Test of Nuclear Wave Functions for Pseudospin Symmetry

Using the fact that pseudospin is an approximate symmetry of the Dirac Hamiltonian with realistic scalar and vector mean fields, we derive the wave functions of the pseudospin partners of eigenstates of a realistic Dirac Hamiltonian and compare these wave functions with the wave functions of the Dirac eigenstates.Comment: 11 pages, 4 figures, minor changes in text and figures to conform with PRL requirement

Number of states for nucleons in a single-jj shell

In this paper we obtain number of states with a given spin $I$ and a given isospin $T$ for systems with three and four nucleons in a single-$j$ orbit, by using sum rules of six-$j$ and nine-$j$ symbols obtained in earlier works.Comment: to be published in Physical Review

Critical-Point Symmetry in a Finite System

At a critical point of a second order phase transition the intrinsic energy surface is flat and there is no stable minimum value of the deformation. However, for a finite system, we show that there is an effective deformation which can describe the dynamics at the critical point. This effective deformation is determined by minimizing the energy surface after projection onto the appropriate symmetries. We derive analytic expressions for energies and quadrupole rates which provide good estimates for these observables at the critical point.Comment: 12 pages, 2 figures, 2 tables, Phys. Rev. Lett. in pres

Algebraic-eikonal approach to medium energy proton scattering from odd-mass nuclei

We extend the algebraic-eikonal approach to medium energy proton scattering from odd-mass nuclei by combining the eikonal approximation for the scattering with a description of odd-mass nuclei in terms of the interacting boson-fermion model. We derive closed expressions for the transition matrix elements for one of the dynamical symmetries and discuss the interplay between collective and single-particle degrees of freedom in an application to elastic and inelastic proton scattering from $^{195}$Pt.Comment: latex, 14 pages, 4 figures uuencoded, to be published in Physical Review

An intrinsic state for an extended version of the interacting boson model

An intrinsic-state formalism for IBM-4 is presented. A basis of deformed bosons is introduced which allows the construction of a general trial wave function which has Wigner's spin-isospin SU(4) symmetry as a particular limit. Intrinsic-state calculations are compared with exact ones showing good agreement.Comment: 12 pages, TeX (ReVTeX). Content changed. Accepted in Phys. Rev.

General pairing interactions and pair truncation approximations for fermions in a single-j shell

We investigate Hamiltonians with attractive interactions between pairs of fermions coupled to angular momentum J. We show that pairs with spin J are reasonable building blocks for the low-lying states. For systems with only a J = Jmax pairing interaction, eigenvalues are found to be approximately integers for a large array of states, in particular for those with total angular momenta I le 2j. For I=0 eigenstates of four fermions in a single-j shell we show that there is only one non-zero eigenvalue. We address these observations using the nucleon pair approximation of the shell model and relate our results with a number of currently interesting problems.Comment: a latex text file and 2 figures, to be publishe

Number of Spin II States of Identical Particles

In this paper we study the enumeration of number (denoted as ${D_I}$) of spin $I$ states for fermions in a single-$j$ shell and bosons with spin $l$. We show that $D_I$ can be enumerated by the reduction from SU$(n+1)$ to SO(3). New regularities of $D_I$ are discerned.Comment: 3 pages, no figures. to be publishe

Dynamical Symmetries of Dirac Hamiltonian

Several dynamical symmetries of the Dirac Hamiltonian are reviewed in a systematic manner and the conditions under which such symmetries hold. These include relativistic spin and orbital angular momentum symmetries, SO(4)\times SU_{\sigma}(2) symmetry for the Dirac Hydrogen atom, SU(3)\times SU_{\sigma}(2) symmetry for the relativistic simple harmonic oscillator. The energy spectrum in each case is calculated from group-theoretic considerations.Comment: 15 pages, V3 typos removed and some new material include

Classification of states of single-jj fermions with JJ-pairing interaction

In this paper we show that a system of three fermions is exactly solvable for the case of a single-$j$ in the presence of an angular momentum-$J$ pairing interaction. On the basis of the solutions for this system, we obtain new sum rules for six-$j$ symbols. It is also found that the "non-integer" eigenvalues of three fermions with angular momentum $I$ around the maximum appear as "non-integer" eigenvalues of four fermions when $I$ is around (or larger than) $J_{\rm max}$ and the Hamiltonian contains only an interaction between pairs of fermions coupled to spin $J=J_{\rm max}=2j-1$. This pattern is also found in five and six fermion systems. A boson system with spin $l$ exhibits a similar pattern.Comment: to be published in Physical Review

Reliabiliy and clinical validity of the italian reflux symptom index

Currently, there is no Italian version of the Reflux Symptom Index (RSI). The aim of this study was to develop an Italian RSI and to evaluate its internal consistency, reliability, and clinical validity. The study design used was a cross-sectional survey study. Eighty patients with a Reflux Finding Score (RFS) >7, and 193 asymptomatic subjects were included in the study. For the RSI reliability analysis, the appositely developed Italian RSI was filled twice, with a week interval, by the 80 patients and 80 control subjects. The test-retest reliability was assessed through the Pearson correlation test, whereas the Cronbach's \u3b1 coefficient was used for internal consistency analysis. For the clinical validity assessment, the scores obtained in the pathological group were compared with the data from the asymptomatic individuals through the Student's t test. Finally, the correlation between RSI and RFS in the 80 patients was assessed. All of the patients filled in the entire questionnaire autonomously. The test-retest reliability in the patients, as well as in the control group, was very high (r > 0.90); the internal consistency also showed very high values (\u3b1 = 0.99). The mean RSI score in the patients was 21.1 \ub1 6.6, whereas in the control group it was 6.3 \ub1 5.6; the difference was statistically significant (P = 0.0001). The mean RFS score in the 80 patients was 9.2 \ub1 2.7 and the correlation between RFS score and RSI score was rather high (r = 0.89). The Italian RSI is easily administered, highly reproducible, and exhibits excellent clinical validity