Download or read book Beam Spin Asymmetry Measurements from Deeply Virtual Meson Production written by Bo Zhao and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Spin Asymmetry Measurements from Deeply Virtual Meson Production written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Study of deeply virtual exclusive meson production (DVMP), is being conducted in the E1-DVCS experiment with the CLAS detector at Jefferson Lab. The main motivation of the experiment is to characterize the partonic properties of the nucleon in the framework of generalized parton distributions (GPDs). The data were taken in the spring of 2005 using a 5.7 GeV longitudinally polarized electron beam and an unpolarized hydrogen target. We report on the on-going beam spin asymmetry analysis for pseudo-scalar channels and future experiments.
Download or read book Beam Target and Double spin Asymmetry Measurements in Deeply Virtual 0 and Meson Production written by Gavin William Murdoch and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Spin Asymmetry Measurements in Deeply Virtual Compton Scattering written by Gagik Gavalian and published by . This book was released on 2004 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Target and Double spin Asymmetry Measurments in Deeply Virtual 0 and Meson Production written by Gavin William Murdoch and published by . This book was released on 2019 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Spin Asymmetry of Exclusive Coherent Electroproduction of the 0 Off 4He written by Frank Thanh Cao and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To understand the partonic structure of nucleons in nuclei, measuring the beam spin asymmetry (BSA) from exclusive processes is important to get at the so-called Generalized Parton Distributions (GPDs) that describe the partons' behavior inside the nucleon. In particular, BSA in Deeply Virtual Meson Production (DVMP) can offer valuable constraints on the transverse GPDs which are not accessible with other exclusive processes. Furthermore, DVMP measurements on bound nucleons can offer insights into structure modification due to the nuclear environment. The interpretation of this bounded nucleon DVMP on nuclear targets rests on the assumption of factorization and that higher-order effects are negligible. These assumptions can be tested through measurement of nuclear DVMP on a spin-0 target, where at leading order the BSA should be zero. In the CLAS EG6 experiment, the spin-0 helium-4 gas target is probed via the deeply virtual (Q^2 > 2 (GeV/c)^2) photons from 6 GeV longitudinally polarized electrons. The results of coherent meson electroproduction of pi-zero off heliium-4, where the BSA is measured to be consistent with zero, will be presented and discussed. This benchmark measurement is in agreement with symmetry arguments of a recent theoretical formulation that offers a framework complementary to that of the GPDs and gives confidence in the assumptions made for future studies of exclusive nuclear processes.
Download or read book Study of Beam Spin Asymmetry in Exclusive Pi Production written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Describing and understanding atomic nuclei is a puzzle that has intrigued scientists for decades. Approximately ten years ago, a description of nucleon structure, referred to as Generalized Parton Distribution (GPD), was introduced. GPDs are a way of describing scattering and production processes in a single framework. Deeply Virtual Compton Scattering (DVCS) is a process that scatters a photon from a proton and detects a scattered electron, a proton, and one photon in the fi nal state. From DVCS, GPDs can be extracted in order to lead us to a more complete picture of nucleon structure. The focus of this study is to understand the beam spin asymmetry (BSA) of the neutral [pi]° meson, a main source of background during the DVCS process. To calculate the BSA, the number of [pi]° events with positive helicity (spin) and negative helicity were counted by integrating histograms with Gaussians fi ts. It is shown that there is a signifi cant non-zero BSA in production of exclusive [pi]°, namely 0.0655±0.0022. In the analysis of previous experiments, the BSA of [pi]° was assumed to be zero and therefore ignored. Now, future analyses of DVCS data may incorporate this evidence of BSA. A deeper understanding of background processes ([pi]°) in the DVCS will allow precision measurements of GPDs, providing new insight concerning the structure of nucleons.
Download or read book Measurement of the Beam Spin Azimuthal Asymmetry Associated with Deeply Virtual Compton Scattering written by and published by . This book was released on 2001 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exclusive Phi Production Beam Spin Asymmetry Measurements with CLAS12 written by Brandon Clary and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the beam spin asymmetry (BSA) of the exclusive electroproduction of the vector phi(1020) meson through its decay into charged Kaons have been performed. The data set used was based on the RG-A run period from the recently upgraded CEBAF Large Acceptance Spectrometer (CLAS12) in Hall B at Jefferson National Lab (JLab). The run period used a 10.6 GeV longitudinally polarized electron beam and an unpolarized hydrogen target. The available statistics collected allow for detailed studies of the W, -t, xB, and Q2 dependencies of the BSA amplitudes from phi production. The BSA measurements will shed light on the exchange mechanisms responsible for phi production at JLab energies. In this dissertation, a non-zero BSA is observed, which suggests a possible enhancement of pseudo-scalar exchange mechanism near production threshold. Therefore, the non-zero BSA may be a result of the interference of the pseudo-scalar exchange mechanism with a scalar one. Ultimately, information on the dominant exchange mechanism will aid in the development of a Generalized Parton Distribution (GPD) based description of these processes in the context of hard to soft transition.
Download or read book First Measurement of the Beam Normal Single Spin Asymmetry in Delta Resonance Production by Q rm Weak written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The beam normal single spin asymmetry ($B_{\rm n}$) is generated in the scattering of transversely polarized electrons from unpolarized nuclei. The asymmetry arises from the interference of the imaginary part of the two-photon exchange with the one-photon exchange amplitude. The $Q_{\rm weak}$ experiment has made the first measurement of $B_{\rm n}$ in the production of the $\Delta$(1232) resonance, using the $Q_{\rm weak}$ apparatus in Hall-C at the Thomas Jefferson National Accelerator Facility. The final transverse asymmetry, corrected for backgrounds and beam polarization, is $B_{\rm n}$ = 43 $\pm$ 16 ppm at beam energy 1.16 GeV at an average scattering angle of about 8.3 degrees, and invariant mass of 1.2 GeV. The measured preliminary $B_{\rm n}$ agrees with a preliminary theoretical calculation. $B_{\rm n}$ for the $\Delta$ is the only known observable that is sensitive to the $\Delta$ elastic form-factors ($\gamma$*$\Delta\Delta$) in addition to the generally studied transition form-factors ($\gamma$*N$\Delta$), but extracting this information will require significant theoretical input.
Download or read book The Spin Structure of the Proton and Polarized Collider Physics written by Steven D. Bass and published by . This book was released on 2002 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Proceedings of the 17th International Spin Physics Symposium written by Kenichi Imai and published by American Inst. of Physics. This book was released on 2007-07-02 with total page 1196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Getting down to the bottom line is what this proceedings digest is all about, as any physicist will tell you: spin is the fundamental concept in physics. The applications are pretty universal due to the fact that, using spin-related phenomena, physicists are trying to reveal the fundamental principles of nature – and things don’t come much more bottom-line than that. This volume is the proceedings of the 17th International Spin Physics Symposium which is a forum to discuss spin physics and related topics.
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 Physics Division Annual Report written by Argonne National Laboratory. Physics Division and published by . This book was released on 2001 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam charge and Beam spin Azimuthal Asymmetries in Deeply virtual Compton Scattering written by Frank Ellinghaus and published by . This book was released on 2004 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam helicity Asymmetry Arising from Deeply Virtual Compton Scattering Measured with Kinematically Complete Event Reconstruction written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
