R Prepost

Learn More
From a sample of hadronic events, produced in e+e-collisions, ue have isolated semi-leptonic decays of heavy particles and used these to obtain a measurement for the bottom-quark lifetime of (1.8 2 0.6 + 0.4) X lo-l2 sec. According to the standard six quark model, the decay of the lowest-lying bottom-flavored hadrons is forbidden in the absence of mixing of(More)
A high-gradient-doping technique is applied to strained polarized photocathodes. A 5.0–7:5 nm p-type surface layer doped to 5 Â 10 19 cm À3 is found sufficient to overcome the surface charge limit while maintaining high beam polarization. This technique can be employed to meet the charge requirements of the Next Linear Collider with a polarization(More)
A single arm Msller polarimeter used to measure the longitudinal beam polarization of the 48GeV electron beam for SLAC fixed target experiment E-154 is described. The polarimeter utilizes an array of silicon strip detectors and a dipole magnetic spectrometer to detect Msller scattered electrons from magnetized Fe-Co alloy target foils. The details of the(More)
The design considerations, construction techniques, prototype tests and performance characteristics, of a pressurized drift chamber used in the MAC detector at PEP are described. The chamber consists of 324 aluminized mylar tubes of 6.9 mm diameter with wall thickness of lOOhm. With appropriate shielding it operates successfully at 4.6 cm from the beam(More)
We present a Next-to-Leading order perturbative QCD analysis of world data on the spin dependent structure functions g p 1 , g n 1 , and g d 1 , including the new experimental information on the Q 2 dependence of g n 1. Careful attention is paid to the experimental and theoretical uncertainties. The data constrain the first moments of the polarized valence(More)
  • W Ford, Colorado, J S Narsh, A L Read, J G Smith, A Marini +45 others
  • 1982
The MAC detector at PEP features a large solid-angle electromagnetic/hadronic calorimeter system, augmented by magnetic charged-particle tracking, muon analysis and scintillator triggering. Its implementation in the context of electron-positron annihilation physics is described. with emphasis on the utilization of calori-metry. Description Detector The MAC(More)
The s and t dependence of incoherent +(3100) photoproduction from deuterium has been measured at the Stanford Linear Accelerator Center. $(3'700) photoproduction and #(3100) photoproduction from hydrogen have also been measured,Two narrow resonances have recently been discovered, the $(3100) and the zjJ(3700). l Since the original discovery, the $(3100) has(More)
Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A^{'}), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-},(More)