scholarly journals EFFECTIVE HADRON MASSES AND COUPLINGS IN NUCLEAR MATTER AND INCOMPRESSIBILITY

2001 ◽  
Vol 10 (03) ◽  
pp. 245-265 ◽  
Author(s):  
KUNITO TUCHITANI ◽  
HIROAKI KOUNO ◽  
AKIRA HASEGAWA ◽  
MASAHIRO NAKANO
Keyword(s):  
Nuclear Matter ◽  
Simple Relation ◽  
Normal Density ◽  
Effective Masses ◽  
Effective Lagrangian ◽  
Hadron Masses

The role of effective hadron masses and effective couplings in nuclear matter is studied using a generalized effective Lagrangian for σ-ω model. A simple relation among the effective masses, the effective couplings and the incompressibility K is derived. Using the relation, it is found that the effective repulsive and the effective attractive forces almost cancel each other out at the normal density. Inversely, if this cancellation is almost complete, K is 250~350 MeV.

EFFECTIVE VECTOR MESON MASSES IN A CUTOFF FIELD THEORY

2000 ◽  
Vol 09 (02) ◽  
pp. 169-183 ◽  
Author(s):  
KATSUAKI SAKAMOTO ◽  
MANABU NAKAI ◽  
HIROAKI KOUNO ◽  
AKIRA HASEGAWA ◽  
MASAHIRO NAKANO
Keyword(s):  
Field Theory ◽  
Mass Formula ◽  
High Energy ◽  
Low Energy ◽  
Meson Mass ◽  
Normal Density ◽  
Effective Masses ◽  
Effective Lagrangian ◽  
Cutoff Dependence ◽  
Energy Quantum

Based on quantum hadrodynamics with a finite cutoff, the effective masses of vector mesons (ω,ρ) in nuclear medium are calculated. We use a low-energy effective Lagrangian which is obtained by integrating high-energy quantum fluctuations. Although we use an artificial cutoff, the cutoff-dependence can be removed order by order. It is also found that the effective ρ-meson mass [Formula: see text] decreases as the density increases. The rate of the decrease becomes smaller at high density. As a result, at the normal density, [Formula: see text] is 0.85~0.92.

scholarly journals KÄHLER STABILIZED, MODULAR INVARIANT HETEROTIC STRING MODELS

2007 ◽  
Vol 22 (08n09) ◽  
pp. 1451-1588 ◽  
Author(s):  
MARY K. GAILLARD ◽  
BRENT D. NELSON
Keyword(s):  
Heterotic String ◽  
Target Space ◽  
Modular Invariant ◽  
Heterotic String Theory ◽  
Effective Lagrangian ◽  
Parity Conservation ◽  
Weakly Coupled ◽  
String Models ◽  
Early Universe Cosmology

We review the theory and phenomenology of effective supergravity theories based on orbifold compactifications of the weakly-coupled heterotic string. In particular, we consider theories in which the four-dimensional theory displays target space modular invariance and where the dilatonic mode undergoes Kähler stabilization. A self-contained exposition of effective Lagrangian approaches to gaugino condensation and heterotic string theory is presented, leading to the development of the models of Binétruy, Gaillard and Wu. Various aspects of the phenomenology of this class of models are considered. These include issues of supersymmetry breaking and superpartner spectra, the role of anomalous U(1) factors, issues of flavor and R-parity conservation, collider signatures, axion physics, and early universe cosmology. For the vast majority of phenomenological considerations the theories reviewed here compare quite favorably to other string-derived models in the literature. Theoretical objections to the framework and directions for further research are identified and discussed.

THE ROLE OF THE NUCLEAR MATTER COMPRESSION MODULUS IN NEUTRON STARS

2004 ◽  
Vol 13 (07) ◽  
pp. 1519-1524 ◽  
Author(s):  
VERÔNICA A. DEXHEIMER ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
MOISÉS RAZEIRA ◽  
MANFRED DILLIG
Keyword(s):  
Neutron Stars ◽  
Nuclear Matter ◽  
Body Problem ◽  
Mean Field Theory ◽  
Mean Field ◽  
Compression Modulus ◽  
Baryon Number ◽  
Many Body ◽  
Relativistic Mean Field

For the nuclear many body problem at high densities, formulated in the framework of a relativistic mean-field theory, we investigate in detail the compression modulus of nuclear matter as a function of the effective nucleon mass. We include consistently in our modelling chemical equilibrium as well as baryon number and electric charge conservation and investigate properties of neutron stars. Among other predictions we focus on the dependence of the maximum mass of a sequence of neutron stars as a function of the compression modulus and the nucleon effective mass.

