Figure 2

Invariant mass (left panel) and pseudoproper decay length (right panel) distributions for \PJpsi candidates with $\pt > 1$ GeV/$c$. The latter distribution is limited to the \PJpsi candidates under the signal peak region $2.92 < m_{\rm e^+e^-} < 3.16$ GeV/$c^2$. The projections of the maximum likelihood fit functions are shown superimposed and the $\chi^2$ values of these projections are also reported for both distributions.