arXiv subjects

SLD Collaboration

Publications and source records attributed to SLD Collaboration.

22 records · Page 2Linked to original sources

arXiv1996

First Measurement of the Left-Right Charge Asymmetry in Hadronic Z Boson Decays and a New Determination of sin^2(theta_eff)

We present the first measurement of the left-right charge asymmetry A_Q^{obs} in hadronic Z boson decays. This was performed at E_cm = 91.27 GeV with the SLD at the SLAC Linear Collider with a polarized electron beam. Using 89838 events, we obtain A_Q^{obs}=0.225+-0.056+-0.019 which leads to a measurement of the electron left-right asymmetry parameter, A_e=0.162+-0.041+-0.014, and sin^2(theta_eff)=0.2297+-0.0052 +-0.0018. Also, the A_Q^{obs} measurement combined with the left-right cross section asymmetry determines A_e independently of the value of the electron-beam polarization.

hep-ex↗

arXiv1996

First Study of Rapidity Gaps in e+e- Annihilation

We present the first study of rapidity gaps in e+e- annihilations using Z0 decays collected by the SLD experiment at SLAC. Our measured rapidity gap spectra fall exponentially with increasing gap size over five decades, and we observe no anomalous class of events containing large gaps. This supports the interpretation of the large-gap events measured in pp and ep collisions in terms of exchange of color-singlet objects. The presence of heavy flavors or additional jets does not affect these conclusions.

hep-ex↗

arXiv1996

Factorial and Cumulant Moments in $e^{+}e^{-}\to$ Hadrons at the Z$^0$ Resonance

We present the first experimental study of the ratio of cumulant to factorial moments of the charged-particle multiplicity distribution in high-energy particle interactions, using hadronic Z$^0$ decays collected by the SLD experiment at SLAC. We find that this ratio, as a function of the moment-rank $q$, decreases sharply to a negative minimum at $q=5$, which is followed by quasi-oscillations. These features are insensitive to experimental systematic effects and are in qualitative agreement with expectations from next-to-next-to-leading-order perturbative QCD.

hep-ex↗

arXiv1994

Precise Determination of the Weak Mixing Angle from a measurement of ALR in e+e- -> Z0

In the 1993 SLC/SLD run, the SLD recorded 50,000 $\z0$ events produced by the collision of longitudinally polarized electrons on unpolarized positrons at a center-of-mass energy of 91.26 GeV. The luminosity-weighted average polarization of the SLC electron beam was (63.0$\pm$1.1)\%. We measure the left-right cross-section asymmetry in $\z0$ boson production, $\alr$, to be 0.1628$\pm$0.0071(stat.)$\pm$0.0028(syst.) which determines the effective weak mixing angle to be $\swein=0.2292\pm0.0009({\rm stat.})\pm0.0004({\rm syst.}).$

hep-ex↗