The transformation properties of the mass-splitting strong interaction are discussed in the framework of the $\mathrm{SU}\left(6\right)\mathrm{}$ scheme. Using the experimental mass values of the 56 baryons and the 35 mesons, the reduced matrix elements of all the possible mass tensor operators are calculated. It is found the the $\mathrm{SU}\left(3\right)\mathrm{}$ symmetry-breaking terms transform mainly as the 35 representation of $\mathrm{SU}\left(6\right)\mathrm{}$, whereas the $\mathrm{SU}\left(3\right)\mathrm{}$-conserving, $\mathrm{SU}\left(6\right)\mathrm{}$- violating terms do not have simple transformation properties.

• Received 1 November 1965

DOI:https://doi.org/10.1103/PhysRev.143.1354