Download or read book Observation of a Narrow Near-Threshold Structure in the $J/\psi\phi$ Mass Spectrum in $B^+\to J/\psi\phi K^+$ Decays written by and published by . This book was released on 2010 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observation is reported for a structure near the J/[psi][phi] threshold in B+ → J/[psi][phi]K+ decays produced in {bar p}p collisions at √s = 1.96 TeV with a statistical significance of beyond 5 standard deviations. There are 19 ± 6 events observed for this structure at a mass of 4143.4{sub -3.0}{sup +2.9}(stat) ± 0.6(syst) MeV/c2 and a width of 15.3{sub -6.1}{sup +10.4}(stat) ± 2.5(syst) MeV/c2, which are consistent with the previous measurements reported as evidence of the Y(4140).