1. Nov 5, 2012

### s3d18

1) How can i calculate/obtain the mass eigenstates and weak eigenstates of neutrino
if we can get those, then how come we cannot obtain the mass eigenvalues.

2) why we know the relation between mass eigenstates and weak eigenstates (the relation involve PMNS matrix) in the beginning.

Thank you.

2. Nov 5, 2012

### ofirg

1) When you diagonalize a mass matrix (or any matrix for that matter) you have the eigenvalues ( mass eigenvalues) and the transformation matrix from the mass eigenstates basis to the weak eigenstate basis (which includes the mixing angles and pssible phases).

The mass eigenvalues are independent of the mixing angles. Therefore knowing the mixing angles (which have been measured) doesn't determine the masses.

2) we know the relation beacause we measure the mixing angles in oscillation experiments ( to a certain accuracy)

3. Nov 5, 2012

### s3d18

Thank you.
So, we cannot obtain the mass eigenvalues through the calculation?

4. Nov 7, 2012

### ofirg

We can't calculate the masses from the parameters measured so far (mixing angles and mass squared differences). The absolute mass scale is an additional independent parameter.