Strong decays of charmed baryons in heavy hadron chiral perturbation theory: An update

We first give a brief overview of the charmed baryon spectroscopy and discuss their possible structure and spin-parity assignments in the quark model. With the new Belle measurement of the widths of capital sigma c(2455) and capital sigma c(2520) and the recent CDF measurement of the strong decays of [Lambda]c(2595) and [Lambda]c(2625), we give updated coupling constants in heavy hadron chiral perturbation theory. We find g2=0.565-0.024+0.011 for P-wave transitions between s-wave and s-wave baryons, and h2, one of the couplings responsible for S-wave transitions between s-wave and p-wave baryons, is extracted from [Lambda]c(2595)+ arrow right [Lambda]c+[pi][pi] to be 0.63+ or -0.07. It is substantially enhanced compared to the old value of order 0.437. With the help from the quark model, two of the couplings h 10 and h 11 responsible for D-wave transitions between s-wave and p-wave baryons are determined from capital sigma c(2880) decays. There is a tension for the coupling h2 as its value extracted from [Lambda]c(2595)+ arrow right [Lambda]c+[pi][pi] will imply [Xi]c(2790)0 arrow right [Xi]c [pi] and [Xi]c(2815)+ arrow right [Xi]c*[pi] rates slightly above the current limits. It is conceivable that SU(3) flavor symmetry breaking can help account for the discrepancy.