A Hadron Blind Detector (HBD) has been developed, constructed and successfully operated within the PHENIX detector at RHIC. The HBD is a Cherenkov detector operated with pure
CF
4
. It has a 50
cm ...long radiator directly coupled in a windowless configuration to a readout element consisting of a triple GEM stack, with a CsI photocathode evaporated on the top surface of the top GEM and pad readout at the bottom of the stack. This paper gives a comprehensive account of the construction, operation and in-beam performance of the detector.
A hadron blind detector for the PHENIX experiment at RHIC Fraenkel, Z.; Kozlov, A.; Naglis, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2005, Letnik:
546, Številka:
3
Journal Article
Recenzirano
Odprti dostop
A Hadron Blind Detector (HBD) is being developed for the PHENIX experiment at RHIC. It consists of a Cherenkov radiator operated with pure
CF
4
directly coupled in a windowless configuration to a ...triple-GEM detector element with a CsI photocathode and pad readout. The HBD operates in the bandwidth 6–11.5
eV (110–200
nm). We studied the detector response to minimum ionizing particles and to electrons. We present measurements of the CsI quantum efficiency, which are in very good agreement with previously published results over the bandwidth 6–8.3
eV and extend them up to 10.3
eV. Discharge probability and aging studies of the GEMs and the CsI photocathode in pure
CF
4
are presented.
During the 1996 lead run time, CERES has accumulated 42 million events, corresponding to a factor of 5 more statistics than in 1995 and 2.5 million events of a special photon-run. We report on the ...results of the low-mass e
+e
−-pair analysis. Since the most critical item is the poor signal-to-background ratio we also discuss the understanding of this background, in absolute terms, with the help of a detailed Monte Carlo simulation. We show preliminary results of the photon analysis and summarize the results of the hadron analysis preliminarily reported on already at QM'97 1.
Event-by-event fluctuations at SPS Appelshäuser, Harald; Sako, Hiro; Adamová, D. ...
Nuclear physics. A,
04/2005, Letnik:
752
Journal Article
Recenzirano
Odprti dostop
Results on event-by-event fluctuations of the mean transverse momentum and net charge in Pb-Au collisions, measured by the CERES Collaboration at CERN-SPS, are presented. We discuss the centrality ...and beam energy dependence and compare our data to cascade calculations.
We present the combined results on electron-pair production in 158 GeV/n Pb-Au (\(\sqrt{s}\) = 17.2 GeV) collisions taken at the CERN SPS in 1995 and 1996, and give a detailed account of the data ...analysis. The enhancement over the reference of neutral meson decays amounts to a factor of 2.31 \(\pm0.19 (stat.)\pm0.55 (syst.)\pm0.69 (decays)\) for semi-central collisions (28\(\%\)\(\sigma/\sigma_{geo}\)) when yields are integrated over m > 200 MeV/c2 in invariant mass. The measured yield, its stronger-than-linear scaling with \(N_{\rm ch}\), and the dominance of low pair pt strongly suggest an interpretation as thermal radiation from pion annihilation in the hadronic fireball. The shape of the excess centring at \(m\approx\) 500 MeV/c2, however, cannot be described without strong medium modifications of the \(\rho\) meson. The results are put into perspective by comparison to predictions from Brown-Rho scaling governed by chiral symmetry restoration, and from the spectral-function many-body treatment in which the approach to the phase boundary is less explicit.
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