A Search for New Physics at the TeV Scale Via a Precise Measurement of the Weak Mixing Angle in Moller Scattering

This dissertation reports on a precise measurement of the parity-violating asymmetry in electron-electron (Moeller) scattering at a four-momentum transfer Q2 = 0.03 (GeV/c)2. The observed parity-violating asymmetry is APV = -128 ± 14 (stat.) ± 12 (syst.) x 10-9. This is the most precise asymmetry ever measured in a parity-violating electron scattering. In the context of the Standard Model, the APV result determines the weak mixing angle, which is one of the fundamental parameters of the model. The result is sin2 θWeff = 0.2403 ± 0.0014, which is consistent with the Standard Model expectation at the current level of precision. The comparison between this measurement of the weak mixing angle at low Q2 and at the Z0 pole establishes the running of sin2 θW with 6.5σ significance. In addition, they report on the first observation of a transverse asymmetry in electron-electron scattering. The observed asymmetry is ATMoeller = 2.7 x 10-6, which is consistent with the theoretical predictions. They also provide a new measurement of the transverse asymmetry in ep scattering ATep = 2 x 10-6. The consistency of the result with the theoretical prediction provides new limits on the TeV scale physics. A limit of 0.9 TeV was set on the mass of the extra Z' boson in the SO(10) Model. A limit of 14 TeV and 6 TeV was set on the compositeness scales Λee+ and Λee-, respectively. Finally a limit of 0.2 TeV was set on ratio of the doubly-charged Higgs mass to the eeΔ coupling geeδ2/mδ2