Analysis of the semileptonic decays $\Lambda_b\to\Lambda_cl\bar{\nu}_l$ and $\Xi_b\to\Xi_cl\bar{\nu}_l$ in QCD sum rules

TL;DR

This paper calculates the form factors and decay properties of specific baryon semileptonic decays using QCD sum rules, providing results consistent with experimental data and predictions for future measurements.

Contribution

It introduces a comprehensive QCD sum rule analysis including vacuum condensates up to dimension 8 for these decays, offering new theoretical predictions.

Findings

Branching ratios for $ ext{Lambda}_b$ decays agree with experimental data.

Predicted branching ratios for $ ext{Xi}_b$ decays serve as references for future experiments.

Form factors are estimated with detailed QCD sum rule calculations.

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 $\Lambda_b\to\Lambda_cl\bar{\nu}_l$ and $\Xi_b\to\Xi_cl\bar{\nu}_l$ ($l=e,\mu$ and $\tau$). Our results for the branching ratios of $\Lambda_b\to\Lambda_cl\bar{\nu}_l$ are comparable with experimental data and the results from other collaborations. In addition, our prediction for the branching ratio of $\Xi_b\to\Xi_cl\bar{\nu}_l$ can provide a valuable reference for future experimental measurements.