With a data sample of 86 000 Z --> tau(+)tau>(-)(gamma) events collected in 1990 through 1993 we have measured the polarization of tau-leptons as a function of the production polar angle using the following 1-prong tau decay modes: tau(-) --> e(-)<(nu)over bar>(e) nu(tau),tau(-) --> mu(-)<(nu)over bar>(mu)nu(tau), tau(-) --> pi(-)(K-)nu(tau),tau(-) --> rho(-)nu(tau) and tau(-) --> a(1)(-)nu(tau). We obtain for the ratio of vector to axial-vector weak neutral couplings for electrons gVe/gAe = 0.0791 +/- 0.0099(stat) +/- 0.0025(syst) and taus gV tau/gA tau = 0.0752 +/- 0.0063(stat) +/- 0.0045(syst) consistent with the hypothesis of e - tau universality. Assuming universality of the e - tau neutral current we determine the effective electroweak mixing angle to be sin(2) theta(W)(eff) = 0.2309 +/- 0.0016.
A measurement of τ polarization at LEP
MONACO, Vincenzo;
1994-01-01
Abstract
With a data sample of 86 000 Z --> tau(+)tau>(-)(gamma) events collected in 1990 through 1993 we have measured the polarization of tau-leptons as a function of the production polar angle using the following 1-prong tau decay modes: tau(-) --> e(-)<(nu)over bar>(e) nu(tau),tau(-) --> mu(-)<(nu)over bar>(mu)nu(tau), tau(-) --> pi(-)(K-)nu(tau),tau(-) --> rho(-)nu(tau) and tau(-) --> a(1)(-)nu(tau). We obtain for the ratio of vector to axial-vector weak neutral couplings for electrons gVe/gAe = 0.0791 +/- 0.0099(stat) +/- 0.0025(syst) and taus gV tau/gA tau = 0.0752 +/- 0.0063(stat) +/- 0.0045(syst) consistent with the hypothesis of e - tau universality. Assuming universality of the e - tau neutral current we determine the effective electroweak mixing angle to be sin(2) theta(W)(eff) = 0.2309 +/- 0.0016.File | Dimensione | Formato | |
---|---|---|---|
1-s2.0-0370269394903166-main.pdf
Accesso riservato
Tipo di file:
POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione
886.15 kB
Formato
Adobe PDF
|
886.15 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.