the "horn" effect which had initially been obtained for the ratio of average values of K+ to pi+ -mesons' multiplicity as a function of the initial energies in the NA49 SPS CERN experiment. To observe the "horn" as a function of centrality, the new more enriched experimental data are required. The data which are expected from NICA/MPD JINR and CBM GSI setups could fulfill the requirement.
Mondal, C.; Agrawal, B. K.; De, J. N.
2015-08-01
Elements of nuclear symmetry energy evaluated from different energy density functionals parametrized by fitting selective bulk properties of few representative nuclei are seen to vary widely. Those obtained from experimental data on nuclear masses across the periodic table, however, show that they are better constrained. A possible direction in reconciling this paradox may be gleaned from comparison of results obtained from use of the binding energies in the fitting protocol within a microscopic model with two sets of nuclei, one a representative standard set and another where very highly asymmetric nuclei are additionally included. A covariance analysis reveals that the additional fitting protocol reduces the uncertainties in the nuclear symmetry energy coefficient, its slope parameter, as well as the neutron-skin thickness in 208Pb nucleus by ˜50 % . The central values of these entities are also seen to be slightly reduced.
Mondal, C; De, J N
2015-01-01
Elements of nuclear symmetry energy evaluated from different energy density functionals parametrized by fitting selective bulk properties of few representative nuclei are seen to vary widely. Those obtained from experimental data on nuclear masses across the periodic table, however, show that they are better constrained. A possible direction in reconciling this paradox may be gleaned from comparison of results obtained from use of the binding energies in the fitting protocol within a microscopic model with two sets of nuclei, one a representative standard set and another where very highly asymmetric nuclei are additionally included. A covariance analysis reveals that the additional fitting protocol reduces the uncertainties in the nuclear symmetry energy coefficient, its slope parameter as well as the neutron-skin thickness in $^{208}$Pb nucleus by $\\sim 50\\%$. The central values of these entities are also seen to be slightly reduced.
Zhou, Zhengzhen; Guo, Laodong
2015-06-19
Colloidal retention characteristics, recovery and size distribution of model macromolecules and natural dissolved organic matter (DOM) were systematically examined using an asymmetrical flow field-flow fractionation (AFlFFF) system under various membrane size cutoffs and carrier solutions. Polystyrene sulfonate (PSS) standards with known molecular weights (MW) were used to determine their permeation and recovery rates by membranes with different nominal MW cutoffs (NMWCO) within the AFlFFF system. Based on a ?90% recovery rate for PSS standards by the AFlFFF system, the actual NMWCOs were determined to be 1.9 kDa for the 0.3 kDa membrane, 2.7 kDa for the 1 kDa membrane, and 33 kDa for the 10 kDa membrane, respectively. After membrane calibration, natural DOM samples were analyzed with the AFlFFF system to determine their colloidal size distribution and the influence from membrane NMWCOs and carrier solutions. Size partitioning of DOM samples showed a predominant colloidal size fraction in the <5 nm or <10 kDa size range, consistent with the size characteristics of humic substances as the main terrestrial DOM component. Recovery of DOM by the AFlFFF system, as determined by UV-absorbance at 254 nm, decreased significantly with increasing membrane NMWCO, from 45% by the 0.3 kDa membrane to 2-3% by the 10 kDa membrane. Since natural DOM is mostly composed of lower MW substances (<10 kDa) and the actual membrane cutoffs are normally larger than their manufacturer ratings, a 0.3 kDa membrane (with an actual NMWCO of 1.9 kDa) is highly recommended for colloidal size characterization of natural DOM. Among the three carrier solutions, borate buffer seemed to provide the highest recovery and optimal separation of DOM. Rigorous calibration with macromolecular standards and optimization of system conditions are a prerequisite for quantifying colloidal size distribution using the flow field-flow fractionation technique. In addition, the coupling of AFlFFF with fluorescence EEMs could provide new insights into DOM heterogeneity in different colloidal size fractions. PMID:25958093
Equation of state for nuclear matter based on density dependent effective interaction
Basu, D. N.
2003-01-01
An interesting method of obtaining equation of state for nuclear matter, from a density dependent M3Y interaction, by minimizing the energy per nucleon is described. The density dependence parameters of the interaction are obtained by reproducing the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. The nuclear matter equation of state thus obtained is then used to calculate the pressure, the energy density, the nuclear incomp...
International Nuclear Information System (INIS)
Internucleonic forces of the semiphenomenological nuclear theory are applied to description of the nUclear matter properties. The latter are found to be as follows: the equilibrium density, rho0=0.202 fm-3; Fermi momentum Ksub(F)=144 fm-1; binding energy per nucleon, E/A=-15.65 MeV stiffness coefficient, k=385.5 MeV
Is nuclear matter perturbative with low-momentum interactions?
Bogner, S K; Furnstahl, R J; Nogga, A
2005-01-01
The nonperturbative nature of inter-nucleon interactions is explored by varying the momentum cutoff of a two-nucleon potential. Conventional force models, which have large cutoffs, are nonperturbative because of strong short-range repulsion, the iterated tensor interaction, and the presence of bound or nearly-bound states. But for low-momentum interactions with cutoffs around 2 fm^{-1}, the softened potential combined with Pauli blocking leads to corrections in nuclear matter in the particle-particle channel that are well converged at second order in the potential, suggesting that perturbation theory can be used in place of Brueckner resummations. Calculations of nuclear matter using the low-momentum two-nucleon force V_{low k} with a corresponding leading-order three-nucleon (3N) force from chiral effective field theory (EFT) exhibit nuclear binding in the Hartree-Fock approximation, and become less cutoff dependent with the inclusion of the dominant second-order contributions. The role of the 3N force is es...
Is nuclear matter perturbative with low-momentum interactions?
International Nuclear Information System (INIS)
The nonperturbative nature of inter-nucleon interactions is explored by varying the momentum cutoff of a two-nucleon potential. Conventional force models, which have large cutoffs, are nonperturbative because of strong short-range repulsion, the iterated tensor interaction, and the presence of bound or nearly-bound states. But for low-momentum interactions with cutoffs around 2 fm-1, the softened potential combined with Pauli blocking leads to corrections in nuclear matter in the particle-particle channel that are well converged at second order in the potential, suggesting that perturbation theory can be used in place of Brueckner resummations. Calculations of nuclear matter using the low-momentum two-nucleon force Vlowk with a corresponding leading-order three-nucleon (3N) force from chiral effective field theory (EFT) exhibit nuclear binding in the Hartree-Fock approximation, and become less cutoff dependent with the inclusion of the dominant second-order contributions. The role of the 3N force is essential to obtain saturation, and the contribution to the total potential energy is compatible with EFT power-counting estimates
Converting of Matter to Nuclear Energy by AB-Generator
Directory of Open Access Journals (Sweden)
Alexander Bolonkin
2009-01-01
Full Text Available Problem statement: Researcher offered a new nuclear generator which allowed to convert any matter to nuclear energy in accordance with Einstein equation E = mc2. The method was based upon tapping the energy potential of a Micro Black Hole (MBH and Hawking radiation created by this MBH. Researcher did not meet the idea and its research in literature to develop the method for getting a cheap energy. Approach: As is well-known, vacuum continuously produced virtual pairs of particles and antiparticles, in particular, photons and anti-photons. MBH event horizon allowed separating them. Anti-photons can be moved to MBH and be annihilated, decreasing mass of MBH, resulting photons leave the MBH neighborhood as Hawking radiation. The offered nuclear generator (named by Researcher as AB-generator utilized Hawking radiation and injected the matter into MBH and kept MBH in a stable state with near-constant mass. Results: AB-generator can be produced gigantic energy outputs and should be cheaper than a conventional electric station by a factor of hundreds of times. One also may be used in aerospace as a photon rocket or as a power source for many vehicles. Conclusion: Many scientists expect Large Hadron Collider at CERN may be produced one MBH every second. A technology to capture them may be developed; than they may be used for the AB-generator.
Quarks and the saturation properties of nuclear matter
International Nuclear Information System (INIS)
A two-region model of the nuclear force is developed. The short-range force is calculated using quark degrees of freedom; the long-range force is calculated using nucleon degrees of freedom. In the quark sector, the Soliton Bag model and the method of generator coordinates are used. This allows the quark fields to undergo a continuous deformation as the two nucleons overlap. In the nucleon sector, the Reid potential is used. The matching radius between the quark and nucleon sectors is approximately 1 fm. The model is used in a nucleon-nucleon scattering calculation and in a lowest-order Brueckner theory calculation of nuclear matter. In the scattering calculation, the spin singlet scattering data is well described with a single choice of parameters. Several approximations are examined. The reference-spectrum method is used in a calculation of the density and binding energy of nuclear matter. Quark effects are important and modify the standard Reid potential results by decreasing both the saturation density and binding energy. The results also indicate that a microscopic meson-exchange theory which includes nucleon resonances should be used for the long-range force
Conventional and Unconventional Pairing and Condensates in Dilute Nuclear Matter
Clark, John W; Stein, Martin; Huang, Xu-Guang; Khodel, Victor A; Shaginyan, Vasily R; Zverev, Mikhail V
2016-01-01
This contribution will survey recent progress toward an understanding of diverse pairing phenomena in dilute nuclear matter at small and moderate isospin asymmetry, with results of potential relevance to supernova envelopes and proto-neutron stars. Application of {\\it ab initio} many-body techniques has revealed a rich array of temperature-density phase diagrams, indexed by isospin asymmetry, which feature both conventional and unconventional superfluid phases. At low density there exist a homogeneous translationally invariant BCS phase, a homogeneous LOFF phase violating translational invariance, and an inhomogeneous translationally invariant phase-separated BCS phase. The transition from the BCS to the BEC phases is characterized in terms of the evolution, from weak to strong coupling, of the pairing gap, condensate wave function, and quasiparticle occupation numbers and spectra. Additionally, a schematic formal analysis of pairing in neutron matter at low to moderate densities is presented that establishes...
Reducible chiral four-body interactions in nuclear matter
Kaiser, N
2015-01-01
The method of unitary transformations generates five classes of leading-order reducible chiral four-nucleon interactions which involve pion-exchanges and a spin-spin contact-term. Their first-order contributions to the energy per particle of isospin-symmetric nuclear matter and pure neutron matter are evaluated in detail. For most of the closed four-loop diagrams the occurring integrals over four Fermi-spheres can be reduced to easily manageable one- or two-parameter integrals. One observes substantial cancelations among the different contributions arising from 2-ring and 1-ring diagrams. Altogether, the net attraction generated by the chiral four-nucleon interaction does not exceed values of $-1.3$\\,MeV for densities $\\rho<2\\rho_0$.
Nonrelativistic nucleon effective masses in nuclear matter: BHF versus RHF
Li, A; Shang, X L; Zuo, W
2015-01-01
The density and isospin dependences of the nonrelativistic nucleon effective mass ($m^*$) are studied, which is a measure of the nonlocality of the single particle (s.p.) potential. We decouple it further into the so called k-mass ($m^*_k$, i.e., the nonlocality in space) and E-mass ($m^*_E$, i.e., the nonlocality in time). Both masses are determined and compared from the latest versions of the nonrelativistic Brueckner-Hartree Fock (BHF) model and the relativistic Hartree-Fock (RHF) model. The latter are achieved based on the corresponding Schr\\"{o}dinger equivalent s.p. potential in a relativistic framework. We demonstrate the origins of different effective masses and discuss also their neutron-proton splitting in the asymmetric matter in different models. We find that the neutron-proton splittings of both the k-mass and the E-mass have the same asymmetry dependences at considered densities, namely $m^*_{k,n} > m^*_{k,p}$ and $m^*_{E,p} > m^*_{E,n}$. However, the resulting splittings of nucleon effective ma...
