Invariant-mass distribution of top-quark pairs and top-quark mass determination
Abstract
We investigate the invariant-mass distribution of top-quark pairs near the 2mt threshold, which has strong impact on the determination of the top-quark mass mt. We show that higher-order non-relativistic corrections lead to large contributions which are not included in the state-of-the-art theoretical predictions. We derive a factorization formula to resum such corrections to all orders in the strong-coupling, and calculate necessary ingredients to perform the resummation at next-to-leading power. We combine the resummation with fixed-order results and present phenomenologically relevant numeric results. We find that the resummation effect significantly enhances the differential cross section in the threshold region, and makes the theoretical prediction more compatible with experimental data. We estimate that using our prediction in the determination of mt will lead to a value closer to the result of direct measurement.