Download or read book CHARGED PION PHOTOPRODUCTION RATIOS AND THE QUARK MODEL written by I. Barbour and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exclusive Photoproduction of Charged Pions in Hydrogen and Deuterium from 1 to 6 GeV written by and published by . This book was released on 2004 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of the transition region in the description of exclusive processes and hadron structure, from the nucleon-meson degrees of freedom in meson-exchange models at low energy to the quark-gluon degrees of freedom in pQCD at high energy, is essential for us to understand the strong interaction. The differential cross section measurements for exclusive reactions at fixed center-of-mass angles enable us to investigate the constituent counting rule, which explicitly connects the quark-gluon degrees of freedom to the energy dependence of differential cross sections. JLab Experiment E94-104 was carried out in Hall A with two high resolution spectrometers. It included the coincidence cross section measurement for the ?n --> ?-[p] process with a deuterium target and the singles measurement for the ?p --> ?+[n] process with a hydrogen target. The untagged real photons were generated by the electron beam impinging on a copper radiator. The photon energies ranged from 1.1 to 5.5 GeV, corresponding to the center-of-mass energies from 1.7 to 3.4 GeV. The pion center-of-mass angles were fixed at 50 deg, 70 deg, 90 deg, and also 100 deg, 110 deg at a few energies. The JLab E94-104 data presented in this thesis contain four interesting features. The data exhibit a global scaling behavior for both ?- and ?+ photoproduction at high energies and high transverse momenta, consistent with the constituent counting rule and the existing ?+ photoproduction data. This implies that the quark-gluon degrees of freedom start to play a role at this energy scale. The data suggests possible substructure of the scaling behavior, which might be oscillations around the scaling value. There are several possible mechanisms that can cause oscillations, for example the one associated with the generalized constituent counting rule involving quark orbital angular momentum. The data show an enhancement in the scaled cross section at center-of-mass energy near 2.2 GeV, where baryon resonances are not as well known as those at low energies. The differential cross section ratios for exclusive ?n --> ?-[p] to ?p --> ?+[n] process at ?cm = 90 deg start to show consistency with the prediction based on one-hard-gluon-exchange diagrams at high energies.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-11 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Charged Pion Photoproduction And Scaling written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The gamma-n -->pi- p and gamma-p --> pi+ n reactions are essential probes of the transition from meson-nucleon degrees of freedom to quark-gluon degrees of freedom in exclusive processes. The cross sections of these processes are also advantageous, for the investigation of oscillatory behavior around the quark counting rule prediction, since they decrease relatively slower with energy compared with other photon-induced processes. In this talk, we discuss recent results on the gamma-p --> pi+ n and gamma-n -->pi- p processes from Jefferson Lab experiment E94-104. We also discuss the CLAS g10 analysis on the gamma-n -->pi- p process.
Download or read book Exclusive Photoproduction of Charged Pions in Hydrogen and Deuterium from 1 to 6 GeV written by Lingyan Zhu and published by . This book was released on 2004 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) or example the one associated with the generalized constituent counting rule involving quark orbital angular momentum. The data show an enhancement in the scaled cross section at center-of-mass energy near 2.2 GeV, where baryon resonances are not as well known as those at low energies. The differential cross section ratios for exclusive ... start to show consistency with the prediction based on one-hard-gluon-exchange diagrams at high energies.
