A study of spin alignment of ρ(770)± and ω(782) mesons in hadronic Z0 decays

UNSPECIFIED (2000) A study of spin alignment of ρ(770)± and ω(782) mesons in hadronic Z0 decays. European Physical Journal C: Particles and Fields, 16 (1). pp. 61-70. ISSN 1434-6044

Abstract

The helicity density matrix elements ρ00 of ρ(770)± and ω(782) mesons produced in Z0 decays have been measured using the OPAL detector at LEP. Over the measured meson energy range, the values are compatible with 1/3, corresponding to a statistical mix of helicity −1, 0 and +1 states. For the highest accessible scaled energy range 0.3 <xE< 0.6, the measured ρ00 values of the ρ± and the ω are 0.373 ± 0.052 and 0.142 ± 0.114, respectively. These results are compared to measurements of other vector mesons.