Branching Fraction Measurements of the Decays B -> EtaC K, where EtaC -> KKbarPi and EtaC -> 4K

TL;DR

This paper reports the observation and measurement of branching fractions for specific B meson decays involving EtaC and kaons, using data from the BABAR detector, providing new experimental insights into these decay processes.

Contribution

First measurement of B -> EtaC K decays with detailed branching fraction values and significance levels, expanding understanding of B meson decay channels.

Findings

Observed B0 -> EtaC K0 and B+ -> EtaC K+ decays with statistical significance.

Measured branching fractions: BF(B+ -> EtaC K+) ≈ 1.50e-3, BF(B0 -> EtaC K0) ≈ 1.06e-3.

Set upper limits for EtaC -> K+K-K+K- decay channels.

Abstract

In this report, we present the observation of the exclusive decays B0 -> EtaC K0 and B+ -> EtaC K+, and the measurement of the related branching fractions. Using a sample of 22.7x10^6 Upsilon(4S) -> BBbar decays collected with the BABAR detector at the SLAC PEP-II asymmetric B Factory during 1999-2000, we have observed statistically significant signals in the EtaC -> KsK+Pi- and K+K-Pi0 channels and set upper limits in the EtaC -> K+K-K+K- channels. All the results presented are preliminary. We have measured BF(B+ -> EtaC K+) = (1.50 +/- 0.19 +/- 0.15 +/- 0.46)x10^{-3} BF(B0 -> Etac K0) = (1.06 +/- 0.28 +/- 0.11 +/- 0.33)x10^{-3} where the first error is statistical, the second systematic and the last due to the uncertainty on the world average EtaC -> KKbarPi branching fraction.