The electron-positron angular correlation was measured for the isoscalar magnetic dipole 18.15 MeV transition in 8Be. Significant, peak-like deviation was observed from the internal pair creation at θ 140° in the angular correlation. This observation might indicate that in an intermediate step a neutral isoscalar particle with a mass of 16:70∞0:35 (stat.)∞0:5(sys.)MeV=c2 and Jπ = 1+ was created.
ASJC Scopus subject areas
- Physics and Astronomy(all)