A New Interpretation of the Observed Heavy Baryons

Abstract

I suggest that the conventional assignment of quantum numbers to the observed charm and bottom baryons is not correct, as these assignments imply large violation of the heavy spin-flavor and light $SU(3)$ symmetries. I propose an alternative interpretation of the observed states, in which the symmetries are preserved. If these novel assignments are right, there is a new state with mass approximately 2380~MeV which decays to ${\Lambda }_c+\gamma$, and another with mass approximately 5760~MeV which decays to ${\Lambda }_b+\gamma$. Although such states have not been seen, neither are they excluded by current analyses.

Comments: REVTeX, 7 pages. This is the final version to appear in Physical Review Letters. Two typos in Eq. (1) have been fixed and several points elsewhere have been clarified; also, there is now a brief discussion of the relationship of this proposal to the nonrelativistic constituent quark model