Dynamical structure factor of correlated hot nuclear matter
RÃ¶pke, G.; Morawetz, K.; Alm, T.
1993-08-01
Starting from a quantum statistical approach to the density-density response function, its relation to the compressibility and to the equation of state of nuclear matter at finite temperature is investigated. In particular, the contribution of two-particle correlations to the dynamical structure factor is taken into account, which becomes important at low temperatures in the low-density limit. It is shown that this treatment for the structure factor is consistent with the equation of state up to the second virial coefficient.
Nuclear matter equation of state and -meson parameters
Indian Academy of Sciences (India)
A B Santra; U Lambardo
2005-01-01
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. We find that it is possible to understand all the saturation observables, namely, saturation density, energy per nucleon and incompressibility, by incorporating in-medium modification of -meson–nucleon coupling constant and -meson mass by a few per cent.
Finite temperature RPA in symmetric nuclear matter with Skyrme interactions
International Nuclear Information System (INIS)
We investigate the RPA response for thermally excited nuclear matter interacting through Skyrme interactions. Closed analytical expressions are obtained for the dynamic susceptibility in each spin-isopspin channel. We compute the strength as a function of energy, transferred momentum and temperature, and examine the evolution of collective states, when present. The energy weighted sum rules Mk, for k = -1, 1 and 3 are also shown to possess explicit expressions as functions of both momentum and temperature. It is seen that thermal effects on the susceptibility are as important as dynamical ones associated to momentum transfer, at least for temperatures as high as 20% of the Fermi energy. (orig.)
Comparison of reaction matrices for free scattering and nuclear matter
International Nuclear Information System (INIS)
The matrix inversion method in momentum space provides a powerful tool for analysing numerically the correlation between the free scattering matrix and the Brueckner reaction matrix in nuclear matter. A study of this correlation is made for the 1S0 Reid soft-core and the de Tourreil-Rouben=Sprung super-soft-core potential. Reaction matrices and binding energies for all uncoupled channels with J less than two are studied. The effect of the important isobar virtual channels on these is also investigated. (author)
Numerical simulation of anomalous wave phenomena in hot nuclear matter
Konyukhov, A. V.; Likhachev, A. P.
2015-11-01
The collective dynamic phenomena accompanying the collision of high-energy heavy ions are suggested to be approximately described in the framework of ideal relativistic hydrodynamics. If the transition from hadron state to quark-gluon plasma is the first-order phase transition (presently this view is prevailing), the hydrodynamic description of the nuclear matter must demonstrate several anomalous wave phenomena—such as the shock splitting and the formation of rarefaction shock and composite waves, which may be indicative of this transition. The present work is devoted to numerical study of these phenomena.
Compression modes and the nuclear matter incompressibility coef?cient
Indian Academy of Sciences (India)
Shalom Shlomo
2001-08-01
We review the current status of the nuclear matter ($N = Z$ and no Coulomb interaction) incompressibility coef?cient, $K_{nm}$, and describe the theoretical and the experimental methods used to determine $K_{nm}$ from properties of compression modes in nuclei. In particular we consider the long standing problem of the con?icting results obtained for $K_{nm}$, deduced from experimental data on excitation cross sections for the isoscalar giant monopole resonance (ISGMR) and data for the isoscalar giant dipole resonance (ISGDR).
Thermodynamic Equilibrium of Nuclear Matter in General Relativity
Rueda, Jorge A; Xue, S -S; Pugliese, D
2011-01-01
We formulate the set of self-consistent ground-state equilibrium equations for nuclear matter taking into account quantum statistics, electro-weak, and strong interactions, within the framework of general relativity. The strong interaction between nucleons is modeled through the $\\sigma$-$\\omega$-$\\rho$ meson exchange in the context of the extended Walecka model, all duly expressed in general relativity. We demonstrate that the thermodynamic equilibrium condition given by the constancy of the generalized chemical potential of each particle-specie, for short the constancy of the Klein potentials, and by the Tolman's isothermal condition, can be properly generalized to include the contribution of all fields.
Mass shift of sigma-Meson in Nuclear Matter
Morones-Ibarra, J R; Santos-Guevara, Ayax; Padilla, Felipe Robledo
2010-01-01
The propagation of sigma meson in nuclear matter is studied in the Walecka model, assuming that the sigma couples to a pair of nucleon-antinucleon states and to particle-hole states, including the in medium effect of sigma-omega mixing. We have also considered, by completeness, the coupling of sigma to two virtual pions. We have found that the sigma meson mass decreases respect to its value in vacuum and that the contribution of the sigma omega mixing effect on the mass shift is relatively small.
Mass shift of sigma-Meson in Nuclear Matter
Morones-Ibarra, J. R.; Maciel, Monica Menchaca; Santos-Guevara, Ayax; Padilla, Felipe Robledo
2010-01-01
The propagation of sigma meson in nuclear matter is studied in the Walecka model, assuming that the sigma couples to a pair of nucleon-antinucleon states and to particle-hole states, including the in medium effect of sigma-omega mixing. We have also considered, by completeness, the coupling of sigma to two virtual pions. We have found that the sigma meson mass decreases respect to its value in vacuum and that the contribution of the sigma omega mixing effect on the mass shif...
Equidistant structure and effective nucleon mass in nuclear matter
International Nuclear Information System (INIS)
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)
From evaporation to explosion of heated nuclear matter
International Nuclear Information System (INIS)
Two sets of experimental data concerning product yield distributions are investigated: one set for nuclei of mass A ? 100 with excitation energies of 0 to ?5 A MeV and one set for a system of A ? 400 with excitation energies of ? 10 to 50 A MeV. The yield distributions of percolation are compared to the data and a critical excitation energy is estimated and compared to the condensation energy in ?-nuclear matter. Shortcomings of the percolation model are discussed. (authors). 27 refs., 4 figs
Chiral relativistic model of nuclear matter including effects of confinement mechanism
International Nuclear Information System (INIS)
This work aims at constructing a model for symmetric and asymmetric nuclear matter in a relativistic approach including effects from quantum chromodynamics, in particular chiral symmetry and confinement. We consider an assembly of nucleons interacting via meson exchange. The attraction is due to a chiral invariant scalar field associated with the fluctuations of the chiral condensate. The inclusion of scalar nucleonic effects due to the quark substructure of the nucleon ensures the saturation to occur. The parameters corresponding to the scalar sector of the interaction and to the quarks confinement in the nucleon are obtained from lattice calculations. The rest of the parameters are obtained as much as possible by hadron phenomenology. With such constrained inputs, the results are nevertheless very good: this constitutes the originality of this work. In one part, we chose to work at the mean-field level in the Hartree-Fock scheme. The propagation of the scalar field in the Hartree-Fock terms induce some rearrangement effects which play an essential role in the Hugenholtz-Van Hove theorem. We discuss also the role of the tensor part of the ? interaction in the symmetry energy and the isospin dependence of the Landau effective mass. Then, in the idea to enlarge this work to neutron stars, we give the equation of state predicted by our model. The last step corresponds to the introduction of effects after the mean-field including the correlation energy due to pion loops. An important ingredient is the Landau-Migdal parameter controlling short range interactions. The correlation energy enhances the description of the saturation point of nuclear matter. (author)
Nuclear condensation and symmetry energy of dilute nuclear matter: An S-matrix approach
International Nuclear Information System (INIS)
Based on the general analysis of the grand canonical partition function in the S-matrix framework, the calculated results on symmetry energy, free energy, and entropy of dilute warm nuclear matter are presented. At a given temperature and density, the symmetry energy or symmetry free energy of the clusterized nuclear matter in the S-matrix formulation deviates, particularly at low temperature and relatively higher density, in a subtle way, from the linear dependence on the square of the isospin asymmetry parameter X=(?n-?p)/(?n+?p), contrary to those obtained for homogeneous nucleonic matter. The symmetry coefficients, in conventional definition, can then be even negative. The symmetry entropy similarly shows a very different behavior
Composition and thermodynamics of nuclear matter with light clusters
International Nuclear Information System (INIS)
We investigate nuclear matter at a finite temperature and density, including the formation of light clusters up to the ? particle (1?A?4). The novel feature of this work is to include the formation of clusters as well as their dissolution due to medium effects in a systematic way using two many-body theories: a microscopic quantum statistical (QS) approach and a generalized relativistic mean-field (RMF) model. Nucleons and clusters are modified by medium effects. While the nucleon quasiparticle properties are determined within the RMF model from the scalar and vector self-energies, the cluster binding energies are reduced because of Pauli blocking shifts calculated in the QS approach. Both approaches reproduce the limiting cases of nuclear statistical equilibrium (NSE) at low densities and cluster-free nuclear matter at high densities. The treatment of the cluster dissociation is based on the Mott effect due to Pauli blocking, implemented in slightly different ways in the QS and the generalized RMF approaches. This leads to somewhat different results in the intermediate density range of about 10-3 to 10-1 fm-3, which gives an estimate of the present accuracy of the theoretical predictions. We compare the numerical results of these models for cluster abundances and thermodynamics in the region of medium excitation energies with temperatures T?20 MeV and baryon number densities from zero to a few times saturation density. The effects of cluster formation on the liquid-gas phase transition and on the density dependence of the symmetry energy are studied. It is demonstrated that the parabolic approximation for the asymmetry dependence of the nuclear equation of state breaks down at low temperatures and at subsaturation densities because of cluster formation. Comparison is made with other theoretical approaches, in particular, those that are commonly used in astrophysical calculations. The results are relevant for heavy-ion collisions and astrophysical applications.
Off-Fermi Shell Nucleons in Superdense Nuclear Matter
McGauley, Michael
2011-01-01
Based on recent progress in understanding the nature of two-nucleon (2N) short range correlations (SRCs) we performed world data analysis on inclusive electro-nuclear reactions at large momentum transfer to extract the probabilities of 2N SRCs for 3He, 4H, 12C, 27Al, 56Fe and 197Au nuclei. Using recent observations on strong dominance of proton-neutron SRCs as compared to proton-proton and neutron-neutron correlations we parameterized the obtained probabilities as a function of nuclear density and asymmetry. Using the obtained functional form of the probabilities we estimated the fractions of the off-Fermi shell protons and neutrons in the superdense nuclear matter relevant to neutron stars. Our results indicate that starting at 3-4 nuclear saturation densities the protons with fractional densities x_p={1\\over 9} will populate mostly the high momentum (off-Fermi shell) tail of the momentum distribution while only 20% of the neutrons will be in the high momentum tail. We discuss the implication of our observat...
Open Heavy Flavor in QCD Matter and in Nuclear Collisions
Prino, Francesco
2016-01-01
We review the experimental and theoretical status of open heavy-flavor (HF) production in high-energy nuclear collisions at RHIC and LHC. We first overview the theoretical concepts and pertinent calculations of HF transport in QCD matter, including perturbative and non-perturbative approaches in the quark-gluon plasma, effective models in hadronic matter, as well as implementations of heavy-quark (HQ) hadronization. This is followed by a brief discussion of bulk evolution models for heavy-ion collisions and initial conditions for the HQ distributions which are needed to calculate HF spectra in comparison to observables. We then turn to a discussion of experimental data that have been collected to date at RHIC and LHC, specifically for the nuclear suppression factor and elliptic flow of semileptonic HF decays, D mesons, non-prompt $J/\\psi$ from B-meson decays, and b-jets. Model comparisons to HF data are conducted with regards to extracting the magnitude, temperature and momentum-dependence of HF transport coe...
