Download or read book The Neutron Magnetic Form Factor at High Q2 written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent progress in improving our knowledge of the four nucleon form factors G{sup p}{sub M}, G{sup p}{sub E}, G(superscript n){sub M}, G(superscript n){sub E} at high momentum transfer is stimulating a new wave of theoretical efforts to describe these fundamental quantities. Both model calculations and lattice QCD can predict the elastic form factors; a definitive, stringent test of these efforts is to predict all of them simultaneously. However, the limited range and quality of the data for the neutron magnetic form factor G(superscript n){sub M} presently reduce the discriminating power of such a test. The present status of our knowledge of G(superscript n){sub M} is discussed, and prospects for future improvements are presented.

Download or read book The Neutron Electric Form Factor to Q2 written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q2, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon. Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measurements of this fundamental quantity. Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2H(e, e')1H scattering is presented. The experiment described here employed the Thomas Jefferson National Accelerator Facility's longitudinally polarized electron beam, a magnetic spectrometer for detection of the scattered electron, and a neutron polarimeter designed specifically for this experiment. Measurements were conducted at three Q2 values of 0.45, 1.13, and 1.45 (GeV/c)2, and the final results extracted from an analysis of the data acquired in this experiment are reported and compared with recent theoretical predictions for the nucleon form factors.

Download or read book The Neutron Magnetic Form Factor for Q2 kleiner Als 1 GeV c 2 written by Günther P. Kubon and published by . This book was released on 1999 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Precise Determination of the Neutron Magnetic Form Factor to Higher Q2 written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron elastic magnetic form factor G{sub M}(superscript n) has been extracted from quasielastic scattering from deuterium in the CEBAF Large Acceptance Spectrometer, CLAS. The kinematic coverage of the measurement is continuous over a broad range, extending from below 1 GeV2 to nearly 5 GeV2 in four-momentum transfer squared. High precision is achieved by employing a ratio technique in which most uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Preliminary results are shown with statistical errors only.

Download or read book Precise Determination of the Neutron Magnetic Form Factor to Higher Q sup 2 written by William K. Brooks and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron elastic magnetic form factor G{sub M}{sup n} has been extracted from quasielastic scattering from deuterium in the CEBAF Large Acceptance Spectrometer, CLAS. The kinematic coverage of the measurement is continuous over a broad range, extending from below 1 GeV{sup 2} to nearly 5 GeV{sup 2} in four-momentum transfer squared. High precision is achieved by employing a ratio technique in which most uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Preliminary results are shown with statistical errors only.

Download or read book Measurements of the Electric Form Factor of the Neutron at Q2 written by Shigeyuki Tajima and published by . This book was released on 2003 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Precise Measurement of the Neutron Magnetic Form Factor GMn in the Few GeV2 Region written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron elastic magnetic form factor GMn has been extracted from quasielastic electron scattering data on deuterium with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic coverage of the measurement is continuous from Q2=1 GeV2 to 4.8 GeV2. High precision was achieved by employing a ratio technique in which many uncertainties cancel, and by a simultaneous in-situ calibration of the neutron detection efficiency, the largest correction to the data. Neutrons were detected using the CLAS electromagnetic calorimeters and the time-of-flight scintillators. Data were taken at two different electron beam energies, allowing up to four semi-independent measurements of GMn to be made at each value of Q2. The dipole parameterization is found to provide a good description of the data over the measured Q2 range.

Download or read book A Measurement of the Neutron Magnetic Form Factor Gn M Form Quasi elastic 2 right Arrow H right Arrow e E at Low Q2 written by Nikolas C. Meitanis and published by . This book was released on 2006 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron magnetic form factor GnM has been measured using the inclusive electro-disintegration 2H(e, e') of the deuteron for the first time. The longitudinally polarized electron beam of the MIT-Bates Linear Accelerator was used in conjunction with an isotopically pure, polarized deuterium internal gas target. The Bates Large Acceptance Spectrometer Toroid (BLAST) was used for the measurement. The form factor GnM was extracted from the ratio of the inclusive asymmetry [alpha]Ved in perpendicular over parallel kinematics and at Q2 = 0.135, 0.189, 0.252, 0.316 (GeV/c)2.

