Abstract
The large enhancement of the sub-barrier fusion cross section observed in a number of mediate-mass heavy ion collisions has been attributed to the effects of coupling of the relative motion to internal degrees of freedom. In this connection, I discuss several aspects of the tunnelling using the influence functional method. I first discuss the properties of the potential renormalization caused by a linear oscillator coupling, showing that in certain limits it has significant energydependence. Then, I discuss a factorization property of the influence functional when several internal modes of excitation are simultaneously involved, showing that there is a saturation effect in the enhancement of the transmission probability. Then, I show that the transmission probability can be factorized as a product of the adiabatic transmission probability and a dissipation factor if the relative motion couples to harmonic oscillators with high frequency. It is suggested that quite different correlations between the dissipation factor and the friction coefficient for a classically accessible process arises depending on the properties of the Hamiltonian of the internal coordinates. Finally, I show that a strong and localized coupling around the potential barrier yields a resonant fusion excitation function.
This is a preview of subscription content, log in via an institution.
Preview
Unable to display preview. Download preview PDF.
References
U. Jahnke, et al., Phys. Rev. Lett. 48, 17 (1982).
N. Takigawa and G.F. Bertsch, Phys. Rev. C29, 2358 (1984).
N. Takigawa and A.B. Balantekin, MSU preprint, June 1984.
R. Broglia, invited talk at this conference.
S. Landowne, invited talk at this conference.
M. Rhoades-Brown, invited talk at this conference.
A.O. Caldeira and A.J. Leggett, Ann. Phys. 149, 374 (1983) and references therein.
A.O. Caldeira and A.J. Leggett, Phys. Rev. Lett. 46, 211 (1981).
A.B. Balantekin and N. Takigawa, Ann. Phys. in press.
S.Y. Lee, Phys. Rev. C29, 1932 (1984).
N. Takigawa, to be published in the Proc. of the Seventh Oaxtepec Symposium on Nuclear Physics, Mexico, 1984; and N. Takigawa and G.F. Bertsch, in preparation.
H. Esbensen, Nucl Phys. A352, 147 (1981).
W.H. Miller, Adv. Chem. Phys. 35, 69 (1974).
S. Coleman, Phys. Rev. D15, 2929 (1977); 16, 1248(E) (1977); C.G. Callan and S. Coleman, ibid. 16, 1762 (1977).
S.Y. Lee and N. Takigawa, Phys. Rev. C28, 1123 (1983).
D.M. Brink and U. Smilansky, Nucl. Phys. A405, 301 (1983).
L.C. Vaz, J.M. Alexander, M. Prakash, and S.Y. Lee, Proc. Int. Conf. on Nuclear Physics with Heavy Ions, Stony Brook, NY, April 1983; Vol. VI Nucl. Sci. Research Conf. Ser. (Harwood Academic Publishers, Amsterdam), p. 31.
A.B. Balantekin, S.E. Koonin, and J.W. Negele, Phys. Rev. C28, 1565 (1983); S. Koonin, invited talk at this conference.
A. Bohr and B.R. Mottelson, Nuclear Structure, Vol. I (Benjamin, New York, 1969) p. 302.
D.M. Brink, M.C. Nemes and D. Vautherin, Ann. Phys. (NY) 147, 171 (1983).
M. Beckerman, invited talk at this conference.
E.R. Cosman, C.E. Ordones and R.J. Ledoux, contribution to this conference.
B. Cujec, invited talk at this conference.
D.M. Brink, in “Progress in Particle and Nuclear Physics”, edited by D. Wilkinson (Pergamon, Oxford, 1981) Vol. IV, p. 323
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1985 Springer-Verlag
About this paper
Cite this paper
Takigawaf, N. (1985). Effects of internal degrees of freedom on the heavy-ion fusion cross section. In: Steadman, S.G. (eds) Fusion Reactions Below the Coulomb Barrier. Lecture Notes in Physics, vol 219. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-13918-4_57
Download citation
DOI: https://doi.org/10.1007/3-540-13918-4_57
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-13918-8
Online ISBN: 978-3-540-39146-3
eBook Packages: Springer Book Archive