Download or read book Measurements of the Q sup 2 Dependence of the Proton and Neutron Spin Structure Functions G sub 1 sup P and G sub 1 sup N written by and published by . This book was released on 2000 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of the Q sup 2 Dependence of the Proton and Neutron SpinStructure Functions G sub 1 sup P and G sub 1 sup N written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure functions g[sub 1][sup p] and g[sub 1][sup n] have been measured over the range 0.014
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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book The Q sup 2 Dependence of the Neutron Spin Structure Function G sub 2 sup N at Low Q sup 2 written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent SLAC Measurements of the Spin Dependent Structure Functions for the Proton and Neutron written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present results from SLAC experiments E142 and E143 for the spin dependent structure functions of the proton g[sub 1][sup p](x, Q[sup 2]) and neutron g[sub 1][sup n](x, Q[sup 2]) measured in deep inelastic scattering of polarized electrons from a polarized target. Experiment E142 measures[integral][sub 0][sup 1] g[sub 1][sup n](x)dx=[minus]0.022[+-] 0.011 atQ[sup 2]= 2 (GeV/c)[sup 2] using a polarized[sup 3]He target. Experiment E143 measures[integral][sub 0][sup 1] g[sub 1][sup p](x)dx= 0.129[+-] 0.011 atQ[sup 2]= 3 (GeV/c)[sup 2] using a polarized NH[sub 3] target. These results are combined at Q[sup 2]= 3 (GeV/c)[sup 2] to yield[integral][sub 0][sup 1][g[sub 1][sup p](x)[minus] g[sub 1][sup n](x)]dx= 0.151[+-] 0.015. The Bjorken sum rule predicts 0.171[+-] 0.008.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of the Q2 Dependence of the Proton and Neutron SpinStructure Functions G1 sup P and G1 20 written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure functions g1{sup p} and g1??20--?? have been measured over the range 0.014
Download or read book Physics Briefs written by and published by . This book was released on 1989 with total page 1384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Proton and Deuteron Spin Structure Functions G1 and G2 written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The SLAC experiment E155 was a deep-inelastic scattering experiment that scattered polarized electrons off polarized proton and deuteron targets in the effort to measure precisely the proton and deuteron spin structure functions. The nucleon structure functions g[sub 1] and g[sub 2] are important quantities that help test our present models of nucleon structure. Such information can help quantify the constituent contributions to the nucleon spin. The structure functions g[sub 1][sup p] and G[sub 1][sup d] have been measured over the kinematic range 0.01[le] x[le] 0.9 and 1[le] Q[sup 2][le] 40 GeV[sup 2] by scattering 48.4 GeV longitudinally polarized electrons off longitudinally polarized protons and deuterons. In addition, the structure functions g[sub 2][sup p] and g[sub 2][sup d] have been measured over the kinematic range 0.01[le] x[le] 0.7 and 1[le] Q[sup 2][le] 17 GeV[sup 2] by scattering 38.8 GeV longitudinally polarized electrons off transversely polarized protons and deuterons. The measurements of g[sub 1] confirm the Bjorken sum rule and find the net quark polarization to be[Delta][Sigma]= 0.23[+-] 0.04[+-] 0.6 while g[sub 2] is found to be consistent with the g[sub 2][sup WW] model.
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.
Download or read book INIS Atomindex written by and published by . This book was released on 1988 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Spin Structure of the Proton in the Resonance Region written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Inclusive double spin asymmetries have been measured for[rvec p]([rvec e], e[prime]) using the CLAS detector and a polarized[sup 15]NH[sub 3] target at Jefferson Lab in 1998. The virtual photon asymmetry A[sub 1], the longitudinal spin structure function, g[sub 1] (x, Q[sup 2]), and the first moment[Gamma][sub 1][sup p], have been extracted for a Q[sup 2] range of 0.15-2.0 GeV[sup 2]. These results provide insight into the low Q[sup 2] evolution of spin dependent asymmetries and structure functions as well as the transition of[Gamma][sub 1][sup p] from the photon point, where the Gerasimov, Drell and Hearn Sum Rule is expected to be satisfied, to the deep inelastic region.
Download or read book Sum Rule Measurements of the Spin dependent Compton Amplitude nucleon Spin Structure at Q sup 2 written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy weighted integrals of the difference in helicity-dependent photo-production cross sections ([sigma][sub [1/2]] - [sigma][sub 3/2]) provide information on the nucleon's Spin-dependent Polarizability ([gamma]), and on the spin-dependent part of the asymptotic forward Compton amplitude through the Drell-Hearn-Gerasimov (DHG) sum rule. (The latter forms the Q[sup 2]=0 limit of recent spin-asymmetry experiments in deep-inelastic lepton-scattering.) There are no direct measurements of [sigma][sub [1/2]] or [sigma][sub 3/2], for either the proton or the neutron. Estimates from current [pi]-photo-production multipole analyses, particularly for the proton-neutron difference, are in good agreement with relativistic-l-loop Chiral calculations ([chi]PT) for [gamma] but predict large deviations from the DHG sum rule. Either (a) both the 2-loop corrections to the Spin-Polarizability are large and the existing multipoles are wrong, or (b) modifications to the Drell-Hearn-Gerasimov sum rule are required to fully describe the isospin structure of the nucleon. The helicity-dependent photo-reaction amplitudes, for both the proton and the neutron, will be measured at LEGS from pion-threshold to 470 MeV. In these double-polarization experiments, circularly polarized photons from LEGS will be used with SPHICE, a new frozen-spin target consisting of [rvec H] [center-dot] [rvec D] in the solid phase. Reaction channels will be identified in SASY, a large detector array covering about 80% of 4[pi]. A high degree of symmetry in both target and detector will be used to minimize systematic uncertainties.
