We propose a new method to measure a theoretically well-defined top quark
mass at the LHC. This method is based on the "weight function method," which we
proposed in our preceding paper. It requires only lepton energy distribution
and is basically independent of the production process of the top quark. We
perform a simulation analysis of the top quark mass reconstruction with
ttĖ pair production and lepton+jets decay channel at the leading order.
The estimated statistical error of the top quark mass is about 0.4 GeV with
an integrated luminosity of 100 fbā1 at sā=14 TeV. We also
estimate some of the major systematic uncertainties and find that they are
under good control.Comment: 8 pages, 7 figures, version to appear in PL