The Mac and Mark Ii Detectors at Pep

Data from PEP are presented for the MAC and MARK II detectors. All data are at a center-of-mass energy of 29 GeV and corresponds to a data set varying from 15-30 pb -1 . R=o /a hadronic p1-l is presented by both groups, and inclusive momentum distributions CS(do/dx)l for SPEAR and PEP energies are presented by the MARK II. The S(da/dx) distributions exhibit sizeable scaling violations. Both groups have measured energy-energy correlations. The measurements yield a S = 0.20? O.Ol+ 0.02 (MAC) and as = 0.195 O.Ol+ 0.03 (MARK II) where a s is the strong coupling constant to first order. It is stressed however that this measurement of as is very sensitive to nonperturbative *t (fragmentation) effects. The NARK II group has observed a clean D signal from which they obtain o(D *') = 0.252 0.10 as the cross section for producing a charged D* at 29 GeV. The charm fragmentation function is measured and it appears to be fairly hard with an average fractional energy for the D *+ of -0.6. The MAC group has measured the T lifetime and finds a value t 10 -13 sees. T = (4.9k 2.0) x The MARK II group has measured the T branching fractions into one (Bl) and three (B3 = 1 Bl) charged prongs. They find Bl = (86+3&l)%. They also find B5 < 0.5% at the 90% confidence level. Also presented from the MARK II group are limits on the production of charged scalar particles (Higgs or technipions; H') which couple to T'S, For 2 < H' mass < 10 GeV/c2, the branching fraction for Hf to decay to 'cvT is found to be less than 5% at the 90% confidence level.