Measurement of the Effective Weak Mixing Angle in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} Events

Area of Science:

• High Energy Physics
• Particle Physics
• Standard Model Physics

Background:

• The weak mixing angle (sin²θeffℓ) is a fundamental parameter in the Standard Model, governing the interplay between weak and electromagnetic forces.
• Precise measurements of this angle test the Standard Model's validity and probe for new physics.

Purpose of the Study:

• To measure the effective weak mixing angle (sin²θeffℓ) with high precision.
• To utilize data from proton-antiproton collisions at the Fermilab Tevatron to achieve this measurement.

Main Methods:

• Analysis of Z/γ* → e+e- events collected by the D0 detector.
• Extraction of the weak mixing angle from the forward-backward charge asymmetry around the Z boson pole.
• Utilizing 9.7 fb⁻¹ of integrated luminosity at a center-of-mass energy of 1.96 TeV.

Main Results:

• The measured value of sin²θeffℓ = 0.23147 ± 0.00047.
• This represents the most precise measurement to date from light quark interactions.
• The precision achieved is comparable to the best results from LEP and SLD experiments.

Conclusions:

• The precise measurement of the weak mixing angle provides a stringent test of the Standard Model.
• The results are consistent with previous high-precision measurements, reinforcing the Standard Model's accuracy.
• This measurement contributes to the ongoing effort to understand the fundamental forces of nature.