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Excitation modes of $^{11}$Li at E$_x \sim$ 1.3 MeV from proton collisions

R. Crespo·I. J. Thompson·A. A. Korsheninnikov
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Abstract

The cross section for p-$^{11}$Li inelastic scattering at 68 MeV/u is evaluated using the Multiple Scattering expansion of the total Transition amplitude (MST) formalism, and compared with the breakup in the shakeoff approximation. Three different potential models for $^{11}$Li are used to calculate the $^{11}$Li(p,p$'$) continuum excitations, and all show peaks below 3 MeV of excitation energy, both in resonant and some non-resonant channels. In the most realistic model of $^{11}$Li, there is a strong dipole contribution associated with attractive but not a fully-fledged resonant phase shifts, and some evidence for a J$_{nn}^π= 0_2^+$ resonant contribution. These together form a pronounced peak at around 1--2 MeV excitation, in agreement with experiment, and this supports the use of the MST as an adequate formalism to study excited modes of two-neutron nuclear halos.

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R. Crespo, I. J. Thompson, A. A. Korsheninnikov. 2002-06-24. Excitation modes of $^{11}$Li at E$_x \sim$ 1.3 MeV from proton collisions. https://doi.org/10.1103/physrevc.66.021002

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