  The observation of a narrow structure near the J/psi phi threshold in
exclusive B+ to J/psi phi K+ decays produced in p-pbar collisions at sqrt(s) =
1.96 TeV is reported. A signal of 19 +- 6(stat) +- 3(syst) events, with
statistical significance of 5.0 standard deviations, is seen in a data sample
corresponding to an integrated luminosity of 6.0 invfb, collected by the CDF II
detector. The mass and natural width of the structure are determined to be m =
4143.4 + 2.9 - 3.0(stat) +- 0.6(syst) MeV and Gamma = 15.3 + 10.4 - 6.1(stat)
+- 2.5(syst) MeV, consistent with the previous measurements reported as
evidence of the Y(4140).
