Isotopic spin selection rules XII: The mirror reactions6Li(d, n)7Be and6Li(d, p)7Li

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Abstract
It is remarked that the mirror reactions 6Li(d, n)7Be and 6Li(d, p)7Li leading to the fist excited states of the mirror nuclei form an excellent testing place for the prediction following the assumption of charge-independence that such mirror reactions have equal intrinsic probability. This is because the reactions are almost non-resonant which makes for the good operation of the isotopic spin rules and because the protons are emitted well above the Coulomb barrier which makes the interpretation of the experimental neutron to proton branching ratio rather simple. It is also remarked that the experiment may be performed without observing the neutrons and protons by using the gamma rays from the excited states to label the two transitions; all higher excited states are unstable to heavy particle emission and so do not yield gamma rays, The branching ratio is determined at 31 deuteron energies between 200 Kev and 1.8 Mev. Over the whole range it agrees to within 15% with that expected from charge independence but there are signs of a resonance like maximum to the ratio at about 450 Kev which departure from the isotopic spin rule is in keeping with the behaviour of the 6Li+d total cross sections.