Recent results from the DELPHI Barrel Ring Imaging Cherenkov counter

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NESTOR experiment in 2003

NESTOR is a submarine high-energy muon and neutrino telescope, now under construction for deployment in the Mediterranean close to Greek shores. The first floor of NESTOR with 12 optical modules was deployed successfully in March 2003 together with the electronics system. All systems and the associated environmental monitoring units are operating properly and data are being recorded. The status of the NESTOR project is presented. We outline briefly the construction of the deepwater neutrino telescope, properties of the NESTOR site, infrastructure of the project, the deployment of the first floor, and its current operation. The first data are presented and plans for the next steps are summarized. © 2004 MAIK "Nauka/Interperiodica"

Recent Results from the DELPHI Barrel Ring Imaging Cherenkov Counter

The DELPHI detector, installed at LEP, is equipped with RICH (Ring Imaging CHerenkov) counters. The Barrel part incorporates a liquid (C6F14) and a gaseous (C5F12) radiator providing particle identification up to 20GeV/c. The Cherenkov photons of both radiators are detected by TPC-like photon detectors. The drift gas (75% CH4 + 25% C2H6) is doped with TMAE, by which the UV Cherenkov photons are converted into single free photo-electrons. These are drifted towards MWPC’s at the end of the drift tubes and the space coordinates of the conversion point are determined. One half of the Barrel RICH is now equipped with drift tubes and has provided results from the liquid radiator since spring 1990. The gas radiator has been tested with C2F6 as a preliminary filling since August 1990. The data obtained demonstrate the good particle identification potential. For the liquid radiator the number of detected photons per ring in hadron jets is N=8, whereas for muon pairs (single tracks) N=10 has been obtained. For the gas radiator 2.1 photons per track were observed, which demonstrates the good functioning of the focussing mirrors, as for C2F6 this is close to the expected value. © 1991 IEE

MEASUREMENT OF THE MASS AND WIDTH OF THE Z0 PARTICLE FROM MULTI - HADRONIC FINAL STATES PRODUCED IN e+ e- ANNIHILATIONS

First measurements of the mass and width of the Z0 performed at the newly commissioned LEP Collider by the DELPHI Collaboration are presented. The measuements are derived from the study of multihadronic final states produced in e+e- annihilations at several energies around the Z0 mass. The values found for the mass and width are M(Z0)=91.06±0.09 (stat) ±0.045 (syst.) GeV and Γ(Z0)=2.42±0.21 (stat.) GeV respectively, froma three-parameter fit to the line shape. A two-parameter fit in the framework of the standard model yields for the number of light neutrino species Nν=2.4±0.4 (stat.) ±0.5 (syst.)0SCOPUS: ar.jinfo:eu-repo/semantics/publishe