Download or read book Coherent Pion Photoproduction from Deuteron written by C. Lazard and published by . This book was released on 1974 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coherent Pion Photoproduction from Deuterium at Intermediate Energies written by P. Osland and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Perturbative QCD and Factorization of Coherent Pion Photoproduction on the Deuteron written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We analyze the predictions of perturbative QCD for pion photoproduction on the deuteron [gamma]D 2![pi]°D at large momentum transfer using the reduced amplitude formalism. The cluster decomposition of the deuteron wave function at small binding only allows the nuclear coherent process to proceed if each nucleon absorbs an equal fraction of the overall momentum transfer. Furthermore, each nucleon must scatter while remaining close to its mass shell. Thus the nuclear photoproduction amplitude [pi]° (u, t) factorizes as a product of three factors: (1) the nucleon photoproduction amplitude N1 [pi]° N1 (u/4, /4) at half of the overall momentum transfer, (2) a nucleon form factor N2(/4) at half the overall momentum transfer, and (3) the reduced deuteron form factor f{sub d}(t), which according to perturbative QCD, has the same monopole fall-off as a meson form factor. A comparison with the recent JLAB data for [gamma]D 2![pi]°D of Meekins et al. and the available [gamma]p 2![pi]°p shows good agreement between the perturbative QCD prediction and experiment over a large range of momentum transfers and center of mass angles. The reduced amplitude prediction is consistent with the constituent counting rule p11 [pi]° 2!([theta] cm) at large momentum transfer. This is found to be consistent with measurements for photon lab energies E> 3 GeV at [theta]cm = 90{sup o} and 136{sup o}.

Download or read book Coherent Pion Photoproduction on Deuterium written by Yordanka Ilieva and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Differential cross sections of the gamma + d -> d + pi{sup 0} reaction were measured at photon beam energies between 0.5 and 2.0 GeV over a wide angular range in CM system. The experiment was performed in Hall B at Jefferson Lab using the CLAS detector. The excitation function, especially at backward CM scattering angles, has been studied with regard to effects due to intermediate on-shell eta and omega rescattering. At CM scattering angles greater than 123 deg our data clearly show an enhancement around 0.7 GeV, which could be attributed to an intermediate on-shell eta-state.

Download or read book I Photoproduction and Electroproduction of Pions as a Possible Way to Measure the Electromagnetic Structure of the Pion written by Fokion Timoleon Hadjioannou and published by . This book was released on 1961 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of the Two pion Photoproduction on the Deuteron written by and published by . This book was released on 2012 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the structure of baryons in terms of the fundamental interaction of the constituent quarks and gluons is one of the primary challenges in strong interaction physics. This interaction is governed by Quantum Chromodynamics (QCD), which is a theory for understanding the dynamics of strong. QCD displays the asymptotic freedom of hadrons at very short distances and also the confinement of quarks and gluons inside hadrons. However, solutions of this QCD theory in the non-perturbative domain of the interaction are extremely difficult to achieve, mainly because confinement happens on the hadronic scale on which the coupling constant is large and prevents any perturbative approach. Thus leaving us with strategies such as lattice QCD or formulating QCD sum rules to get around this problem. In exclusive hadron production the yN interaction is recognized for being a powerful method for investigating hadrons and the mysteries that still exist within the strong interaction. From reactions with the nucleon, the strong interaction can be investigated through the transition amplitudes to the N and Delta resonances. More specifically, if an electromagnetic interaction is well known then the intermediate resonance states may be evaluated through meson photoproduction. To gain more detailed insight into this interaction, we look to probe the baryon structure of the nucleon and the photo-excited resonance decays through photon scattering off a deuteron producing two pions in the final state. This photoproduction process off the deuteron will be used to investigate known baryon resonances in the two pion channel. The two pion final state will be investigated for unraveling new information into the photo-coupling strengths. We want to explore final state interactions, search for properties of known resonances, and to explore the possibility of seeing missing states that are predicted by quark models but have not yet been found experimentally. Using the CEBAF Large Acceptance Spectrometer (CLAS), the hadronic products are detected in coincidence with the incident scattered photon on a deuterium target. This makes it possible to measure the single differential cross sections and the decay angular distributions for the production of two pion final states. The measured cross sections will contribute significantly to a better understanding of the coupling strengths that govern the baryonic and mesonic resonances which will push the knowledge of the strong interaction to a next level. We use CLAS to study the two pion channel from the eg3 data set, for resonance production, specifically investigating the exclusive reaction of yd --> p pi^+pi^?n, and comparing the relevant cross sections to already existing data sets. The eg3 data set provided an excellent data set for investigating photo-induced baryonic and mesonic resonances. It contains a large photon tagging range from 1.1 to 5.5 GeV in the study of photo-coupling strengths, as well as an available two pion reaction channel for resonant decay study. These measurements provide unique and coherent results from tagged photons over a broad range of energy, and represent the only two pion production data above 5 GeV at this present time. We found that the data produced good comparable single-differentials cross sections to other existing CLAS (gll dataset) two pion differential cross sections, and an excellent comparable total cross section to published (ELSA and ABBHHM) two pion total cross sections.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976-06 with total page 1216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coherent P Production Off Deuteron Near Threshold written by Eed M. Darwish and published by LAP Lambert Academic Publishing. This book was released on 2015-12-10 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherent -photoproduction off the deuteron near -threshold is investigated within an approach which includes the amplitudes of impulse approximation, two-step process with N- and N-rescattering, and intermediate NN interaction. Results for unpolarized and polarized cross sections as well as for all possible polarization observables with polarized photons and/or oriented deuterons are predicted and compared with available data, and differences with other theoretical models are analyzed. The contribution of this reaction to the deuteron spin asymmetry is calculated and its contribution to the GDH integral is explicitly evaluated by integration up to a photon energy of 900 MeV. In addition, the sensitivity of the results to the elementary amplitude and the choice of the NN potential model governs the deuteron wave function is also investigated. This work is motivated by the measurements of the CLAS Collaboration at Jefferson laboratory, where a cusp-like structure in the energy dependence of the differential cross section has been observed at extremely backward pion angles."

