For many years charm physics has suffered from a lack of precision and statistics. With the development of high resolution vertex detectors excellent signal/background ratios have been obtained for charmed hadrons. However, the use of more sophisticated tagging techniques needed for further purification of the event samples leads to a big loss in usable data. Thus large acceptance spectrometers and very high statistics are needed to study rare events including all the topics discussed above as well as simply charmed baryons.
Owing to its special target detector COMPASS can contribute to a high precision determination of baryon lifetimes and to the study of semileptonic decays. Although high statistics may seem of lesser importance for the lifetime measurement it is needed for a careful study of the systematics. The precision of the mass measurement of ground state hadrons is less related to statistics but to a good calibration of the complete apparatus. Established states which will be observed in large quantities will serve as calibration lines over a large part of the available phase space.
Large statistics on the other hand is essential to observe broader excited states which might only be detected by their decay chain via intermediate charm resonances. Currently only one 3/2 state is known for the baryons, no radially excited charmed meson has yet been observed. There is no guarantee that the foreseen COMPASS statistics will reveal many new states. However, at present we are still far from the situation in the light quark system where large data samples allow the use of complex analysis procedures revealing the nature of the observed states. A large increase in statistics should thus improve the situation in the charm sector considerably.
Concerning the spectroscopy of charmed strange baryons, E781 using a hyperon beam might do just as well as COMPASS and be ahead in time by about 4 years. No other experiment will probably reach the expected yields. If the advantage of a strange quark in the beam is clearly demonstrated COMPASS also can switch to a hyperon beam of intensities again about a factor 10 higher as compared to E781.