A preliminary direct measurement of the parity-violating coupling of the Z{sup 0} to strange quarks, A{sub s}
- Aomori Univ. (Japan)
- Nagoya Univ. (Japan)
- Stanford Univ., CA (US). Stanford Linear Accelerator Center; and others
The authors present a preliminary direct measurement of the parity violating coupling of the Z{sup 0} to strange quarks, A{sub s}, derived from a sample of approximately 300,000 hadronic decays of Z{sup 0} bosons produced with a polarized electron beam and recorded by the SLD experiment at SLAC between 1993 and 1997. Z{sup 0} {yields} s{bar s} events are tagged by the presence in each event hemisphere of a high-momentum K{sup {+-}}, K{sub s}{sup 0} or {Lambda}{sup 0}/{bar {Lambda}}{sup 0} identified using the Cherenkov Ring Imaging Detector and/or a mass tag. The CCD vertex detector is used to suppress the background from heavy flavor events. The strangeness of the tagged particle is used to sign the event thrust axis in the direction of the initial s quark. The coupling A{sub s} is obtained directly from a measurement of the left-right-forward-backward production asymmetry in polar angle of the tagged s quark. To reduce the model dependence of the measurement, the background from u{bar u} and d{bar d} events is measured from the data, as is the analyzing power o the method for s{bar s} events. The authors measure A{sub s} = 0.82 {+-} 0.10(stat.) {+-} 0.07(syst.)(preliminary).
- Research Organization:
- Stanford Univ., Stanford Linear Accelerator Center, CA (US); Boston Univ., MA (US); Univ. of California, Santa Barbara, CA (US); Univ. of California, Santa Cruz, CA (US); Colorado State Univ., Fort Collins, CO (US); Univ. of Colorado, Boulder, CO (US); Univ. of Illinois, Urbana, IL (US); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of Massachusetts, Amherst, MA (US); Massachusetts Inst. of Tech., Cambridge, MA (US); Univ. of Oregon, Eugene, OR (US); Univ. of Tennessee, Knoxville, TN (US); Univ. of Wisconsin, Madison, WI (US); Yale Univ., New Haven, CT (US)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (US); National Science Foundation, Washington, DC (US); United Kingdom Particle Physics and Astronomy Research Council (United Kingdom); Japan-US Cooperative Research Project on High Energy Physics, Nagoya (Japan) (US)
- DOE Contract Number:
- AC03-76SF00515; FG02-91ER40676; FG03-91ER40618; FG03-92ER40689; FG03-93ER40788; FG02-91ER40672; FG02-91ER40677; AC03-76SF00098; FG02-92ER40715; FC02-94ER40818; FG03-96ER40969; FG02-91ER40627; FG02-95ER40896; FG02-92ER40704
- OSTI ID:
- 664471
- Report Number(s):
- SLAC-PUB-7825; CONF-980748-; ON: DE98059224; CNN: Grant NSF PHY-91-13428; Grant NSF PHY-89-21320; Grant NSF PHY-92-04239; Grant NSF PHY-95-10439; Grant NSF PHY-88-19316; Grant NSF PHY-92-03212; TRN: US200305%%634
- Resource Relation:
- Conference: ICHEP '98: 29. international conference on high-energy physics, Vancouver, British Columbia (CA), 07/23/1998--07/30/1998; Other Information: Supercedes report DE98059224; PBD: Jun 1998; PBD: 1 Jun 1998
- Country of Publication:
- United States
- Language:
- English
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