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Creators/Authors contains: "Milner, R. G."

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  1. ; ; ; ; ; ; ; ; ; ; et al ( , The European Physical Journal A)
    Abstract

    We propose a new measurement of the ratio of positron-proton to electron-proton elastic scattering at DESY. The purpose is to determine the contributions beyond single-photon exchange, which are essential for the Quantum Electrodynamic (QED) description of the most fundamental process in hadronic physics. By utilizing a 20 cm long liquid hydrogen target in conjunction with the extracted beam from the DESY synchrotron, we can achieve an average luminosity of$$2.12\times 10^{35}$$2.12×1035 cm$$^{-2}\cdot $$-2·s$$^{-1}$$-1 ($$\approx 200$$≈200times the luminosity achieved by OLYMPUS). The proposed two-photon exchange experiment (TPEX) entails a commissioning run at a beam energy of 2 GeV, followed by measurements at 3 GeV, thereby providing new data up to$$Q^2=4.6$$Q2=4.6 (GeV/c)$$^2$$2(twice the range of current measurements). We present and discuss the proposed experimental setup, run plan, and expectations.

     
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  2. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review C)
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  3. ; ; ; ; ; ; ; ; ; ; et al ( , The European Physical Journal A)
    The double-spin-polarization observable E for γ p → pπ0 has been measured with the CEBAF Large Acceptance Spectrometer (CLAS) at photon beam energies Eγ from 0.367 to 2.173 GeV (corresponding to center-ofmass energies from 1.240 to 2.200 GeV) for pion center-ofmass angles, cos θc.m. π0 , between − 0.86 and 0.82. These new CLAS measurements cover a broader energy range and have smaller uncertainties compared to previous CBELSA data and provide an important independent check on systematics. These measurements are compared to predictions as well as new global fits from The George Washington University, Mainz, and Bonn-Gatchina groups. Their inclusion in multipole analyses will allow us to refine our understanding of the single-pion production contribution to the Gerasimov-Drell- Hearn sum rule and improve the determination of resonance properties, which will be presented in a future publication. 
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    Free, publicly-accessible full text available September 1, 2024
  4. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review Letters)
    Free, publicly-accessible full text available July 1, 2024
  5. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review Letters)
    Free, publicly-accessible full text available May 1, 2024
  6. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review C)
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  7. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review Letters)
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  8. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review Letters)
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  9. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review Letters)
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  10. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review Letters)
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