The Jetset experiment at lear

The Jetset experiment (PS 202) at LEAR will search for gluonic hadrons and other exotics in the interaction of in‐flight antiprotons with protons at rest. The mass range to be covered extends from 1.96 to 2.43 GeV. Our experiment uses a molecular hydrogen cluster jet target which is inserted in the LEAR ring and is surrounded by a general‐purpose detetor of advanced design. In ‘‘Phase I’’ the detector has been constructed to provide selection at the trigger level of four kaon events, allowing a search for resonances in the OZI‐forbidden, gluon‐rich reaction pp→φφ→4K. The combination of LEAR with our detector is unique in that it allows scanning over a large momentum range with excellent momentum resolution, implying corresponding excellent mass resolution. The physics interest in this process is outlined briefly, and the design of the detector elments is described in some detail. A brief discussion of possible upgrade paths (‘‘Phase II’’) for the detecor is given at the end.