Download or read book A Comprehensive Study of the Reaction Gammad Pi0d Above 500 MeV written by Yordanka Ilieva and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here we present differential cross sections for coherent pion photoproduction on the deuteron for photon energies between 0.5 and 2.0 GeV and pion center-of-mass angles between 50? and 150?. Our analysis shows that around the eta-photoproduction threshold the reaction is sensitive to intermediate eta formation and rescattering through N* (1535) excitation. At large pion angles, our scaled invariant cross sections s13((d sigma)/dt) vary about a constant value as a function of s. In a limited kinematic range, at high s and t, the invariant amplitude can be factorized in terms of deuteron and nucleon form factors, and the elementary amplitude for pion production on the free nucleon.

Download or read book Coherent Photoproduction of rho Mesons from Deuterium written by Irving Dean Overman and published by . This book was released on 1971 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photoproduction and Electroproduction of Pions as a Possible Way to Measure the Electromagnetic Structure of the Pion written by Fokion Timoleon Hadjioannou and published by . This book was released on 1961 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Energy Physics Index written by and published by . This book was released on 1994 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book N Physics Proceedings Of The Fourth Cebaf int Workshop written by Harry Tsung-shung Lee and published by World Scientific. This book was released on 1997-06-27 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been well recognized that the study of the excitations of the nucleon can shed light on the nonperturbative aspects of QCD. New opportunities for such study will be opened in the next few years with the commissioning of experiments in Hall B of the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility (JLab). Photo- and electroproduction studies of single and double pions, rhos, omegas, and kaons will be conducted with unprecedented precision. The Hall B CLAS detector is a major step forward, promising to provide kinematically complete measurements of cross sections and spin observables. The task of extracting new insights from such detailed measurements will require close coordination between experimental and theoretical physicists.To help optimize this interface between theory and experiment, a joint CEBAF/INT workshop was held at the Institute of Nuclear Theory in Seattle, September 9-13, 1996. The foci of the 1996 workshop included: N → N∗ transition form factors as predicted by QCD-inspired models and their experimental consequences; theoretical techniques employing QCD sum rules, perturbative QCD, and lattice QCD; reaction theories of photo- and electro-production of mesons; theoretical issues in the eta meson, vector meson, and two-pion production channels; progress in developing amplitude analyses for the available and expected data; the relationship between the Hall B program and those of other new experimental facilities.This proceeding will serve readers as both a current perspective on the field and a guide to future experimental and theoretical research directions.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1971 with total page 1330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IBZ written by Otto Zeller and published by . This book was released on 1977 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the International Symposium Electromagnetic Interactions in Nuclear and Hadron Physics written by Mamoru Fujiwara and published by World Scientific. This book was released on 2002 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the following topics: (1) meson and hadron production by real and virtual photon interaction with nucleons and nuclei; (2) astrophysical studies via photoreactions and hadron reactions; (3) new technologies for the electromagnetic probes and detector development; (4) nuclear structure studies with electromagnetic probes; (5) fundamental symmetries with electromagnetic probes and related problems.The proceedings have been selected for coverage in: ? Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)

Download or read book Energy Research Abstracts written by and published by . This book was released on 1985 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt: