Collective Excitation of Nuclear Matter

Abstract

Collective excitations of nuclear matter which have their origin in the short-range interaction between nucleons in nucleus are studied in order to correlate strongly excited level groups in nuclear reactions of relatively high energy with nuclear structure. Making use of an effective inter-nucleon potential which is determined from the analysis of pairing energies of various nuclei, the collective excitation energies are estimated in one particle-hole pair approximation of the new Tamm-Dancoff method.Three stable modes of excitations are possible, that is, spin wave, isospin wave and coupled spin-isospin wave. Of these three modes the spin wave is the lowest exciting wave, the coupled spin-isospin wave is the second and the isospin wave is the highest. Each of them has its own critical momentum above which they become unstable.The strengths of coupling of these exciting waves with particle motion are also estimated. The higher exciting wave has the stronger coupling with particle motion and therefore the larger width of excitation energy.These exciting mechanisms would have some connection with the experimental results on inelastic scattering of nucleons and photonuclear reactions. at Southern Illinois University on June 3, 2015 http://ptp.oxfordjournals.org/ Downloaded from Collective Excitation of Nuclear Matter § 2. Eigenvalue equation for one particle-hole pair state We begin wIth the following nuclear Hamiltonian, H=Ho+H1' Ho= __ 1_ r dxcjJ*(X)V2cjJ(X) , 2M J H,= ~ dx l dx 2 cjJ*(X2) cjJ*(x l ) V(Xl' x 2 ) cjJ(x l ) cjJ(x 2 ),(1) * where M is the effective mass of nucleon in nucleus, cjJ(x) the wave function of nucleon which includes both spin and isospin, and V the effective residual inter-* We lise the natural unit h=c=l.

Spectral characterization of hydrogen-like atoms confined by oscillating systems

“…A peak of the transmission amplitude does corresponds to a resonant eigenstate [21]. According with [9] a number of four resonant states are found for the considered potential shape (s = 3), corresponding to the four peaks, as figure (3) shows.…”

Nucleon, Two-Nucleon Reactions Above 100 MEV

“…Such enhancement would be expected not only for transitions into the levels which would also be most strongly populated by interactions with photons, but also into other types of giant resonance ; Balashov & Tulinov (22) calculate that giant spin-wave resonances, centering about the same energy as, but being much wider than, the photonuclear giant dipole (isospin-wave) resonance, would be as important as the latter in in elastic scattering of nucleons having hundreds of MeV; a somewhat different conclusion was drawn by Hatano (113). Such an increased width was ap parently observed by Azhgirei et al (17).…”