First Measurements of the Exclusive Decays of the Upsilon(5S) to B Meson Final States and Improved B^*_s Mass Measurement

TL;DR

This paper reports the first measurements of exclusive B meson decay modes from the Upsilon(5S) resonance, providing new decay rate data and a precise B_s* mass measurement using CLEO III data.

Contribution

It presents the first measurements of specific B meson production rates from Upsilon(5S) decays and an improved B_s* mass value, advancing understanding of bottomonium decays.

Findings

Measured inclusive B cross-section as 0.176 nb

First measurements of B*B* and BB* production rates

Set upper limits on certain B decay channels

Abstract

Using 420 pb^-1 of data collected on the Upsilon(5S) resonance with the CLEO III detector, we reconstruct B mesons in 25 exclusive decay channels to measure or set upper limits on the decay rate of Upsilon(5S) into B meson final states. We measure the inclusive B cross-section to be sigma(Y(5S)-->BB(X))=(0.176+-0.030+-0.016) nb and make the first measurements of the production rates of sigma(Y(5S)-->B*B*)=(0.131+-0.025+-0.014) nb and sigma(Y(5S)-->BB*)=(0.043+-0.016+-0.006) nb, respectively. We set 90% confidence level limits of sigma(Y(5S)-->B B-bar)<0.038 nb, sigma(Y(5S)-->B(*)B(*)(pi))<0.055 nb and sigma(Y(5S)-->BBpipi)<0.024 nb. We also extract the most precise value of the B_s* mass to date, M(B_s*)=(5411.7+-1.6+-0.6) MeV/c^2.