Download or read book The Spin Structure of the Neutron Determined Using a Polarized 3 He Target written by Hunter Leigh Middleton and published by . This book was released on 1994 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 The Precision Measurement of the Neutron Spin Structure Function Using Polarized HE 3 Target written by and published by . This book was released on 2004 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Spin Structure on the Neutron in Deep Inelastic Scattering of Polarized Electrons on Polarized Neutrons written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The internal spin structure of the neutron, was studied in deep inelastic scattering of longitudinally polarized electrons from a polarized [sup 3]He target in the End Station A of the Stanford Linear Accelerator Center (SLAC). The spin asymmetry of the neutron was measured at energies between 19 and 26 GeV in the range 0.03 [le] x [le] 0.06 at an average Q[sup 2] of 2 (GeV/c)[sup 2]. The results are in agreement with a new measurement of the asymmetry by SMC within their six times larger uncertainties. The spin dependent structure function g[sub 1](x) for the neutron was determined from the asymmetry measurement and, its integral over x is found to be [integral]g[sub 1][sup n](x)dx = -0.038 [+-] 0.009. This result is 2.7 standard deviations from the Ellis-Jaffe Sum Rule and combined with the EMC results from the proton in very good agreement with the Bjorken Sum Rule. In the Quark Parton Model (QPM), in conjunction with the weak coupling constants F and D, from baryon decay, the result implies that the quarks contribute approximately 32% of the nucleon helicity. Finally, different ways of evolving the data, based on various theoretical models, is attempted and future aspects for spin physics, with emphasis at spin physics at SLAC, are discussed.
Download or read book A Determination of the Neutron Spin Structure Function written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors report the results of the experiment E142 which measured the spin dependent structure function of the neutron, g[sub 1][sup n](x, Q[sup 2]). The experiment was carried out at the Stanford Linear Accelerator Center by measuring an asymmetry in the deep inelastic scattering of polarized electrons from a polarized[sup 3]He target, at electron energies from 19 to 26 GeV. The structure function was determined over the kinematic range 0.03
Download or read book Polarized He 3 as an Effective Neutron Target for Deep Inelastic Scattering written by Kyle Johnston and published by . This book was released on 2015 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: In undergraduate physics courses, we are all taught that a proton and a neutron both have a quantity called 'spin' which has a simple value of 1/2 in units of ħ. It was first naively understood that this value comes from the addition of the spins of the basic constituents, quarks and gluons. However, experiments revealed that it is not enough. The value of 1/2 has yet to be reconciled with the addition of not only the spins of the constituents but also their orbital motion. Clearly, the spin structure in terms of the basic constituents needs more investigation. This thesis aims to describe the polarization and calibration of a polarized 3He target, which can be used for probing the spin structure of the neutron in terms of its constituents, quarks and gluons.
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.
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 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 Affiges Affiches des grands operateurs de Mirlinde written by and published by . This book was released on 1618 with total page 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 Measurement of the Spin Structure Function of the Neutron G1 N from Deep Inelastic Scattering of Polarized Electrons from Polarized Neutrons in He 3 written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polarized electrons of energies 19.42, 22.67, and 25.5 GeV were scattered off a polarized [sup 3]He target at SLAC's End Station A to measure the spin asymmetry of the neutron. From this asymmetry, the spin dependent structure function g[sub 1][sup n](x) was determined over a range in x from 0.03 to 0.6 with an average Q[sup 2] of 2 (GeV/C)[sup 2]. The value of the integral of g[sub 1][sup n] over x is [integral]g[sub 1][sup n](x)dx = -0.036 [+-] 0.009. The results were interpreted in the frame work of the Quark Parton Model (QPM) and used to test the Ellis-Jaffe and Bjorken sum rules. The value of the integral is 2.6 standard deviations from the Ellis-Jaffe prediction while the Bjorken sum rule was found to be in agreement with this data and proton data from SMC and E-143.
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 Search for Higher Twist Effects in the Spin structure Functions of the Neutron written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Jefferson Lab experiment E97-103 measured the spin structure function gn2 from a Q^2 of 0.58 to 1.36 with a nearly constant x of 0.2. Combining this data with a fit to the world gn1 data, the size of higher twist contributions to gn2 can be extracted using the Wandzura-Wilczek relation. These higher twist contributions result from quark-gluon correlations and are expected to be larger as Q^2 decreases. This experiment was performed in Hall A with a longitudinally polarized electron beam and a high density polarized He-3 target. The physics motivation and an overview of the experiment will be presented.
Download or read book Measurement of the Neutron Spin Structure Function and Its Implications for QCD Sum Rules written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have determined the neutron spin structure function g[sub 1][sup n] over the range 0.03 [le] x [le] 0.6 at an average Q[sup 2] of 2(GeV/c)[sup 2] by measuring the asymmetry in deep inelastic scattering of polarized electrons from a polarized [sup 3]He target. The experiment was performed at SLAC and used energies between 19 and 26 GeV. The neutron asymmetry turned out to be small and negative, and the integral of the neutron spin structure function is [integral][sub 0][sup 1]g[sub 1][sup n](x)dx = -0.024 [+-] 0.006(stat.) [+-] 0.008(syst.). Combined with the current available worldwide proton data, this result confirmed the Bjorken sum rule at 10% level, once high-order perturbative QCD corrections are taken into account. The Ellis-Jaffe sum rule for the neutron predicts [integral][sub 0][sup 1] g[sub 1][sup n](x)dx = -0.010 [+-] 0.012, roughly consistent with their result.
