  Strong decays of charmed baryons are analyzed in the framework of heavy
hadron chiral perturbation theory (HHChPT) in which heavy quark symmetry and
chiral symmetry are synthesized. HHChPT works excellently for describing the
strong decays of s-wave charmed baryons. For L=1 orbitally excited states, two
of the unknown couplings, namely, $h_2$ and $h_{10}$, are determined from the
resonant $\Lambda_c^+\pi\pi$ mode produced in the $\Lambda_c(2593)$ decay and
the width of $\Sigma_c(2800)$, respectively. Predictions for the strong decays
of the p-wave charmed baryon states $\Lambda_c(2625)$, $\Xi_c(2790)$ and
$\Xi_c(2815)$ are presented. Since the decay
$\Lambda_c(2593)^+\to\Lambda_c^+\pi\pi$ receives non-resonant contributions,
our value for $h_2$ is smaller than the previous estimates. We also discuss the
first positive-parity excited charmed baryons. We conjecture that the charmed
baryon $\Lambda_c(2880)$ with $J^P=\frac52^+$ is an admixture of
$\Lambda_{c2}(\frac52^+)$ with and $\tilde\Lambda''_{c3}(\frac52^+)$; both are
L=2 orbitally excited states. The potential model suggests $J^P=\frac52^-$ or
$\frac32^+$ for $\Lambda_c(2940)^+$. Measurements of the ratio of
$\Sigma_c^*\pi/\Sigma_c\pi$ will enable us to discriminate the $J^P$
assignments for $\Lambda_c(2940)$. We advocate that the $J^P$ quantum numbers
of $\Xi_c(2980)$ and $\Xi_c(3077)$ are $\frac12^+$ and $\frac52^+$,
respectively. Under this $J^P$ assignment, it is ready to understand why
$\Xi_c(2980)$ is broader than $\Xi_c(3077)$.

High Energy Physics - Phenomenology;High Energy Physics - Experiment