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Experimental constraints on the possible JPC quantum numbers of the X(3872)

K. Abe

hep-exarXiv:hep-ex/0505038

Abstract

We examine possible JPC quantum number assignments for the X(3872). Angular correlations between final state particles in X(3872) --> pi+pi- J/psi decays are used to rule out JPC values of 0++ and 0-+. The shape of the pi+pi- mass distribution near its upper kinematic limit favors S-wave over P-wave as the relative orbital angular momentum between the final-state dipion and J/psi, which strongly disfavors 1-+ and 2-+ assignments. The accumulated evidence strongly favors a JPC = 1++ assignment for the X(3872), although the 2++ possibility is not ruled out by tests reported here. The analysis is based on a sample of X(3872) mesons produced via the exclusive process B --> K X(3872) in a 256 fb-1 data sample collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider.

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