The semi-leptonic form factors of ${\Lambda }_b\to {\Lambda }_c$ and ${\Xi }_b\to {\Xi }_c$ in QCD sum rules

Abstract

In this work, the full leading order results of the form factors for ${\Xi }_b\to {\Xi }_c$ and ${\Lambda }_b\to {\Lambda }_c$ are obtained in QCD sum rules. Contributions from up to dim-5 have been considered. For completeness, we also study the two-point correlation function to obtain the pole residues of ${\Xi }_Q$ and ${\Lambda }_Q$, and higher accuracy is achieved. For the three-point correlation function, since stable Borel regions can not be found, about $20\%$ uncertainties are introduced for the form factors of ${\Xi }_b\to {\Xi }_c$ and ${\Lambda }_b\to {\Lambda }_c$. Our results for the form factors are consistent with those of the Lattice QCD within errors.

Comments: 17 pages, 5 figures