Superscaling of Inclusive Electron Scattering from Nuclei

We investigate the degree to which the concept of superscaling, initially developed within the framework of the relativistic Fermi gas model, applies to inclusive electron scattering from nuclei. We find that data obtained from the low energy loss side of the quasielastic peak exhibit the superscaling property, i.e., the scaling functions f(\psi') are not only independent of momentum transfer (the usual type of scaling: scaling of the first kind), but coincide for A \geq 4 when plotted versus a dimensionless scaling variable \psi' (scaling of the second kind). We use this behavior to study as yet poorly understood properties of the inclusive response at large electron energy loss.Comment: 33 pages, 12 color EPS figures, LaTeX2e using BoxedEPSF macros; email to [email protected]

Messungen im Neutronen- und Gamma-Strahlungsfeld eines beladenen Castor-IIa-Behaelters im Transportbehaelterlager Gorleben und Vergleich der Messergebnisse fuer Neutronen mit Monte-Carlo-Rechnungen

Measurements of the neutron and gamma radiation field generated by a CASTOR IIa cask loaded with spent PWR fuel elements in the interim storage facility Gorleben are presented. A variety of measuring devices was used, i.e. two different Bonner-Sphere Systems, a liquid organic scintillator NE 213, a tissue equivalent proportional counter (TEPC) and several commercially used neutron rem counters and gamma counters. Essential results are differential and integral fluence and dose rates (ICRP 21 and ICRP 60) for neutrons and gammas. The measured neutron results are compared with MCNP calculations. Additionally, the results of the neutron rem counters are compared and spatial distributions of the radiation field are discussed. (orig.)Es werden Messungen des Neutronen- und Gamma-Strahlungsfeldes eines mit abgebrannten DWR-Brennelementen beladenen CASTOR IIa-Behaelters im Transportbehaelterlager Gorleben praesentiert. Unter anderem wurden zwei unabhaengige Bonner-Kugel-Systeme, ein fluessiger organischer Szintillator NE 213, ein gewebeaequivalentes Niederdruckproportionalzaehlrohr (TEPC) sowie verschiedene handesluebliche Neutronen- und Gammamonitoren verwendet. Den Schwerpunkt der Ergebnisse bilden spektrale und integrale Neutronen- und Gammafluenzraten sowie Neutronen- und Photonendosisleistungen nach ICRP 21 und ICRP 60. Die Messergebnisse fuer Neutronen werden mit MCNP-Rechnungen vergleichen. Ausserdem wird ein Vegleich handeslueblicher Neutronenmonitore vorgenommen sowie die Orts- und Abstandsabhaengigkeit des Strahlungsfeldes diskutiert. (orig.)SIGLEAvailable from TIB Hannover: RO 9716(24) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Υ\Upsilon(9.46 GeV) and the gluon discovery (a critical recollection of PLUTO results)

The hadronic decays of Y(9.46GeV) were first studied by PLUTO experiment at DORIS e+e- storage ring (DESY). To determine the contribution of PLUTO to the discovery of the gluon, as members of the collaboration, we have reconsidered all the material produced by it in 1978 and the first half of 1979. It results clearly that the experiment demonstrated the main decay of the Y resonance to be mediated by 3 gluons hadronizing into 3 jets. Jettiness resulted evident by the with respect to the thrust axis, which was as observed by PLUTO itself at nearby continuum c.m.s. energies for 2-quark jet events. Instead, the average sphericity , more topological variables and the momentum distribution showed a net difference with the same data, results compatible with jettiness only in case of more than 2 jets. Flatness as consequence of a 3-body decay (therefore 3 jets) was indicated by the low , altogether a result independent of models. The charged multiplicity was observed to be larger than in the continuum and in case of MC 3 gluon jets fragmenting like quarks, as expected for gluon jets. In June 1979 PLUTO measured the matrix element of the 3-gluon decay to be quantitatively according QCD (even after hadronization, which does not obscure the perturbative predictions) and demonstrated the spin 1 nature of the gluon by excluding spin 0 and spin 1/2. The gluon hadronization like a quark jet, as in 3-gluon jet MC, was compatible with topological data and multiplicity; this was the first experimental study of (identified) gluon jets. The PLUTO results were confirmed both by other experiments at DORIS and later by more sophisticated detectors. At higher energies at PETRA the existence of gluons of spin 1 was confirmed by PLUTO and by 3 more experiments by measuring the gluon radiation, soft gluons by jet broadening, hard gluons by the emission of (now clearly visible) gluon jets by quarks.Comment: 41 pages, 18 figures, substantially revised version of DESY report 10-130, published 21. Oct. 2011 in "The European Physical Journal H (Perspectives on Contemporary Physics)". The final published version is available at http//:www.epj.org. The final author's corrected version is available at arXiv:1008.1869v3 [hep-ex], 18. Nov. 201

On the discovery of the gluon

Quantum chromodynamics, the theory of the strong interaction, is a field theory of quarks and gluons. When it was formulated, the existence of its basic ingredients was still unproven and controversial. While for the quarks the case had been settled by 1975, it remained open for the gluons until in 1979 experiments at the electron-positron collider PETRA at DESY in Hamburg led to a breakthrough. Peculiar final configurations of hadrons produced in the electron-positron annihilation process at high energies, so-called planar events and three-jet events, were discovered. In a close cooperation between experiment and theory they were unambiguously identified as signatures of the radiation of hard gluons by quarks (“hard gluon bremsstrahlung”), providing the first clear and direct observational evidence for the existence of the gluon and confirming crucial predictions of quantum chromodynamics