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)
Non-Abelian energy loss in cold nuclear matter
International Nuclear Information System (INIS)
We use a formal recurrence relation approach to multiple parton scattering to find the complete solution to the problem of medium-induced gluon emission from partons propagating in cold nuclear matter. The differential bremsstrahlung spectrum, where Landau-Pomeranchuk-Migdal destructive interference effects are fully accounted for, is calculated for three different cases: (i) a generalization of the incoherent Bertsch-Gunion solution for asymptotic on-shell jets (ii) initial-state energy loss of incoming jets that undergo hard scattering, and (iii) final-state energy loss of jets that emerge out of a hard scatter. Our analytic solutions are given as an infinite opacity series, which represents a cluster expansion of the sequential multiple scattering. These new solutions allow, for the first time, direct comparison between initial- and final-state energy loss in cold nuclei. We demonstrate that, contrary to the naive assumption, energy loss in cold nuclear matter can be large. Numerical results to first order in opacity show that, in the limit of large jet energies, initial- and final-state energy losses exhibit different path length dependences, linear versus quadratic, in contrast to earlier findings. In addition, in this asymptotic limit, initial-state energy loss is considerably larger than final-state energy loss. These new results have significant implications for heavy-ion phenomenology in both p+A and A+A reactions
Mukherjee, Abhishek
2008-01-01
We apply the variational theory for fermions at finite temperature and high density, developed in an earlier paper, to symmetric nuclear matter and pure neutron matter. This extension generalizes to finite temperatures, the many body technique used in the construction of the zero temperature Akmal-Pandharipande-Ravenhall equation of state. We discuss how the formalism can be used for practical calculations of hot dense matter. Neutral pion condensation along with the associated isovector spin...
Antiferromagnetic spin phase transition in nuclear matter with effective Gogny interaction
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 D1S effective force undergoes a phase transition to the antiferromagnetic spin state (the opposite direction of neutron and proton spins). The self--consistent equations of spin polarized nuclear matter with D1S force ha...
ANDREAS MARKWITZ; Hopke, Philip K.; DIAH DWIANA LESTIANI; MUHAYATUN SANTOSO
2010-01-01
Nuclear analytical techniques such as Instrumental neutron activation analysis (INAA) and Particle Induced X-ray Emission (PIXE) have been used in quantification of environmental pollutant. INAA and PIXE have been turned out to be particularly useful in the analysis of airborne particulate matter. Nuclear Energy Agency of Indonesia has carried out the monitoring air quality especially for airborne particulate matter using nuclear analytical techniques. Sampling of airborne particulate matter ...
Nuclear fusion in dense matter: Reaction rate and carbon burning
Gasques, L R; Aguilera, E F; Beard, M; Chamon, L C; Ring, P; Wiescher, M; Yakovlev, D G
2005-01-01
In this paper we analyze the nuclear fusion rate between equal nuclei for all five different nuclear burning regimes in dense matter (two thermonuclear regimes, two pycnonuclear ones, and the intermediate regime). The rate is determined by Coulomb barrier penetration in dense environments and by the astrophysical S-factor at low energies. We evaluate previous studies of the Coulomb barrier problem and propose a simple phenomenological formula for the reaction rate which covers all cases. The parameters of this formula can be varied, taking into account current theoretical uncertainties in the reaction rate. The results are illustrated for the example of the ^{12}C+^{12}C fusion reaction. This reaction is very important for the understanding of nuclear burning in evolved stars, in exploding white dwarfs producing type Ia supernovae, and in accreting neutron stars. The S-factor at stellar energies depends on a reliable fit and extrapolation of the experimental data. We calculate the energy dependence of the S-f...
2010-01-29
...EA-09-147, NRC-2010- 0028] In the Matter of Beta Gamma Nuclear Radiology; Confirmatory Order Modifying License (Effective Immediately) I Beta Gamma Nuclear Radiology (BGNR) (Licensee) is the holder of medical License No....
Symmetry Energy of Nuclear Matter at Low Densities and Clustering at the Nuclear Surface
International Nuclear Information System (INIS)
We present a density functional theory which connects nuclear matter equation of state, which incorporates clustering at low densities, with clustering in medium and heavy nuclei at the nuclear surface. This explains the large values of symmetry energy reported by Natowitz et al for densities ?3 in addition to the binding energies and charge rms radii of 367 spherical nuclei. The present theory which is partly macroscopic competes with other high quality microscopic-macroscopic approaches. Merits of the results with clustering and no-clustering are discussed. We also make connection with realistic interactions (AV18+UIX/IL2) which have been used in ab initio calculations in s- and p-shell nuclei and neutron matter. Theory predicts new situations and regimes to be explored both theoretically and experimentally. It is demonstrated that, due to clustering, the neutron skin thickness reduces significantly.
International Nuclear Information System (INIS)
The effects of intensified and asymmetric barrier penetration by complex particles exhibiting intrinsic structure are investigated in the framework of the time-dependent mean-field theory using an effective one-dimensional layer geometry and a simplified Skyrme nucleon-nucleon effective interaction. The transmission coefficient D(E) has been investigated as a function of incident energy E anU layer thickness. The appearance of discontinuities in D(E) is discussed in detail. It is argued that quantum corrections to the standard TDHF picture as well as the transition to three dimensions possibly smearing out the discontinuities should not alter the qualitative results. In nearly all considered cases the penetrability is really substantially intensified and the asymmetry effect manifests itself as predicted earlier using a simple quasideuteron model
Resilience of nuclear matter in light ion induced reactions
International Nuclear Information System (INIS)
Cavitation and heating of the target nucleus in the first instances of 3He-induced collisions in the GeV/u range are investigated in an intranuclear cascade model for the formation of this structure and a stochastic one-body dynamics calculation to study its evolution. The hard collisions having essentially ceased when the structure is fully developed, the latter model is particularly suited to study the possible break-up of the system. It is shown, however, that the target recovers a spherical shape rather rapidly, and has thus a good chance to decay by standard evaporation, justifying the use of a cascade + evaporation model to analyze the data. It is also shown that the system should be modified to break up into pieces instead of recovering a compact shape: in these reactions, it is thus expected that nuclear matter is resilient to shape deformation and thermal excitation. (author)
The dispersion relation of the pion in nuclear matter
International Nuclear Information System (INIS)
We put forward a formalism to calculate the relativistic particle-hole and delta-hole excitation polarization insertion for pion propagator by using the particle-hole-antiparticle representation of nucleon and delta propagators in nuclear matter. The real and the imaginary part of the polarization insertion and the dispersion relation for pion propagator are calculated numerically. We find that the short range correlation enhances the delta-hole excitation but suppresses the particle-hole excitation, it also suppresses the pion condensation. We find that the effect of the short range correlation on the pion dispersion relation depends very much on the form of the short range correlation and the parameters involved. (orig.)
Unstable three dimensional nuclear matter in stochastic mean field approach
International Nuclear Information System (INIS)
A semi-classical stochastic mean-field approach is discussed. In the case of unstable infinite nuclear matter, the characteristic time of the exponential growing of fluctuations and the diffusion coefficients associated to the unstable modes are calculated in the framework of the Boltzmann-Langevin theory. In order to make realistic 3D calculations feasible, the complicated Boltzmann-Langevin theory is suggested to be replaced by a simpler stochastic meanfield approach corresponding to a standard Boltzmann evolution, complemented by a simple noise chosen to reproduce the dynamics of the most unstable modes. Finally, it is explained how to approximately implement this method by simply tuning the noise associated to the use of a finite number of test particles in Boltzmann-like calculations. (authors) 17 refs., 5 figs
Collective expansion of hot and compressed nuclear matter
International Nuclear Information System (INIS)
Central collisions of Au + Au at incident energies of 90, 150, 250 and 400 A· MeV were studied with the complete FOPI - facility at GSI Darmstadt. The complete phase space distributions at 250 A· MeV confirms the spherical symmetry. The energies corresponding to the onset of collective expansion and side-flow are obtained and compared with the transition energies at which the azimuthal distributions show a change from in-plane to out-of-plane enhancement. A semianalytical model for the expansion and clusterization of hot and compressed nuclear matter is used to explain some of the experimental trends. Modulation of the mean value and the slope of the energy spectra for different fragments as a function of azimuth is evidenced for mid-central collisions. (authors)
Finite baryon density in lattice simulations and nuclear matter
International Nuclear Information System (INIS)
A simple model for the partition function of an interacting nucleon gas can explain the early onset of the baryon density observed when using staggered fermions on the lattice at finite chemical potential. The onset, which is very sensitive to the number of lightest nucleon states formed, represents the point where condensation into nuclear matter occurs. The lattice simulations have been done with staggered fermions or 4 degenerate valence quarks, which can bind into 40 lightest nucleons for which the model can fit the early onset as found on the lattice for various quark masses. The statistical model contains scalar interactions, producing attractive energies scaling as mN-2, among nucleons which propagate in effective volumes that exclude the hard nucleon cores determined by m?. Extrapolating the number of flavours and masses to the values in nature, where we have 4 lowest nucleon states, the model shows and onset close to the nucleon mass as desired. (orig.)
Empirical observations on the unpredictable behavior of nuclear matter
International Nuclear Information System (INIS)
While many aspects of matter are unpredictable from basic principles, there are some that are susceptible to empirical descriptions which can be quite accurate and beautiful. One such example from the field of ''Nuclear Matter Under Extreme Conditions'' is the distribution of the number of particles produced, or alternatively, of the energy carried by these particles, in energetic collisions of atomic nuclei. The present work consists of a series of published scientific papers on measurements of the distribution of particles produced, or the energy carried by these particles, in collisions of various nuclei, spanning more than a decade of research. Due to the unpredictability of the theory, the work includes empirical studies of the regularity of the measured distributions from which significant knowledge is gained. The aesthetics of this subject derives from the physical beauty of the measured curves, the characteristic changes of shape with different species of nuclei, and the deep understanding obtained by the use of a simple and elegant mathematical function to describe the data
Study of the nuclear matter flow with the multidetector INDRA
International Nuclear Information System (INIS)
The work presented in this thesis relates to the study of the products which are not emitted by the statistical deexcitation of the projectile and target. The experiment on which this work is based on was performed at GANIL with the detector INDRA on two systems: 36 Ar + 58 Ni and 129 Xe + 119 Sn. A whole characterization (mass, composition, multiplicities and energy properties) of mid-rapidity emission has been done for the system 36 Ar + 58 Ni between 52 and 95 A.MeV. The amount of matter associated to this emission seems to be independent of the incident energy and directly linked with the centrality of the collision. The available energy per nucleon for the production of mid-rapidity products seems to be insensitive to the impact parameter. A systematic study of the nuclear matter in-plane flow has also been carried out. It has been established that the usual methods for reaction plane determination do not allow one to measure accurately the value of flow parameter at intermediate energies. Nevertheless, the inversion energy of the system 36 Ar + 58 Ni can be calculated for central collisions. This energy is independent of the nature of the products. Its value and the features of the mid-rapidity emission should allow one to extract in-medium nucleon-nucleon cross section by comparison with theoretical results. (author)
Short-range correlations in quark and nuclear matter
International Nuclear Information System (INIS)
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.)
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.)
Sound waves and solitons in hot and dense nuclear matter
International Nuclear Information System (INIS)
Assuming that nuclear matter can be treated as a perfect fluid, we study the propagation of perturbations in the baryon density. The equation of state is derived from a relativistic mean field model, which is a variant of the non-linear Walecka model. The expansion of the Euler and continuity equations of relativistic hydrodynamics around equilibrium configurations leads to differential equations for the density perturbation. We solve them numerically for linear and spherical perturbations and follow the propagation of the initial pulses. For linear perturbations we find single soliton solutions and solutions with one or more solitons followed by 'radiation'. Depending on the equation of state a strong damping may occur. We consider also the evolution of perturbations in a medium without dispersive effects. In this case we observe the formation and breaking of shock waves. We study all these equations also for matter at finite temperature. Our results may be relevant for the analysis of RHIC data. They suggest that the shock waves formed in the quark gluon plasma phase may survive and propagate in the hadronic phase
Investigation of nuclear matter properties by means of high energy nucleus-nucleus collisions
International Nuclear Information System (INIS)
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.)
