The β-NQR (nuclear quadrupole resonance) signals of B8 (Iπ=2+,T1/2=770 ms) implanted in TiO2 (rutile) have been detected to determine the electric quadrupole moment of B8 with high precision. The ratio of the quadrupole moments of B8 and B12 was determined as |Q(B8)/Q(B12)|=4. 88±0.04. Combined with the known sign, the quadrupole moment of B8 was obtained as Q(B8)=+(64.5±1.4) mb, which is consistent with and more precise than the previously reported value. The experimental values of the Q moment, the proton and neutron radii and the density distribution of B8 were compared with several theoretical predictions and were found to be best reproduced by a microscopic cluster model, which suggests the existence of a proton halo.
ASJC Scopus subject areas
- Nuclear and High Energy Physics