Joint Institute for Nuclear Research, Dubna 141980, Russia.
University of Oklahoma, Norman, Oklahoma 73019, USA.
Phys Rev Lett. 2018 Jun 15;120(24):241802. doi: 10.1103/PhysRevLett.120.241802.
We present a measurement of the effective weak mixing angle parameter sin^{2}θ_{eff}^{ℓ} in pp[over ¯]→Z/γ^{}→μ^{+}μ^{-} events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at the Fermilab Tevatron Collider and corresponding to 8.6 fb^{-1} of integrated luminosity. The measured value of sin^{2}θ_{eff}^{ℓ}[μμ]=0.23016±0.00064 is further combined with the result from the D0 measurement in pp[over ¯]→Z/γ^{}→e^{+}e^{-} events, resulting in sin^{2}θ_{eff}^{ℓ}[comb]=0.23095±0.00040. This combined result is the most precise measurement from a single experiment at a hadron collider and is the most precise determination using the coupling of the Z/γ^{*} to light quarks.
我们展示了在费米实验室 Tevatron 对撞机上的 D0 探测器收集的质心能量为 1.96 TeV 的 pp[over ¯]→Z/γ^{}→μ^{+}μ^{-}事件中，有效弱混合角参数 sin^{2}θ_{eff}^{ℓ}的测量结果，该数据集对应的积分亮度为 8.6 fb^{-1}。测量得到的 sin^{2}θ_{eff}^{ℓ}[μμ] 值为 0.23016±0.00064，并与 D0 在 pp[over ¯]→Z/γ^{}→e^{+}e^{-}事件中的测量结果进行了组合，得到 sin^{2}θ_{eff}^{ℓ}[comb] 值为 0.23095±0.00040。这一组合结果是强子对撞机单次实验中最精确的测量结果，也是利用 Z/γ^{*}与轻夸克的耦合得到的最精确的结果。
