120145616
The inclusive transverse-momentum distribution in hadronic systems produced in proton-proton collisions
Summary. The single.particle inclusive transverse-momentum distribution in the multiparticle systems produced in low-1~T proton-proton interactions at ~- 30 and 62 GoV has been studied. The analysis was performed removing from the final state the leading proton and redefining the effective hadronie energy available for particle production. Excellent agreement for effective hadronic energies up to 13 GoV is found between (pp) and (e+e-). At higher energy the (pp) data show a less pronounced growth than the (e+e -) data.
120660902
The energy dependence of charged particle multiplicity in p-p interactions
Abstract The average charged multiplicity in proton-proton interactions has been studied at √ s = 62 GeV. A very good agreement with the average charged multiplicity measured in e + e − annihilation at different energies is obtained by redefining, in p-p, the correct energies available for particle production. This means that a p-p collision at √ s = 62 GeV does in fact correspond to a large range of effective hadronic energies available for particle production.
122073109
A check of quantum electrodynamics and of electron-muon equivalence
SummaryA study of the timelike reaction e+e-→μ∓μ± and of its comparison with the spacelike dominated reaction e+e−→e±e± allows us to establish the validity of QED in terms of production angular distributions, absolute rates, energy dependence and angular correlations between the pair of final-state leptons, in two very different ranges of invariant four-momentum transfer. No sign of QED break is detected in the electromagnetic interaction of leptons and the muon behaves like a heavy electron, within the accuracy of the present investigation.RiassuntoSi è compiuto uno studio della reazione «timelike» e+e-→μ∓μ± ed un confronto di questa con la reazione e+e−→e±e± nella quale la parte «spacelike» è dominante. Si sono studiate le distribuzioni angolari delle particelle prodotte, la loro dipendenza dall'energia, le correlazioni geometriche fra le coppie di leptoni nello stato finale, i valori assoluti delle sezioni d'urto, al fine di stabilire la validità dell'elettrodinamica quantica in due intervalli diversi di quadrimomento trasferito. Entro gli errori sperimentali (±8%) non si trova alcuna evidenza di violazione della elettrodinamica quantica nell'interazione elettromagnetica dei leptoni, ed il muone si comporta come un elettrone pesante.РезюмеИсследование времениподобной реакции e+e-→μ∓μ± и ее сравнение с пространственноподобной доминирующей реакцией e+e−→e±e± позволяет нам установить справедливость квантовой электродинамики в терминах угловых распределений рождения, авсолютных интенсивностей, энергетической зависимости и углобых корреляций между парами лептонов в конечном состоянии, в двух очень различиых областях инвариантного четырехмерного передаваемого импульса. Не определен знак нарушения квантовой электродинамики и мюон ведет себя подобно тяжелому электрону в пределах точности настоящего исследования.
109989158
The ZEUS vertex and forward muon detectors readout electronics
Abstract The readout electronics for the Vertex and Forward Muon detectors of the ZEUS experiment at HERA is presented. The system architecture, based on a multilevel modular hierarchical structure, and the system performance are outlined.
118668557
Search for Fractional Charges in Cosmic Rays with Ams
Preliminary results on the flux of non strongly-interacting, fractionally charged particles in primary cosmic rays at 400 Km above sea level are given. Cosmic ray data collected by AMS-01 in June 1998 have been analysed on the hypotheses of 2/3 charged leptons. The search is carried on by looking at the energy deposition measurements by the time of flight system scintillator counters. A preliminary flux limit is given.
118788527
A Modified time expansion chamber as a vertex detector
The design presented is one of two proposals for a Vertex Detector for the experiment ZEUS at HERA.
110850685
First level trigger using pixel detector for the CMS experiment
A proposal for a pixel-based Level 1 trigger for the Super-LHC is presented. The trigger is based on fast track reconstruction using the full pixel granularity exploiting a readout which connects different layers in specific trigger towers. The trigger will implement the current CMS high level trigger functionality in a novel concept of intelligent detector. A possible layout is discussed and implications on data links are evaluated.
2971912
The CMS tracker Data Quality Monitoring expert GUI
Data Quality Monitoring (DQM) is mandatory in a high energy physics experiment like the Compact Muon Solenoid (CMS) at the CERN Large Hadron Collider (LHC). For the CMS Silicon Strip Tracker, the largest detector of this kind ever built, the DQM tasks translate into monitoring of 15148 silicon detector modules for a total of 9.3 million channels. An expert level Graphical User Interface has been developed to manage this highly granular information where the statistical characteristics of more than 350000 histograms are analyzed online during data-taking in order to raise warnings or alarms. In addition, specific quantities can be recalled on demand for problems investigation or online feedback on the data quality.
102340714
CMS Tracker, ECAL and Pixel Optical Cabling: Installation and Performance Verification
The installation of 52304 optical links for the readout and control of the CMS Tracker, ECAL and Pixel detectors is complete. 768 96-way optical cables were installed and tested using an optical time-domain reflectometer. The testing was followed by connections at high density optical fibre patchpanels. Finally, a further round of testing and troubleshooting following feedback from system commissioning with the Tracker Data Acquisition was carried out. Over 90% of the faults found were recovered, resulting overall in only 0.1% of dead optical link channels in the CMS Tracker.
121781476
First performance studies of a pixel-based trigger in the CMS experiment
An important tool for the discovery of new physics at LHC is the design of a low level trigger with an high power of background rejection. The contribution of pixel detector to the lowest level trigger at CMS is studied focusing on low-energy jet identification, matching the information from calorimeters and pixel detector. In addition, primary vertex algorithms are investigated. The performances are evaluated in terms of, respectively, QCD rejection and multihadronic jets final states efficiency.