Download or read book Fron written by and published by . This book was released on 1960 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Precision Measurement of the Neutron Spin Structure Functions Using a Polarized HE 3 Target written by T. Smith and published by . This book was released on 2003 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a precision measurement of the neutron spin dependent structure function, g{sub 1}{sup n}(x). The measurement was made by the E154 collaboration at SLAC using a longitudinally polarized, 48.3 GeV electron beam, and a {sup 3}He target polarized by spin exchange with optically pumped rubidium. A target polarization as high as 50% was achieved. The elements of the experiment which pertain to the polarized {sup 3}He target will be described in detail in this thesis. To achieve a precision measurement, it has been necessary to minimize the systematic error from the uncertainty in the target parameters. All of the parameters of the target have been carefully measured, and the most important parameters of the target have been measured using multiple techniques. The polarization of the target was measured using nuclear magnetic resonance techniques, and has been calibrated using both proton NMR and by measuring the shift of the Rb Zeeman resonance frequency due to the {sup 3}He polarization. The fraction of events which originated in the {sup 3}He, as measured by the spectrometers, has been determined using a physical model of the target and the spectrometers. It was also measured during the experiment using a variable pressure {sup 3}He reference cell in place of the polarized {sup 3}He target. The spin dependent structure function g{sub 1}{sup n}(z) was measured in the Bjorken x range of 0.014
Download or read book A Precision Measurement of the Neutron Spin Structure Functions Using a Polarized 3He Target written by Todd B. Smith and published by . This book was released on 1998 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precision Measurement of the Neutron Spin Dependent Structure Functions written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In experiment E154 at the Stanford Linear Accelerator Center the spin dependent structure function g[sub 1][sup n] (x, Q[sup 2]) of the neutron was measured by scattering longitudinally polarized 48.3 GeV electrons off a longitudinally polarized[sup 3]He target. The high beam energy allowed the author to extend the kinematic coverage compared to the previous SLAC experiments to 0.014[le] x[le] 0.7 with an average Q[sup 2] of 5 GeV[sup 2]. The author reports the integral of the spin dependent structure function in the measured range to be[integral][sub 0.014][sup 0.7] dx g[sub 1][sup n](x, 5 GeV[sup 2])=[minus]0.036[+-] 0.004(stat.)[+-] 0.005(syst.). The author observes relatively large values of g[sub 1][sup n] at low x that call into question the reliability of data extrapolation to x[r-arrow] 0. Such divergent behavior disagrees with predictions of the conventional Regge theory, but is qualitatively explained by perturbative QCD. The author performs a Next-to-Leading Order perturbative QCD analysis of the world data on the nucleon spin dependent structure functions g[sub 1][sup p] and g[sub 1][sup n] paying careful attention to the experimental and theoretical uncertainties. Using the parameterizations of the helicity-dependent parton distributions obtained in the analysis, the author evolves the data to Q[sup 2]= 5 GeV[sup 2], determines the first moments of the polarized structure functions of the proton and neutron, and finds agreement with the Bjorken sum rule.
Download or read book Laser Polarized 3He Target Used for a Precision Measurement of the Neutron Spin Structure written by Mikhail V. Romalis and published by . This book was released on 1997 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Polarized 3He Target Used for a Precision Measurement of the Neutron Spin Structure written by Mikhail V. Romalis and published by . This book was released on 1997 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Neutron Spin Structure Function Gn1 with a Polarized 3He Internal Target written by HERMES Collaboration and published by . This book was released on 1997 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Neutron and 3He Spin Structure Functions at Low Q 2 written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 $
Download or read book Neutron 3He Spin Structure Functions at Low Q 2 written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Internal Spin Structure Of The Nucleon Proceedings Of The Symposium written by Vernon W Hughes and published by World Scientific. This book was released on 1995-07-14 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topic of the internal spin structure of the nucleon has become an unusually active subfield of particle and nuclear physics, together with the relevant technologies. This volume presents up-to-date coverage.All the talks given at the symposium can be found in the volume. In addition, selected articles are reprinted, including two early papers which record initial thinking about the topic, all experimental papers giving data on nucleon spin structure functions determined from polarized lepton-nucleon scattering, and two valuable previously unpublished papers.