Quantum Molecular Dynamics Approach to the Nuclear Matter Below the Saturation Density
Maruyama, Toshiki; Niita, Koji; Oyamatsu, Kazuhiro; MARUYAMA, Tomoyuki; Chiba, Satoshi; Iwamoto, Akira
1997-01-01
Quantum molecular dynamics is applied to study the ground state properties of nuclear matter at subsaturation densities. Clustering effects are observed as to soften the equation of state at these densities. The structure of nuclear matter at subsaturation density shows some exotic shapes with variation of the density.
International Nuclear Information System (INIS)
Non-destructive analytical methods based on interactions of nuclear radiation with matter are overviewed in this chapter of the textbook. The three major categories discussed are Moessbauer spectroscopy based on the nuclear resonance absorption of gamma radiation, positronium chemistry developed from the study of the interaction of positive beta radiation with matter, and the chemistry of muonium and muonic atoms connected with the interaction of mesons with matter. (R.P.)
Nuclear matter equation of state including few-nucleon correlations $(A\\leq 4)$
RÃ¶pke, G.
2014-01-01
Light clusters (mass number $A \\leq 4$) in nuclear matter at subsaturation densities are described using a quantum statistical approach. In addition to self-energy and Pauli-blocking, effects of continuum correlations are taken into account to calculate the quasiparticle properties and abundances of light elements. Medium-modified quasiparticle properties are important ingredients to derive a nuclear matter equation of state applicable in the entire region of warm dense matter below saturatio...
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 diï¬€erence in (isospin asymmetric nuclear matter and ï¬nite nuclei is studied in the framework of a medium-modiï¬ed Skyrme model. The proposed eï¬€ective Lagrangian incorporates both the medium inï¬‚uence of the surrounding nuclear environment on the single nucleon properties and an explicit isospin-breaking eï¬€ect 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 diï¬€erence is mainly dictated by its strong part and that it markedly decreases in neutron matter. Furthermore, the possible interplay between the eï¬€ective nucleon mass in ï¬nite nuclei and the Nolen-Schiï¬€er anomaly is discussed. In particular, we ï¬nd that a correct description of the properties of mirror nuclei leads to a stringent restriction of possible modiï¬cations of the nucleonâ€™s eï¬€ective mass in nuclei.
International Nuclear Information System (INIS)
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)
Functional renormalization group approach to neutron matter
Directory of Open Access Journals (Sweden)
Matthias Drews
2014-11-01
Full Text Available The chiral nucleon-meson model, previously applied to systems with equal number of neutrons and protons, is extended to asymmetric nuclear matter. Fluctuations are included in the framework of the functional renormalization group. The equation of state for pure neutron matter is studied and compared to recent advanced many-body calculations. The chiral condensate in neutron matter is computed as a function of baryon density. It is found that, once fluctuations are incorporated, the chiral restoration transition for pure neutron matter is shifted to high densities, much beyond three times the density of normal nuclear matter.
Self-consistent tensor effects on nuclear matter system under relativistic Hartree-Fock approach
Jiang, Li Juan; YANG, SHEN; Dong, Jian Min; Long, Wen Hui(School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China)
2014-01-01
With the relativistic representation of the nuclear tensor force that is included automatically by the Fock diagrams, we explored the self-consistent tensor effects on the properties of nuclear matter system. The analysis were performed within the density-dependent relativistic Hartree-Fock (DDRHF) theory. The tensor force is found to notably influence the saturation mechanism, the equation of state and the symmetry energy of nuclear matter, as well as the neutron star prope...
Study of Charmonium Production in Asymmetric Nuclear Collisions by the PHENIX Experiment at RHIC
,
2015-01-01
The measurement of quarkonia production in relativistic heavy ion collisions provides a powerful tool for studying the properties of the hot and dense matter created in these collisions. To be really useful, however, such measurements must cover a wide range of quarkonia states and colliding species. The PHENIX experiment at RHIC has successfully measured J/psi, psi-prime, chi_c and Upsilon production in different colliding systems at various energies. In this talk I will present recent results from the PHENIX collaboration on charmonium production in d+Au, Cu+Au and U+U collisions at 200 GeV/c.
On hypothesis of partial conservation of the axial-vector current in nuclear matter
International Nuclear Information System (INIS)
Expressions extending the vacuum relations of the axial-vector current conservation (PCAC) to the case of infinite nuclear matter are obtained. It is shown that the account of the S wave ?N interaction results in a modification of PCAC in the matter. The weak axial and the pion-nucleon vertices in the nuclear matter are obtained basing on the theory of finite Fermi systems. Contributions from transitions far from the Fermi surface are taken into account by means of the corresponding phenomenological constants. The pion decay amplitude in the matter is found, as well as its time component. Relation of the renormalization of the pion decay amplitude in the matter to the problem of the pion-condensate instability of the nuclear matter is discussed
The Brueckner G matrix for a slab of nuclear matter
International Nuclear Information System (INIS)
The Brueckner theory G matrix is investigated for the slab geometry. A method of calculating the G matrix in a slab of nuclear matter is developed for the case of a separate form of the NN-interaction potential. In particular, the separable representation of the Paris potential is used. The singlet 1S0 and triplet 3S1-3D1 channels are examined. The mixed coordinate-momentum representation is used, the momentum one in the slab plane and the coordinate one, in the perpendicular direction. The complete Hilbert space is split onto a rather small model subspace and the complementary one. The 2-particle propagators are considered explicitly in the model space, whereas the local-potential approximation is used in the complementary one. This approximation was suggested previously for treating the effective pairing interaction. Numerical calculations are carried out for the case of the model space constructed from the negative energy single-particle states. The G matrix contains a parametric dependence on the two-particle energy E and the total perpendicular momentum Pperpendicular. Keeping in mind the subsequent use of the G matrix for evaluating the Landau-Migdal interaction amplitude, we fix the value of E =- 2?, where ? is the chemical potential of the system under consideration. The detailed calculations were made for the value of Pperpendicular = 0. The contribution of nonzero values of Pperpendicular is evaluated. A pronounced ? dependence of the G matrix in the surface region is demonstrated
The hadronization time of heavy quark in nuclear matter
Song, Taesoo
2016-01-01
We study the hadronization time of heavy quark in nuclear matter by using the coalescence model and the spatial diffusion constant of heavy quark from lattice Quantum Chromodynamic calculations, assuming that the main interaction of heavy quark at the critical temperature is hadronization. It is found that the hadronization time of heavy quark is about 3 fm/c for $2\\pi T_c D_s=6$, if a heavy quark is combined with the nearest light antiquark in coordinate space without any correlation between momentum of heavy quark and that of light antiquark which form a heavy meson. However, the hadronization time reduces to 0.6-1.2 fm/c for charm and 0.4-0.9 fm/c for bottom, depending on heavy meson radius, in the presence of momentum correlation. Considering the interspace between quarks and antiquarks at the critical temperature, it seems that the hadronization of heavy quark does not happen instantaneously but gradually for a considerable time, if started from the thermal distribution of quarks and antiquarks.
Numerical comparison of three theories of nuclear matter
International Nuclear Information System (INIS)
Three independent evaluations of the ground-state energy of a simple model of nuclear matter are compared. The potential chosen is central, consisting of a state-independent hard core surrounded by a spin-dependent Serber square well with parameters adjusted to produce a fit of the low-energy two-nucleon data. A careful evaluation of the energy expectation value with respect to a Jastrow wave function is performed within the Fermi-hypernetted-chain scheme of Fantoni and Rosati. At the test point ksub(F)=1.56 fm-1, the variational result lies about 2 MeV above the best available Pade approximants to the R-matrix expansion for the energy. This may be regarded as excellent agreement, considering the state-independence of the assumed Jastrow correlations. An estimate of the correction to the variational result due to the state dependence of the realistic correlations is made within the framework of the method of correlated basis functions (CBF). Both theories, R-matrix-Pade and Jastrow-CBF, yield substantially more binding than lowest-order Brueckner theory based on the choice of a self-consistent hole potential and zero particle potential in intermediate states. (Auth.)
Zero sound and the renormalization scale in relativistic nuclear matter
International Nuclear Information System (INIS)
In this paper we report a study on the poles of the propagators of ? and ? mesons in the space-like region. In this region a zero sound can appear (a collective mode having a dispersion relation analogue to that obtained in sound propagation, but appearing at zero temperature) when the nucleon-nucleon interaction used is sufficiently repulsive. We have determined this zero sound by using a relativistic Hartree approximation, a model in which the vacuum fluctuations depend on a renormalization scale. Two renormalization schemes, corresponding to two different values of this scheme are physically acceptable. The first one corresponds to the relativistic Hartree approximation usually utilized, which minimizes the three and four body vacuum interactions. This leads to an incompressibility module which is two times higher than its experimental value. The second procedure minimizes the tree and four body interactions in the medium at saturation density, thus permitting the correct reproduction of the nuclear matter compressibility. We have shown that the zero sound which appears near the saturation density with the pure Hartree approximation occurs now at a density which is two times higher than the saturation density when the second choice of renormalization scale is done
Resilience of nuclear matter in light ion induced reactions
International Nuclear Information System (INIS)
Cavitation and heating of the target nucleus in the first instances of 3He-induced collisions in the GeV/nucleon range are investigated in an intranuclear cascade model for the formation of this structure and a stochastic one-body dynamics calculation to study its evolution. The hard collisions having essentially ceased when the structure is fully developed, the latter model is particularly suited to study the possible breakup of the system. It is shown, however, that the target recovers a spherical shape rather rapidly, and has thus a good chance to decay by standard evaporation, justifying the use of a cascade + evaporation model to analyze the data. It is also shown that the system has to be much more modified to break up into pieces instead of recovering a compact shape: in these reactions, it is thus expected that nuclear matter is resilient to shape deformation and thermal excitation. Arguments are given to explain that expansion of the system, not important in these reactions, is required to overcome this resilience. copyright 1997 The American Physical Society
Multiplicity and cold-nuclear matter effects from Glauber-Gribov theory at LHC
Arsene, I. C.; Bravina, L.; Kaidalov, A. B.; Tywoniuk, K.; Zabrodin, E.
2007-01-01
We present predictions for nuclear modification factor in proton-lead collisions at LHC energy 5.5 TeV from Glauber-Gribov theory of nuclear shadowing. We have also made predictions for baseline cold-matter nuclear effects in lead-lead collisions at the same energy.
International Nuclear Information System (INIS)
Full text : Large Hadron Collider at the European Center for Nuclear Research, Geneva Switzerland is the biggest Collider and Physics experiment in history. Over the last 30-35 years a lot of efforts have been made to search for QGP - new phases of matter under extreme conditions of high temperature and baryon density, as predicted by Quantum Chromodynamics. In 2000 CERN announced some evidences for the existence of a new state of matter. In this article it is discussed some possibilities to identify the nuclear matter under extreme conditions of high temperature and baryon density -newly created matter in ultra-relativistic heavy ion collisions
Nucleon mean free path in nuclear matter based on nuclear Schwinger-Dyson formalism
International Nuclear Information System (INIS)
The mean free path of a nucleon moving through nuclear matter with kinetic energy larger than 100 MeV is formulated based on the bare vertex nuclear Schwinger-Dyson (BNSD) method in the Walecka model. The self-energy which is derived from diagrams of higher than fourth order includes the Feynman part of the propagator of an energetic nucleon and grows up rapidly with its kinetic energy increasing. To avoid too large a growth of these diagrams, meson propagators are modified by introducing some form factors to take into account an internal structure of hadrons. It is confirmed that a reasonable form factor is necessary to compare our numerical results of the mean free path with experimental data. (author)
Experimental aspects of quarkonia production and suppression in cold and hot nuclear matter
Frawley, A D
2015-01-01
When heavy Quarkonia are formed in collisions between between nuclei, their production cross section is modified relative to that in p+p collisions. The physical effects that cause this modification fall into two categories. Hot matter effects are due to the large energy density generated in the nuclear collision, which disrupts the formation of the quarkonium state. Cold nuclear matter effects are due to the fact that the quarkonium state is created in a nuclear target. I will review experimental aspects of quarkonia production due to both hot and cold matter effects.
