Analysis of the semileptonic decays ${\Lambda }_b\to {\Lambda }_{c}l{\bar{\nu }}_l$ and ${\Xi }_b\to {\Xi }_{c}l{\bar{\nu }}_l$ in QCD sum rules

Abstract

In this article, the electroweak transition form factors of ${\Lambda }_b\to {\Lambda }_c$ and ${\Xi }_b\to {\Xi }_c$ are analyzed within the framework of three-point QCD sum rules. In phenomenological side, all possible couplings of interpolating current to hadronic states are considered. In QCD side, the perturbative part and the contributions of vacuum condensates up to dimension 8 are also included. With the estimated form factors, we study the decay widths and branching ratios of semileptonic decays ${\Lambda }_b\to {\Lambda }_{c}l{\bar{\nu }}_l$ and ${\Xi }_b\to {\Xi }_{c}l{\bar{\nu }}_l$ ($l=e,\mu$ and $\tau$). Our results for the branching ratios of ${\Lambda }_b\to {\Lambda }_{c}l{\bar{\nu }}_l$ are comparable with experimental data and the results from other collaborations. In addition, our prediction for the branching ratio of ${\Xi }_b\to {\Xi }_{c}l{\bar{\nu }}_l$ can provide a valuable reference for future experimental measurements.

Comments: 14 pages, 8 figures