Single particle calculations for a Woods-Saxon potential with triaxial deformations, and large Cartesian oscillator basis

We present a computer program which solves the Schrodinger equation of the stationary states for an average nuclear potential of Woods-Saxon type. In this work, we take specifically into account triaxial (i.e. ellipsoidal) nuclear surfaces. The deformation is specified by the usual Bohr parameters. The calculations are carried out in two stages. In the first, one calculates the representative matrix of the Hamiltonian in the cartesian oscillator basis. In the second stage one diagonalizes this matrix with the help of subroutines of the EISPACK library. If it is wished, one can calculate all eigenvalues, or only the part of the eigenvalues that are contained in a fixed interval defined in advance. In this latter case the eigenvectors are given conjointly. The program is very rapid, and the run-time is mainly used for the diagonalization. Thus, it is possible to use a significant number of the basis states in order to insure a best convergence of the results.Comment: no figures, but tbles in separate pdf file

Analytical relationship for the cranking inertia

The wave function of a spheroidal harmonic oscillator without spin-orbit interaction is expressed in terms of associated Laguerre and Hermite polynomials. The pairing gap and Fermi energy are found by solving the BCS system of two equations. Analytical relationships for the matrix elements of inertia are obtained function of the main quantum numbers and potential derivative. They may be used to test complex computer codes one should develop in a realistic approach of the fission dynamics. The results given for the $^{240}$Pu nucleus are compared with a hydrodynamical model. The importance of taking into account the correction term due to the variation of the occupation number is stressed.Comment: 12 pages, 4 figure

Shell corrections for finite depth potentials with bound states only

A new method of calculating unique values of ground-state shell corrections for finite depth potentials is shown, which makes use of bound states only. It is based on (i) a general formulation of extracting the smooth part from any fluctuating quantity proposed by Strutinsky and Ivanjuk, (ii) a generalized Strutinsky smoothing condition suggested recently by Vertse et al., and (iii) the technique of the Lanczos $\sigma$ factors. Numerical results for some spherical heavy nuclei ($^{132,154}$Sn, $^{180,208}$Pb and $^{298}$114) are presented and compared to those obtained with the Green's function oscillator expansion method.Comment: 5 pages, 2 tables and 3 figures. Accepted in Physics Letters

Coherent Pair State of Pion in Constituent Quark Model

A coherent state of pions is introduced to the nonrelativistic quark model. The coherent pair approximation is employed for the pion field in order to maintain the spin-isospin symmetry. In this approximation the pion is localized in the momentum space, and the vertex form factor in the pion-quark interaction is derived from this localization. The nucleon masses and wave functions are calculated using this model, and our results are compared to those of the quark model with the one pion exchange potential. Similar result is obtained for the mass spectrum, but there exists a clear difference in the internal structure of nucleon resonances.Comment: 17 pages, 2 figures, revtex, submitted to Phys. Rev.

Thermal conductivity of one-dimensional lattices with self-consistent heat baths: a heuristic derivation

We derive the thermal conductivities of one-dimensional harmonic and anharmonic lattices with self-consistent heat baths (BRV lattice) from the Single-Mode Relaxation Time (SMRT) approximation. For harmonic lattice, we obtain the same result as previous works. However, our approach is heuristic and reveals phonon picture explicitly within the heat transport process. The results for harmonic and anharmonic lattices are compared with numerical calculations from Green-Kubo formula. The consistency between derivation and simulation strongly supports that effective (renormalized) phonons are energy carriers in anharmonic lattices although there exist some other excitations such as solitons and breathers.Comment: 4 pages, 3 figures. accepted for publication in JPS

Some remarks on off-shell scattering in the eikonal approximation

Using the Abel inversion for the eikonal phase as function of the interaction we derive simple integral relations between half and on-shell eikonal phases. A frequently used short-range approximation for the half off-shell phase and profile appears supported by the above-mentioned relation. We work out some examples and also address the half off-shell eikonal phase pertinent to a diffractive amplitude. The latter is relevant for a calculation of selected transparencies ${\cal T}$ of nuclei for a proton, knocked-out in selected semi-inclusive (SI) $A(e,e'p)X$ reactions. Some numerical results for ${\cal T}$ are given.Comment: 12 pages, uuencoded PS files for text and fig

Thermal conductivity of the Toda lattice with conservative noise

We study the thermal conductivity of the one dimensional Toda lattice perturbed by a stochastic dynamics preserving energy and momentum. The strength of the stochastic noise is controlled by a parameter $\gamma$. We show that heat transport is anomalous, and that the thermal conductivity diverges with the length $n$ of the chain according to $\kappa(n) \sim n^\alpha$, with $0 < \alpha \leq 1/2$. In particular, the ballistic heat conduction of the unperturbed Toda chain is destroyed. Besides, the exponent $\alpha$ of the divergence depends on $\gamma$

Asymmetric Heat Flow in Mesoscopic Magnetic System

The characteristics of heat flow in a coupled magnetic system are studied. The coupled system is composed of a gapped chain and a gapless chain. The system size is assumed to be quite small so that the mean free path is comparable to it. When the parameter set of the temperatures of reservoirs is exchanged, the characteristics of heat flow are studied with the Keldysh Green function technique. The asymmetry of current is found in the presence of a local equilibrium process at the contact between the magnetic systems. The present setup is realistic and such an effect will be observed in real experiments. We also discuss the simple phenomenological explanation to obtain the asymmetry.Comment: 13 pages, 3 figure

Shell Corrections for Finite-Depth Deformed Potentials: Green's Function Oscillator Expansion Method

Shell corrections of the finite deformed Woods-Saxon potential are calculated using the Green's function method and the generalized Strutinsky smoothing procedure. They are compared with the results of the standard prescription which are affected by the spurious contribution from the unphysical particle gas. In the new method, the shell correction approaches the exact limit provided that the dimension of the single-particle (harmonic oscillator) basis is sufficiently large. For spherical potentials, the present method is faster than the exact one in which the contribution from the particle continuum states is explicitly calculated. For deformed potentials, the Green's function method offers a practical and reliable way of calculating shell corrections for weakly bound nuclei.Comment: submitted to Phys. Rev. C, 12 pages, 7 figure