Download or read book The Electric Form Factor of the Neutron at Q2 written by and published by . This book was released on 2003 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Jefferson Laboratory E93-038 collaboration measured the ratio of the electric form factor to the magnetic form factor of the neutron, g = Gne/Gnm, via recoil polarimetry from the quasielastic 2H(e,en)1 H reaction at q2 = 0.45, 1.17 and 1.47 (GeV/c)2 in Hall C of the Thomas Jefferson National Accelerator Facility. A polarimeter designed specifically for E93-038 was used to measure the up-down scattering asymmetry from the transverse component of the recoil neutron's polarization vector, and a dipole magnet located in front of the polarimeter was used to precess the polarization vector in the scattering plane through an angle of x. Sequential measurements of the scattering asymmetry with the polarization vector precessed through angles ? = 0° and ? = ±90° for Q2 = 1.47 (GeV/c)2 were made during January 2001 and through angles ? = ±40° for Q2 = 1.17 (GeV/c)2 during April 2001 and will be reported on in this dissertation. This ratio method removes the need to know the analyzing power.

Download or read book Exclusive Processes at High Momentum Transfer written by A. V. Radyushkin and published by World Scientific. This book was released on 2002 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the physics of exclusive processes at high momentum transfer and their description in terms of generalized parton distributions, perturbative QCD, and relativistic quark models. It covers recent developments in the field, both theoretical and experimental.

Download or read book The Neutron Electric Form Factor to Q2 written by Bradley Robert Plaster and published by . This book was released on 2004 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2H(e, e')1H scattering is presented. The experiment described here employed the Thomas Jefferson National Accelerator Facility's longitudinally polarized electron beam, a magnetic spectrometer for detection of the scattered electron, and a neutron polarimeter designed specifically for this experiment. Measurements were conducted at three Q2 values of 0.45, 1.13, and 1.45 (GeV/c)2, and the final results extracted from an analysis of the data acquired in this experiment are reported and compared with recent theoretical predictions for the nucleon form factors.

Download or read book Exclusive Reactions At High Momentum Transfer Proceedings Of The International Workshop written by Anatoly Radyushkin and published by World Scientific. This book was released on 2008-03-13 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exclusive reactions are becoming one of the major sources of information about the deep structure of nucleons and other hadrons. The 2007 International Workshop held at Jefferson Lab in Newport News, Virginia, USA — the world's leading facility performing research on nuclear, hadronic and quark-gluon structure of matter — focused on the application of a variety of exclusive reactions at high momentum transfer, utilizing unpolarized and polarized beams and targets, to obtain information about nucleon ground-state and excited-state structure at short distances. This is a subject which is central to the programs of current accelerators and especially planned future facilities.This proceedings volume contains, in concentrated form, information about the newest developments, both theoretical and experimental, in the study of hard exclusive reactions.

Download or read book Measurements of the Electric Form Factor of the Neutron at Q2 written by and published by . This book was released on 2003 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Precise measurements of the electric form factor of the neutron, Gn E, over a wide range of the square of the four-momentum transfer, Q2, are important for understanding nucleon and nuclear electromagnetic structure. In the non-relativistic limit, the electric and magnetic form factors are related to the charge and magnetization distribution inside a nucleon, respectively. The measured values of the form factors also serve as an important test for nucleon models. Among the four nucleon form factors, the electric form factor of the neutron, Gn E, is the most difficult one to measure and therefore has been very poorly known especially in the region Q2 > 1 (GeV/c)2 due to the lack of a free neutron target and the small value of Gn E. The Jefferson Laboratory E93-038 collaboration measured the ratio of the electric to magnetic form factor of the neutron, g = Gn E/Gn M, at three acceptance-averaged Q2 values of 0.45, 1.13 and 1.45 (GeV/c)2 using the quasi-elastic 2H(ẽ, e0ñ)1H reaction. In our experiment, an electron was scattered quasielastically from a neutron in a liquid-deuterium target, and the electron was detected in an electron spectrometer in coincidence with the neutron which was detected in a neutron polarimeter. The polarimeter was used to analyze the polarization of the recoil neutrons by measuring the np elastic scattering asymmetry. The experiment was performed in Hall-C at Thomas Jefferson National Accelerator Facility during the period from September 2000 to April 2001. The value of g was determined from the measured ratio of the sideways and longitudinal components of the neutron polarization vector. The values for Gn E were computed from our measured values of g = Gn E/Gn M using the Gn M values obtained from a fit to the world data. The E93-038 collaboration reported the first measurements of Gn E using polarization techniques at Q2 greater than 1 (GeV/c)2. Furthermore, our measurements of Gn E at the two higher Q2 values of 1.13 and 1.45 (GeV/c)2 are more precise than prior measurements at lower Q2. In this dissertation, the data analyses and our results for g and Gn E at Q2=0.45 (GeV/c)2 and Q2=1.13 (GeV/c)2 are given. Our high-accuracy data are included with the 'world' data for Gn E to form an improved data set that was fit with an empirical function to give a simple parameterization of Gn E as a function of Q2. In addition, the data for the ratio Gn E/Gn M are compared to theoretical models of the nucleon. We found that no theoretical model predicts both proton and neutron form factor data.

