Physical Review Letters 96,10 (2006) 102002;
We measure the dipion mass spectrum in X(3872) -> J/psi pi(+)pi(-) decays using 360 pb(-1) of (p) over barp collisions at root s = 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity (S-3(1), P-1(1), and D-3(J)) charmonia decaying to J/psi pi(+)pi(-), as well as even C-parity states in which the pions are from rho(0) decay. The latter case also encompasses exotic interpretations, such as a D-0(D) over bar*(0) molecule. Only the S-3(1) and J/psi rho hypotheses are compatible with our data. Since S-3(1) is untenable on other grounds, decay via J/psi rho is favored, which implies C = +1 for the X(3872). Models for different J/psi-rho angular momenta L are considered. Flexibility in the models, especially the introduction of rho-omega interference, enables good descriptions of our data for both L = 0 and 1.
hadronic transitions;; cdf-ii;; detector;; x(3872);; upgrade;; states
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