[PDF] Measurement Of The Neutron 3he Spin Structure Functions At Low Q2 eBook

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File Size : 21,46 MB
Release : 2000
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The spin dependent cross sections,?{sup T}12 and?{sup T}32, and asymmetries, A{sub {parallel}} and A{sub {perp}}, for 3He have been measured at the Jefferson Lab's Hall A facility. The inclusive scattering process 3{vec He}({vec e}, e)X was performed for initial beam energies ranging from 0.86 to 5.1 GeV, at a scattering angle of 15.5°. Data includes measurements from the quasielastic peak, resonance region, and the deep inelastic regime. An approximation for the extended Gcrasimov-Drell-Hcarn integral is presented at a 4-momentum transfer Q2 of 0.2-1.0 GeV2 . Also presented are results on the performance of the polarized 3He target. Polarization of 3He vvas achieved by the process of spin-exchange collisions with optically pumped rubidium vapor. The 3He polarization was monitored using the NMR technique of adiabatic fast passage (AFP). The average target polarization was approximately 35% and was determined to have a systematic uncertainty of roughly ±4% relative.

Author : John Steffen Jensen
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Page : 248 pages
File Size : 50,16 MB
Release : 2001
Category : Electronic dissertations
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The spin dependent cross sections, [sigma]T1/2 and [sigma]T3/2, and asymmetries, A[parallel] and A[perpendicular] for 3He have been measured at the Jefferson Lab's Hall A facility. The inclusive scattering process 3He(e, e)X was performed for initial beam energies ranging from 0.86 to 5.1 GeV, at a scattering angle of 15.5°. Data includes measurements from the quasielastic peak, resonance region, and the deep inelastic regime. An approximation for the extended Gerasimov-Drell-Hearn integral is presented at a 4-momentum transfer Q2 of 0.2-1.0 GeV2. Also presented are results on the performance of the polarized 3He target. Polarization of 3He was achieved by the process of spin-exchange collisions with optically pumped rubidium vapor. The 3He polarization was monitored using the NMR technique of adiabatic fast passage (AFP). The average target polarization was approximately 35% and was determined to have a systematic uncertainty of roughly [plus or minus]4% relative.

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Page : 216 pages
File Size : 30,60 MB
Release : 2007
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Since the 1980's, the study of nucleon (proton or neutron) spin structure has been an active field both experimentally and theoretically. One of the primary goals of this work is to test our understanding of Quantum Chromodynamics (QCD), the fundamental theory of the strong interaction. In the high energy region of asymptotically free quarks, QCD has been verified. However, verifiable predictions in the low energy region are harder to obtain due to the complex interactions between the nucleon's constituents: quarks and gluons. In the non-pertubative regime, low-energy effective field theories such as chiral perturbation theory provide predictions for the spin structure functions in the form of sum rules. Spin-dependent sum rules such as the Gerasimov-Drell-Hearn (GDH) sum rule are important tools available to study nucleon spin structure. Originally derived for real photon absorption, the Gerasimov-Drell-Hearn (GDH) sum rule was first extended for virtual photon absorption in 1989. The extension of the sum rule provides a unique relation, valid at any momentum transfer ($Q{̂2}$), that can be used to study the nucleon spin structure and make comparisons between theoretical predictions and experimental data. Experiment E97-110 was performed at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) to examine the spin structure of the neutron and ${̂3}$He. The Jefferson Lab longitudinally-polarized electron beam with incident energies between 1.1 and 4.4 GeV was scattered from a longitudinally or transversely polarized ${̂3}$He gas target in the Hall A end station. Asymmetries and polarized cross-section differences were measured in the quasielastic and resonance regions to extract the spin structure functions $g_{1}(x,Q{̂2})$ and $g_{2}(x,Q{̂2})$ at low momentum transfers (0.02 $

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File Size : 20,66 MB
Release : 2009
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Experiment E97-110 was performed at the Thomas Jefferson National Accelerator Facility to provide a precise measurement of the $^{3}$He spin structure functions at low $Q^{2}$ from 0.02 to 0.3~[GeV$/c$]$^{2}$. A longitudinally-polarized electron beam was scattered from a longitudinally or transversely polarized $^{3}$He target. From these data, we have extracted moments of the neutron and $^{3}$He spin structure functions at very low momentum transfers. These data allow us to make a benchmark check of Chiral Perturbation Theory calculations in a region where they are expected to be valid. In these proceedings, the experimental details are discussed and preliminary results on the first moments of the $g_1\left(x, Q^{2}\right)$ and $g_2\left(x, Q^{2}\right)$ structure functions are presented.

Author : Vincent Sulkosky
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Page : 12039 pages
File Size : 31,32 MB
Release : 2006
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Thomas Jefferson National Accelerator Facility experiment E97-110 was performed to provide a precise measurement of the extended Gerasimov-Drell-Hearn integral and of moments of the neutron and of the {sup 3}He spin structure functions. The momentum transfer range 0.02

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File Size : 31,53 MB
Release : 2009
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Experiment E97-110 was performed at the Thomas Jefferson National Accelerator Facility in Hall A to provide a precise measurement of the moments of the neutron and $^{3}$He spin structure functions. A longitudinally-polarized electron beam was scattered from a longitudinally or transversely polarized $^{3}$He target. The extended Gerasimov-Drell-Hearn integral and other moments of the neutron and $^{3}$He spin structure functions were extracted at very low momentum transfers (0.02 $