First measurement of the Q2 distribution of X(3915) single-tag two-photon production

We report the first measurement of the Q2 distribution of X(3915) produced by single-tag two-photon interactions. The decay mode used is X(3915) & RARR; J/& psi;& omega;. The covered Q2 region is from 1.5 (GeV/c)2 to 10.0 (GeV/c)2. We observe 7.9 1 3.1(stat) 1 1.5(syst) events, where we expect 4.1 10.7 events based on the Q2 = 0 result from the no-tag two-photon process, extrapolated to higher Q2 region using the cc over bar model of Schuler, Berends, and van Gulik. The shape of the distribution is also consistent with this model; we note that statistical uncertainties are large.

Automated summary

We report the first measurement of the Q2 distribution of X(3915) produced by single-tag two-photon interactions. The observed number of events in the higher Q2 region exceeds the expected value, and the shape of the distribution is consistent with the model, although with large statistical uncertainties.