Luminosity Upgrades For The Slc

Recent performance improvements at the SLAC Linear Collider (SLC) have led to a proposal to further increase the luminosity up to a factor of four through a series of modest hardware upgrades. New final focus optics introduced in 1997 combined with permanent magnet octupoles have reduced the contribution to the final beam size due to higher order aberrations. The minimum betas achievable at the IP are presently limited by the increase in detector backgrounds as the beam is focused more strongly. By moving the final quadrupoles closer to the interaction point (IP), one can reduce the synchrotron radiation background while decreasing the IP betas. Other upgrades include increasing the bending radius in the final focus to minimize emittance dilutions due to synchrotron radiation, a fast feedforward from the linac to the final focus to cancel trajectory jitter, and a change in the horizontal damping ring partition number to reduce the emittance of the extracted beam. With these upgrades, t..

First measurement of the left-right asymmetry in Z boson production

We present the first measurement of the left-right cross-section asymmetry (A(LR)) in Z-boson production observed at the SLAC Linear Collider. In 1992 the SLD detector recorded 10 224 Z events produced by the collision of longitudinally polarized electrons with an unpolarized positron beam at a center-of-mass energy of 91.55 GeV. The average electron beam polarization during the run was (22.4 +/- 0.6)%. We measure A(LR) to be 0.100 +/- 0.044 (stat.) +/- 0.004 (syst.), which determines the effective weak mixing angle to be sin2 theta(W)eff = 0.2378 +/- 0.0056 (stat.) +/- 0.0005 (syst.)

First measurement of the left-right cross-section asymmetry in Z boson production by e+ e- collisions

We present the first measurement of the left-right cross section asymmetry (A(LR)) for Z boson production by e+e- collisions. The measurement was performed at a center-of-mass energy of 91.55 GeV with the SLD detector at the SLAC Linear Collider which utilized a longitudinally polarized electron beam. The average beam polarization was (22.4 +/- 0.6)%. Using a sample of 10224 Z decays, we measure A(LR) to be 0.100 +/- 0.044(stat) +/- 0.004(syst), which determines the effective weak mixing angle to be sin2theta(W)eff=0.2378 +/- 0.0056(stat) +/- 0.0005(syst)