Binary nuclear molecules of an ?-particle and a heavier cluster

Abstract

a heavier cluster Abstract. A simple nuclear molecule is used as a model to interpret the band structure observed in elastic a-scattering and a-transfer reactions in the sd-shell. As in spectra of halogen acid molecules the bands have even and odd spins and parities. Due to the broadening and fine structure of the rotational levels they are characterized as giant resonances. The big moment of inertia and the line broadening is discussed in terms of performed measurements of scattering and the (c~, p) reaction. A fine structure of prominent peaks in the inelastic scattering crosssections hints at the existence of rotational states with an e-particle orbiting an excited core. PACS: 21.60.Gx; 24.30.Cz; 25.55.Ci

Alpha+28Si cluster structure as solitons on the nuclear surface

“…This solution yields 1uI2 as a static soliton and Re@) as a static breather-like soliton (lo]. A more general solution of equation (3), given by the modulated travelling wave packet, of amplitude ro, half-width L and envelope velocity V, (4) U(@, t ) = ro sech((@ -Vt)L-')exp(i(p@ + q t ) ) connects the Lagrangian equation (2) with the classical hydrodynamic approach [SI. We find that in this case equation (3) reduces to a modified Korteweg-de Vries (MKdV) equation for U [IO].…”

“…In order to quantize these soliton or breather solutions we use the well known nonperturbative weak-coupling procedure which consists in finding the normal modes of oscillation about the lowest state of the classical soliton and then exactly quantizing these normal modes [Ill. We write the potential energy in equation (2) as a functional Taylor expansion about the solutions which are its extrema, SU(u)/Su* = 0. These are also solutions of the stationaq part of equation (3). There are two classes of such solutions: trivial static solutions u r ( @ j = J m ) e x p e x p ( i k @ ) depending on the label k and describing the vacuum sector of the system; and a non-trivial solution uo(4) = 48 s ~h ( 2 8 4 ) describing the solitons.…”

Observation techniques and properties of α-cluster states at high excitation inA = 16-40 nuclei

“…This linear behaviour vs.``+ 1 indicates a rotational behaviour in the + 28 Si system. The moment of inertia can be obtained as I = 4 : 85 h 2 MeV ,1 , which indicates an object slightly more extended [14,15] than the "ground-state band". Further, experimentally the so-called parity splitting is absent -in serious conflict with most potential-scattering model predictions.…”

Alpha-particle transfer from 6Li to 28Si leading to high excitation of 32S

“…When the angular distributions were fitted by the squared Legendre polynomials P 2 l , the spin J was obtained as the order l, of the best fit at the resonance peak and the parity by (−1) l . By these means the mean excitation energy E exc of some dominating resonances in 32 S is E exc = 0.103J (J + 1) + 12.6 MeV [4]. A resonance, observed near the 31 MeV break-up threshold, is therefore expected to have the spin 12.…”

“…Thus the sudden perishing of the yield of alpha particles elastically scattered backward from 28 Si at 27.5 MeV [1] as shown in figure 1 is unexpected. Several studies [2][3][4][5] have addressed the pattern of resonance-like peaks between 6 MeV and 28 MeV in the scattering of alpha particles from silicon. It is assumed that the alpha particles are fused with the silicon nuclei of the target.…”