scholarly journals Future Measurements of the Nucleon Elastic Electromagnetic Form Factors at Jefferson Lab

2018 ◽  
Vol 172 ◽  
pp. 02004 ◽  
Author(s):  
Gerard Gilfoyle
Keyword(s):  
United States ◽  
Electron Beam ◽  
Form Factors ◽  
The United States ◽  
Precision Measurements ◽  
Electromagnetic Form Factors ◽  
Jefferson Lab ◽  
Atomic Nuclei ◽  
Perturbative Regime ◽  
Nucleon Form Factors

The elastic, electromagnetic form factors are fundamental observables that describe the internal structure of protons, neutrons, and atomic nuclei. Jefferson Lab in the United States has completed the 12 GeV Upgrade that will open new opportunities to study the form factors. A campaign to measure all four nucleon form factors (electric and magnetic ones for both proton and neutron) has been approved consisting of seven experiments in Halls A, B, and C. The increased energy of the electron beam will extend the range of precision measurements to higher Q2 for all four form factors together. This combination of measurements will allow for the decomposition of the results into their quark components and guide the development of a QCD-based understanding of nuclei in the non-perturbative regime. I will present more details on the 12 GeV Upgrade, the methods used to measure the form factors, and what we may learn.

scholarly journals Epoxy Resins in Electron Microscopy

1960 ◽  
Vol 7 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Henry Finck
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Electron Beam ◽  
Epoxy Resins ◽  
The United States ◽  
High Viscosity

A method of embedding biological specimens in araldite 502 (Ciba) has been developed for materials available in the United States. Araldite-embedded tissues are suitable for electron microscopy, but the cutting qualities of the resin necessitates more than routine attention during microtomy. The rather high viscosity of araldite 502 also seems to be an unnecessary handicap. The less viscous epoxy epon 812 (Shell) produces specimens with improved cutting qualities, and has several features—low shrinkage and absence of specimen damage during cure, minimal compression of sections, relative absence of electron beam-induced section damage, etc.—which recommends it as a routine embedding material. The hardness of the cured resin can be easily adjusted by several methods to suit the materials embedded in it. Several problems and advantages of working with sections of epoxy resins are also discussed.

The Genesis of Geomagnetic Observatories in Portugal

2005 ◽  
Vol 24 (1) ◽  
pp. 113-126 ◽  
Author(s):  
Isabel Malaquias ◽  
Emília Vaz Gomes ◽  
Décio Martins
Keyword(s):  
United States ◽  
Nineteenth Century ◽  
The United States ◽  
Precision Measurements ◽  
Magnetic Intensity ◽  
Special Concern ◽  
Magnetic Observatories

Interest in mapping not merely the heavens but also the lands, a special concern of modern civilizations, increased mainly at the end of the eighteenth and beginning of the nineteenth centuries. Although knowledge about geomagnetism was old, only in the nineteenth century was it possible to improve precision measurements of magnetic intensity. After Carl Friedrich Gauss (1777-1855) established an international Magnetic Union (Magnetische Verein) based in Göttingen in 1836, a network of magnetic observatories promoted a worldwide collaboration in order to get a deeper understanding of Earth's magnetism. While the participation of England, Russia, and the United States in this network is better known, Portugal also participated in this Union. This article aims to show how Portuguese institutions were influenced by the development of this branch of science and to detail their participation in the international geomagnetic network in the nineteenth century.

scholarly journals THE SUPERBIGBITE PROJECT A STUDY OF NUCLEON FORM FACTORS

2010 ◽  
Vol 19 (05n06) ◽  
pp. 844-855 ◽  
Author(s):  
◽  
KEES DE JAGER
Keyword(s):  
Form Factors ◽  
Electromagnetic Form Factors ◽  
Nucleon Form Factors ◽  
Existing Data

A proposed set of instrumentation, collectively referred to as the Super Bigbite project, is presented. Used in three different configurations it will allow measurements of three nucleon electromagnetic form factors [Formula: see text], [Formula: see text], and [Formula: see text] with unprecedented precision to Q2-values up to three times higher than existing data.

NUCLEON STRUCTURE AT JEFFERSON LAB: FROM TWO DIMENSIONS TO THREE DIMENSIONS

2009 ◽  
Vol 18 (10) ◽  
pp. 2181-2186
Author(s):  
MICHEL GUIDAL
Keyword(s):  
Phase Space ◽  
Degrees Of Freedom ◽  
Form Factors ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Nucleon Structure ◽  
Parton Distributions ◽  
Jefferson Lab ◽  
Generalized Parton Distributions ◽  
Nucleon Form Factors

We review very briefly a few recent highlight results from Jefferson Lab concerning nucleon Form Factors and Generalized Parton Distributions for which data with unprecedented precision and phase space coverage have be obtained these past few years. Along with new theoretical developements, these data allow to make some nucleon imaging in terms of partonic degrees of freedom in both momentum and space dimensions.

HCAL-J: hadron calorimeter for the study of nucleon form factors at Jefferson Lab

2018 ◽  
Vol 173 (9-10) ◽  
pp. 857-871
Author(s):  
V. Brio ◽  
V. Bellini ◽  
C. Petta ◽  
L. Re ◽  
C. M. Sutera ◽  
...  
Keyword(s):  
Form Factors ◽  
Hadron Calorimeter ◽  
Jefferson Lab ◽  
Nucleon Form Factors

scholarly journals Empirical Consequences of Emergent Mass

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1468 ◽  
Author(s):  
Craig D. Roberts
Keyword(s):  
Standard Model ◽  
Quantum Chromodynamics ◽  
Strong Interaction ◽  
Effective Charge ◽  
Form Factors ◽  
Electromagnetic Form Factors ◽  
Parton Distributions ◽  
Atomic Nuclei ◽  
The Standard Model ◽  
High Level

The Lagrangian that defines quantum chromodynamics (QCD), the strong interaction piece of the Standard Model, appears very simple. Nevertheless, it is responsible for an astonishing array of high-level phenomena with enormous apparent complexity, e.g., the existence, number and structure of atomic nuclei. The source of all these things can be traced to emergent mass, which might itself be QCD’s self-stabilising mechanism. A background to this perspective is provided, presenting, inter alia, a discussion of the gluon mass and QCD’s process-independent effective charge and highlighting an array of observable expressions of emergent mass, ranging from its manifestations in pion parton distributions to those in nucleon electromagnetic form factors.

scholarly journals Precision Measurements of the Timelike Electromagnetic Form Factors of Pion, Kaon, and Proton

2005 ◽  
Vol 95 (26) ◽  
Author(s):  
T. K. Pedlar ◽  
D. Cronin-Hennessy ◽  
K. Y. Gao ◽  
D. T. Gong ◽  
J. Hietala ◽  
...  
Keyword(s):  
Form Factors ◽  
Precision Measurements ◽  
Electromagnetic Form Factors
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