International Nuclear Information System (INIS)
Various 2H and 31P nuclear magnetic resonance (NMR) spectroscopy techniques are applied to probe the component dynamics of the binary glass former tripropyl phosphate (TPP)/polystyrene-d3 (PS) over the full concentration range. The results are quantitatively compared to those of a dielectric spectroscopy (DS) study on the same system previously published [R. Kahlau, D. Bock, B. Schmidtke, and E. A. Rössler, J. Chem. Phys. 140, 044509 (2014)]. While the PS dynamics does not significantly change in the mixtures compared to that of neat PS, two fractions of TPP molecules are identified, one joining the glass transition of PS in the mixture (?1-process), the second reorienting isotropically (?2-process) even in the rigid matrix of PS, although at low concentration resembling a secondary process regarding its manifestation in the DS spectra. Pronounced dynamical heterogeneities are found for the TPP ?2-process, showing up in extremely stretched, quasi-logarithmic stimulated echo decays. While the time window of NMR is insufficient for recording the full correlation functions, DS results, covering a larger dynamical range, provide a satisfactory interpolation of the NMR data. Two-dimensional 31P NMR spectra prove exchange within the broadly distributed ?2-process. As demonstrated by 2H NMR, the PS matrix reflects the faster ?2-process of TPP by performing a spatially highly hindered motion on the same timescale
Effect of sound branch of pion on non-mesonic ? decay in nuclear matter
International Nuclear Information System (INIS)
It is studied the effect of the sound branch of pion on the non-mesonic decay width of the ? in nuclear matter. It is funded that its effect is sensitive to the energy release and the correlation parameter g'
Nuclear matter equation of state including few-nucleon correlations $(A\\leq 4)$
Röpke, G
2014-01-01
Light clusters (mass number $A \\leq 4$) in nuclear matter at subsaturation densities are described using a quantum statistical approach. In addition to self-energy and Pauli-blocking, effects of continuum correlations are taken into account to calculate the quasiparticle properties and abundances of light elements. Medium-modified quasiparticle properties are important ingredients to derive a nuclear matter equation of state applicable in the entire region of warm dense matter below saturation density. Moreover, the contribution of continuum states to the equation of state is considered. The effect of correlations within the nuclear medium on the quasiparticle energies is estimated. The properties of light clusters and continuum correlations in dense matter are of interest for nuclear structure calculations, heavy ion collisions, and for astrophysical applications such as the formation of neutron stars in core-collapse supernovae.
Size-shrinking of deuterons in very dilute superfluid nuclear matter
U. LombardoU. Catania and LNS-INFN; P. SchuckIPN,U. Paris-Sud
2014-01-01
It is shown within the strong-coupling BCS approach that, starting from the zero-density limit of superfluid nuclear matter, with increasing density deuterons first shrink before they start expanding.
Interplay between collision dynamics and nuclear matter properties from microscopic viewpoint
Directory of Open Access Journals (Sweden)
Ono Akira
2012-07-01
Full Text Available Nuclear matter properties have been explored through heavy-ion collisions. Studies with microscopic dynamical models, such as antisymmetrized molecular dynamics, are reviewed putting some emphasis on fragmentation and clusterization.
Variational Calculation for the Equation of State of Nuclear Matter at Finite Temperatures
Kanzawa, H; Sumiyoshi, K; Takano, M
2007-01-01
An equation of state (EOS) for uniform nuclear matter is constructed at zero and finite temperatures with the variational method starting from the realistic nuclear Hamiltonian composed of the Argonne V18 and UIX potentials. The energy is evaluated in the two-body cluster approximation with the three-body-force contribution treated phenomenologically so as to reproduce the empirical saturation conditions. The obtained energies for symmetric nuclear matter and neutron matter at zero temperature are in good agreement with those by Akmal, Pandharipande and Ravenhall at low densities. At high densities, the EOS is stiffer, and the maximum mass of the neutron star is 2.3 M . At finite temperatures, a variational method by Schmidt and Pandharipande is employed to evaluate the free energy, which is used to derive various thermodynamic quantities of nuclear matter necessary for supernova simulations. The result of this variational method at finite temperatures is found to be self-consistent.
Influence of spin polarizability on liquid gas phase transition in the nuclear matter
Rezaei, Z; Bordbar, G H
2015-01-01
In this paper, we investigate the liquid gas phase transition for the spin polarized nuclear matter. Applying the lowest order constrained variational (LOCV) method, and using two microscopic potentials, $AV_{18}$ and $UV_{14}$+TNI, we calculate the free energy, equation of state, order parameter, entropy, heat capacity and compressibility to derive the critical properties of spin polarized nuclear matter. Our results indicate that for the spin polarized nuclear matter, the second order phase transition takes place at lower temperatures with respect to the unpolarized one. It is also shown that the critical temperature of our spin polarized nuclear matter with a specific value of spin polarization parameter is in good agreement with the experimental result.
Jung, Ju-Hyun; Yakhshiev, Ulugbek; Kim, Hyun-Chul
2016-03-01
We investigate the medium modification of the generalized vector form factors of the nucleon, which include the electromagnetic and energy-momentum tensor form factors, based on an in-medium modified Ï€ -Ï -Ï‰ soliton model. We find that the vector form factors of the nucleon in nuclear matter fall off faster than those in free space, which implies that the charge radii of the nucleon become larger in nuclear medium than in free space. We also compute the corresponding transverse charge densities of the nucleon in nuclear matter, which clearly reveal the increasing of the nucleon size in nuclear medium.
Constraints on the equation of state of cold dense matter from nuclear physics and astrophysics
Directory of Open Access Journals (Sweden)
Fantina A. F.
2014-03-01
Full Text Available The Brussels-Montreal equations of state of cold dense nuclear matter that have been recently developed are tested against various constraints coming from both nuclear physics and astrophysics. The nuclear physics constraints include the analysis of nuclear flow and kaon production in heavy-ion collision experiments, as well as recent microscopic many-body calculations of infinite homogeneous neutron matter. Astrophysical observations, especially recent neutron-star mass measurements, provide valuable constraints on the high-density part of the equation of state that is not accessible in laboratory experiments.
Jung, Ju-Hyun; Kim, Hyun-Chul
2015-01-01
We investigate the medium modification of the generalized vector form factors of the nucleon, which include the electromagnetic and energy-momentum tensor form factors, based on an in-medium modified $\\pi$-$\\rho$-$\\omega$ soliton model. We find that the vector form factors of the nucleon in nuclear matter fall off faster than those in free space, which implies that the charge radii of the nucleon become larger in nuclear medium than in free space. We also compute the corresponding transverse charge densities of the nucleon in nuclear matter, which clearly reveal the increasing of the nucleon size in nuclear medium.
Properties of nuclear and neutron matter using D1 Gogny force
International Nuclear Information System (INIS)
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 ?, 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
Do Skyrme forces that fit nuclear matter work well in finite nuclei?
Stevenson, P D; Stone, J R; Dutra, M
2012-01-01
A shortlist of Skyrme force parameterizations, recently found to have passed a series of constraints relating to nuclear matter properties is analyzed for their ability to reproduce data in finite nuclei. We analyse binding energies, isotope shifts and fission barriers. We find that the subset of forces have no common ability to reproduce (or otherwise) properties of finite nuclei, despite passing the extensive range of nuclear matter constraints.
Derivative-coupling models and the nuclear-matter equation of state
International Nuclear Information System (INIS)
The equation of state of saturated nuclear matter is derived using two different derivative-coupling Lagrangians. We show that both descriptions are equivalent and can be obtained from the ?-? model through an appropriate rescaling of the coupling constants. We introduce generalized forms of this rescaling to study the correlations amongst observables in infinite nuclear matter, in particular, the compressibility and the effective nucleon mass. (orig.)
Neutrino propagation in Neutron Matter and the Nuclear Equation of State
Margueron, J.; Navarro, J.; N. Van Giai(Institut de Physique Nucleaire, Orsay, France); 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...
Fractal structure of near-threshold quarkonium production off cold nuclear matter
Bhaduri, Partha Pratim
2013-01-01
We investigate near-threshold production of quarkonium resonances in cold nuclear matter through a scaling theory with two exponents which are fixed by existing data on near-threshold J/psi production in proton-nucleus collisions. Interestingly, it seems possible to extend one of the multifractal dimensions to the production of other mesons in cold nuclear matter. The scaling theory can be tested and refined in experiments at the upcoming high-intensity FAIR accelerator complex in GSI.
International Nuclear Information System (INIS)
Dielectric spectroscopy as well as 2H and 31P nuclear magnetic resonance spectroscopy (NMR) are applied to probe the component dynamics of the binary glass former tripropyl phosphate (TPP)/polystyrene (PS/PS-d3) in the full concentration (cTPP) range. In addition, depolarized light scattering and differential scanning calorimetry experiments are performed. Two glass transition temperatures are found: Tg1(cTPP) reflects PS dynamics and shows a monotonic plasticizer effect, while the lower Tg2(cTPP) exhibits a maximum and is attributed to (faster) TPP dynamics, occurring in a slowly moving or immobilized PS matrix. Dielectric spectroscopy probing solely TPP identifies two different time scales, which are attributed to two sub-ensembles. One of them, again, shows fast TPP dynamics (?2-process), the other (?1-process) displays time constants identical with those of the slow PS matrix. Upon heating the ?1-fraction of TPP decreases until above some temperature Tc only a single ?2-population exists. Inversely, below Tc a fraction of the TPP molecules is trapped by the PS matrix. At low cTPP the ?2-relaxation does not follow frequency-temperature superposition (FTS), instead it is governed by a temperature independent distribution of activation energies leading to correlation times which follow Arrhenius laws, i.e., the ?2-relaxation resembles a secondary process. Yet, 31P NMR demonstrates that it involves isotropic reorientations of TPP molecules within a slowly moving or rigid matrix of PS. At high cTPP the super-Arrhenius temperature dependence of ?2(T), as well as FTS are recovered, known as typical of the glass transition in neat systems
The phase diagram of nuclear and quark matter at high baryon density
Fukushima, Kenji
2013-01-01
We review theoretical approaches to explore the phase diagram of nuclear and quark matter at high baryon density. We first look over the basic properties of quantum chromodynamics (QCD) and address how to describe various states of QCD matter. In our discussions on nuclear matter we cover the relativistic mean-field model, the chiral perturbation theory, and the approximation based on the large-Nc limit where Nc is the number of colors. We then explain the liquid-gas phase transition and the inhomogeneous meson condensation in nuclear matter with emphasis put on the relevance to quark matter. We commence the next part focused on quark matter with the bootstrap model and the Hagedorn temperature. Then we turn to properties associated with chiral symmetry and exposit theoretical descriptions of the chiral phase transition. There emerge some quark-matter counterparts of phenomena seen in nuclear matter such as the liquid-gas phase transition and the inhomogeneous structure of the chiral condensate. The third reg...
