The decay of theT=1 isospin triplet inA=12 systems. III. Higher order effects in the evaluation of the asymmetry parameters α? for the electron emission from aligned12B and12N

Nuclear Structure: calculation of the asymmetry α_? ofβ rays emitted from polarized¹²B and¹²N nuclei including higher order contributions. Comparison with recent experimental values. The asymmetry parameters α_? and α₊ were evaluated including higher order corrections in the framework of the formulae derived in a previous paper. It was found that since α_? is affected by strong cancellation effects the corrective terms give in this case a very important contribution. The agreement between predicted theoretical values and very recent experimental data is excellent for bothβ ^? andβ ⁺ decays. The experimental results can be understood without invoking the existence of the induced pseudotensor interaction.