Download or read book Pion Photoproduction on Hydrogen and Deuterium written by Laura S. Wiener and published by . This book was released on 1984 with total page 212 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 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 Threshold Neutral Pion Photoproduction in Hydrodgen hydrogen and Deuterium written by and published by . This book was released on 2007 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cross Section Measurement of Charged Pion Photoproduction from Hydrogen and Deuterium written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the differential cross section for the gamma n --> pi- p and gamma p --> pi+ n reactions at center of mass angle of 90 degree in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at photon energies greater than 3.3 GeV exhibit a global scaling behavior for both pi- and pi+ photoproduction, consistent with the constituent counting rule and the existing pi+ photoproduction data. Possible oscillations around the scaling value were observed. The cross section ratio of exclusive pi- to pi+ photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams. The data also indicate a resonance structure at a center-of-mass energy near 2.2 GeV.
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 PHOTOPRODUCTION OF NEUTRAL PIONS IN HYDROGEN AND DEUTERIUM written by and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoproduction of Positive Pions From Hydrogen and Deuterium Near Threshold written by and published by . This book was released on 1956 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Study of N 1238 Through the Photoproduction of Charged Pions from Hydrogen and Deuterium written by Richard Alan Singer and published by . This book was released on 1967 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pion Photoproduction in Hydrogen and Beryllium written by Martial Thiebaux and published by . This book was released on 1963 with total page 56 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 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 Single pion Photoproduction from Hydrogen written by Merlin Gene Taylor and published by . This book was released on 1968 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photopion Production from Deuterium Near Threshold written by William Paul Swanson and published by . This book was released on 1960 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoproduction of Positive Pions from Hydrogen Near Threshold written by Maurice Jacques Bazin and published by . This book was released on 1962 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutral Pion Photoproduction from Deuterium in the Energy Range 1 2 to 1 Bev written by Harry H. Bingham and published by . This book was released on 1960 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two Topics in Pion Physics written by Robert Henry Traxler and published by . This book was released on 1962 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoproduction of Pion Pairs in Hydrogen written by Richard Morris Friedman and published by . This book was released on 1956 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
