The theory is very difficult, I only state the result.

There are 4 main mesons for strong nuclear force.

type mass [MeV] range symmetry force type
 \pi  135  long  pseudo scalar  -\sigma_{1}\cdot\sigma_{2},-S_{12}
 \sigma  400 ~ 2000  medium  scalar -1, -L\cdot S
 \rho  775  short  vector  -2\sigma_1\cdot\sigma_2, +S_{12}
 \omega  783  short vector  +1, -3L\cdot S
Advertisements