Predictions for Charm Baryon Semileptonic Decays in the SU(4) Limit, the Non‐relativistic, and MIT Bag Quark Models

Abstract

The predictions for charm baryon semileptonic decays (CBSD) are given in three different models: SU(4) symmetry limit, non-relativistic (NRQM), and the MIT Bag (MBM) quark models. The comparison with the only available data-the A: semileptonic decay-gives ample room for the existence of a fourth generation. Semileptonic decays of %+ charm baryons should be interesting to study experimentally and theoretically. On the one hand, the very large mass difference between the charm quark c and the s, u and d quarks guarantees a big phase space. This should make their observation easier and high statistic experiments should be attainable without too much effort. On the other hand, for %+ 5' decays the transition amplitude involves four relevant form factors when the emitted charged lepton is an electron. Because of the large momentum transfer, the four become almost equally important. Since they are all rich in information about strong interactions, their detailed measurement should give very important guidance to disentangle the theory of strong interactions at low energy, especially with respect to flavor symmetry breaking, which is now expected to be substan~ially large. The '12' are classified in the 20 representation whose SU(3) content is 8 + 6 + 3 + 3. The selection rules allow for 60 different decays among the 20 baryons. Of these, 12 correspond to the semileptonic decays between ordinary non-charm baryons described by the Cabbibo theory, which we do not discuss here. The processes A,+ Z and 2,' A have zero Clebsch-Gordan coefficients, they are forbidden by isospin because A,+ and A are singlets and 2,' and Z belong to triplets. We are, thus, left with 46