Download or read book Single Spin Asymmetries in Semi inclusive DIS at CLAS written by D. S. Hwang and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single Spin Asymmetries at CLAS written by Latifa Elouadrhiri and published by . This book was released on 2003 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present recent results from Jefferson Lab's CLAS detector on beam and target single-spin asymmetries in single pion electroproduction off unpolarized hydrogen and polarized NH 3 targets. Non-zero single-beam and single-target spin asymmetries are observed for the first time in semi-inclusive and exclusive pion production in hard-scattering kinematics.
Download or read book Single Spin Asymmetries at CLAS written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Single spin asymmetries (SSA) are crucial tools in the study of the spin structure of hadrons in pion electroproduction, since they are directly related to some hot topics, including transverse polarization distribution functions, fragmentation of polarized quarks and generalized parton distribution functions. At low beam energies, when the virtual photon has a relatively large angle with respect to the initial spin direction, the measured single-target spin-dependent sin [phi] moment in the cross section for the longitudinally polarized target contain contributions from the target spin components, both longitudinal and transverse with respect to the photon direction. This contribution presents preliminary results from Jefferson Lab's CLAS detector on beam and target SSA in pion azimuthal distributions in one particle inclusive electroproduction in the DIS regime (Q2> 1GeV 2,W> 2GeV) off a polarized NH3 target.
Download or read book Single Spin Asymmetries in Electroproduction at CLAS written by Latifa Elouadrhiri and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present measurements of spin asymmetries in semi-inclusive processes in hard scattering kinematics using a 5.7 GeV electron beam and the CEBAF Large Acceptance Spectrometer (CLAS) at JLab. Scattering of longitudinally polarized electrons of an unpolarized liquid-hydrogen and off a polarized NH{sub 3} targets was studied over a wide range of kinematics. Non-zero single-beam and single-target spin asymmetries have been observed in semi-inclusive pion production in hard-scattering kinematics (Q{sup 2}> 1.2 GeV{sup 2}, W{sup 4}> 4 GeV{sup 2}). Systematic studies of factorization of x and z dependences have been done for different spin-dependent and spin-independent observables. No significant x/z dependence has been observed within statistical uncertainties, which is consistent with factorization of hard scattering and fragmentation processes.
Download or read book Spin Azimuthal Asymmetries in DIS at CLAS written by Harut Avakian and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present latest measurements of beam and target single-spin asymmetries in the single pion electroproduction in the DIS. In addition to significant target single-spin asymmetries the CLAS detector at Jlab also measures a significant beam-spinasymmetry when the analysis is restricted to events for which the pion carries a large fraction of the virtual photon momentum.
Download or read book Spin Asymmetries for Exclusive and Semi exclusive Reactions with CLAS written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An extensive experimental program to measure the spin structure of the nucleons is being carried out with the CLAS detector at Jefferson Lab using a longitudinally polarized electron beam incident on a longitudinally polarized target. Spin degrees of freedom offer new tools to explore the baryon structure and test the many theoretical approaches that attempt to characterize it, such as effective Lagrangian models and transverse momentum dependent parton distributions. I will present preliminary results for single and double spin asymmetries for exclusive [pi][sup 0], [pi][sup +], and [eta] electroproduction in the resonance region compared with unitary isobar and dynamical models, as well as [rho] electroproduction for DIS kinematics. I will also report on an analysis of the semi-inclusive and exclusive channels where double and single spin asymmetries were used to study transverse momentum dependent parton distributions.
Download or read book Proceedings of the International Congress on Comparative Physiology written by and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Double Spin Asymmetry in Exclusive Pi Electro production with CLAS written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The eg1b run was conducted using CLAS at Jefferson Lab in 2000 by the CLAS collab- oration. A 1.6 GeV - 5.6 GeV polarized electron beam and polarized nuclear targets (composed of NH3 and ND3) were used, allowing single and double spin asymmetries to be measured. This analysis deals with the double spin asymmetry A.
Download or read book Single and Double Spin Asymmetries for Deeply Virtual Compton Scattering Measured with CLAS and a Longitudinally Polarized Proton Target written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton e→p→e'p'[gamma] are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally polarized 14NH3 target. The three asymmetries were measured in 165 4-dimensional kinematic bins, covering the widest kinematic range ever explored simultaneously for beam and target-polarization observables in the valence quark region. The kinematic dependences of the obtained asymmetries are discussed and compared to the predictions of models of Generalized Parton Distributions. As a result, the measurement of three DVCS spin observables at the same kinematic points allows a quasi-model-independent extraction of the imaginary parts of the H and H~ Compton Form Factors, which give insight into the electric and axial charge distributions of valence quarks in the proton.
Download or read book Spin Physics with CLAS written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Inelastic scattering using polarized nucleon targets and polarized charged lepton beams allows the extraction of double and single spin asymmetries that provide information about the helicity structure of the nucleon. A program designed to study such processes at low and intermediate Q2 for the proton and deuteron has been pursued by the CLAS Collaboration at Jefferson Lab since 1998. Our inclusive data with high statistical precision and extensive kinematic coverage allow us to better constrain the polarized parton distributions and to accurately determine various moments of spin structure function g1 as a function of Q2. The latest results are shown, illustrating our contribution to the world data, with comparisons of the data with NLO global fits, phenomenological models, chiral perturbation theory and the GDH and Bjorken sum rules. The semi-inclusive measurements of single and double spin asymmetries for charged and neutral pions are also shown, indicating the importance of the orbital motion of quarks in understanding of the spin structure of the nucleon.