Download or read book Exclusive Reactions at High Momentum Transfer written by A. V. Radyushkin and published by World Scientific. This book was released on 2008 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exclusive reactions are becoming one of the major sources of information about the deep structure of nucleons and other hadrons. The 2007 International Workshop held at Jefferson Lab in Newport News, Virginia, USA ? the world's leading facility performing research on nuclear, hadronic and quark-gluon structure of matter ? focused on the application of a variety of exclusive reactions at high momentum transfer, utilizing unpolarized and polarized beams and targets, to obtain information about nucleon ground-state and excited-state structure at short distances. This is a subject which is central to the programs of current accelerators and especially planned future facilities.This proceedings volume contains, in concentrated form, information about the newest developments, both theoretical and experimental, in the study of hard exclusive reactions.

Download or read book Precise Extraction of the Neutron Magnetic Form Factor from Quasi elastic 3He pol e pol E at Q 2 written by and published by . This book was released on 2006 with total page 34003 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the transverse asymmetry A{sub T'} in the quasi-elastic 3/rvec He/(/rvec e/, e') process with high precision at Q2-values from 0.1 to 0.6 (GeV/c)2. The neutron magnetic form factor G{sub M}(superscript n) was extracted at Q2-values of 0.1 and 0.2 (GeV/c)2 using a non-relativistic Faddeev calculation which includes both final-state interactions (FSI) and meson-exchange currents (MEC). Theoretical uncertainties due to the FSI and MEC effects were constrained with a precision measurement of the spin-dependent asymmetry in the threshold region of 3/rvec He/(/rvec e/, e'). We also extracted the neutron magnetic form factor G{sub M}(superscript n) at Q2-values of 0.3 to 0.6 (GeV/c)2 based on Plane Wave Impulse Approximation calculations.

Download or read book Exclusive Reactions at High Momentum Transfer IV written by A. V. Radyushkin and published by World Scientific. This book was released on 2011 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Proceedings include talks given at the 4th Workshop on Exclusive Reactions at High Momentum Transfer at Jefferson Lab, Newport News, VA, USA, the world''s leading facility performing research on nuclear, hadronic and quark-gluon structure of matter. Exclusive reactions are becoming one of the major sources of information about the deep structure of the nucleons and other hadrons. The workshop focused on the application of a variety of exclusive reactions at high momentum transfer, utilizing unpolarized and polarized beams and targets, to obtain information about nucleon ground state and excited state structure at short distances. This is a subject which is central to the programs of current accelerators and especially planned future facilities. The topics include: generalized parton distributions, deeply virtual Compton scattering, deeply virtual meson production (DVMP), transverse structure of hadrons (TMD), hadron form factors - elastic and transition, quantum chromodynamics (perturbative, non-perturbative, lattice calculations), and physics to study at an Electron Ion Collider.

Download or read book The Structure of the Nucleon written by Anthony W. Thomas and published by John Wiley & Sons. This book was released on 2010-11-17 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the only stable baryon, the nucleon is of crucial importance in particle physics. Since the nucleon is a building block for all atomic nuclei, there is a need to analyse the its structure in order to fully understand the essential properties of all atomic nuclei. After more than forty years of research on the nucleon, both the experimental and theoretical situations have matured to a point where a synthesis of the results becomes indispensable. Here, A.W. Thomas and W. Weise present a unique report on the extensive empirical studies, theoretical foundations and the different models of the nucleon. The appendices provide an extensive summary of formulae needed in practical calculations. From the contents: electromagnetic structure of the nucleon, weak probes of nucleon structure, deep inelastic lepton scattering on the nucleon; elements of QCD, aspects of non-perturbative QCD, Chiral Symmetry and nucleon structure, models of the nucleon