Angular correlations in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:mrow></mml:math> decay of excited states in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Be</mml:mi><mml:mprescripts /><mml:none /><mml:mn>8</mml:mn></mml:mmultiscripts></mml:math>

Motivated by the recent observation of anomalous electron-positron angular correlations in decay 18.15 MeV 1+ excited states 8Be, we reexamine detail Standard Model expectations for these correlations. The state is above particle threshold, and several multipoles can contribute to its $e^+e^-$ decay. We present general theoretical expressions distributions nuclear C0, C1, C2 M1, E1, E2 multipoles, examine their relative contribution 8Be at MeV. find that this resonance dominated M1 E1 decay, ratio strength a strong function energy. This contract original analysis distributions, where M1/E1 was assumed be constant over energy region Ep = 0:8-1:2 existence `bump' measured distribution strongly dependent on ratio, with finding large-angle contributions lower than expectation. Thus, current no evidence axion 8Be.