Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic $ep$ scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

A Search for Selectrons and Squarks at HERA

Data from electron-proton collisions at a center-of-mass energy of 300 GeV are used for a search for selectrons and squarks within the framework of the minimal supersymmetric model. The decays of selectrons and squarks into the lightest supersymmetric particle lead to final states with an electron and hadrons accompanied by large missing energy and transverse momentum. No signal is found and new bounds on the existence of these particles are derived. At 95% confidence level the excluded region extends to 65 GeV for selectron and squark masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure

An open strip-field system at its tipping point in the German-Dutch River Dinkel catchment. Part 1

Three questions were addressed. Firstly, where in pre-19th century landscape did farmers hold strips, camps, meadows and shares in commons? Secondly, did farmers each own strips and camps or were some specialised strip and others exclusively camp farmers? Finally, can we corroborate or reject one of the alternative hypotheses: strip-field-first versus camp-first. The area of interest is the current cadastral district cum medieval parish Epe at today’s German-Dutch border as pars pro toto for the surrounding area of about 100 kilometer diameter in the NW European cover sand belt. Our key data source was the 1827 A.D. cadastre complemented by the historical topographic map and geological, soil and elevation maps. For population estimates, we used six tax registers from 1499-1750 A.D. All parcels per farmstead were identified in the cadastral registry, farms located on parcel maps and hamlet territories delineated as the aggregate of its farms. The following farm features were extracted from the cadastre and averaged per settlement: number of strips and strip-fields, parcel type, farm size, tenure, number of meadows, oak camps, crop camps and pasture camps. Next, the following landscape features were identified from the map set per settlement: farmstead pattern, type of settlement, commons, strip-field, soil and watercourse. We presented the historical context, followed by a description and discussion of farm and landscape features of settlement categories. Finally, we synthesised our findings and discussion, concluding with a hypothetical narrative consistent with our findings, and provided answers to our research questions.https://www.tandfonline.com/loi/rlsh202021-04-17hj2020Geography, Geoinformatics and Meteorolog