Biomedical subjects

F Iachello

Publications and source records attributed to F Iachello.

At least 19 recordsLinked to original sources

PubMed2005

Dynamic supersymmetries of differential equations with applications to nuclear spectroscopy.

Dynamic supersymmetries of differential equations are defined. The case of a liquid drop with quadrupole deformation coupled to a particle with j = 3/2 is shown as an example of a situation where the dynamic supersymmetry OSp(5/4) may occur. A special solution, called E(5/4), of interest in the spectroscopy of odd-even nuclei in the transitional region between spherical and gamma unstable is explicitly worked out.

Journal Article↗

PubMed2004

Phase structure of the two-fluid proton-neutron system.

The phase structure of a two-fluid bosonic system is investigated. The proton-neutron interacting boson model possesses a rich phase structure involving three control parameters and multiple order parameters. The surfaces of quantum phase transition between spherical, axially symmetric deformed, and SU(*)(pinu)(3) triaxial phases are determined.

Journal Article↗

PubMed2004

Quantum phase transitions in mesoscopic systems.

Quantum phase transitions in mesoscopic systems are studied. It is shown that the main features of phase transitions, defined for infinite number of particles, N--> infinity, persist even for moderate N approximately 10. A Landau analysis of first order transitions is done and a "critical" exponent at the spinodal point is defined. Two order parameters are introduced to distinguish first from second order transitions. Applications to atomic nuclei, molecules, atomic clusters, and finite polymers are mentioned. Experimental evidence in atomic nuclei is presented.

Journal Article↗

PubMed2003

Phase transitions in angle variables.

Phase transitions in angle variables are studied. An example of angular phase transition, an axially to triaxially deformed "shape" transition in nuclei, is discussed. Spectroscopic signatures for the occurrence of these transitions are suggested. Preliminary experimental evidence is presented.

Journal Article↗

PubMed2001

Analytic description of critical point nuclei in a spherical-axially deformed shape phase transition.

An approximate solution at the critical point of the spherical to axially deformed shape phase transition in nuclei is presented. The eigenvalues of the Hamiltonian are expressed in terms of zeroes of Bessel functions of irrational order.

Journal Article↗

PubMed2000

Dynamic symmetries at the critical point

A new class of dynamic symmetries is introduced. It is suggested that an element of this class, associated with zeros of Bessel functions, be used to describe spectra of nuclei at or around the critical point of the U(5)-SO(6) shape phase transition, and, in general, spectra of systems undergoing a (second order) phase transition between the algebraic structures U(n-1) and SO(n).

Journal Article↗

PubMed1996