The D0 experiment at Fermilab's Tevatron will record several petabytes of data over the next five years in pursuing the goals of understanding nature and searching for the origin of mass. Computing resources required to analyze these data far exceed capabilities of any one institution. Moreover, the widely scattered geographical distribution of D0 collaborators poses further serious difficulties for optimal use of human and computing resources. These difficulties will exacerbate in future high energy physics experiments, like the LHC. The computing grid has long been recognized as a solution to these problems. This technology is being made a more immediate reality to end users in D0 by developing a grid in the D0 Southern Analysis Region (D0SAR), D0SAR-Grid, using all available resources within it and a home-grown local task manager, McFarm. We will present the architecture in which the D0SAR-Grid is implemented, the use of technology and the functionality of the grid, and the experience from operating the grid in simulation, reprocessing and data analyses for a currently running HEP experiment.

Cross sections are presented for the inclusive production of A hyperons in electron-positron annihilations at square-root s=29 GeV based on the full 291-pb-1 sample of data taken in the High Resolution Spectrometer experiment at the SLAC e+e- storage ring PEP. These results, and the associated correlation analyses, are consistent with the Lund model predictions with the strange diquark suppression ratio-delta fixed at 0.59+/-0.10+/-0.18, as compared to the standard Lund value of 0.32. The LAMBDA multiplicity has been found to be 0. 182+/-0.020 per event. The opposite-strangeness multiplicity [n(LAMBDA-LAMBDABAR)] has been measured to be 0.046+/-0.020, whereas the like-strangeness multiplicity [n(LAMBDA-LAMBDA+LAMBDABAR-LAMBDABAR)] is 0.009+/-0.028. A strong correlation is found between LAMBDA's and LAMBDABAR's; when one is found in an event, the other is found in the same event with a probability that exceeds 50%.

Total and dift'erential K cross sections are presented from e+e collisions at &s =29 GeV in the High Resolution Spectrometer detector.K and charged-particle distributions are compared in a study of the hadronization of quarks of known flavor.Events of the reaction e e ~cc are tagged by identifying D*'s while uu, dd, or ss events are tagged through the identification of a charged par- ticle with fractional momentum near 1.Parton-shower models with cluster and string fragmenta- tion are compared with these data.Also, certain particle scaling tests are performed using the quark-flavor tags.In addition, K production in two-and three-jet events is compared to these models.

We report measurements of the lifetimes of the D0, D+, and Ds+ (F+) mesons produced in e+e− collisions at a center-of-mass energy of 29 GeV. The decay vertex distributions in the processes D0→K−π+, D+→K−π+π+, and Ds+→φπ+ were made using a vertex chamber installed in the High Resolution Spectrometer at the SLAC storage ring PEP. The measured lifetimes are & =(4.4±1.0±0.6)×10−13 s, &=(9.2−1.3+1.7± 1.6)×10−13 s, and &=(3.1−2.0+2.4±0.5) ×10−13 s. In addition the lifetime of the B0 meson is determined assuming that only the B0 and not the B− decays to a D*+ meson. The B0 is not directly observed. The lifetime & is estimated indirectly to be (8.2−3.7+5.7±2.7) ×10−13 s.Received 31 May 1988DOI:https://doi.org/10.1103/PhysRevD.39.123©1989 American Physical Society

We report new measurements of the production cross section for the reaction e+e ~~+~at &s =29 GeV, as well as the topological decay branching fractions of the ~lepton.The data were taken with the High Resolution Spectrometer at the SLAC e e colliding-beam facility PEP.The measured cross section yields R"=1.044+0.014+0.030[where the first (second) error is statistical (systematic)], consistent with QED and corresponding to QED cutoff parameters of A+ )129 GeV and A & 284 GeV at the 95%%uo C.L. The fractions of ~decays into one and three charged particles are B =0.864+0.003+0.003and B3 =0.135+0.003+0.003.

We use data from the Mark II experiment at PEP to search for the process B→h0X for mh0 between 50 and 210 MeV/c2. No evidence for the Higgs boson is seen in this mass range. The limit obtained rules out the standard Higgs boson for masses between 70 and 210 MeV/c2 and significantly constrains extensions of the Higgs sector.

This paper reports cross-section measurements for the ρ0 and K∗(890) vector mesons produced in e+e− annihilation at √s=29 GeV. The data, which were taken with the High Resolution Spectrometer operating at the SLAC colliding-beam facility PEP, correspond to an integrated luminosity of 291 pb−1. The measured multiplicities for fractional momentum x>0.05 are Nρ0=0.79±0.04 and NK*0(890)=0.53±0.04. The measured fragmentation functions agree well with the predictions of the Lund model and when extrapolated to threshold, the corresponding total multiplicities are Nρ0=0.90±0.05 and NK*0(890)=0.59±0.05.Received 14 February 1989DOI:https://doi.org/10.1103/PhysRevD.40.706©1989 American Physical Society

The D0→K−π+ branching fraction has been measured by tagging a sample of D∗+→D0π+ decays, independent of the D0 decay mode. The D∗ mesons were obtained in e+e− annihilations at √s=29 GeV using data obtained with the HRS detector at PEP. The result iss Br(D0→K−π+) = 4.5±0.8±0.5%.

