Is the X(3915) the x(c0)(2P)?

Abstract

The Particle Data Group Meson Summary Table lists the X(3915) meson, omega J/psi. mass peak seen in B -> K omega J/psi decays and gamma gamma -> omega J/psi two-photon fusion reactions, as the x(c0)(2P), the 2(3)P(0) charmonium state. Here, with some reasonable assumptions, it is shown that if the X(3915) is the x(c0)(2P), the measured strength of the gamma gamma -> X(3915) signal implies an upper limit on the branching fraction B(x(c0)(2P) -> omega J/psi) that is below a lower limit inferred for the same quantity from the B -> KX(3915) decay rate. Also, the absence any signal for X(3915) -> D-0(D) over bar (0) in B+ -> (K+D0)(D) over bar (0) decays is used to infer the limit B(X(3915) -> D-0(D) over bar (0)) < 1.2 x B(X(3915) -> omega J/psi). This contradicts expectations that x(c0)(2P) decays to D-0<(D)over bar>(0) should be a dominant process, while decays to omega J/psi, which are Okubo-Zweig-Iizuka suppressed, should be relatively rare. These, plus reasons given earlier by Guo and Meissner, raise concerns about the X(3915) = x(c0)(2P) assignment.