Resonance strength of the 1175 keV resonance in6Li(α, γ)10B

Preciseγ-ray intensity measurements in10B

“…We found that the electric quadrupole radiation from the first excited 2 + state is an almost pure Isoscalar motion, corresponding to tumbling of the di-alpha core. The Isovector influence of the two neutrons in 10 Be, or the two protons in 10 C is surprisingly small. Counter-intuitively, the Isovector contribution is destructive in 10 C, and the extra charge leads to slower radiation of photons.…”

“…Currently, for the T=1, 2 + state in 10 B, the width is reasonably well known [10,11], at the 7% level, the alpha-decay branch moderately well known [12,13], at the 25% level, but the γ-ray branch has several conflicting published results and the most recent data evaluation [14] reports only an upper limit of <0.5% for the transition of interest.…”

“…The measurements of the matrix element in the eveneven nuclei 10 Be and 10 C is straightforward as the state of interest, the first excited J π =2 + state, is bound in both cases and decays 100% by γ-ray emission, so the matrix element is inversely proportional to the square root of the half life. Consequently, a precise measurement of the lifetime of the state directly provides the quadrupole matrix element.…”

“…The analog transition in 10 B can further constrain these new calculations and probe the symmetry of the wave functions across the A=10 multiplet. We report on a careful measurement of the γ-ray intensities from states populated in the 10 B(p,p') reaction at 10 MeV, including a determination of the key E2 branch from the J=2 T=1 state at 5164 keV to the J=0 T=1 state at 1740 keV of 0.16(4)%.…”

“…Precise electromagnetic transition matrix elements in 10 Be and 10 C have provided surprisingly stringent tests of modern ab-initio calculations using realistic nuclear forces. The analog transition in 10 B can further constrain these new calculations and probe the symmetry of the wave functions across the A=10 multiplet.…”