Observation of a 1750 MeV/c2 enhancement in the diffractive photoproduction of K+ K-
Using the FOCUS spectrometer with photon beam energies between 20 and 160 GeV, we confirm the existence of a diffractively photoproduced enhancement in K+K- at 1750 MeV/c2 with nearly 100 times the statistics of previous experiments. Assuming this enhancement to be a single resonance with a Breit-Wigner mass shape, we determine its mass to be 1753.5 ± 1.5 ± 2.3 MeV/c2 and its width to be 122.2 ± 6.2 ± 8.0 MeV/c2. We find no corresponding enhancement at 1750 MeV/c2 in K*K, and again neglecting any possible interference effects we place limits on the ratio Γ(X(1750) → K*K)/Γ(X(1750) → K+K-). Our results are consistent with previous photoproduction experiments, but, because of the much greater statistics, challenge the common interpretation of this enhancement as the φ(1680) seen in e+e- annihilation experiments. © 2002 Elsevier Science B.V. All rights reserved.
Link, J. M.; Reyes, M.; Yager, P. M.; Anjos, J. C.; Bediaga, I.; Göbel, C.; Magnin, J.; Massafferri, A.; Kryemadhi, Abaz; and Pepe, I. M., "Observation of a 1750 MeV/c2 enhancement in the diffractive photoproduction of K+ K-" (2002). Educator Scholarship & Departmental Newsletters. 212.