The possibility of time resonance (explosion) phenomena in high-energy nuclear reactions

Abstract

This study shows that the exponential decrease of the energy spectra, accompanied by slight oscillations, with final-fragment energy in high-energy nuclear reaction, and independent of fragments, targets, projectiles, and projectile energies, can be explained under some conditions in the range of strongly overlapping compound resonances by a new phenomenon of time resonances (explosions). These time resonances (explosions) correspond to the formation of a few highlyexcited, non-exponentially decaying nuclear clots (partial compound nuclei consisting of certain small groups of target and projectile nucleons). The proposed approach is an alternative way of analyzing experimental data compared with the majority of known descriptions (for instance, fireball models). This is a new and more general version of the time-evolution approach compared with the Izumo-Araseki time compound-nucleus model.

Time as Quantum Observable, Canonical Conjugated to Energy

“…(Olkhovsky, 1984;1990;1992;1998); as well as of new phenomena, about time delays-advances in nuclear physics and about time resonances or explosions of highly excited compound nuclei, in Refs. (D'Arrigo et al, 1992;Olkhovsky et al, 2006). Let us also recall that, besides the time operator, other quantities, to which (maximal) hermitian operators correspond, can be analogously regarded as quantum-physical observables: For example, von Neumann himself (Recami, 1976;Von Neumann, 1955)) considered the case of the momentum operator −i∂/∂x in a semi-space with a rigid wall orthogonal to the x-axis at x = 0, or of the radial momentum −i∂/∂r, even if both act on packets defined only over the positive x or r axis, respectively.…”

“…4. Section 4 has been devoted to the association of unstable states (decaying "resonances") with the eigenvectors of quasi-hermitian (Agodi et al, 1973;Olkhovsky et al, 2006;Recami et al, 1983) Hamiltonians. 5.…”

On new experimental data manifesting the time resonances (or explosions)

“…The theoretic origin of the earlier revealed phenomena "time resonances (explosions)" rises either from the strict self-consistent time analysis of the compound nuclei or clots at the range of strongly overlapped energy resonances (see [1]), or, in an alternative way, from the qualitative analysis of eigen values of the time operator T defined by appropriate complex values of the compound-nucleus Hamiltonian H through the commutation relation [H T ] = (see [2]). …”

“…[1] by "time resonance (or explosion)". In the previous above-mentioned paper [1] it was shown that the reaction amplitude αβ can have a more general form like…”

“…[1], the evolution of the surviving compound nucleus (at an instant during the life and decay after its formation) can be described by the following function…”