Invariant-mass distribution of top-quark pairs and top-quark mass determination

In this study, we investigate the invariant-mass distribution of top-quark pairs near the 2m(t)threshold, which strongly influences the determination of the top-quark massm(t). Higher-order non-relativistic corrections lead to large contributions, which are not included in the state-of-the-art theoretical predictions. A factorization formula is derived to resum such corrections to all orders in the strong-coupling, and necessary ingredients are calculated to perform the resummation at next-to-leading power. We combine the resummation with fixed-order results and present phenomenologically relevant numerical results. The resummation effect significantly increases 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 ofm(t)will lead to a value closer to the direct measurement result.