Description and performance of MEA, The magnetic detector at adone

Abstract The experimental detector at Adone, MEA, which operates with its magnetic field perpendicular to the e + e − beams is described. Studies of the magnetic compensation for operation at Adone and resulting magnetic fields are presented. Particles are detected and analyzed using narrow-gap and wide-gap spark chambers which are triggered by scintillation and proportional counters. Momentum measurements for charged particles are made with Δ / p / p = ±0.07 at p = 1 Gev/ c ( B = 2.5 kG) and angles are measured to better than ± 1.5° over a solid angle of ∼0.3 × 4 π sr

Measurement of 3 jet distributions sensitive to the gluon spin in e+ e- annihilations at S**(1/2) = 91-GeV

Contains fulltext : 125117.pdf (preprint version ) (Open Access

A search for doubly charged higgs production in z0 decays

Contains fulltext : 124394.pdf (preprint version ) (Open Access

Search for a scalar top quark using the OPAL detector

Contains fulltext : 124482.pdf (preprint version ) (Open Access

EXPERIMENTAL INVESTIGATION OF THE ENERGY DEPENDENCE OF THE STRONG COUPLING STRENGTH

AbstractThe energy dependence of the relative production rate of three-jet events is studied in hadronic e+e− annihilation events at center of mass energies between 22 and 46.7 GeV. Three-jet events are defined by a jet finding algorithm which is closely related to the definition of resolvable jets used in O(αs2) perturbative QCD calculations, where the relative production rate of three-jet events is roughly proportional to the size of the strong coupling strength. The production rates of three-jet events in the data decrease significantly with increasing centre of mass energy. The experimental rates, which are independent of fragmentation model calculations, can be directly compared to theoretically calculated jet production rates and are in good agreement with the QCD expectations of a running coupling strength. The hypothesis of an energy independent coupling constant can be excluded with a significance of four standard derivations

Measurement and analysis of the reaction #gamma##gamma##->#3#pi#"+3#pi#"-

SIGLETIB: RA 2999(91-003) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A comparison of measured jet cross sections with QCD calculations for e"+e"- annihilation

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman