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U.S. Department of Energy
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First results from DELCO at PEP

Technical Report ·
DOI:https://doi.org/10.2172/6368198· OSTI ID:6368198
Preliminary results from DELCO are presented on several topics which utilize the particle identification capabilities of the detector: (1) we measure the Cabbibo angle in tau decays to be tan/sup 2/ theta/sub c/ = 0.08 +- 0.03 +- 0.04; (2) in the intermediate x (p/E/sub BEAM/) range, 0.2 < x < 0.55, the fraction of ..pi../sup + -/ relative to all charged particles is found to be approximately 60% and to show only a weak energy dependence; and (3) we observe a large D*/sup + -/ cross section ratio, R/sub D*/sup + -// = sigma(e/sup +/e/sup -/ ..-->.. D*/sup + -/X)/sigma/sub ..mu mu../ = 2.0 +- 0.6 +- 0.7 in the z (E/sub D*//E/sub BEAM/) range above 0.3. In contrast with the lighter quarks, the fragmentation of charmed quarks occurs predominantly at large values of z; we measure = 0.6 +- 0.1.
Research Organization:
California Inst. of Tech., Pasadena (USA); Stanford Linear Accelerator Center, CA (USA); Stanford Univ., CA (USA)
DOE Contract Number:
AC03-76SF00515
OSTI ID:
6368198
Report Number(s):
SLAC-PUB-2981; CONF-820718-30; ON: DE83007005
Country of Publication:
United States
Language:
English