Soft E1 excitation of neutron-halo nuclei

✍ Scribed by T. Nakamura

• Book ID: 104069695
• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 358 KB
• Volume: 788
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2007.01.011

✦ Synopsis

Soft electric dipole (E1) response of 11 Li has been investigated by a kinematical complete measurement of the Coulomb breakup at about 70 MeV/nucleon. A two-wall neutron detector setup allowed us to employ a kinematical condition to exclude fully the cross talk events even for the low relative energies (E rel ) down to 0 MeV, thereby enhancing the experimental sensitivities in this energy region. In the E rel spectrum, a strong peak corresponding to the soft E1 excitation has been observed at about E x =0.6 MeV with B(E1)=1.42(18) e 2 fm 2 (4.5(6) Weisskopf units) for 0 ≤ E rel ≤ 3 MeV. The spectral shape as well as its amplitude is in excellent agreement with a three-body model with strong neutron-neutron correlation in the halo. Such correlation is further supported by the E1 non-energy weighted cluster sum rule.