Towards an assessment of the ATLAS data on the branching ratio Gamma(Lambda_b(0) -> psi(2S) Lambda(0))/Gamma(Lambda_b(0) -> J/psi Lambda(0))

TL;DR

This paper analyzes the ATLAS measurement of the Lambda_b decay branching ratio, comparing it with theoretical predictions, and employs a model-independent approach for heavy-to-light form factors to interpret the results.

Contribution

It introduces a model-independent framework for analyzing heavy-to-light form factors in Lambda_b decays, providing a detailed assessment of experimental data against theoretical models.

Findings

Measured branching ratio R(Lambda_b) = 0.501 pm 0.033 (stat) pm 0.019 (syst)

The measured value is lower than the covariant quark model prediction of 0.8 pm 0.1

The analysis offers insights into the discrepancies between experimental results and theoretical models.

Abstract

Recently the ATLAS Collaboration at CERN reported on the measurement of the branching ratio R(Lambda_b) = Gamma(Lambda_b(0) -> psi(2S) Lambda(0))/Gamma(Lambda_b(0) -> J/psi Lambda(0)). The measured branching ratio R(Lambda_b) = 0.501 pm 0.033$ (stat) pm 0.019 (syst) was found to be lower than the covariant quark model prediction of R(Lambda_b) = 0.8 pm 0.1 calculated by us recently. We present a detailed analysis of the branching ratio R(Lambda_b) using a model-independent framework for the heavy-to-light form factors based on results from our previos papers.