Physics Commons^™

Measurement Of The Helicity Asymmetry E In Ω → Π+Π−Π0 Photoproduction, Z. Akbar, P. Roy, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, V. A. Nikonov, A. V. Sarantsev, K. P. Adhikari, S. Adhikari, M. J. Amaryan, S. Anefalos Pereira, H. Avakian, J. Ball, M. Battaglieri, V. Batourine, I. Bedlinskiy, S. Boiarinov, W. J. Briscoe, J. Brock, W. K. Brooks, V. D. Burkert, F. T. Cao, C. Carlin, D. S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, Wesley P. Gohn

Physics and Astronomy Faculty Publications

The double-polarization observable E was studied for the reaction γp → pω using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at the Thomas Jefferson National Accelerator Facility and the longitudinally polarized frozen-spin target (FROST). The observable was measured from the charged decay mode of the meson, ω → π⁺π⁻π⁰, using a circularly polarized tagged-photon beam with energies ranging from the ω threshold at 1.1 to 2.3 GeV. A partial-wave analysis within the Bonn-Gatchina framework found dominant contributions from the 3/2⁺ partial wave near threshold, which is identified with the subthreshold N …

Extraction Of The Neutron Electric Form Factor From Measurements Of Inclusive Double Spin Asymmetries, V. Sulkosky, G. Jin, E. Long, Y. -W. Zhang, M. Mihovilovic, A. Kelleher, B. Anderson, D. W. Higinbotham, S. Širca, K. Allada, J. R. M. Annand, T. Averett, W. Bertozzi, W. Boeglin, P. Bradshaw, A. Camsonne, M. Canan, G. D. Cates, C. Chen, J. -P. Chen, E. Chudakov, R. De Leo, X. Deng, A. Deur, C. Dutta, L. El Fassi, D. Flay, S. Frullani, F. Garibaldi, Wolfgang Korsch

Physics and Astronomy Faculty Publications

Background: Measurements of the neutron charge form factor, Gⁿ_E, are challenging because the neutron has no net charge. In addition, measurements of the neutron form factors must use nuclear targets which require accurately accounting for nuclear effects. Extracting Gⁿ_E with different targets and techniques provides an important test of our handling of these effects.

Purpose: The goal of the measurement was to use an inclusive asymmetry measurement technique to extract the neutron charge form factor at a four-momentum transfer of 1 (GeV/c)². This technique has very different systematic uncertainties …

Compton Scattering From 4He At 61 Mev, M. H. Sikora, M. W. Ahmed, A. Banu, C. Bartram, B. Crowe, E. J. Downie, G. Feldman, H. Gao, H. W. Grießhammer, H. Hao, C. R. Howell, H. J. Karwowski, D. P. Kendellen, Michael A. Kovash, X. Li, D. M. Markoff, S. Mikhailov, V. Popov, R. E. Pywell, J. A. Silano, M. C. Spraker, P. Wallace, H. R. Weller, C. S. Whisnant, Y. K. Wu, W. Xiong, X. Yan, Z. W. Zhao

Physics and Astronomy Faculty Publications

The Compton scattering cross section from ⁴He has been measured with high statistical accuracy over a scattering angle range of 40^∘−159^∘ using a quasimonoenergetic 61-MeV photon beam at the High Intensity Gamma-Ray Source. The data are interpreted using a phenomenological model sensitive to the dipole isoscalar electromagnetic polarizabilities (α_s and β_s) of the nucleon. These data can be fit with the model using values of α_s and β_s that are consistent with the currently accepted values. These data will serve as benchmarks of future calculations from effective field theories and …