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Title: Quasifree pion photoproduction on the deuteron: Single spin asymmetries

Abstract

ifree single-pion photoproduction on the deuteron via the exclusive reaction d({gamma}, {pi}0n)p is studied in the {delta}(1232)-resonance region including all leading {pi}NN effects. Special emphasizes are given to single spin observables. The elementary pion photoproduction amplitude from free nucleons is taken from the dynamical model of Sato and Lee (SL model) [Phys. Rev. C54 (1996) 2660]. The interactions in the final two-body subsystems are taken in separable form. Final-state interaction effects are found to be significant and lead to an improved agreement with the most recent experimental data from Brookhaven National Laboratory (LEGS-exp.L3b)

Authors:
 [1]
  1. Physics Department, Faculty of Science, Sohag University, Sohag 82524 (Egypt)
Publication Date:
OSTI Identifier:
20900816
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 881; Journal Issue: 1; Conference: CICHEP II: Cairo international conference on high energy physics, Cairo (Egypt), 14-17 Jan 2006; Other Information: DOI: 10.1063/1.2435301; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; BNL; DELTA-1232 BARYONS; DEUTERONS; EXPERIMENTAL DATA; FINAL-STATE INTERACTIONS; NUCLEONS; PHOTON-NEUTRON INTERACTIONS; PHOTON-PROTON INTERACTIONS; PHOTOPRODUCTION; PIONS; SPIN; TWO-BODY PROBLEM

Citation Formats

Darwish, Eed M. Quasifree pion photoproduction on the deuteron: Single spin asymmetries. United States: N. p., 2007. Web. doi:10.1063/1.2435301.
Darwish, Eed M. Quasifree pion photoproduction on the deuteron: Single spin asymmetries. United States. doi:10.1063/1.2435301.
Darwish, Eed M. Fri . "Quasifree pion photoproduction on the deuteron: Single spin asymmetries". United States. doi:10.1063/1.2435301.
@article{osti_20900816,
title = {Quasifree pion photoproduction on the deuteron: Single spin asymmetries},
author = {Darwish, Eed M.},
abstractNote = {ifree single-pion photoproduction on the deuteron via the exclusive reaction d({gamma}, {pi}0n)p is studied in the {delta}(1232)-resonance region including all leading {pi}NN effects. Special emphasizes are given to single spin observables. The elementary pion photoproduction amplitude from free nucleons is taken from the dynamical model of Sato and Lee (SL model) [Phys. Rev. C54 (1996) 2660]. The interactions in the final two-body subsystems are taken in separable form. Final-state interaction effects are found to be significant and lead to an improved agreement with the most recent experimental data from Brookhaven National Laboratory (LEGS-exp.L3b)},
doi = {10.1063/1.2435301},
journal = {AIP Conference Proceedings},
number = 1,
volume = 881,
place = {United States},
year = {Fri Jan 12 00:00:00 EST 2007},
month = {Fri Jan 12 00:00:00 EST 2007}
}
  • We analyze single transverse-spin asymmetries for hadronic pion production at large transverse momenta using QCD factorization. In the large x{sub F} region, leading contributions to the asymmetries are naturally produced by twist-3 parton correlation functions that couple quark fields and gluon field strengths. With a simple model for these matrix elements, leading-order asymmetries calculated from QCD are consistent with data on pion production from Fermilab, and can be used to predict single-spin asymmetries at BNL RHIC. We argue that our perturbative calculation for the asymmetries is relevant to pion transverse momenta as low as a few GeV. {copyright} {ital 1998}more » {ital The American Physical Society}« less
  • The analyzing power {ital A}{sub {ital N}} in inclusive {pi}{sup {minus}} and {pi}{sup +} production has been measured with a 200GeV/c transversely polarized antiproton beam over a wide {ital x}{sub {ital F}} range (0.2{le}{ital x}{sub {ital F}}{le}0.9) and at moderate {ital p}{sub {ital T}} (0.2{le}{ital p}{sub {ital T}}{le}1.5 GeV/c). The asymmetry {ital A}{sub {ital N}} increases with increasing {ital x}{sub {ital F}} from zero to large positive values for {pi}{sup {minus}}{close_quote}s, and decreases from zero to large negative values for {pi}{sup +}{close_quote}s. A threshold for the onset of the asymmetry is observed about {ital p}{sub {ital T}}{approximately}0.5 GeV/c, below whichmore » {ital A}{sub {ital N}} is essentially zero and above which {ital A}{sub {ital N}} increases (decreases) with {ital p}{sub {ital T}} for {pi}{sup {minus}}{close_quote}s ({pi}{sup +}{close_quote}s) in the covered {ital p}{sub {ital T}} range. {copyright} {ital 1996 The American Physical Society.}« less
  • No abstract prepared.
  • We report precision measurements of the Feynman-x (x{sub F}) dependence, and first measurements of the transverse momentum (p{sub T}) dependence, of transverse single spin asymmetries for the production of {pi}{sup 0} mesons from polarized proton collisions at {radical}s = 200 GeV. The x{sub F} dependence of the results are in fair agreement with perturbative QCD (pQCD) model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the p{sub T} dependence at fixed x{sub F} are not consistent with these same pQCD-based calculations.
  • We report precision measurements of the Feynman x (x{sub F}) dependence, and first measurements of the transverse momentum (p{sub T}) dependence, of transverse single-spin asymmetries for the production of {pi}{sup 0} mesons from polarized proton collisions at {radical}s = 200 GeV. The x{sub F} dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the p{sub T} dependence at fixed x{sub F} are not consistent with these same perturbative QCD-based calculations.