K
S
0,
Λ,
Ξ,
Ω and negative particle yields and transverse mass spectra have been measured at central rapidity in Pb–Pb and p–Pb collisions at 158
A GeV/
c. Yields are studied as a function of the ...number of nucleons participating in the collision
N
part, which is estimated with the Glauber model. From p–Pb to Pb–Pb collisions the particle yields per participant increase substantially. The enhancement is more pronounced for multistrange particles, and exceeds an order of magnitude for the
Ω. For a number of participants,
N
part, greater than 100, however, all yields per participant appear to be constant.
A search has been performed for the Standard Model Higgs boson in the data sample collected with the ALEPH detector at LEP, at centre-of-mass energies up to 209
GeV. An excess of 3
σ beyond the ...background expectation is found, consistent with the production of the Higgs boson with a mass near 114
GeV/
c
2. Much of this excess is seen in the four-jet analyses, where three high purity events are selected.
Factors influencing the performances of micro-strip gas chambers Mack, V; Brom, J.M; Fang, R ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/1995, Letnik:
367, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Damages to MSGCs induced by discharges have been investigated. Optimization of electrode shapes and/or deposition of a protective coating allows the increase of the potential difference between anode ...and cathode, thus increasing the gain.
For prototypes of MSGCs made at the Centre de Recherches Nucléaires, each step of the manufacturing processes was carefully controlled. Results are presented on the influence of cleaning processes on the surface resistance of glass substrates.
Microstrip gas chambers on implanted substrates Pallarès, A; Barthe, S; Bergtold, A.M ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/1995, Letnik:
367, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We have studied the performance of several Microstrip Gas Chamber (MSGC) prototypes made on standard Desag D263 boron implanted glass. The purpose of the implantation is to reduce the surface ...resistance. The long term stability of this implantation has been measured under applied bias voltage. Comparative tests have been carried out on prototypes made on implanted and unimplanted detectors under electron (
90Sr) and X-ray (8 keV) irradiation. The total dose was approximately 7 mC/cm.
During the beam test of a tracker prototype for the Compact Muon Solenoid detector proposed for the LHC, the time response of the Microstrip Gas Chambers was studied using different gases and chamber ...gaps. The subsequent efficiency to identify the bunch crossing at LHC is discussed for several algorithms used in the off-line signal processing of the data.
This study concerns the evolution of the information seeking and use models for professionals essentially, the information access practices. Coming from Anglo-Saxon literature, this new information ...science research trend, evolve with paradigms and different information seeking and use models have emerged, in order to explain how professional seeks information and what can be done in order to help them. Two main categories can be distinguished : the information seeking and use model versus the information retrieval model. So we will present today this diversity of models and we will evaluate them in order to see if a convergence is possible with the same vocabulary and procedures.
The triple gauge-boson couplings involving the W are determined using data samples collected with the ALEPH detector at mean centre-of-mass energies of 183 GeV and 189 GeV, corresponding to ...integrated luminosities of 57 pb\(^{-1}\) and 174 pb\(^{-1}\), respectively. The couplings, \(g^Z_1\), \(\kappa_\gamma\) and \(\lambda_\gamma\), are measured using W-pair events, single-{\it W} production and single-\(\gamma\) production. Each coupling is measured individually with the other two couplings fixed at their standard model value. Including ALEPH results from lower energies, the 95% confidence level intervals for the deviation to the standard model are \(-0.087 <\Delta{g}^{Z}_1 < 0.141\), \(-0.200 < \Delta\kappa_\gamma < 0.258\), and \(-0.062 < \lambda_\gamma < 0.147\).Fits are also presented where two or all three couplings are allowed to vary. In addition, W-pair events are used to set limits on the C- or P-violating couplings \(g^V_4\), \(g^V_5\), \({\tilde{\kappa}_{V}}\), and \({\tilde{\lambda}_{V}}\), where V denotes either \(\gamma\) or Z. No deviations from the standard model expectations are observed.
Relative production rates of hyperons and antihyperons from heavy ion collisions are expected to be sensitive signals of quark-gluon plasma formation. They have to be confronted to corresponding ...quantities from
pp and
pA collisions which are evaluated here.
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