Analysis of the ${\Lambda }_c(2625)$ and ${\Xi }_c(2815)$ with QCD sum rules

Abstract

In this article, we study the charmed baryon states ${\Lambda }_c(2625)$ and ${\Xi }_c(2815)$ with the spin-parity ${\frac{3}{2}}^{-}$ by subtracting the contributions from the corresponding charmed baryon states with the spin-parity ${\frac{3}{2}}^{+}$ using the QCD sum rules, and suggest a formula $\mu =\sqrt{M_{{\Lambda }_c/{\Xi }_c}^2-{\mathbb{M}}_c^2}$ with the effective mass ${\mathbb{M}}_c=1.8\mathrm{GeV}$ to determine the energy scales of the QCD spectral densities, and make reasonable predictions for the masses and pole residues. The numerical results indicate that the ${\Lambda }_c(2625)$ and ${\Xi }_c(2815)$ have at least two remarkable under-structures.

Comments: 15 pages, 10 figures