Publikace na Matematicko-fyzikální fakulta |
2011
Abstrakt
We present results from a study of X(3872) -} pi pi J/psi decays produced via exclusive B -} KX(3872) decays. We determine the mass to be M(X(3872)) = (3871.85 +/- 0.27(stat) +/- 0.19(syst)) MeV, a 90% confidence level upper limit on the natural width of Gamma(X(3872)) { 1.2 MeV, the product branching fraction B(B(+) -} K(+)X(3872)) X B(X(3872) -} pi(+)pi(-) J/psi) = (8.63 +/- 0.82(stat) +/- 0.52(syst)) X 10(-6), and a ratio of branching fractions B(B(0) -} K(0)X(3872))/B(B(+) -} K(+)X(3872)) = 0.50 +/- 0.14(stat)) +/- 0.04(syst).
The difference in mass between the X(3872) -} pi(+)pi(-) J/psi signals in B(+) and B(0) decays is Delta M(X(3872)) = (-0.71 +/- 0.96(stat) +/- 0.19(syst)) MeV.