# B Neutrinos and Fermi-Dirac Distribution

1. Jul 13, 2016

### TDanskin

I'm an A level student currently trying to understand the behaviour and properties of neutrinos, and wanted to check that I've understood the basics of neutrino properties. As neutrinos are half-integer spin particles, can the Fermi-Dirac distribution be used to calculated the probable distribution of neutrinos in any system?
Thanks

2. Jul 13, 2016

### vanhees71

Neutrinos are indeed fermions. I'm not sure what you mean by "Fermi-Dirac distribution". Usually one understands it to be the thermal-equilibrium distribution,
$$f=\frac{1}{\exp(E/T)+1}.$$
Since neutrinos are very elusive guys, it's very hard to imagine to have them in thermal equilibrium. Of course, in the very early universe they in fact were in thermal equilibrium.

3. Jul 13, 2016

### TDanskin

Thanks! Would it then be correct to say that, due to neutrinos being relatively non interactive compared to other fermions, the thermal-equilibrium distribution cannot predict their distribution in a system?