Search for the glueball content of hadrons in gamma p interactions at   GlueX
  We suggest a theoretical framework for the description of double photon and proton-antiproton photoproduction off the proton gamma + p -> 2 gamma + p and gamma + p -> antip + p + p which takes into account the contribution of the scalar mesons f0(1370), f0(1500) and f0(1710). These scalars are considered as mixed states of a glueball and nonstrange and strange quarkonia. Our framework is based on the use of effective hadronic Lagrangians that phenomenologically take into account two-gluon exchange effects governing the gamma + p -> 2 gamma + p and gamma + p -> antip + p + p processes. Present results can be used to guide the possible search for these reactions by the GlueX Collaboration at JLab. 
Thomas Gutsche, Serguei Kuleshov, Valery E. Lyubovitskij, Igor T.   Obukhovsky
hep-ph