The hadronic background, so-called minijets, has been estimated for the proposed linear colliders at recent workshops. [16, 10, 4, 5] Since the calculations depend on the poorly known gluon content of a photon at a small Feynman x value of less than 0.1, they have a large ambiguity, for instance more than 100%. For a comparison between various linear colliders, the method of P.Chen et.al. [17] has been employed as the standard calculation in the TRC report. According to the report, the number of minijets are 0.0052 and 0.0032 per a bunch crossing for JLC-I(c) and TESLA, respectively, with GeV and 5GeV, while the 5GeV hadronic events are 3- and 5-times more than the minijets. Since the rates are still low, and, also, the events are boosted in the very forward angular region, no serious problem is expected at least at 500GeV.

Fri, Dec 20, 1996 02:24:05 PM