Measurement of the Neutral Weak Form Factors of the Proton
HAPPEX Collaboration, K. A. Aniol
Abstract
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The kinematic point (thetalab = 12.3 degrees and Q2=0.48 (GeV/c)2) is chosen to provide sensitivity, at a level that is of theoretical interest, to the strange electric form factor GEs. The result, A=-14.5 +- 2.2 ppm, is consistent with the electroweak Standard Model and no additional contributions from strange quarks. In particular, the measurement implies GEs + 0.39GMs = 0.023 +- 0.034 (stat) +- 0.022 (syst) +- 0.026 (delta GEn), where the last uncertainty arises from the estimated uncertainty in the neutron electric form factor.
Create a lesson
Related papers
Direct measurement of the in-medium η mass spectrum through the γγ decay channel
Y. Matsumura, N. Muramatsu, T. A. Hashimoto et al.
STAR Highlights II: Study of Small Systems and the Search for New, Exotic Physics
Jiangyong Jia
Cluster emission and its impact on the r-process nucleosynthesis
Natalia Thomas, Silvia Bara, Thomas Elias Cocolios et al.
Core Breaking at Low Spin in 68Zn from Nuclear Resonance Fluorescence
S. R. Johnson, R. V. F. Janssens, B. A. Brown et al.
Isoscalar Giant Resonances in the even-A Pd Isotopes
J. Arroyo, U. Garg, T. Furuno et al.
Efficient production of 229m,gTh via neutron capture in VUV-transparent crystals
Zhong-yi Chen, Hao-yang Lan, Di Wu et al.