skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Theoretical Issues

Abstract

The theoretical issues in the interpretation of the precision measurements of the nucleon-to-Delta transition by means of electromagnetic probes are highlighted. The results of these measurements are confronted with the state-of-the-art calculations based on chiral effective-field theories (EFT), lattice QCD, large-Nc relations, perturbative QCD, and QCD-inspired models. The link of the nucleon-to-Delta form factors to generalized parton distributions (GPDs) is also discussed.

Authors:
Publication Date:
Research Org.:
Thomas Jefferson National Accelerator Facility, Newport News, VA
Sponsoring Org.:
USDOE - Office of Energy Research (ER)
OSTI Identifier:
910566
Report Number(s):
JLAB-THY-07-691; DOE/OR/23177-0105
Journal ID: ISSN 0094-243X; APCPCS; TRN: US0704257
DOE Contract Number:
AC05-06OR23177
Resource Type:
Conference
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 904; Conference: Workshop On The Shape Of Hadrons, 27-29 Apr 2006, Athens, Greece
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ACCURACY; FORM FACTORS; HADRONS; PROBES; QUANTUM CHROMODYNAMICS; SHAPE

Citation Formats

Marc Vanderhaeghen. Theoretical Issues. United States: N. p., 2007. Web. doi:10.1063/1.2734290.
Marc Vanderhaeghen. Theoretical Issues. United States. doi:10.1063/1.2734290.
Marc Vanderhaeghen. Sun . "Theoretical Issues". United States. doi:10.1063/1.2734290. https://www.osti.gov/servlets/purl/910566.
@article{osti_910566,
title = {Theoretical Issues},
author = {Marc Vanderhaeghen},
abstractNote = {The theoretical issues in the interpretation of the precision measurements of the nucleon-to-Delta transition by means of electromagnetic probes are highlighted. The results of these measurements are confronted with the state-of-the-art calculations based on chiral effective-field theories (EFT), lattice QCD, large-Nc relations, perturbative QCD, and QCD-inspired models. The link of the nucleon-to-Delta form factors to generalized parton distributions (GPDs) is also discussed.},
doi = {10.1063/1.2734290},
journal = {AIP Conference Proceedings},
number = ,
volume = 904,
place = {United States},
year = {Sun Apr 01 00:00:00 EDT 2007},
month = {Sun Apr 01 00:00:00 EDT 2007}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • An interesting component of the physics program at Fermilab during the next ten years will be the precision verification of the standard model, rather than its extension. While there is a window for finding Z{prime} gauge bosons, it is unlikely that it is possible to discover the standard model Higgs boson. Measurements of W + {gamma} rates can place limits on non-standard gauge boson couplings. QCD will be further tested by observation of W or Z plus multiple jets, a signal which is also interesting as a background to new particle searches. Precision measurements of the W and Z massesmore » and the forward-backward asymmetry in Z decays can put limits on new physics. 26 refs., 1 fig., 2 tabs.« less
  • The authors study a class of discrete dynamical systems that is motivated by the generic structure of simulations. The systems consist of the following data: (a) a finite graph Y with vertex set {l_brace}1,...,n{r_brace} where each vertex has a binary state, (b) functions F{sub i}:F{sub 2}{sup n} {r_arrow} F{sub 2}{sup n} and (c) an update ordering {pi}. The functions F{sub i} update the binary state of vertex i as a function of the state of vertex i and its Y-neighbors and leave the states of all other vertices fixed. The update ordering is a permutation of the Y-vertices. They derivemore » a decomposition result, characterize invertible SDS and study fixed points. In particular they analyze how many different SDS that can be obtained by reordering a given multiset of update functions and give a criterion for when one can derive concentration results on this number. Finally, some specific SDS are investigated.« less
  • Theoretical models of coupled metal hydride reactors are necessary for design and optimization studies and must be formulated for an entire system in order to have useful predicative capability. The archtypical system (which may be used as a heat pump or for hydrogen storage) includes two reactors with the active and inactive constituents forming a porous matrix which must accommodate heat and hydrogen transfer at high rates. When the heat transfer between reactors and their surroundings, as well as the time varying boundary conditions which occur in actual operation are considered, a comprehensive system theory becomes extremely complicated, even atmore » the one-dimensional level. Idealizations and compromises are required in order to obtain a theory which can be solved and which captures the essential features of experimental systems. This paper addresses the major problems that arose in the development of such a comprehensive theory and discusses the compromises that were required in order to obtain a solution.« less
  • The subject of this paper is the development of mathematical foundations for a theory of simulation. Sequentially updated cellular automata (sCA) over arbitrary graphs are employed as a paradigmatic framework. In the development of the theory, the authors focus on the properties of causal dependencies among local mappings in a simulation. The main object of and study is the mapping between a graph representing the dependencies among entities of a simulation and a representing the equivalence classes of systems obtained by all possible updates.
  • After pioneering works on hypernuclei, strangeness production mechanisms have been studied in hadron collisions and photoreactions in the sixties. Recent experiments at SATURNE and COSY, in the hadronic sector, as well as ELSA and JLab, in the electromagnetic sector, have confirmed our basic ideas on the reaction mechanisms. In the near future, strangeness production at JLab, HERMES and COMPASS may prove to be a powerful tool to study hadronic matter.