Recent Results from Mark Ii at Spear and Pep*
نویسنده
چکیده
Three results'are presented: (1) The semi-leptonic branching ratio of the A, has been measured at SPEAR to be B(A+ -+ efx) = (4.5? 1.7)%. of T-pair production have been measuredCat PEP at fi = 29 GeV: (2) Properties orr/,QED = 0.972 0.05 + 0.06; the forward-backward asymmetry is A,, = (-3.5 t 5.0)%; inclusive branching ratios are B(T -+ 1 Prong) = (86 +4)%, B(T + 3 Prongs) = (14 ?4)%, B(-c + 5 Prongs) < 0.6% (95% C.L.). (3) A search has been performed for the pair production of charged, point-like, spin 0 particles. The existence of such particles can be ruled out at a 90% confidence level for 3 ,$ M 5 10 GeV/c2 and branching ratio into hadrons 5 90%. (Presented at the XVIIth Rencontre de Moriond: Electroweak Interactions and Grand Unified Theories, Les Arcs, France, March 14-20, 1982.) * Work supported in part by the Department of Energy, contracts DE-AC03-76SF0051.5 and W-7405-ENG-48.
منابع مشابه
Recent Results from the Mark Ii Experiment+
The Mark II experiment first started taking data in 1978 at the SLAC SPEAR storage ring. It was the first e+edetector with a large, many layer cylindrical drift chamber (CDC) and a large liquid argon calorimeter!” After two years at SPEAR, it was moved to the PEP storage ring, where it was upgraded a year later with a seven layer precision vertex drift chamber!’ located between the CDC and the ...
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