2013-05-17
...NUCLEAR REGULATORY COMMISSION [NRC-2013-0096...DPR-48] In the Matter of Zion Solutions, LLC; Zion Nuclear Power Station, Units 1 and 2...licensee and owner of the Zion Nuclear Power Station, Units 1 and...
Equation of state for nuclear matter in core-collapse supernovae by the variational method
International Nuclear Information System (INIS)
We construct a new nuclear equation of state (EOS) for core-collapse supernova (SN) simulations using the variational many-body theory. For uniform nuclear matter, the EOS is constructed with the cluster variational method starting from the realistic nuclear Hamiltonian composed of the Argonne v18 two-body potential and the Urbana IX three-body potential. The masses and radii of neutron stars calculated with the obtained EOS at zero temperature are consistent with recent observational data. For non-uniform nuclear matter, we construct the EOS in the Thomas-Fermi approximation. In this approximation, we assume a functional form of the density distributions of protons, neutrons, and alpha-particles, and minimize the free energy density in a Wigner-Seitz cell with respect to the parameters included in the assumed density distribution functions. The phase diagram of hot nuclear matter at a typical temperature is reasonable as compared with that of the Shen EOS
Gupta, V K; Singh, S; Anand, J D; Gupta, Asha
2002-01-01
We have studied phase transition from hadron matter to quark matter in the presence of high magnetic fields incorporating the trapped electron neutrinos at finite temperatures. We have used the density dependent quark mass (DDQM) model for the quark phase while the hadron phase is treated in the frame-work of relativistic mean field theory. It is seen that the nuclear energy at phase transition decreases with both magnetic field and temperature. A brief discussion of the effect of magnetic field in supernova explosions and proto-neutron star evolution is given.
Takacs, Maria; Petoukhov, Maxim V.; Atkinson, R. Andrew; Roblin, Pierre; Ogi, François-Xavier; Demeler, Borries; Potier, Noelle; Chebaro, Yassmine; Dejaegere, Annick; Svergun, Dmitri I.; Moras, Dino; Billas, Isabelle M. L.
2013-01-01
Background PGC-1? is a crucial regulator of cellular metabolism and energy homeostasis that functionally acts together with the estrogen-related receptors (ERR? and ERR?) in the regulation of mitochondrial and metabolic gene networks. Dimerization of the ERRs is a pre-requisite for interactions with PGC-1? and other coactivators, eventually leading to transactivation. It was suggested recently (Devarakonda et al) that PGC-1? binds in a strikingly different manner to ERR? ligand-binding domains (LBDs) compared to its mode of binding to ERR? and other nuclear receptors (NRs), where it interacts directly with the two ERR? homodimer subunits. Methods/Principal Findings Here, we show that PGC-1? receptor interacting domain (RID) binds in an almost identical manner to ERR? and ERR? homodimers. Microscale thermophoresis demonstrated that the interactions between PGC-1? RID and ERR LBDs involve a single receptor subunit through high-affinity, ERR-specific L3 and low-affinity L2 interactions. NMR studies further defined the limits of PGC-1? RID that interacts with ERRs. Consistent with these findings, the solution structures of PGC-1?/ERR? LBDs and PGC-1?/ERR? LBDs complexes share an identical architecture with an asymmetric binding of PGC-1? to homodimeric ERR. Conclusions/Significance These studies provide the molecular determinants for the specificity of interactions between PGC-1? and the ERRs, whereby negative cooperativity prevails in the binding of the coactivators to these receptors. Our work indicates that allosteric regulation may be a general mechanism controlling the binding of the coactivators to homodimers. PMID:23874451
Comparative study of three-nucleon force models in nuclear matter
Logoteta, Domenico; Bombaci, Ignazio; Kievsky, Alejandro
2015-01-01
We calculate the energy per particle of symmetric nuclear matter and pure neutron matter using the microscopic many-body Brueckner-Hartree-Fock (BHF) approach and employing the Argonne V18 (AV18) nucleon-nucleon (NN) potential supplemented with two different three-nucleon force models recently constructed to reproduce the binding energy of $^3$H, $^3$He and $^4$He nuclei as well as the neutron-deuteron doublet scattering length. We find that none of these new three-nucleon force models is able to reproduce simultaneously the empirical saturation point of symmetric nuclear matter and the properties of three- and four-nucleon systems.
The volume effect on nuclear fragmentation of supernova matter
International Nuclear Information System (INIS)
We proposed and have been studying a new heavy element synthesis process during supernova explosion which is proceeded by fragmentation of supernova matter through the liquid-gas phase transition. We have found that there appear the characteristic fragment distributions in the liquid-gas coexisting state during the ?-equilibrium of supernova matter. However, our model used for the distribution has some problems near the normal density ?0. In this talk, we take into account some medium effects of supernova matter in order to improve our model. (author)
Nuclear matter saturation point and symmetry energy with modern nucleon-nucleon potentials
International Nuclear Information System (INIS)
We determine the saturation properties of nuclear matter within the Brueckner-Hartree-Fock approach based on a large set of modern nucleon-nucleon potentials and confirm the validity of the Coester band. The improvement of the saturation point when including nuclear three-body forces is pointed out and comparison with the Dirac-Brueckner-Hartree-Fock results is made
International Nuclear Information System (INIS)
In this contribution, we review the most important physics presented originally in our recent publications. Some new analyses, insights and perspectives are also provided. We showed recently that the symmetry energy Esym (?) and its density slope L(?) at an arbitrary density ? can be expressed analytically in terms of the magnitude and momentum dependence of the single-nucleon potentials using the Hugenholtz-Van Hove (HVH) theorem. These relationships provide new insights about the fundamental physics governing the density dependence of nuclear symmetry energy. Using the isospin and momentum (k) dependent MDI interaction as an example, the contribution of different terms in the single-nucleon potential to the Esym (?) and L(?) are analyzed in detail at different densities. It is shown that the behavior of Esym is mainly determined by the first-order symmetry potential Usym,1(?, k) of the single-nucleon potential. The density slope L(?) depends not only on the first-order symmetry potential Usym,1(?, k) but also on the second-order one Usym,2(?, k). Both the Usym,1(?, k) and Usym,2(?, k) at normal density ? 0 are constrained by the isospin- and momentum-dependent nucleon optical potential extracted from the available nucleon-nucleus scattering data. The Usym,2(?, k) especially at high density and momentum affects significantly the L(?), but it is theoretically poorly understood and currently there is almost no experimental constraints known. (orig.)
Effective interaction: From nuclear reactions to neutron stars
Indian Academy of Sciences (India)
D N Basu
2014-05-01
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 slope agree well with experimentally extracted values. Folded microscopic potentials using this effective interaction, whose density dependence is determined from nuclear matter calculations, provide excellent descriptions for proton, alpha and cluster radioactivities, elastic and inelastic scattering. The nuclear deformation parameters extracted from inelastic scattering of protons agree well with other available results. The high density behaviour of symmetric and asymmetric nuclear matter satisfies the constraints from the observed flow data of heavy-ion collisions. The neutron star properties studied using -equilibrated neutron star matter obtained from this effective interaction reconcile with the recent observations of the massive compact stars.
Constraining the nuclear matter equation of state around twice saturation density
Le Fèvre, A.; Leifels, Y.; Reisdorf, W.; Aichelin, J.; Hartnack, Ch.
2016-01-01
Using FOPI data on elliptic flow in Au + Au collisions between 0.4 and 1.5 A GeV we extract constraints for the equation of state (EOS) of compressed symmetric nuclear matter using the transport code IQMD by introducing an observable describing the evolution of the size of the elliptic flow as a function of rapidity. This observable is sensitive to the nuclear EOS and a robust tool to constrain the compressibility of nuclear matter up to 3?0.
International Nuclear Information System (INIS)
The method of correlated basis functions is studied and applied to the Fermi systems: liquid 3He, nuclear matter and neutron matter. The reduced cluster integrals xsub(ijkl...) and so the subnormalization integrals Isub(ijkl...) are generalized to coinciding quantum numbers out of the set [i, j, k, l,...]. This generalization has an important consequence for the radial distribution function g(r) (and then for the liquid structure function); g(r) has no contributions of the order 0(A-1). For 3He the state-independent two-body correlation function f(r) is calculated from the Euler-Lagrange equation (in the limit of r ? 0) for the unrenormalized two-body energy functional. For nuclear matter and neutron matter we adopt the three-parameter correlation function of Baeckman et al. Then the energy expectation values are calculated by including up to the three-body terms in the un-renormalized and renormalized version of the correlated basis functions method. (orig.)
The particle-hole interaction and pion condensation in nuclear matter
International Nuclear Information System (INIS)
Following a general introduction in chapter one, the second chapter describes the calculation of the pion p-wave self-energy in nuclear matter. This quantity represents the amount of binding a pion gains by interacting with the medium. The third chapter exploits the formalism developed to work out a simple conclusion which can be drawn from the general notion of the divergence of a series of diagrams. Clearly, if the pion propagator in the medium develops a pole at some density, this implies that the one-pion-exchange NN interaction in the medium will be drastically modified. In Chapter four, the contribution to the binding energy of nuclear matter is calculated for a special set of diagrams - ring diagrams. Finally, in chapter five the low and intermediate momentum components of the nuclear matter G matrix which are relevant for nuclear structure, are studied. (Auth.)
A beyond-mean-field example with zero–range effective interactions in infinite nuclear matter
Directory of Open Access Journals (Sweden)
Colò G.
2012-12-01
Full Text Available Zero–range effective interactions are commonly used in nuclear physics to describe a many-body system in the mean-field framework. If they are employed in beyond-mean-field models, an artificial ultraviolet divergence is generated by the zero-range of the interaction. We analyze this problem in symmetric nuclear matter with the t0 – t3 Skyrme model. In this case, the second-order energy correction diverges linearly with the momentum cutoff ?. After that, we extend the work to the case of nuclear matter with the full Skyrme interaction. A strong divergence (? ?5 related to the velocity-dependent terms of the interaction is obtained. Moreover, a global fit can be simultaneously performed for both symmetric and nuclear matter with different neutron-to-proton ratios. These results pave the way for applications to finite nuclei in the framework of beyond mean-field theories.
Intrinsic neutron background of nuclear emulsions for directional Dark Matter searches
Aleksandrov, A; Asada, T.; Buonaura, A.(Dipartimento di Fisica dell’Università Federico II di Napoli, 80125 , Naples, Italy); Consiglio, L.(INFN Sezione di Napoli, 80125 , Naples, Italy); D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.(INFN-Laboratori Nazionali del Gran Sasso, 67010 , Assergi, L’Aquila, Italy); di Vacri, M. L.; Furuya, S; Galati, G.; Gentile, V.; T. Katsuragawa(Nagoya University, J-464-8602 Nagoya, Japan); Laubenstein, M; Lauria, A.(Dipartimento di Fisica dell’Università Federico II di Napoli, 80125 , Naples, Italy)
2015-01-01
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 s...
Systematic analysis of the incoming quark energy loss in cold nuclear matter
Li-hua SONG; Duan, Chun-Gui; Liu, Na
2012-01-01
The investigation into the fast parton energy loss in cold nuclear matter is crucial for a good understanding of the parton propagation in hot-dense medium. By means of four typical sets of nuclear parton distributions and three parametrizations of quark energy loss, the parameter values in quark energy loss expressions are determined from a leading order statistical analysis of the existing experimental data on nuclear Drell-Yan differential cross section ratio as a function of the quark mom...
