Nuclear excitation in 176Lu by positron annihilation on K-shell electrons

In the process of nuclear excitation in positron-electron annihilation (NEPEA) experimental results have been found to be larger than theoretical predictions. In our previous works we have analyzed the NEPEA experimental data for 1078 keV in 115In and for 1330 keV in 111Cd, respectively, by applying our model of indistinguishable quantum oscillators. In the present work we extend this model to estimate the cross section of nuclear excitation in positron-electron annihilation for 176Lu from the experimentally measured effective cross section of σeff = (2.6±0.9)·10−29 cm2. The estimated NEPEA cross section of σ=2.7·10−26 cm2 is in very good agreement with that of the theoretical prediction σth=2.2·10−26 cm2.