Improved Light-cone QCD Sum Rule Analysis Of The Rare Decays $\Lambda_b\rightarrow\Lambda\gamma$ And $\Lambda_b\rightarrow\Lambda l^+l^-$

TL;DR

This paper uses light-cone QCD sum rules to analyze rare decay processes of the Lambda_b baryon, highlighting how different interpolating currents impact theoretical predictions within the Standard Model.

Contribution

It systematically reanalyzes Lambda_b decay processes with improved baryonic distribution amplitudes and compares different interpolating currents, including the first LCSR analysis of Lambda_b→Lambda gamma with Ioffe current.

Findings

Interpolating current choice significantly affects decay predictions.

Provides updated LCSR calculations for Lambda_b→Lambda gamma and Lambda_b→Lambda l+ l-.

Highlights the importance of current selection in theoretical models.

Abstract

We present a systematic light-cone QCD sum rule study of the exclusive rare radiative decay $\Lambda_b\rightarrow\Lambda\gamma$ and rare semileptonic decay $\Lambda_b\rightarrow\Lambda l^+l^-$ within the framework of the standard model. Although some LCSR studies on these rare processes can be found in different literatures, it is necessary to reanalyze them systematically for the reason that either the baryonic distribution amplitudes are improved or different interpolating currents for the $\Lambda_b$ baryon may lead to quite different results. In addition, the rare process $\Lambda_b\rightarrow\Lambda\gamma$ has not yet been analyzed by LCSR with the Ioffe-type current. Taking all these reasons into account, we perform LCSR calculations of both the processes with two types of interpolating currents. Our calculations show that the choice of the interpolating current for the $\Lambda_b$ baryon can affect the predictions significantly, especially for the rare radiative decay process.