ρ Meson Production in Two Photon Collision at LEP with L3 Detector

摘要

The reaction γγ → π⁺π^?π⁺π^? has been studied with the L3 detector at LEP. The data sample was collected by L3 at centre-of-mass energies from 160 GeV to 202 GeV with a total integrated luminosity of 466.2 pb^?1. The process is dominated by ρ⁰ρ⁰ production. A spin-parity analysis of the ρ⁰ρ⁰ system for W_γγ P = 2⁺ and helicity 2. A contribution of J^P = 0⁺ is also observed whereas contributions of negative parity states are found to be negligible.