Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Looking at the decay chain, I saw it undergoes double beta decay. How is it feasible for something to undergo a simultaneous double decay?

share|cite|improve this question
up vote 1 down vote accepted

The condition for double beta decay to be the preferred mode are that the energy (mass) of the three states

  • The initial nucleus (m)
  • The would-be single-beta-decay daughter plus the electron and the anti-neutrino (s)
  • The double-beta-decay daughter plus the two electrons and the two anti-neutrinos (d)

have a relationship like

$$ E_d < E_m < E_s \,.$$

The result is that it is not possible for a single decay to proceed (there is not enough energy) but it is possible for a double decay to happen (though it will be a slow process).

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.