HEAL DSpace

Shape resonances as poles of the semiclassical Green's function obtained from path-integral theory: Application to the autodissociation of the He-2(++) (1)Sigma(+)(g) state

Αποθετήριο DSpace/Manakin

Εμφάνιση απλής εγγραφής

dc.contributor.author Nicolaides, CA en
dc.contributor.author Douvropoulos, TG en
dc.date.accessioned 2014-03-01T01:54:47Z
dc.date.available 2014-03-01T01:54:47Z
dc.date.issued 2005 en
dc.identifier.issn 0021-9606 en
dc.identifier.uri https://dspace.lib.ntua.gr/xmlui/handle/123456789/27463
dc.subject.classification Physics, Atomic, Molecular & Chemical en
dc.subject.other VOLCANIC GROUND-STATES en
dc.subject.other ENERGIES en
dc.subject.other HE-2(2+) en
dc.subject.other WIDTHS en
dc.subject.other DISSOCIATION en
dc.subject.other POTENTIALS en
dc.subject.other QUANTUM en
dc.subject.other IONS en
dc.subject.other WKB en
dc.title Shape resonances as poles of the semiclassical Green's function obtained from path-integral theory: Application to the autodissociation of the He-2(++) (1)Sigma(+)(g) state en
heal.type journalArticle en
heal.identifier.secondary 024309 en
heal.language English en
heal.publicationDate 2005 en
heal.abstract It is known that one-dimensional potentials, V(R), with a local minimum and a finite barrier towards tunneling to a free particle continuum, can support a finite number of shape resonance states. Recently, we reported a formal derivation of the semiclassical Green's function, G(SC)(E), for such V(R), with one and two local minima, which was carried out in the framework of the theory of path integrals [Th. G. Douvropoulos and C. A. Nicolaides, J. Phys. B 35, 4453 (2002); J. Chem. Phys. 119, 8235 (2003)]. The complex poles of G(SC)(E) represent the energies and the tunneling rates of the unstable states of V(R). By analyzing the structure of G(SC)(E), here it is shown how one can compute the energy, E-nu, and the radiationless width, Gamma(nu), of each resonance state beyond the Wentzel-Kramers-Brillouin approximation. In addition, the energy shift, Delta(nu), due to the interaction with the continuum, is given explicitly and computed numerically. The dependence of the accuracy of the semiclassical calculation of E-nu and of Gamma(nu) on the distance from the top of the barrier is demonstrated explicitly. As an application to a real system, we computed the vibrational energies, E-nu, and the lifetimes, tau(nu), of the He-4(2)++, nu=0, 1, 2, 3, 4, and (HeHe++)-He-4-He-3 nu=0, 1, 2, 3, (1)Sigma(g)(+) states, which autodissociate to the He++He+ continuum. We employed the V(R) that was computed by Wolniewicz [J. Phys. B 32, 2257 (1999)], which was reported as being accurate, over a large range of values of R, to a fraction of cm(-1). For example, for J=0, the results for the lowest and highest vibrational levels for the He-4(2)+ (1)Sigma(g)(+) state are nu=0 level, E-0=10 309 cm(-1) below the barrier top, tau(0)=6400 s; nu=4 level, E-4=96.6 cm(-1) below the barrier top, tau(4)=31x10(-11) s. A brief presentation is also given of the quantal methods (and their results) that were applied previously for these shape resonances, such as the amplitude, the exterior complex scaling, and the lifetime matrix methods. (c) 2005 American Institute of Physics. en
heal.publisher AMER INST PHYSICS en
heal.journalName JOURNAL OF CHEMICAL PHYSICS en
dc.identifier.isi ISI:000230653700015 en
dc.identifier.volume 123 en
dc.identifier.issue 2 en


Αρχεία σε αυτό το τεκμήριο

Αρχεία Μέγεθος Μορφότυπο Προβολή

Δεν υπάρχουν αρχεία που σχετίζονται με αυτό το τεκμήριο.

Αυτό το τεκμήριο εμφανίζεται στην ακόλουθη συλλογή(ές)

Εμφάνιση απλής εγγραφής