par Tursunov, E. M.;Descouvemont, Pierre 
Référence Nuclear Physics A, 793, 1-4, page (52-66)
Publication Publié, 2007
Référence Nuclear Physics A, 793, 1-4, page (52-66)
Publication Publié, 2007
Article révisé par les pairs
| Résumé : | M1 transitions from the 6Li (0+ ; T = 1) state at 3.563 MeV to the 6Li (1+) ground state and to the α + d continuum are studied in a three-body model. The bound states are described as an α + n + p system in hyperspherical coordinates on a Lagrange mesh. The ground-state magnetic moment and the gamma width of the 6Li (0+) resonance are well reproduced. The halo-like structure of the 6Li (0+) resonance is confirmed and is probed by the M1 transition probability to the α + d continuum. The spectrum is sensitive to the description of the α + d phase shifts. The corresponding gamma width is around 1.0 meV, with optimal potentials. Charge symmetry is analyzed through a comparison with the β-delayed deuteron spectrum of 6He. In 6He, a nearly perfect cancellation effect between short-range and halo contributions was found. A similar analysis for the 6Li (0+ ; T = 1) γ decay is performed; it shows that charge-symmetry breaking at large distances, due to the different binding energies and to different charges, reduces this effect. The present branching ratio Γγ (0+ → α + d) / Γγ (0+ → 1+) ≈ 1.3 × 10-4 should be observable with current experimental facilities. © 2007 Elsevier B.V. All rights reserved. |
