The (J,T) = (1,1) parity doublet in Ne-20 at 11.26 MeV is a good candidate to study parity violation in nuclei. However, its energy splitting is known with insufficient accuracy for quantitative estimates of parity violating effects. To improve on this unsatisfactory situation, nuclear resonance fluorescence experiments using linearly and circularly polarized gamma-ray beams were used to determine the energy difference of the parity doublet Delta E = E(1(-)) - E(1(+)) = -3.2(+/- 0.7) stat((+0.6)(-1.2)) (sys) keVand the ratio of their integrated cross sections I-s,0((+))/ I-s,0((-)) = 29(+/- 3) (stat)((+14)(-7) )(sys). Shell-model calculations predict a parity violating matrix element having a value in the range 0.46-0.83 eV for the parity doublet. The small energy difference of the parity doublet makes Ne-20 an excellent candidate to study parity violation in nuclear excitations.
- Parity doublet
- Parity violation