Preliminary measurement of D*/D production and D* spin alignment at the Z{sup 0} resonance
Using hadronic Z{sup 0} decays recorded by the SLD experiment at SLAC, we have measured the vector/(vector+pseudoscalar) production ratio, V/(V+P), for the prompt charmed mesons, D{sup *+} and D{sup +}. Using the channels D{sup *+}{r_arrow}D{sup 0}{pi}{sup +}{sub s}, D{sup 0}{r_arrow} K{sup -}{pi}{sup +}, and D{sup 0}{r_arrow} K{sup - }{pi}{sup +}{pi}{sup -}{pi}{sup +}, as well as D{sup +}{r_arrow} K{sup -}{pi}{sup +}{pi}{sup -}, we find V/(V+P) = 0.57 {+-} 0.07 ({ital stat}){+-} 0.02({ital BR}), which disfavors the expectations of 0.75 from naive spin counting. We have also measured the degree of D{sup *+} spin alignment along the flight direction and find it to be consistent with the zero for D{sup *+} fractional momenta {chi} {triple_bond} E{sub D{sup *}}/D{sub {ital beam}} {gt} 0.2. We compare these results with QCD model predictions.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States); Science and Engineering Research Council, Swindon (United Kingdom); Istituto Nazionale di Fisica Nucleare, Rome (Italy); Japan-US Cooperative Research Project on High Energy Physics, Nagoya (Japan)
- DOE Contract Number:
- FG02-91ER40676; FG03-91ER40618; FG03-92ER40689; FG03-93ER40788; FG02-91ER40672; FG02-91ER40677; AC03-76SF00098; FG02-92ER40715; AC02-76ER03069; FG06-85ER40224; AC03-76SF00515; FG05-91ER40627; FG02-95ER40896; FG02-92ER40704
- OSTI ID:
- 282853
- Report Number(s):
- SLAC-PUB-7200; CONF-960765-8; ON: DE96014142; CNN: Grant PHY-91-13428; Grant PHY-89-21320; Grant PHY-92-04239; Grant PHY-88-17930; Grant PHY-88-19316; Grant PHY-92-03212; TRN: 96:020950
- Resource Relation:
- Conference: 28. international conference on high-energy physics, Warsaw (Poland), 25-31 Jul 1996; Other Information: PBD: Jun 1996
- Country of Publication:
- United States
- Language:
- English
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