1,744 research outputs found
Diffractive Interactions
The general framework of diffractive deep inelastic scattering is introduced
and reports given in the session on diffractive interactions at the
International Workshop on Deep-Inelastic Scattering and Related Phenomena,
Rome, April 1996, are presented.Comment: LaTeX with procl.sty, 20 pages. To appear in the Proceedings of the
International Workshop on Deep Inelastic Scattering and Related Phenomena,
Roma, Italy, April 199
Diffraction at HERA and Prospects with H1
In the context of the tremendous progress achieved at HERA in diffraction and the need for a new level of statistical and systematic precision, the new very large acceptance forward spectrometer planned by H1 (VFPS) is presented and the physics issues are stressed
On the possibility of measuring at HERA using radiative events
It is shown that a significant measurement of the longitudinal structure
function can be performed at HERA, for and and for x around , using radiative events with hard photon
emission collinear to the incident lepton beam, under the present running
conditions and with an integrated luminosity of 10 . The influence of
experimental conditions is discussed.Comment: 12 pages (6 figures
Easy as : On the Interpretation of Recent Electroproduction Results
Exclusive electroproduction from nucleons was first suggested by
Ahmad, Goldstein and Liuti for extracting from experimental data the tensor
charge, transversity and other quantities related to chiral odd combinations of
generalized parton distributions. We now explain the details of the process:
{\it i)} the connection between the helicity description and the cartesian
basis; {\it ii)} the dependence on the momentum transfer squared, , and
{\it iii)} the angular momentum, parity, and charge conjugation constraints
( quantum numbers).Comment: 15 pages, 2 figures, some changes in formalism, and text. Introduced
section title
Charged rho meson production in neutrino-induced reactions at E_nu = 10 GeV
The neutrinoproduction of charged mesons on nuclei and nucleons is
investigated for the first time at moderate energies ( 10
GeV), using the date obtained with SKAT bubble chamber. No strong nuclear
effects are observed in and production. The fractions of
charged and neutral pions originating from decays are obtained and
compared with higher energy data. From analysis of the obtained and available
data on and (892) neutrinoproduction, the strangeness
suppression factor in the quark string fragmentation is extracted: . Estimations are obtained for cross sections of quasiexclusive
single and coherent neutrinoproduction on nuclei. The
estimated coherent cross section = (0.29 cm is compatible with theoretical predictions.Comment: 7 pages, 6 figure
Shadowing in neutrino deep inelastic scattering and the determination of the strange quark distribution
We discuss shadowing corrections to the structure function in neutrino
deep-inelastic scattering on heavy nuclear targets. In particular, we examine
the role played by shadowing in the comparison of the structure functions
measured in neutrino and muon deep inelastic scattering. The importance of
shadowing corrections in the determination of the strange quark distributions
is explained.Comment: 22 pages, 7 figure
Interannual population dynamics of the green spruce aphid Elatobium abietinum (Walker) in France
The hypothesis that similar processes govern interannual dynamics of green spruce aphid in the UK and France, is generally supported by the application of a general discrete model. A simple model based on relatively few parameters was able to closely characterise interannual population dynamics from completely independent aerial and arboreal samples of aphids. Long term field population estimates of the green spruce aphid Elatobium abietinum (Walker) in France have provided the opportunity to select and evaluate the generality of a model which was developed in the UK to explain the yearâtoâyear variations in peak abundance of the aphid.
Aims
The objective was to observe the influence of the local climates and disturbing climate factors on the population densities of the insect in two regions of France.
Methods
The model uses climate variables and aphid population data from regular samples in the two regions that were investigated. A general discrete model was used to predict aphid population densities.
Results
The model performed well in tracking the interannual patterns of population but was less likely to predict absolute population density.
Conclusion
To improve predictions, further account would need to be taken of additional siteâspecific climate variables and the strength of overcompensating density dependence. Nevertheless it is clear that broadly similar processes are at work in the population dynamics of this insect across its biogeographical range
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