A simple event weighting technique for optimizing the measurement of the forward-backward asymmetry of Drell-Yan dilepton pairs at hadron colliders

Understand

We describe a simple technique for optimizing the extraction of the forward-backward asymmetry ($A_{fb}$) of Drell-Yan lepton pairs ($e^+e^-$,$ \mu^+\mu^-$) produced in $\bar{p}p$ and $pp$ collisions at hadron colliders.

• The method employs simple event weights which are functions of the rapidity and $cos\theta$ decay angle of the lepton pair.
• It yields the best estimate of the acceptance corrected parton level ($\bar{q}q$) forward backward asymmetry as a function of final state dilepton mass ($M_{\ell\ell}$).
• Typically, when compared to the simple count method, the technique reduces the statistical errors by 20% for $\bar{p}p$, and 40% for $pp$ collisions, respectively.