Role of relativistic effects and three-body forces in nuclear matter properties

2019 ◽  
Vol 99 (2) ◽  
Author(s):  
S. Heidari ◽  
S. Zaryouni ◽  
H. R. Moshfegh ◽  
S. Goudarzi
Keyword(s):  
Nuclear Matter ◽  
Relativistic Effects ◽  
Body Forces ◽  
Three Body

scholarly journals The role of N*(2120) nucleon resonance in KΛ(1520) photon and hadronic productions

2014 ◽  
Vol 29 ◽  
pp. 1460244
Author(s):  
Ju-Jun Xie ◽  
En Wang ◽  
Bo-Chao Liu ◽  
J. Nieves
Keyword(s):  
Experimental Data ◽  
Invariant Mass ◽  
Cross Sections ◽  
Dalitz Plot ◽  
Total Cross Sections ◽  
Effective Lagrangian ◽  
Hadronic Production ◽  
Current Experimental Data ◽  
Theoretical Results

The associate KΛ(1520) photon and hadronic production in the γp → K+Λ(1520), pp → pK+Λ(1520) and π-p → K0Λ(1520) reactions are investigated within the effective Lagrangian approach and the isobar model. We are interested in the contribution from the N*(2120) (previously called N*(2080)) resonance, which has a significant coupling to the KΛ(1520) channel. The theoretical results show that the current experimental data for the γp → K+Λ(1520) reaction favor the existence of the N*(2120) resonance, and that these measurements can be used to further constrain its properties. We present results, including the N*(2120) contribution, for total cross sections of the γp → K+Λ(1520), π-p → K0Λ(1520), and pp → pK+Λ(1520) reactions. For this latter one, we also calculate invariant mass and Dalitz plot distributions.

CHARGE CARRIER MASS IN HIGH Tc SUPERCONDUCTORS

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3582-3584
Author(s):  
MARCO ZOLI
Keyword(s):  
Charge Carrier ◽  
Numerical Study ◽  
Small Polaron ◽  
Electron Mass ◽  
High Tc Superconductors ◽  
High Tc ◽  
Effective Masses ◽  
Polaron Theory ◽  
Holstein Model

The theory of polarons has experienced a surge of activity in the last years partly due to the possible role of polaronic quasiparticles in high Tc superconductors. This numerical study of the Holstein model shows that the polaronic effective masses become essentially dimension independent and of order ≃10–50 times the electron mass at sufficiently strong intermolecular coupling forces. Such values (which are much lower than those obtained by traditional small polaron theory) would erase one the serious objections against a (bi)polaronic picture for high Tc superconductors.

scholarly journals TDDFT WITH SKYRME FORCES: EFFECT OF TIME-ODD DENSITIES ON ELECTRIC GIANT RESONANCES

2008 ◽  
Vol 17 (01) ◽  
pp. 89-99 ◽  
Author(s):  
V. O. NESTERENKO ◽  
W. KLEINIG ◽  
J. KVASIL ◽  
P. VESELY ◽  
P.-G. REINHARD
Keyword(s):  
Ground State ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Galilean Invariance ◽  
Giant Resonances ◽  
Nd Isotopes ◽  
Effective Masses ◽  
Self Consistent ◽  
A Chain

Time-odd densities and their effect on electric giant resonances are investigated within the self-consistent separable random-phase-approximation (SRPA) for a variety of Skyrme forces (SkT6, SkO, SkM*, SIII, SGII, SLy4, SLy6, SkI3). Time-odd densities are essential for maintaining the Galilean invariance of the Skyrme functional. Their contribution is determined by the values and signs of the isovector and isoscalar effective-mass parameters of the force. In even-even nuclei these densities are not active in the ground state but can affect the dynamics. As a particular case, we explore the role of the current density in the description of isovector E1 and isoscalar E2 giant resonances in a chain of spherical and deformed Nd isotopes with A=134-158. The relation of the current to the effective masses and relevant parameters of the Skyrme functional is analyzed. It is shown that the current contributes substantially to E1 and E2 and the contribution is the same for all the isotopes along the chain, i.e. for both standard and exotic nuclei.

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