1. Sep 29, 2012

### snorkack

The lifetime of a deuteron in the ground state of HD molecule has been calculated as 10^47 years.

Obviously, at zero pressure and temperature it is slightly shorter, because hydrogen is solid at these conditions - but not much shorter, because in solid hydrogen at zero pressure the other neighbours are much further than the moleculemate.

Radioactive decays start to become relevant and measurable from the lifetime of 10^20 years - spontaneous fission, double beta, alpha activity like Bi-209 are in that range.

For comparison, protium lifetime in red dwarfs is around 10^13 years.

What is the density and pressure of hydrogen, at zero temperature, where deuteron lifetime is 10^20 years?

2. Sep 29, 2012

### phyzguy

I'm missing the point of the question. Where does the estimate of deuterium lifetime come from and what is the mechanism of the decay?

3. Sep 29, 2012

### snorkack

The mechanism is tunnelling of the proton into deuteron.

Numeric estimate for lifetime comes from a letter to Nature, vol 339, 29th June 1989, pages 690-691, Koonin&Nauenberg.

A Confusion regarding the $\partial_{\mu}$ operator Jul 24, 2017