Difference between revisions of "Measurement of the beam asymmetry Σ for π^0 and η photoproduction on the proton at E sub γ=9 GeV"
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− | | (a) Photon beam intensity versus energy as measured by the pair spectrometer (not corrected for instrumental acceptance). (b) Photon beam polarization as a function of beam energy, as measured by the triplet polarimeter, with data points offset horizontally by ±0.015 GeV for clarity. || <img src="https://halldweb.jlab.org/DocDB/0031/003102/036/fig0_beam.pdf" /> | + | | (a) Photon beam intensity versus energy as measured by the pair spectrometer (not corrected for instrumental acceptance). (b) Photon beam polarization as a function of beam energy, as measured by the triplet polarimeter, with data points offset horizontally by ±0.015 GeV for clarity. || <img src="https://halldweb.jlab.org/DocDB/0031/003102/036/fig0_beam.pdf" /> |
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Revision as of 22:59, 20 November 2017
Abstract
We report measurements of the photon beam asymmetry Σ for the reactions γ⃗p→π0p and γ⃗p→ηp from the GlueX experiment using a 9 GeV linearly-polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous π0 measurements, and are the first η measurements in this energy regime. The results are compared with theoretical predictions based on t-channel, quasi-particle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models.
Caption | Figures |
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(a) Photon beam intensity versus energy as measured by the pair spectrometer (not corrected for instrumental acceptance). (b) Photon beam polarization as a function of beam energy, as measured by the triplet polarimeter, with data points offset horizontally by ±0.015 GeV for clarity. | <img src="https://halldweb.jlab.org/DocDB/0031/003102/036/fig0_beam.pdf" /> |