Download or read book Testing QCD Through Spin Observables in Nuclear Targets written by Don G. Crabb and published by World Scientific. This book was released on 2003 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the invited talks and contributed papers presented at the workshop on ?Testing QCD Through Spin Observables in Nuclear Targets?, held at the University of Virginia in April 2002.The workshop was proposed in the context of the large number of experiments that have used polarized deuterons or polarized 3He to extract information about the spin parameters of the neutron. The motivation for this workshop was to study the effects of the nuclear medium on the spin properties of the bound nucleon and to explore issues in QCD that might be resolved through spin observables in nuclear targets: What is the effect of the nuclear medium on the measured asymmetries? How have the latest results on the spin structure of the nucleon and the nucleon form factors changed our thinking? What advances are anticipated in the development of polarized targets?
Download or read book Measurement of Single Spin Asymmetry and Fifth Structure Function for the P vec e E K Lambda Reaction with CEBAF Large Acceptance Spectrometer CLAS written by and published by . This book was released on 2004 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: The single spin asymmetry, ALT', and the polarized structure function, ?LT', for the p($\vec{e}$, e' K+) reaction in the resonance region have been measured and extracted using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Data were taken at an electron beam energy of 2.567 GeV. The large acceptance of CLAS allows for full azimuthal angle coverage over a large range of center-of-mass scattering angles. Results were obtained that span a range in Q2 from 0.5 to 1.3 GeV2 and W from threshold up to 2.1 GeV and were compared to existing theoretical calculations. The polarized structure function is sensitive to the interferences between various resonant amplitudes, as well as to resonant and non-resonant amplitudes. This measurement is essential for understanding the structure of nucleons and searching for previously undetected nucleon excited states (resonances) predicted by quark models. The W dependence of the ?LT' in the kinematic regions dominated by s and u channel exchange (cos ?$cm\atop{k}$ = -0.50, -0.167, 0.167) indicated possible resonance structures not predicted by theoretical calculations. The ?LT' behavior around W = 1.875 GeV could be the signature of a resonance predicted by the quark models and possibly seen in photoproduction. In the very forward angles where the reaction is dominated by the t-channel, the average ?LT' was zero. There was no indication of the interference between resonances or resonant and non-resonant amplitudes. This might be indicating the dominance of a single t-channel exchange. Study of the sensitivity of the fifth structure function data to the resonance around 1900 MeV showed that these data were highly sensitive to the various assumptions of the models for the quantum number of this resonance. This project was part of a larger CLAS program to measure cross sections and polarization observables for kaon electroproduction in the nucleon resonance region.
Download or read book Spin Structure of the Nucleon written by Erhard Steffens and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive survey of the most recent results from the field of quark-gluon structure of the nucleon, in particular how the spin of the nucleon is shared by its constituents. After very intriguing results from CERN and SLAC at the end of the 1980s, the last decade has seen a set of second-generation experiments at high energy accelerators that have yielded precise information on the solution of the 'Spin Crisis' - as well as opening up new questions. The articles are written by experts from the leading collaboration and theory groups as well as providing an expert summary of the state of the art, the book points the way to future research directions. Its main focus is on semi-inclusive and exclusive measurements of deep inelastic lepton scattering, which enables for the first time the determination of the flavor-separated quark spin distributions. Future developments on generalized parton distributions and their interpretation as well as the transverse spin structure are also covered. An indispensable volume for all working in hadronic physics.
Download or read book Transversity and SIDIS at CLAS written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The single-spin asymmetries (SSA) in semi-inclusive DIS have emerged as a powerful tool to access transverse momentum distributions of partons and to give access to the spin-orbit correlations. SSA enable measurements of some essentially unexplored physical observables, including transversity, {\it time-reversal odd} distribution and fragmentation functions. In this talk we present an overview of the latest studies of transverse spin effects and discuss newly released results, ongoing activities, as well as planned near term and future measurements of spin-orbit correlations at CLAS.
Download or read book Transversity 2005 written by Dr. Vincenzo Barone and published by World Scientific. This book was released on 2006 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: The notion of transversity in hadronic physics has been with us for over 25 years. Intriguing though it might have been, for much of that time transversity remained an intangible and remote object, of interest principally to a few theoreticians. In recent years transversity and transverse-spin effects in general have grown as both theoretical and experimental areas of active research. This increasing attention has now matured into a thriving field with a driving force of its own. The ever-growing bulk of data on asymmetries in collisions involving transversely polarised hadrons demands a more solid and coherent theoretical basis for its description. Indeed, it now appears rather clear that transversity and other closely related properties play a significant role in such phenomena.As part of a Ministry-funded inter-university Research Project, this workshop was organised to gather together experimentalists and theoreticians engaged in investigating the nature of transverse spin in hadronic physics, with the intent of favouring the exchange of up-to-date theoretical and experimental ideas and news on the subject. Over 70 physicists took part and very nearly all the major experiments involved in transverse-spin studies were officially represented, as too were the main theory groups working in the field. New results and new analyses sparked many interesting and lively discussions.
Download or read book Double Spin Asymmetry in Exclusive pi Electroproduction with CLAS written by Joshua James Pierce and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strangeness and Spin in Fundamental Physics written by Mauro Anselmino and published by IOS Press. This book was released on 2008 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents discussion of the role played by two subtle and somehow puzzling quantum numbers, the strangeness and the spin, in fundamental physics.
