Beta decay

"In beta decay experiments it is generally some properties of the emitted , the electron and neutrino, that are measured, such as their energy, polarization or angular distribution. ...In beta decay, angular momentum is conserved but it is now known that parity is not conserved. The leptons are emitted in states of indefinite parity."

"Beta decay was…like a dear old friend. There would always be a special place in my heart reserved especially for it."