Download or read book Beam spin Asymmetries in the Azimuthal Distribution of Pion Electroproduction written by and published by . This book was released on 2006 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precise Measurements of Beam Spin Asymmetries in Semi Inclusive pi 0 Production written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial sin [Phi]h amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle [Phi]h of the produced neutral pion. The dependence of this amplitude on Bjorken x and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations.
Download or read book Beam spin Asymmetries from Semi inclusive Pion Electroproduction written by and published by . This book was released on 2014 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the moment A{sup sin?}{sub LU} corresponding to the polarized electron beam-spin asymmetry in SIDIS. A{sup sin?}{sub LU} is a twist-3 quantity providing information about quark-gluon correlations. Data were taken with the CLAS Spectrometer at Jefferson Lab using a 5.498 GeV longitudinally polarized electron beam and an unpolarized liquid hydrogen target. All three pion channels (pi, pi° and pi−) were measured simultaneously over a large range of kinematics within the virtuality range Q2 ̃1.0-4.5 GeV2. The observable was measured with good statistical precision over a large range of z, P{sub T}, x{sub B}, and Q2, which permits comparison with several reaction models. The discussed measurements provide an upgrade in statistics over previous measurements, and serve as the first evidence for the negative sign of the?− sin? Moment.
Download or read book Measurement of Beam Spin Asymmetries for Deep Inelastic Pi Electroproduction written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first evidence for a non-zero beam-spin azimuthal asymmetry in the electroproduction of positive pions in the deep-inelastic region. Data have been obtained using a polarized electron beam of 4.3 GeV and with the CLAS detector at the Thomas Jefferson National Accelerator Facility (JLab). The amplitude of the sin phi modulation increases with the momentum of the pion relative to the virtual photon, z, with an average amplitude of 0.038+/-0.005+/-0.003 for 0.5
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 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 Beam Target Double Spin Asymmetry A sub LT sub in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized sup 3 sup He Target at 1 4 Q sup 2 sup 2 7 GeV sup 2 sup written by and published by . This book was released on 2012 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first measurement of the double-spin asymmetry ALT for charged pion electroproduction in semi-inclusive deep inelastic electron scattering on a transversely polarized 3He target. The kinematics focused on the valence quark region, 0.16 x 0.35 with 1.4 Qsup2/sup 2.7 GeVsup2/sup. The corresponding neutron AsubLT/sub asymmetries were extracted from the measured sup3/supHe asymmetries and proton/sup3/supHe cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function gsub 1T/subsupq/sup and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for?sup-
Download or read book Measurement of Single and Double Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first measurement of the transverse momentum dependence of double spin asymmetries in semi-inclusive production of pions in deep inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Thomas Jefferson National Accelerator Facility (JLab). A significant non-zero $\sin2\phi$ single spin asymmetry was also observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton. The azimuthal modulations of single spin asymmetries have been measured over a wide kinematic range.
Download or read book Measurement of Single target Spin Asymmetries in the Electroproduction of Negative Pions in the Semi inclusive Deep Inelastic Reaction N1 e E pi X on a Transversely Polarized 3He Target written by and published by . This book was released on 2010 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experiment E06010 measured the target single spin asymmetry (SSA) in the semiinclusive deep inelastic (SIDIS) n1!e, e'[pi]- )X reaction with a transversely polarized 3He target as an e ective neutron target. This is the very rst independent measurement of the neutron SSA, following the measurements at HERMES and COMPASS on the proton and the deuteron. The experiment acquired data in Hall A at Je erson Laboratory with a continuous electron beam of energy 5.9 GeV, probing the valence quark region, with x = 0.13 2!0.41, at Q2 = 1.31 2!3.1 GeV2. The two contributing mechanisms to the measured asymmetry, viz, the Collins effect and the Sivers effect can be realized through the variation of the asymmetry as a function of the Collins and Sivers angles. The neutron Collins and Sivers moments, associated with the azimuthal angular modulations, are extracted from the measured asymmetry for the very first time and are presented in this thesis. The kinematics of this experiment is comparable to the HERMES proton measurement. However, the COMPASS measurements on deuteron and proton are in the low-x region. The results of this experiment are crucial as the first step toward the extraction of quark transversity and Sivers distribution functions in SIDIS. With the existing results on proton and deuteron, these new results on neutron will provide powerful constraints on the transversity and Sivers distributions of both the u and d-quarks in the valence region.
Download or read book Measurement of Single target Spin Asymmetries in the Electroproduction of Negative Pions in the Semi inclusive Deep Inelastic Reaction N u2191 e e X on a Transversely Polarized 3He Target written by and published by . This book was released on 2010 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experiment E06010 measured the target single spin asymmetry (SSA) in the semiinclusive deep inelastic (SIDIS) n↑(e,e'?-)X reaction with a transversely polarized 3He target as an e ective neutron target. This is the very rst independent measurement of the neutron SSA, following the measurements at HERMES and COMPASS on the proton and the deuteron. The experiment acquired data in Hall A at Je erson Laboratory with a continuous electron beam of energy 5.9 GeV, probing the valence quark region, with x = 0.13 → 0.41, at Q2 = 1.31 → 3.1 GeV2. The two contributing mechanisms to the measured asymmetry, viz, the Collins effect and the Sivers effect can be realized through the variation of the asymmetry as a function of the Collins and Sivers angles. The neutron Collins and Sivers moments, associated with the azimuthal angular modulations, are extracted from the measured asymmetry for the very first time and are presented in this thesis. The kinematics of this experiment is comparable to the HERMES proton measurement. However, the COMPASS measurements on deuteron and proton are in the low-x region. The results of this experiment are crucial as the first step toward the extraction of quark transversity and Sivers distribution functions in SIDIS. With the existing results on proton and deuteron, these new results on neutron will provide powerful constraints on the transversity and Sivers distributions of both the u and d-quarks in the valence region.
Download or read book Testing Qcd Through Spin Observables In Nuclear Targets written by Jian-ping Chen and published by World Scientific. This book was released on 2003-01-16 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 Azimuthal Asymmetries in Semi inclusive Electroproduction of Pions and Kaons on a Longitudinally Pilarised Deuterium Target written by and published by . This book was released on 2002 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Double Spin Asymmetry AL T in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized 3He Target written by Jin Huang (Ph. D.) and published by . This book was released on 2012 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis I discuss the first measurement of the beam-target double-spin asymmetry ALT for charged pion electroproduction in deep inelastic electron scattering on a transversely polarized 3He target. These data were taken between October 2008 to February 2009 using a 5.9 GeV polarized electron beam at Thomas Jefferson National Accelerator Facility Experimental Hall A. The kinematics focused on the valence quark region, 0.16
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 Single Spin Azimuthal Asymmetries in Electroproduction of Neutral Pions in Semi inclusive Deep Inelastic Scattering written by and published by . This book was released on 2001 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Target Double Spin Asymmetry ALT in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized 3He Target at 1 4 Q2 2 7 GeV2 written by and published by . This book was released on 2012 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first measurement of the double-spin asymmetry ALT for charged pion electroproduction in semi-inclusive deep inelastic electron scattering on a transversely polarized 3He target. The kinematics focused on the valence quark region, 0.16
Download or read book Measurement of Single spin Azimuthal Asymmetries in Semi inclusive Electroproduction of Pions and Kaons on a Longitudinally Polarised Deuterium Target written by and published by . This book was released on 2002 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
