scholarly journals Determination of the weak charge of the proton through parity violating asymmetry measurements in the elastic e+p scattering

2014 ◽  
Author(s):  
Adesh Subedi
Keyword(s):  
Weak Charge ◽  
Parity Violating Asymmetry

scholarly journals Determination of the Proton's Weak Charge and Its Constraints on the Standard Model

2019 ◽  
Vol 69 (1) ◽  
pp. 191-217 ◽  
Author(s):  
Roger D. Carlini ◽  
Willem T.H. van Oers ◽  
Mark L. Pitt ◽  
Gregory R. Smith
Keyword(s):  
Standard Model ◽  
Parity Violation ◽  
Valence Quark ◽  
Weak Mixing Angle ◽  
Weak Charge ◽  
Mixing Angle ◽  
The Standard Model ◽  
History Of ◽  
Bsm Physics

This article discusses some of the history of parity-violation experiments that culminated in the Qweak experiment, which provided the first determination of the proton's weak charge [Formula: see text]. The guiding principles necessary to the success of that experiment are outlined, followed by a brief description of the Qweak experiment. Several consistent methods used to determine [Formula: see text] from the asymmetry measured in the Qweak experiment are explained in detail. The weak mixing angle sin2θw determined from [Formula: see text] is compared with results from other experiments. A description of the procedure for using the [Formula: see text] result on the proton to set TeV-scale limits for new parity-violating semileptonic physics beyond the Standard Model (BSM) is presented. By also considering atomic parity-violation results on cesium, the article shows how this result can be generalized to set limits on BSM physics, which couples to any combination of valence quark flavors. Finally, the discovery space available to future weak-charge measurements is explored.

First Determination of the Proton's Weak Charge

2015 ◽  
Vol 8 (3) ◽  
Author(s):  
Shelley A. Page
Keyword(s):  
Standard Model ◽  
High Precision ◽  
Standard Model Prediction ◽  
Data Set ◽  
Weak Charge ◽  
Newport News ◽  
The Standard Model ◽  
First Results ◽  
First Time

The weak charge of the proton has been determined for the first time via a high precision electron-proton scattering experiment, Qweak, carried out at Jefferson Laboratory (JLab) in Newport News, USA. The weak charge is a basic property in subatomic physics, analogous to electric charge. The Standard Model makes a prediction for the weak charges of protons and other particles. First results described here are based on an initial 4% of the data set reported in 20131, with the ultimate goal of the experiment being a high precision Standard Model test conducted with the full Qweak data set. These initial results are consistent with the Standard Model prediction; they serve as an important first determination of the proton’s weak charge and a proof of principle that the ultimate goals are within reach.

scholarly journals ATOMIC PARITY VIOLATION: PRINCIPLES, RECENT RESULTS, PRESENT MOTIVATIONS

2005 ◽  
Vol 20 (06) ◽  
pp. 375-389 ◽  
Author(s):  
J. GUÉNA ◽  
M. LINTZ ◽  
M.-A. BOUCHIAT
Keyword(s):  
Parity Violation ◽  
Precision Measurement ◽  
Calibration Procedure ◽  
New Physics ◽  
Stimulated Emission ◽  
Atomic Parity Violation ◽  
Weak Charge ◽  
The Status ◽  
Left Right Asymmetry

We review the progress made in the determination of the weak charge, QW, of the cesium nucleus which raises the status of Atomic Parity Violation measurements to that of a precision electroweak test. Not only is it necessary to have a precision measurement of the electroweak asymmetry in the highly forbidden 6S–7S transition, but one also needs a precise calibration procedure. The 1999 precision measurement by the Boulder group implied a 2.5 σ deviation of QW from the theoretical prediction. This triggered many particle physicist suggestions as well as examination by atomic theoretical physicists of several sources of corrections. After about three years, the disagreement was removed without appealing to "New Physics". Concurrently, an original experimental approach was developed in our group for more than a decade. It is based on detection by stimulated emission with amplification of the left–right asymmetry. We present our decisive, recent progress together with our latest results. We emphasize the important impact for electroweak theory, of future measurements in cesium possibly pushed to the 0.1% level. Other possible approaches are currently explored in several atoms.

scholarly journals First Determination of the Weak Charge of the Proton

2013 ◽  
Vol 111 (14) ◽  
Author(s):  
D. Androic ◽  
D. S. Armstrong ◽  
A. Asaturyan ◽  
T. Averett ◽  
J. Balewski ◽  
...  
Keyword(s):  
Weak Charge
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