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 1320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Refereed and selected contributions from International Conference on Quark Nuclear Physics written by Charlotte Elster and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the refereed and selected contributions from the International Conference on Quark Nuclear Physics (QNP2002), held from 9 to 14 June 2002 in Jülich, Germany.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1986 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Generalised Veneziano Model for Charged Pion Photoproduction written by E. Reya and published by . This book was released on 1970 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Charged Pion Photoproduction from Hydrogen and Deuterium at Jefferson Lab written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The [gamma]n [yields] [pi][sup -]p and [gamma]p [yields] [pi][sup +]n reactions are essential probes of the transition from meson-nucleon degrees of freedom to quark-gluon degrees of freedom in exclusive processes. The cross sections of these processes are also, advantageous, for the investigation of oscillatory behavior around the quark counting prediction, since they decrease relatively slower with energy compared with other photon-induced processes. Moreover, these photoreactions in nuclei can probe the QCD nuclear filtering and color transparency effects. In this talk, I discuss the preliminary results on the [gamma]p [yields] [pi][sup +]n and [gamma]n [yields] [pi][sup -]p processes at a center-of-mass angle of 90[sup o] from Jefferson Lab experiment E94-104. I also discuss a new experiment in which singles [gamma]p [yields] [pi][sup +]n measurement from hydrogen, and coincidence [gamma]n [yields] [pi][sup -]p measurements at the quasifree kinematics from deuterium and [sup 12]C for photon energies between 2.25 GeV to 5.8 GeV in fine steps at a center-of-mass angle of 90[sup o] are planned. The proposed measurement will allow a detailed investigation of the oscillatory scaling behavior in photopion production processes and the study of the nuclear dependence of rather mysterious oscillations with energy that previous experiments have indicated. The various nuclear and perturbative QCD approaches, ranging from Glauber theory, to quark-counting, to Sudakov-corrected independent scattering, make dramatically different predictions for the experimental outcomes.
Download or read book High Energy Physics Index written by and published by . This book was released on 1990 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Response of Atomic Nuclei written by Sigfrido Boffi and published by Clarendon Press. This book was released on 1996 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the structure and dynamics of atomic nuclei in terms of nucleons, pions, and quarks, all within a unified treatment of the nuclear response to an electromagnetic probe. The basic formalism is presented to describe the electromagnetic field and its interaction with nuclear matter for both real and virtual photons. Nuclear response is then analyzed in terms of structure functions in the case of inclusive and semi-inclusive inelastic electron scattering. The discussion covers pion production and one- or two-nucleon emission and compares the results with available data. The formalism is also extended to incident polarized electrons, polarized targets and nuclear recoil polarization. It contains a comprehensive description of photonuclear reactions at intermediate energies and a review of experimental data and previous theoretical approaches.
Download or read book Charged Pion Photoproduction from Hydrogen and Deuterium at Jefferson Lab written by Haiyan Gao and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The {gamma}n {yields} {pi}{sup -}p and {gamma}p {yields} {pi}{sup +}n reactions are essential probes of the transition from meson-nucleon degrees of freedom to quark-gluon degrees of freedom in exclusive processes. The cross sections of these processes are also, advantageous, for the investigation of oscillatory behavior around the quark counting prediction, since they decrease relatively slower with energy compared with other photon-induced processes. Moreover, these photoreactions in nuclei can probe the QCD nuclear filtering and color transparency effects. In this talk, I discuss the preliminary results on the {gamma}p {yields} {pi}{sup +}n and {gamma}n {yields} {pi}{sup -}p processes at a center-of-mass angle of 90{sup o} from Jefferson Lab experiment E94-104. I also discuss a new experiment in which singles {gamma}p {yields} {pi}{sup +}n measurement from hydrogen, and coincidence {gamma}n {yields} {pi}{sup -}p measurements at the quasifree kinematics from deuterium and {sup 12}C for photon energies between 2.25 GeV to 5.8 GeV in fine steps at a center-of-mass angle of 90{sup o} are planned. The proposed measurement will allow a detailed investigation of the oscillatory scaling behavior in photopion production processes and the study of the nuclear dependence of rather mysterious oscillations with energy that previous experiments have indicated. The various nuclear and perturbative QCD approaches, ranging from Glauber theory, to quark-counting, to Sudakov-corrected independent scattering, make dramatically different predictions for the experimental outcomes.
Download or read book Models for High Energy Charged Pion Photo production written by Jacob Lee Farber and published by . This book was released on 1967 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Charged Pion Photoproduction from 10B written by John Alexander Nelson and published by . This book was released on 1990 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt:
