Towards a precise parton luminosity determination at the CERN LHC

A new approach to determine the Large Hadron Collider (LHC) luminosity is investigated. Instead of employing the proton-proton luminosity measurement, we suggest to measure directly the parton-parton luminosity. It is shown that the electron and muon pseudorapidity distributions, originating from the decay of ${W}^{+}$, ${W}^{\ensuremath{-}}$, and ${Z}^{0}$ bosons produced at 14 TeV $\mathrm{pp}$ collisions (CERN LHC), constrain the $x$ distributions of sea and valence quarks and antiquarks in the range from $\ensuremath{\approx}3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ to $\ensuremath{\approx}{10}^{\ensuremath{-}1}$ at a ${Q}^{2}$ of about ${10}^{4}$ GeV${}^{2}$. Furthermore, it is demonstrated that, once the quark and antiquark structure functions are constrained from the ${W}^{\ifmmode\pm\else\textpm\fi{}}$ and ${Z}^{0}$ production dynamics, other $q\overline{q}$ related scattering processes at the LHC such as $q\overline{q}\ensuremath{\rightarrow}{W}^{+}{W}^{\ensuremath{-}}$ can be predicted accurately. Thus, the lepton pseudorapidity distributions provide the key to a precise parton luminosity monitor at the LHC, with accuracies of $\ensuremath{\approx}\ifmmode\pm\else\textpm\fi{}1$% compared to the so far considered goal of $\ifmmode\pm\else\textpm\fi{}$5%.