Measurement ofsin2θeffleptusinge+e−pairs from

Abstract

Measurement of sin 2 θ lept eff using e þ e − pairs from γ Ã =Z bosons produced in pp collisions at a center-of-momentum energy of 1.96 TeV At the Fermilab Tevatron proton-antiproton (pp) collider, Drell-Yan lepton pairs are produced in the process pp → e þ e − þ X through an intermediate γ Ã =Z boson. The forward-backward asymmetry in the polar-angle distribution of the e − as a function of the e þ e − -pair mass is used to obtain sin 2 θ lept eff , the effective leptonic determination of the electroweak-mixing parameter sin 2 θ W . The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to 9.4 fb −1 of integrated luminosity from pp collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of sin 2 θ lept eff is found to be 0.23248 AE 0.00053. The combination with the previous CDF measurement based * Deceased.

Measurement of the weak mixing angle using the forward–backward asymmetry of Drell–Yan events in $$\mathrm {p}\mathrm {p}$$ p p collisions at 8 $$\,\text {TeV}$$ TeV

“…There is, however, a known discrepancy of about 3 standard deviations between the two most precise values. Other measurements of sin 2 θ eff have also been reported by the Tevatron and LHC experiments [5][6][7][8][9][10][11][12][13][14][15].…”

Study of weak corrections to Drell-Yan, top-quark pair, and dijet production at high energies with MCFM

“…This observable is sensitive to the weak mixing angle and, in the vicinity of the Z resonance where the number of events is very high, precision measurements of this quantity have been made both at the Tevatron [126,127] and the LHC [128][129][130]. However, it is also interesting to study this observable far from the resonance region.…”

Electroweak physics at the LHC

“…) at highy | | are therefore intrinsically more sensitive to the undiluted value and have smaller theory uncertainties related to PDFs. In proton-anti-proton collisions, valence quark/ valence anti-quark annihilation predominates, and so dilution and its associated uncertainties are vastly reduced, making the Tevatron experimental measurements [82][83][84] . In the last case the forward electron is identified with calorimeters alone, still the resulting pairs have a signal purity at the Z pole of 95%.…”

“…A comparison of experimental measurements of q sin W 2 eff [82] is shown in figure 21. The best single measurements from the Tevatron are more than twice as precise as the best measurements from the LHC, and the separate A b FB 0, and A l results from +e e collisions are more than four times as precise.…”