The forward-backward asymmetries for the processes e(+)e(-) --> c (c) over bar and e(+)e(-) --> b (b) over bar at the Z resonance are measured using identified D*(+/-) mesons. In 905,000 selected hadronic events, taken in 1991 and 1992 with the DELPHI detector at LEP, 4757 D*(+) --> D degrees pi(+) decays are reconstructed. The c and b quark forward-backward asymmetries are determined to be: A(FB)(c (c) over bar) = 0.077 +/- 0.029 (stat) +/- 0.012 (sys), A(FB)(b (b) over bar) = 0.059 +/- 0.062 (stat) +/- 0.025 (sys). Constraining the b asymmetry to the value measured by DELPHI using independent analyses, the charm asymmetry is determined to be: A(FB)(c,const) = 0.068 +/- 0.027 (stat) +/- 0.011 (sys). This result corresponds to an effective electroweak mixing angle measured using charm quark events of: sin2 theta(eff)(lept) = 0.2307 +/- 0.0062 (stat) +/- 0.0026 (sys).

Measurement of the forward-backward asymmetry of charm and bottom quarks at the Z-pole using D-asterisk(+/-)-mesons

CACCIA, MASSIMO;PREST, MICHELA;
1995

Abstract

The forward-backward asymmetries for the processes e(+)e(-) --> c (c) over bar and e(+)e(-) --> b (b) over bar at the Z resonance are measured using identified D*(+/-) mesons. In 905,000 selected hadronic events, taken in 1991 and 1992 with the DELPHI detector at LEP, 4757 D*(+) --> D degrees pi(+) decays are reconstructed. The c and b quark forward-backward asymmetries are determined to be: A(FB)(c (c) over bar) = 0.077 +/- 0.029 (stat) +/- 0.012 (sys), A(FB)(b (b) over bar) = 0.059 +/- 0.062 (stat) +/- 0.025 (sys). Constraining the b asymmetry to the value measured by DELPHI using independent analyses, the charm asymmetry is determined to be: A(FB)(c,const) = 0.068 +/- 0.027 (stat) +/- 0.011 (sys). This result corresponds to an effective electroweak mixing angle measured using charm quark events of: sin2 theta(eff)(lept) = 0.2307 +/- 0.0062 (stat) +/- 0.0026 (sys).
DELPHI; forward-backward asymmetry; QCD
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11383/1791228
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 14
social impact