The distribution of M1 strength in Pb208 has been measured between 5.8 and 7.4 MeV with highly polarized tagged photons. 02(M1)=14.6-1.3+1.5 eV corresponding to B(M1)=(10.7-0.9+1.1)N2 was found, and can fully account for the much discussed "missing" M1 in Pb208. When the present result is combined with known 1+ transitions above neutron threshold, an M1 giant resonance emerges at 7.3 MeV, 1 MeV wide, with B(M1)15.6N2. Smaller 1+ resonances are also seen at both 5.85 and 6.24 MeV. The total M1 strength below 6.4 MeV amounts to B(M1)=(1.9-0.4+0.7)N2.
ASJC Scopus subject areas
- Physics and Astronomy(all)