16 research outputs found
Rare decays of the Z at LEP
No full textI discuss the preliminary results of the LEP experiments ALEPH, DELPHI, L3, and OPAL on the rare Z decays. Limits of about 105I−5 on the branching ratios are reported by most experiments. The question of excess in the ττV final state remains unsettled. From the analysis of the L3 data the ZZ′ mixing angle is confined to ±1.5° for most extensions of the Standard Model of electroweak interactions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87709/2/1315_1.pd
Symposium in honor of Lawrence W. Jones : Tofigh Azemoon "Fifteen Years of the L3 Hadron Calorimeter"
No full textRecommended from our members
Real-time Data Access Monitoring in Distributed, Multi-petabyte Systems
No full textPetascale systems are in existence today and will become common in the next few years. Such systems are inevitably very complex, highly distributed and heterogeneous. Monitoring a petascale system in real-time and understanding its status at any given moment without impacting its performance is a highly intricate task. Common approaches and off-the-shelf tools are either unusable, do not scale, or severely impact the performance of the monitored servers. This paper describes unobtrusive monitoring software developed at Stanford Linear Accelerator Center (SLAC) for a highly distributed petascale production data set. The paper describes the employed solutions, the lessons learned, the problems still to be addressed, and explains how the system can be reused elsewhere
Operational Aspects of Dealing . . .
No full textTo date, the BaBar experiment has stored over 0.7PB of data in an Objectivity/DB database. Approximately half this data-set comprises simulated data of which more than 70 % has been produced at more than 20 collaborating institutes outside of SLAC. The operational aspects of managing such a large data set and providing access to the physicists in a timely manner is a challenging and complex problem. We describe the operational aspects of managing such a large distributed data-set as well as importing and exporting data from geographically spread BaBar collaborators. We also describe problems common to dealing with such large datasets
Test results from a uranium hadron calorimeter using wire chamber readout
No full textA uranium gas sampling calorimeter has been tested with electrons and pions between 1 and 50 GeV. A comparative evaluation of the response and the resolution for proportional and streamer mode operation of the gas wire chamber detectors is given for two different gas mixtures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26795/1/0000351.pd
On the Verge of One Petabyte - the Story Behind the BaBar Database System
No full textOn the behalf of BaBar Computing Group The BaBar database has pioneered the use of a commercial ODBMS within the HEP community. The unique object-oriented architecture of Objectivity/DB has made it possible to manage over 700 terabytes of production data generated since May'99, making the BaBar database the world's largest known database. The ongoing development includes new features, addressing the ever-increasing luminosity of the detector as well as other changin g physics requirements. Significant efforts are focused on reducing space requirements and operational costs. The paper discusses our experience with developing a large scale database system, emphasizing universal aspects which may be applied to any large scale system, independently of underlying technology used. 1
An enhancement in the ΛΛ invariant mass spectrum
No full textA 2.1 GeV/c K- exposure in a heavy liquid bubble chamber has been used to search for the final states KΛΛ. An enhancement in the ΛΛ invariant mass spectrum at 2370 MeV/c2 is interpreted as a possible resonance produced in Ξ-nucleon interactions. An estimate of the cross-section for ΛΛ production in Ξ-nucleus reations is given. © 1972.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
A measurement of the hyperon lifetimes and parameters
No full textIn an experiment using a heavy liquid bubble chamber the Ξ hyperon lifetimes and α parameters were measured to be τΞo = (3.04 ± 0.230.26) × 10-10 sec, τΞ- = (1.73 ± 0.070.08) × 10-10 sec, αΞo = -0.84 ± 0.27 and αΞ- = -0.42 ± 0.11. These values agree with measurements which employed different techniques and are consistent with the predictions of the ΔI = 1 2 rule. © 1972.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Evidence for higher twist effects in fast π- production by antineutrinos in neon
No full textEvidence for a significant higher twist contribution to high z π- production in antineutrino scattering is presented. In events with W>3 GeV and Q2>1 GeV2 in our data, it accounts for (51 ±8)% of all π- with z above 0.5. It is consistent with the z-Q2 correlations of Berger's higher twist prediction. The data are inconclusive concerning the predicted y-z correlation and pT dependence. The z -Q2 correlation is not adequately described by the Lund Monte-Carlo. © 1986 Springer-Verlag
UvA-DARE (Digital Academic Repository) Link to publication Citation for published version (APA): Inclusive search for the charmless radiative decay of the b-quark (b L3 Collaboration
No full textGeneral rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 29 Jun 2019 Physics Letters B 317 ( 1993 ) We report on the search for the electromagnetic penguin decay b --* s7 at v~ ~ mz. We find no evidence for a signal and place an upper limit on the decay rate Br(b ~ s~,) < 1.2 × 10 -3 at 90% C.L