Download or read book The Spin Structure of the Neutron Determined Using a Polarized He 3 Target written by and published by . This book was released on 2004 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Described is a study of the internal spin structure of the neutron performed by measuring the asymmetry in spin-dependent deep inelastic scattering of polarized electrons from nuclear polarized 3He. Stanford Linear Accelerator experiment E142's sample of 400 million scattering events collected at beam energies between 19 and 26 GeV led to the most precise measurement of a nucleon spin structure function to date. The 3He target represents a major advance in polarized target technology, using the technique of spin exchange with optically pumped rubidium vapor to produce a typical 3He nuclear polarization of 34% in a 30cm long target cell with a gas density of 2.3 x 102° cm−3. The target polarization was measured to "7% using an Adiabatic Fast Passage NMR system calibrated with the thermal equilibrium polarization of the protons in a sample of water. The relatively high polarization and target thickness were the result of the development of large volume glass target cells which had inherent nuclear spin relaxation times for the 3He gas of as long as 70 hours. A target cell production procedure is presented which focuses on special glass blowing techniques to minimize surface interactions with the 3He nuclei and careful gas purification and vacuum system procedures to reduce relaxation inducing impurities.
Download or read book Precision Measurement of the Neutron Spin Structure Function written by Piotr A. Zyla and published by . This book was released on 1998 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Ninth International Workshop Polarized Sources and Targets written by Vladimir P. Derenchuk and published by World Scientific. This book was released on 2002 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an up-to-date survey of the science and technology of creating polarized beams and polarized targets. The papers in this collection describe state-of-the-art sources of polarized electrons, ions, atoms, neutrons, and radioactive isotopes, discuss new polarized solid and gas target techniques, present recent advances in polarimetry, and review the use of polarized gas in medical imaging.
Download or read book A Precise Measurement of the Spin Structure Functions G p2 and G d2 from Slac Experiment E155X written by Dustin Edward McNulty and published by . This book was released on 2002 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precision Measurement of the Neutron Twist 3 Matrix Element Dn2 written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Double-spin asymmetries and absolute cross sections were measured at large Bjorken x (0.25 lte x lte 0.90), in both the deep-inelastic and resonance regions, by scattering longitudinally polarized electrons at beam energies of 4.7 and 5.9 GeV from a transversely and longitudinally polarized 3He target. In this dedicated experiment, the spin structure function g2 on 3He was determined with precision at large x, and the neutron twist-three matrix element dn2 was measured at?Q2? of 3.21 and 4.32 GeV2/c2, with an absolute precision of about 10?5. Our results are found to be in agreement with lattice QCD calculations and resolve the disagreement found with previous data at?Q2?= 5 GeV2/c2. Combining dn2 and a newly extracted twist-four matrix element, fn2, the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about 60 MeV/fm in magnitude.
Download or read book Measurements of the Double Spin Asymmetry A1 on Helium 3 written by and published by . This book was released on 2011 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: The spin structure of protons and neutrons has been an open question for nearly twenty-five years, after surprising experimental results disproved the simple model in which valence quarks were responsible for nearly 100% of the nucleon spin. Diverse theoretical approaches have been brought to bear on the problem, but a shortage of precise data - especially on neutron spin structure - has prevented a thorough understanding. Experiment E06-014, conducted in Hall A of Jefferson Laboratory in 2009, presented an opportunity to add to the world data set for the neutron in the poorly covered valence-quark region. Jefferson Laboratory's highly polarized electron beam, combined with Hall A's facilities for a high-density, highly polarized 3He target, allowed a high-luminosity double-polarized experiment, while the large acceptance of the BigBite spectrometer gave coverage over a wide kinematic range: 0.15
Download or read book The Spin Structure Of The Nucleon written by Bernard Frois and published by World Scientific. This book was released on 1998-02-24 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: From its early beginnings at SLAC in the 1970's, the study of nucleon spin structure using polarized lepton beams and polarized nucleon targets has become increasingly important in nuclear and particle physics, with current experiments at several of the world's high energy and nuclear physics laboratories (CERN, DESY, SLAC and Jefferson Lab) and with enormous related theoretical studies. The understanding of the fascinating but complicated problem of nucleon spin structure has progressed substantially, but fundamental questions remain and it can be confidently predicted that future activity will be high.The Erice Course on The Spin Structure of the Nucleon covered both the experimental and theoretical aspects of the subject, and this volume includes the lectures given at the School. In many cases the lecture material has been extended and updated by the authors. In addition, several recent publications on experimental work have been added in an appendix.