The matter of probability controlling melting of nuclear ship reactor
International Nuclear Information System (INIS)
In the first part of this work beside description of split power, power of radioactivity disintegration and afterpower and its ability to extinguish, the genera condition of melting nuclear reactor core and its detailed versions were described. This paper also include the description of consequences melting nuclear reactor core both in case of stationary and mobile (ship) reactor and underline substantial differences. Next, fulfilled with succeed, control under melting of stationary nuclear reactor core was characterized.The middle part describe author's idea of controlling melting of nuclear ship reactor core. It is based on: - the suggestion of prevention pressure's untightness in safety tank of nuclear ship reactor by '' corium '' - and the suggestion of preventing walls of this tank from melting by '' corium ''. In the end the technological and construction barriers of the prevention from melting nuclear ship reactor and draw conclusions was presented. (author)
Clusterized nuclear matter in the (proto-)neutron star crust and the symmetry energy
Energy Technology Data Exchange (ETDEWEB)
Raduta, A.R. [IFIN-HH, Bucharest-Magurele (Romania); Aymard, F.; Gulminelli, F. [CNRS, UMR6534, LPC, Caen (France); ENSICAEN, UMR6534, LPC, Caen (France)
2014-02-15
Though generally agreed that the symmetry energy plays a dramatic role in determining the structure of neutron stars and the evolution of core-collapsing supernovae, little is known in what concerns its value away from normal nuclear matter density and, even more important, the correct definition of this quantity in the case of unhomogeneous matter. Indeed, nuclear matter traditionally addressed by mean-field models is uniform while clusters are known to exist in the dilute baryonic matter which constitutes the main component of compact objects outer shells. In the present work we investigate the meaning of symmetry energy in the case of clusterized systems and the sensitivity of the proto-neutron star composition and equation of state to the effective interaction. To this aim an improved Nuclear Statistical Equilibrium (NSE) model is developed, where the same effective interaction is consistently used to determine the clusters and unbound particles energy functionals in the self-consistent mean-field approximation. In the same framework, in-medium modifications to the cluster energies due to the presence of the nuclear gas are evaluated. We show that the excluded volume effect does not exhaust the in-medium effects and an extra isospin and density-dependent energy shift has to be considered to consistently determine the composition of subsaturation stellar matter. The symmetry energy of diluted matter is seen to depend on the isovector properties of the effective interaction, but its behavior with density and its quantitative value are strongly modified by clusterization. (orig.)
Cylindrically asymmetric hydrodynamic equations
Chojnacki, Mikolaj
2006-01-01
We show that the boost-invariant and cylindrically asymmetric hydrodynamic equations for baryon-free matter may be rewritten as only two coupled partial differential equations. In the case where the system exhibits the cross-over phase transition, the standard numerical methods may be applied to solve these equations. An example of our results describing non-central gold on gold collisions at RHIC energies is presented.
Pötzschner, B.; Mohamed, F.; Lichtinger, A.; Bock, D.; Rössler, E. A.
2015-10-01
We study a dynamically asymmetric binary glass former with the low-Tg component m-tri-cresyl phosphate (m-TCP: Tg = 206 K) and a spirobichroman derivative as a non-polymeric high-Tg component (Tg = 382 K) by means of 1H nuclear magnetic resonance (NMR), 31P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two Tg are identified, Tg1 and Tg2. The slower one is attributed to the high-Tg component (?1-process), and the faster one is related to the m-TCP molecules (?2-process). Yet, there are indications that a small fraction of m-TCP is associated also with the ?1-process. While the ?1-relaxation only weakly broadens upon adding m-TCP, the ?2-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations—as probed by 31P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the ?2-process and it reflects an isotropic, liquid-like motion which is observed even below Tg1, i.e., in the matrix of the arrested high-Tg molecules. As proven by 2D 31P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(ln??2). At Tg1 a crossover is found for the temperature dependence of (mean) ??2(T) from non-Arrhenius above to Arrhenius below Tg1 which is attributed to intrinsic confinement effects. This "fragile-to-strong" transition also leads to a re-decrease of Tg2(cm-TCP) at low concentration cm-TCP, i.e., a maximum is observed in Tg2(cm-TCP) while Tg1(cm-TCP) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously reported for polymer-plasticizer systems.
Pötzschner, B; Mohamed, F; Lichtinger, A; Bock, D; Rössler, E A
2015-10-21
We study a dynamically asymmetric binary glass former with the low-Tg component m-tri-cresyl phosphate (m-TCP: Tg = 206 K) and a spirobichroman derivative as a non-polymeric high-Tg component (Tg = 382 K) by means of (1)H nuclear magnetic resonance (NMR), (31)P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two Tg are identified, Tg 1 and Tg 2. The slower one is attributed to the high-Tg component (?1-process), and the faster one is related to the m-TCP molecules (?2-process). Yet, there are indications that a small fraction of m-TCP is associated also with the ?1-process. While the ?1-relaxation only weakly broadens upon adding m-TCP, the ?2-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations-as probed by (31)P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the ?2-process and it reflects an isotropic, liquid-like motion which is observed even below Tg 1, i.e., in the matrix of the arrested high-Tg molecules. As proven by 2D (31)P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(ln?? 2). At Tg 1 a crossover is found for the temperature dependence of (mean) ?? 2(T) from non-Arrhenius above to Arrhenius below Tg 1 which is attributed to intrinsic confinement effects. This "fragile-to-strong" transition also leads to a re-decrease of Tg 2(cm - TCP) at low concentration cm - TCP, i.e., a maximum is observed in Tg 2(cm - TCP) while Tg 1(cm - TCP) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously reported for polymer-plasticizer systems. PMID:26493914
International Nuclear Information System (INIS)
Recent developments of gravitational wave detectors like LIGO and Virgo provide us an optimistic opportunity of expecting first few events in near future. One of the exciting possibilities is that we can probe the inner structure of compact objects like neutron star by analyzing the observed pattern of gravitational waves. Among the characteristic features of the equation of state (EoS), the symmetry energy of dense hadronic matter is discussed. A model which implements a new scaling law of physical parameters of hadronic matter is briefly sketched to demonstrate how it affects the equation of state and the outcome for the mass and radius estimation is discussed for an n-p asymmetric configuration
International Nuclear Information System (INIS)
Effects due to the temperature dependence of the nuclear binding energy upon the equation of state (EOS) for hot nuclear matter are studied. Nuclear contributions to the free energy are represented by temperature dependent liquid drop model terms. Phase coexistence is assumed for temperatures of the order of 1 MeV ? T ? 6 MeV, baryon number densities ? of the order of 10-4fm-3 ? ? ? 10-1fm-3 and lepton fractions of the order of 0.2 ? y1 ? 0.4. It is found that the total pressure of the system is not affected by the temperature dependence of the nuclear free energy, in spite of changes observed in the nuclear pressure due to the different parametrizations used to represent the nuclear binding energy. (orig.)
Inductive asymmetric cell division
Ishidate, Takao; Kim, Soyoung; Mello, Craig C; Shirayama, Masaki
2013-01-01
C. elegans, with its invariant cell lineage, provides a powerful model system in which to study signaling-dependent asymmetric cell division. The C. elegans ?-catenin-related protein, WRM-1, specifies endoderm at the 4-cell stage during the first cell signaling-induced asymmetric cell division of embryogenesis. During this interaction, Wnt signaling and the cell cycle regulator CDK-1 act together to induce the asymmetric cortical release of WRM-1 at prophase of the EMS cell cycle. Genetic studies suggest that release of WRM-1 unmasks a cortical site that drives EMS spindle rotation onto the polarized axis of the cell, simultaneously making WRM-1 available for nuclear translocation, and downstream signaling to specify endoderm. These studies suggest a general paradigm for how cortical factors like WRM-1 can function at the cell cortex to mask potentially confounding polarity cues, and when released with appropriate cell cycle timing, can also function downstream to define cell fate. PMID:24524013
Tabulated equation of state for supernova matter including full nuclear ensemble
Energy Technology Data Exchange (ETDEWEB)
Buyukcizmeci, N.; Botvina, A. S.; Mishustin, I. N. [Frankfurt Institute for Advanced Studies, J.W. Goethe University, D-60438 Frankfurt am Main (Germany)
2014-07-01
This is an introduction to the tabulated database of stellar matter properties calculated within the framework of the Statistical Model for Supernova Matter (SMSM). The tables present thermodynamical characteristics and nuclear abundances for 31 values of baryon density (10{sup –8} < ?/?{sub 0} < 0.32, ?{sub 0} = 0.15 fm{sup –3} is the normal nuclear matter density), 35 values of temperature (0.2 MeV < T < 25 MeV), and 28 values of electron-to-baryon ratio (0.02 < Y{sub e} < 0.56). The properties of stellar matter in ? equilibrium are also considered. The main ingredients of the SMSM are briefly outlined, and the data structure and content of the tables are explained.
Tabulated Equation of State for Supernova Matter Including Full Nuclear Ensemble
Buyukcizmeci, N.; Botvina, A. S.; Mishustin, I. N.
2014-07-01
This is an introduction to the tabulated database of stellar matter properties calculated within the framework of the Statistical Model for Supernova Matter (SMSM). The tables present thermodynamical characteristics and nuclear abundances for 31 values of baryon density (10-8 < Ï/Ï0 < 0.32, Ï0 = 0.15 fm-3 is the normal nuclear matter density), 35 values of temperature (0.2 MeV < T < 25 MeV), and 28 values of electron-to-baryon ratio (0.02 < Ye < 0.56). The properties of stellar matter in Î² equilibrium are also considered. The main ingredients of the SMSM are briefly outlined, and the data structure and content of the tables are explained.
Jet Quenching and Radiative Energy Loss in Dense Nuclear Matter
Gyulassy, Miklos; Vitev, Ivan; Wang, Xin-Nian; Zhang, Ben-Wei
2003-01-01
We review recent finite opacity approaches (GLV, WW, WOGZ) to the computation of the induced gluon radiative energy loss and their application to the tomographic studies of the density evolution in ultra-relativistic nuclear collisions.
Nuclear matter equation of state including two-, three-, and four-nucleon correlations
Röpke, G.
2015-11-01
Light clusters (mass number A ?4 ) in nuclear matter at subsaturation densities are described using a quantum statistical approach to calculate the quasiparticle properties and abundances of light elements. I review the formalism and approximations used and extend it with respect to the treatment of continuum correlations. Virial coefficients are derived from continuum contributions to the partial densities which depend on temperature, densities, and total momentum. The Pauli blocking is modified taking correlations in the medium into account. Both effects of continuum correlations lead to an enhancement of cluster abundances in nuclear matter at higher densities. Based on calculations for A =2 , estimates for the contributions with A =3 ,4 are given. The properties of light clusters and continuum correlations in dense matter are of interest for nuclear structure calculations, heavy-ion collisions, and astrophysical applications such as the formation of neutron stars in core-collapse supernovae.
Phase transition patterns of nuclear matter based on extended linear sigma model
International Nuclear Information System (INIS)
We study systematically various types of phase transitions in nuclear matter at finite temperature T and baryon chemical potential ? based on the extended linear sigma model with nucleon degrees of freedom. It is shown that there are three types of phase transitions in nuclear matter: the chiral symmetry nonrestoration (SNR) at high temperature, the well-known liquid–gas (LG) phase transition at sub-saturation density and the Lifshitz phase transition (LPT) from the fully-gapped state to the state with Fermi surface. Their phase diagrams are established in the (T, ?)-plane and their physical properties are investigated in detail. The relationship between the chiral phase transition and the LG phase transition in nuclear matter is discussed. (author)
Diffusion of dark matter in a hot and dense nuclear environment
Cermeño, Marina; Silk, Joseph
2015-01-01
We calculate the mean free path in a hot and dense nuclear environment for a fermionic dark matter particle candidate interacting with nucleons via scalar and vector couplings. We determine the effects of density and temperature in the medium by using nuclear distribution functions to size the importance of the final state blocking. Our results show that stellar nuclear scenarios, where dark matter may be accreted, provide opacities several orders of magnitude larger than those for Standard Model neutrinos in the context of cooling of proto-neutron stars. We also show that in a diffusive approximation with couplings of Fermi's constant strength the obtained dark matter-nucleon crosss sections display the same sensitivity that upper limits constrained with collider searches in the mass region $m_\\chi \\lesssim$ 5 GeV.
