Measurement of the ratio of branching fractions $\mathcal{B}(B_{c}^{+} \to J/\psi K^{+})/\mathcal{B}(B_{c}^{+} \to J/\psi\pi^{+})$

TL;DR

This paper reports a precise measurement of the ratio of branching fractions for Bc+ decays to J/psi K+ and J/psi pi+ using LHCb data, confirming previous results with improved accuracy.

Contribution

The study provides a more precise measurement of the branching ratio of Bc+ decays, reducing uncertainties compared to earlier measurements.

Findings

Measured ratio R_{K/π} = 0.079 ± 0.007 ± 0.003

Results are consistent with previous measurements

Uncertainties are significantly reduced

Abstract

The ratio of branching fractions $R_{K/\pi} \equiv \mathcal{B}(B_{c}^{+} \to J/\psi K^{+})/\mathcal{B}(B_{c}^{+} \to J/\psi\pi^{+})$ is measured with $pp$ collision data collected by the LHCb experiment at centre-of-mass energies of 7 TeV and 8 TeV, corresponding to an integrated luminosity of 3${\mbox{fb}^{-1}}$. It is found to be $ R_{K/\pi} = 0.079\pm0.007\pm0.003$, where the first uncertainty is statistical and the second is systematic. This measurement is consistent with the previous LHCb result, while the uncertainties are significantly reduced.