Speaker
Description
We propose a new method for measuring the top-quark width based on the on-/off-shell ratio of b-charge asymmetry in pp>Wbj production at the LHC. The charge asymmetry removes virtually all backgrounds and related uncertainties, while remaining systematic and theoretical uncertainties can be taken under control by the ratio of cross sections. Limited only by statistical errors, we find that our approach leads to good precision at high integrated luminosity, at about a few hundred MeV at HL-LHC. This approach directly probes the total width, in such a way that model-dependence can be minimized. It is complementary to existing cross section measurements which always leave a degeneracy between the total rate and the branching ratio, and provides valuable information about the properties of the top quark. The proposal opens up new opportunities for precision top measurements using a b-charge identification algorithm.
