Fourth generation effect on $\Lambda_b$ decays

TL;DR

This paper explores how the fourth quark generation (SM4) affects rare $ ext{Lambda}_b$ baryon decays, showing significant deviations from the Standard Model predictions and highlighting potential experimental observability at LHCb.

Contribution

It demonstrates the impact of the fourth quark generation on $ ext{Lambda}_b$ decay observables, providing predictions that differ from the Standard Model and are testable at LHCb.

Findings

Branching ratios deviate significantly from SM predictions.

Some decay modes are within LHCb's experimental reach.

SM4 explains anomalies in CP violation parameters of B mesons.

Abstract

The rare decays of $\Lambda_b$ baryon governed by the quark level transitions $ b \to s$, are investigated in the fourth quark generation model popularly known as SM4. Recently it has been shown that SM4, which is a very simple extension of the standard model, can successfully explain several anomalies observed in the CP violation parameters of $B$ and $B_s$ mesons. We find that in this model due to the additional contributions coming from the heavy $t'$ quark in the loop, the branching ratios and other observables in rare $\Lambda_b$ decays deviate significantly from their SM values. Some of these modes are within the reach of LHCb experiment and search for such channels are strongly argued.