Inclusive Production of the omega and eta Mesons in Z Decays, and the Muonic Branching Ratio of the omega

TL;DR

This paper measures the production rates of omega and eta mesons in Z decays and determines the muonic branching ratio of the omega meson using data from the ALEPH detector, providing new experimental insights.

Contribution

It provides the first measurement of the omega meson's muonic branching ratio and compares meson production rates to theoretical models in Z decays.

Findings

Omega production rate: 0.585 ± 0.019_stat ± 0.033_sys per event

Eta production rate: 0.355 ± 0.011_stat ± 0.024_sys per event

Omega -> mu+ mu- branching ratio: (9.0 ± 2.9_stat ± 1.1_sys)×10^-5

Abstract

The inclusive production of the omega(782) vector meson in hadronic Z decays is measured and compared to model predictions. The analysis is based on 4 million hadronic Z decays recorded by the ALEPH detector between 1991 and 1995. The production rate for x_p = p_meson/p_beam > 0.05 is measured in the omega -> pi^+ pi^- pi^0 decay mode and found to be 0.585 +- 0.019_stat +- 0.033_sys per event. Inclusive eta meson production is also measured in the same decay channel for x_p > 0.10, obtaining 0.355 +- 0.011_stat +- 0.024_sys per event. The branching ratio for omega -> mu^+ mu^- is investigated. A total of 18.1 +- 5.9 events are observed, from which the muonic branching ratio is measured for the first time to be BR(omega -> mu^+ mu^-) = (9.0 +- 2.9_stat +- 1.1_sys)*10^-5.