Speaker
E. C. Pinilla
(Universite Libre de Bruxelles)
Description
We use a four-body eikonal model to analyze the experimental breakup cross section of 11Li on 208Pb at 70 MeV/A [1]. It is a
current debate if the large concentration of dipole strength at low energies is due to the 11Li low binding energy or if it is due to a
resonance effect. First we compute 9Li+n+n three-body phase shifts for J=0+,1- and 2+. A relatively narrow structure is found in the 1- partial wave at low energies. Then we investigate 11Li breakup through a 9Li+n+n three-body model of the projectile. The dipole strength is
computed with two descriptions of the three-body continuum: (i) an exact treatment, involving proper asymptotic conditions [2],
and (ii) the simpler pseudo-state method, where the continuum is discretized over a square-integrable basis [3]. We show that
significant differences may show up. The experimental determination of the dipole strenghts from breakup cross sections is also discussed.
[1] T. Nakamura et al., Phys. Rev. Lett. 96 (2006) 252502.
[2] P. Descouvemont, E. Tursunov, and D. Baye, Nucl. Phys. A765 (2006) 370.
[3] E.C. Pinilla et al., Nucl. Phys. A865 (2011) 43.
Primary author
E. C. Pinilla
(Universite Libre de Bruxelles)