Upper limits for the decay widths of the D∗+ and D∗0 mesons have been measured using data from e+e− annihilations at √s=29 GeV obtained with the High Resolution Spectrometer at PEP. We find ΓD∗+ < 1.1 MeV/c2 at 90% CL from an analysis of the mass difference distribution for the decay mode D∗+→D0π+. The D∗+−D0 mass difference is also measured to be ((45.40±0.05±0.10) MeV/c2. We determine ΓD∗0<2.1 MeV/c2at 90% CL for a D∗0mass of 2007.2 MeV/c2, from a search for the decay mode D∗0→D+π− which could occur if the width were sufficiently large.

Data from e+e− annihilations at 29 GeV have been used to measure the production cross section and fragmentation function of η mesons. The signal is observed in the η→γγ decay channel. The fragmentation for pη>1.5 GeV/c agrees well with the prediction of the Lund model, whereas the prediction of the Webber model lies above the data. The mean multiplicity is measured to be 〈nη〉=0.58±0.10 η mesons per hadronic event, of which 0.51 represents the direct production of η and η′ mesons in the fragmentation chain.

A search was made in 29-GeV ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilations for massive neutrinos decaying to ${e}^{\ifmmode\pm\else\textpm\fi{}}$${X}^{\ensuremath{\mp}}$(\ensuremath{\nu}) where X is a muon or meson. A 300-${\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$ data sample yielded just one candidate event with a mass ${m}_{\mathrm{eX}}$>1.8 GeV. Significant limits are found for new neutrinos with masses from 1.8 to 6.7 GeV and with mixing parameters in the range 3\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}6}$\ensuremath{\Vert}U${\ensuremath{\Vert}}^{2}$1. .AE

The production of D* and D mesons has been studied in e+e− annihilations at √s = 29GeV. The data, corresponding to an integrated luminosity of 300 pb−1, were obtained using the HRS detector at PEP. The cross section is measured to be R (D0 + D+) = 2.40±0.35 and we determine the electroweak asymmetry to be −9.9 ± 2.7%, which corresponds to an axial vector coupling constant product gegc = 0.26 ± 0.07.

Multihadronic e+e− annihilation events at a center-of-mass energy of 29 GeV have been studied with both the original (PEP 5) Mark II and the upgraded Mark II detectors. Detector-corrected distributions from global shape analyses such as aplanarity, Q2-Q1, sphericity, thrust, minor value, oblateness, and jet masses, and inclusive charged-particle distributions including x, rapidity, p⊥, and particle flow are presented. These distributions are compared with predictions from various multihadron event models which use leading-logarithmic shower evolution or QCD matrix elements at the parton level and string or cluster fragmentation for hadronization. The new generation of parton-shower models gives, on the average, a better description of the data than the previous parton-shower models. The energy behavior of these models is compared to existing e+e− data. The predictions of the models at a center-of-mass energy of 93 GeV, roughly the expected mass of the Z0, are also presented.Received 14 May 1987DOI:https://doi.org/10.1103/PhysRevD.37.1©1988 American Physical Society

The production of strange baryons ${\ensuremath{\Sigma}}^{\ifmmode\pm\else\textpm\fi{}}$ (1385) and ${\ensuremath{\Xi}}^{\mathrm{\ensuremath{-}}}$ has been observed in ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilations at 29 GeV center-of-mass energy, by use of data obtained with the High Resolution Spectrometer at the SLAC storage ring PEP. The total mean multiplicities are measured to be 〈${n}_{\ensuremath{\Sigma}}^{\ifmmode\pm\else\textpm\fi{}}$(1385)〉=0.033\ifmmode\pm\else\textpm\fi{}0.006\ifmmode\pm\else\textpm\fi{}0.005 and =0.016\ifmmode\pm\else\textpm\fi{}0.004 \ifmmode\pm\else\textpm\fi{}0.004 per hadronic event. The results are in good agreement with the Lund string model.

Using a data sample corresponding to an integrated luminosity of 300 pb−1 collected by the High Resolution Spectrometer, a 95%-confidence-level upper limit of 76 MeV/c2 is found for the mass of the τ neutrino. The experiment is based on a study of the hadronic mass spectrum in the decays τ→5π±ντ and τ→5π±π0ντ.Received 23 December 1986DOI:https://doi.org/10.1103/PhysRevD.35.2880©1987 American Physical Society

We report a measurement of the charged K∗ (892) production in e+e− annihilations at 29 GeV center-of-mass energy. The 300 pb−1 data sample used for this analysis is obtained with the High Resolution Spectrometer at the SLAC storage ring PEP. The total mean multiplicity is measured to be 〈nK∗±(892)〉=0.62±0.045±0.04 per hadronic event. Evidence is also given for the production of a charged K2∗ (1430) tensor meson.

Neutral D∗ meson production in e+e− annihilation at √s=29 GeV has been studied using the high resolution spectrometer. The decay of D∗0 into D0γ, where the D0 decays into K−π+, has been observed. The production cross section in units of the point cross section is 0.63±0.22 for fractional energy Z⩾0.5. The fragmentation function is compared with that of the D∗+ meson measured in the same experiment.