Evidence of sigma particle in J / psi ---> omega pi pi
Jing-Zhi Bai, Ze-Pu Mao, Jie Chi Yang, Y. K. Heng et autres
Based on a sample of 7.8 million BESI $J/\\psi$ events, the decay of $ J/\\psi \\to \\omega \\pi^+ \\pi^-$ is studied. A low mass enhancement in the $\\pi^+ \\pi^-$ invariant mass spectrum recoiling against $\\omega$ particle is clearly seen which does not …