IB Physics HL E.3.9 Neutrinos and antineutrinos Question Bank

Magnesium-27 nuclei $\left({ }_{12}^{27} \mathrm{Mg}\right)$ decay by beta-minus $\left(\beta^{-}\right)$decay to form nuclei of aluminium-27 (Al).

A Magnesium-27 nucleus can decay by one of two routes:

Route 1: 70\% of the beta particles are emitted with a maximum kinetic energy of 1.76656 MeV , accompanied by a gamma photon of energy 0.84376 MeV .

Route 2: 30 % of the beta particles have a maximum kinetic energy of 1.59587 MeV with a gamma photon of energy 1.01445 MeV .

The final state of the aluminium-27 nucleus is the same for both routes.

Calculate the difference between the magnitudes of the total energy transfers in parts (a) and (b).
(ii) Explain how the difference in part (b)(ii) arises.