The future of the nuclear industry: a matter of communication
International Nuclear Information System (INIS)
Since the very first successes achieved by the early scientists the infant nuclear industry was plagued by an atmosphere of uncertainty, conflict, anxiety and expectations. After the initial euphoria the Chernobyl accident shocked public opinion and perspectives changed. Nuclear energy is experience by the public in three dimensions. Firstly there are the technical realities of the reactor and its fantastically reduced source of power. Secondly, there is a psychological and political meaning, including the association of modern technology with authority, government, and control. The third dimension is the product of old myths about 'divine secrets', mad scientists dreadful pollution and cosmic apocalypse. To a large extent the nuclear industry is at fault for these emotional connotations. An early lapse in the communication process can be blamed for many of the misconceptions. The nuclear industry lost an opportunity by sticking to 'vagueness'. Recent trends show that a pattern of conditional acceptance is present in public opinion with regard to the nuclear industry. Possible solutions, including better communication, aggressive marketing, and the training of scientists to become communicators, are discussed. A study was done of community attitudes around Koeberg, and it is concluded that the public must be convinced of the fact that nuclear power is clean, safe, cheap and accepted as such by the industrially developed word. 62 refs., 13 figs
Jet-induced modifications of the characteristic of the bulk nuclear matter
Marcinkowski, P; KikoÅ‚a, D; Sikorski, J; Porter-Sobieraj, J; Gawryszewski, P; Zygmunt, B
2015-01-01
We present our studies on jet-induced modifications of the characteristic of the bulk nuclear matter. To describe such a matter, we use efficient relativistic hydrodynamic simulations in (3+1) dimensions employing the Graphics Processing Unit (GPU) in the parallel programming framework. We use Cartesian coordinates in the calculations to ensure a high spatial resolution that is constant throughout the evolution of the system. We show our results on how jets modify the hydrodynamics fields and discuss the implications.
Analysis of zero-frequency solutions of the pion dispersion equation in nuclear matter
Sadovnikova, V. A.
2005-01-01
In this paper we consider instability of nuclear matter which takes place when the frequencies of the collective excitations turn to zero. We investigate collective excitations with pion quantum numbers J^\\pi=0^-. We study the dependence of zero-frequency solutions of the pion dispersion equation on the value of the spin-isospin quasiparticle interaction G'. The solutions of the pion dispersion equation describe the different types of the excitations in the matter, \\omega_i(...
Jet-induced modifications of the characteristic of the bulk nuclear matter
Marcinkowski, P.; S?odkowski, M.; Kiko?a, D.; Sikorski, J.; Porter-Sobieraj, J.; Gawryszewski, P.; Zygmunt, B.
2016-01-01
We present our studies on jet induced modifications of the characteristics of bulk nuclear matter. To describe such matter, we use efficient relativistic hydrodynamic simulations in (3+1)-dimension, employing the Graphics Processing Unit (GPU) in the parallel programming framework. We use Cartesian coordinates in the calculations to ensure a high spatial resolution that is constant throughout the evolution of the system. We show our results on how jets modify the hydrodynamics fields and discuss the implications.
Hyper matter-properties and formation in relativistic nuclear collisions
International Nuclear Information System (INIS)
The extension of the Periodic System into hitherto unexplored domains - antimatter and hyper matter - is discussed. Starting from an analysis of hyperon and single hypernuclear properties we investigate the structure of multi-hyperon objects (MEMOs) using and extended relativistic meson field theory. Those are contrasted with multi-strange quark states (strange lets). Their production mechanism is studied for relativistic collisions of heavy ions from present day experiments at Ags and Sps to future opportunities at RHIC and LH C. It is pointed out that absolutely stable hyper matter is unlikely to be produced in heavy ion collisions. New attention should be focused on short lived metastable hyper clusters (? ? 10 -1- s) and on intensity interferometry of multi-strange-baryon correlations. (author)
Fermionic condensation in ultracold atoms, nuclear matter and neutron stars
Salasnich, Luca
2013-01-01
We investigate the Bose-Einstein condensation of fermionic pairs in three different superfluid systems: ultracold and dilute atomic gases, bulk neutron matter, and neutron stars. In the case of dilute gases made of fermionic atoms the average distance between atoms is much larger than the effective radius of the inter-atomic potential. Here the condensation of fermionic pairs is analyzed as a function of the s-wave scattering length, which can be tuned in experiments by usin...
2013-07-10
...In the Matter of Duke Energy Carolinas, LLC; (Oconee Nuclear Station, Units 1, 2...Modifying License I Duke Energy Carolinas, LLC (Duke...to the Licensee, Duke Energy Carolinas, LLC, Oconee Nuclear Station, 7800...
Papa, Massimo
2012-01-01
Constraint Molecular dynamics CoMD calculations have been performed for symmetric nuclear matter (NM) by using a simple effective interactions of the Skyrme type. The set of parameter values reproducing common accepted saturation properties of nuclear matter have been obtained for different degree of stiffness characterizing the iso-vectorial potential density dependence. A comparison with results obtained in the limit of the Semi-Classical Mean Field approximation performed using the same kind of interaction put in evidence the role played by the many-body correlations present in the model explaining also the noticeable differences obtained in the parameter values in the two cases
-matrix approach to the equation of state of dilute nuclear matter
Indian Academy of Sciences (India)
J N De; S K Samaddar; B K Agrawal
2014-04-01
Based on the general analysis of the grand canonical partition function in the -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 all the ground and excited states of all the stable nuclear species and their scattering channels. The multiplicity distribution of these species to keep the matter in statistical equilibrium is found out and then the pressure, incompressibility and the symmetry energy of the system are evaluated. The calculated symmetry energy coefficients are found to be in fair agreement with the recent experimental data.
Morpho-quantitative analysis of nuclear inclusions in periaqueductal grey matter neurons in the cat.
Bianchi, R; M. Gioia
1985-01-01
The morpho-quantitative analysis carried out in the neuronal population of the periaqueductal grey matter of the cat has shown that nuclear inclusions are mainly of the filamentous type and that they are distributed predominantly in the external region, i.e. in the part of the periaqueductal grey matter situated furthest from the cerebral aqueduct, where 30% of the cells contain nuclear inclusions. In the internal region, i.e. in the part nearest the subependymal zone, only 2% of the neurons ...
A cluster-variational investigation of static density waves in nuclear matter
International Nuclear Information System (INIS)
A detailed comparison of the energy of the uniform phase and of phases exhibiting periodic density fluctuation is presented for extended nuclear systems. The short-range correlations are taken to be of Jastrow type and the calculations are carried through two-body cluster order. With semi-realistic central potentials containing hard cores, no energetic advantage of a non-uniform state is detected, either in symmetrical nuclear matter or in pure neutron matter. However, the analysis gives useful information on the conditions favoring an instability of the homogeneous phase and points to the essential role of the tensor force in the formation of spin-(isospin-) density waves. (Auth.)
International Nuclear Information System (INIS)
Constraint Molecular dynamics CoMD calculations have been performed for symmetric nuclear matter (NM) by using a simple effective interactions of the Skyrme type. The set of parameter values reproducing common accepted saturation properties of nuclear matter have been obtained for different degree of stiffness characterizing the iso-vectorial potential density dependence. A comparison with results obtained in the limit of the Semi-Classical Mean Field approximation performed using the same kind of interaction put in evidence the role played by the many-body correlations present in the model explaining also the noticeable differences obtained in the parameter values in the two cases.
Vacuum Effects and Compressional Properties of Nuclear Matter in Cutoff Field Theory
Kouno, H; Iwasaki, Y; Noda, N; Mitsumori, T; Koide, K; Hasegawa, A; Nakano, M; Kouno, Hiroaki; Sakamoto, Katsuaki; Iwasaki, Yoshitaka; Noda, Nobuo; Mitsumori, Tomohiro; Koide, Kazuharu; Hasegawa, Akira; Nakano, Masahiro
1997-01-01
Including the vacuum effects, the compressional properties of nuclear matter are studied in the cutoff field theory. Under the Hartree approximation, the low-energy effective Lagrangian is derived in the framework of the renormalization group methods. The coefficients are determined in a way where the physical results hardly depend on the value of the cutoff which is conveniently introduced into the theory. It is shown that, to reproduce the empirical data of the nucleus incompressibility, the compressibility of the nuclear matter is favorable to be 250$\\sim$350MeV.
Fundamentals and Elementary Outline of the Many-Body Theory of Nuclear Matter
International Nuclear Information System (INIS)
1. Introduction; 2. Nuclear matter; 3. Fermi gas; 4. Perturbation theory; 5. Second quantization; 6. Calculation of ?E with the help of Wick’s theorem; 7. Diagrams; 8. Linked-cluster theorem; 9. Momentum representation. Time integration; 10. Low-density approximation; 11. Hole self-energies; 12. Solution of the K-matrix equation; 13. The Brueckner-Gammel calculation; 14. The Q = 1 approximation; 15. Convergence of the theory; 16. Bethe's treatment of the three-body energy; 17. Review of nuclear-matter calculations. (author)
Pigato, Daniele
2013-01-01
The main goal of this Thesis, is the study of the thermodynamic properties of strongly interacting and dense nuclear matter, away from the nuclear ground state. This analysis constitutes one of the most interesting aspect and one of the major tasks in the modern high-energy nuclear physics. The first part of this dissertation, addresses the phenomenological and theoretical study of the nuclear matter equation of state, under the extreme conditions reached in high energy heavy ion collision ex...
Spectral functions for relativistic models of nuclear matter
International Nuclear Information System (INIS)
We introduce a quick method to determine the spectral function for relativistic fermions with a given spinor structure of their self energy. The method is applied to include tensor parts of the self energy, which might be of importance in nuclear systems. (orig.)
Pinning down nuclear. To the core of the matter
Energy Technology Data Exchange (ETDEWEB)
Boeck, Helmut; Gerstmayr, Michael [Technische Univ., Vienna (Austria); International Atomic Energy Agency, Vienna (Austria); Radde, Eileen [Nuclear Engineering Seibersdorf GmbH (Austria); International Atomic Energy Agency, Vienna (Austria)
2014-07-01
The nuclear disaster in Fukushima shocked the world tremendously. The call to pull out of nuclear energy is getting louder - and more often than not by politicians trying to lure the favour of voters. Through the media there are half-truths and false information floating about the global consequences of the disaster and sensational prognoses for the future, all of which are in turn unsettling for the general public. Are the opposers to nuclear energy playing with the fear of the public or is the threat real? This book tells, in a captivating manner - authenticated with examples and incidents not known by many - what the threat for the area actually looks like. They confront the level of truth in the frightening scenarios and inform about the situation in case of emergency. Furthermore, they examine factors that preceded the disaster and broach the subject of the incredible hunger for energy, which dominates the world and continues to drive the commercial use of nuclear energy. Also the ghost of Chernobyl and its aftermath, which has been dismissed from our minds, is re-examined based on current knowledge. The book impresses with insider know-how, latest detailed knowledge, amazing facts and an entertaining narrative style.
Fluctuation effects on bubble growth in hot nuclear matter
International Nuclear Information System (INIS)
The evolution of bubbles with arbitrary density in an infinite nuclear system is studied in a simplified treatment. Kinetic pressure fluctuations on the bubble surface are considered. The critical radius, evolution time and probability for bubble expansion are shown to depend significantly on the initial bubble density. (author)