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Title: Contribution of two-boson exchange with {delta}(1232) excitation to parity-violating elastic electron-proton scattering

Journal Article · · Physical Review. C, Nuclear Physics
;  [1];  [2];  [3]
  1. Department of Physics, Chung-Yuan Christian University, Chung-Li 32023, Taiwan (China)
  2. Department of Physics, Southeast University, Nanjing 211189 (China)
  3. Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China)

We study the leading electroweak corrections in the precision measurement of the strange form factors. Specifically, we calculate the two-boson exchange (TBE), two-photon exchange (TPE) plus {gamma}Z exchange ({gamma}ZE), and corrections with {delta}(1232) excitation to the parity-violating asymmetry of the elastic electron-proton scattering. The interplay between nucleon and {delta} contributions is found to depend strongly on the kinematics, as {delta}{sub {delta}} begins as negligible at backward angles but becomes very large and negative and dominant at forward angles, while {delta}{sub N} always stays positive and decreases monotonically with increasing {epsilon}. The total TBE corrections to the extracted values of G{sub E}{sup s}+{beta}G{sub M}{sup s} in recent experiments of HAPPEX and G0 are, depending on kinematics, found to be large and range between 13% and -75%, but are found to be small in the case of A4 experiments.

OSTI ID:
21289898
Journal Information:
Physical Review. C, Nuclear Physics, Vol. 79, Issue 6; Other Information: DOI: 10.1103/PhysRevC.79.062501; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
Country of Publication:
United States
Language:
English