Measuring the Weak Charge of the Proton via Elastic Electron-Proton Scattering

Jones, Donald C.

doi:10.2172/1227207

Title: Measuring the Weak Charge of the Proton via Elastic Electron-Proton Scattering

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Abstract

The Qweak experiment which ran in Hall C at Jefferson Lab in Newport News, VA, and completed data taking in May 2012, measured the weak charge of the proton Q^p_W via elastic electron-proton scattering. Longitudinally polarized electrons were scattered from an unpolarized liquid hydrogen target. The helicity of the electron beam was flipped at approximately 1 kHz between left and right spin states. The Standard Model predicts a small parity-violating asymmetry of scattering rates between right and left helicity states due to the weak interaction. An initial result using 4% of the data was published in October 2013 [1] with a measured parity-violating asymmetry of -279 ± 35(stat) ± 31 (syst) ppb. This asymmetry, along with other data from parity-violating electron scattering experiments, provided the world's first determination of the weak charge of the proton. The weak charge of the proton was found to be ^p_W = 0.064 ± 0.012, in good agreement with the Standard Model prediction of ^p_W(SM) = 0.0708 ± 0.0003[2].

Authors:

Jones, Donald C. ^[1]

Univ. of Virginia, Charlottesville, VA (United States)

Publication Date:: Thu Oct 01 00:00:00 EDT 2015

Research Org.:: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Nuclear Physics (NP)

OSTI Identifier:: 1227207

Report Number(s):: JLAB-PHY-15-2175; DOE/OR/23177-3612

DOE Contract Number:: AC05-06OR23177

Resource Type:: Thesis/Dissertation

Country of Publication:: United States

Language:: English

Subject:: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats


                    Jones, Donald C. Measuring the Weak Charge of the Proton via Elastic Electron-Proton Scattering.  United States: N. p., 2015. 
        Web.  doi:10.2172/1227207.

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                    Jones, Donald C. Measuring the Weak Charge of the Proton via Elastic Electron-Proton Scattering.  United States.  https://doi.org/10.2172/1227207

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                    Jones, Donald C. 2015.  
        "Measuring the Weak Charge of the Proton via Elastic Electron-Proton Scattering".  United States.  https://doi.org/10.2172/1227207.  https://www.osti.gov/servlets/purl/1227207.

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@article{osti_1227207,

  title        = {Measuring the Weak Charge of the Proton via Elastic Electron-Proton Scattering},

  author       = {Jones, Donald C.},

  abstractNote = {The Qweak experiment which ran in Hall C at Jefferson Lab in Newport News, VA, and completed data taking in May 2012, measured the weak charge of the proton QpW via elastic electron-proton scattering. Longitudinally polarized electrons were scattered from an unpolarized liquid hydrogen target. The helicity of the electron beam was flipped at approximately 1 kHz between left and right spin states. The Standard Model predicts a small parity-violating asymmetry of scattering rates between right and left helicity states due to the weak interaction. An initial result using 4% of the data was published in October 2013 [1] with a measured parity-violating asymmetry of -279 ± 35(stat) ± 31 (syst) ppb. This asymmetry, along with other data from parity-violating electron scattering experiments, provided the world's first determination of the weak charge of the proton. The weak charge of the proton was found to be pW = 0.064 ± 0.012, in good agreement with the Standard Model prediction of pW(SM) = 0.0708 ± 0.0003[2].},

  doi          = {10.2172/1227207},

  url          = {https://www.osti.gov/biblio/1227207},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {Thu Oct 01 00:00:00 EDT 2015},

  month        = {Thu Oct 01 00:00:00 EDT 2015}

}

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