@article{12ad6868cfac43c0a6cf16c1e04448f1,
title = "Coexistence of molecular and shape resonances in 12C + 12C",
abstract = "The structure observed in 12C + 12C excitation functions is interpreted in terms of the double resonance and doorway mechanisms, which generate bands of shape and molecular resonances, respectively.",
author = "K. Langanke and Koonin, {S. E.}",
note = "Funding Information: Since the discovery of pronounced structures in the 12C + 12C elastic and inelastic excitation functions \[1\] and in the fusion cross section at energies below and above the barrier \[2,3\],t he search for the origin of these structures has led to much experimental and theoretical activity. These resonances have been interpreted in terms of a single type of rotating dinuclear complex (molecular band) in the partial waves l ~< 16 \[4,5\].T he strong grouping of several resonances with the same spin assignment and with typical widths of less than a few 100 keV (intermediate structure) is explained in this model by the coupling of these molecular states to other collective degrees of freedom. However, this interpretation has been challenged by recent measurements of the gamma/particle decay branching ratios of possible 14 + members of the molecular band at excitation energies E = 25.2, 25.8 MeV \[6\]; the small branching ratios found support the identification of these particular resonances as structure in a shape resonance rather than as molecular states. By a molecular state, we mean, following ref. \[7\]a, long-lived rotating di-nuclear configuration with a narrow width (~< 300 keV) localized in a pocket in the internuclear potential at an energy below the barrier. A shape resonance we also envison as a dinuclear configuration, but, in contrast to a molecular state, it is short-lived with a large Supported in part by the National Science Foundation (PHY82-07332 and PHY79-23638) at Caltech and the Deutsche Forschungsgemeinschaft. 1 On leave from the University of Munster. Copyright: Copyright 2014 Elsevier B.V., All rights reserved.",
year = "1983",
month = mar,
day = "24",
doi = "10.1016/0370-2693(83)90949-8",
language = "English (US)",
volume = "123",
pages = "21--24",
journal = "Physics Letters B",
issn = "0370-2693",
publisher = "Elsevier B.V.",
number = "1-2",
}