NLO and off-shell effects in top quark mass determinations

Abstract

We study the impact of different theoretical descriptions of top quark pair production on top quark mass measurements in the di-lepton channel. To this aim, the full NLO corrections to $pp\to W^{+}{W}^{-}b\bar{b}\to (e^{+}{\nu }_e)({\mu }^{-}{\bar{\nu }}_{\mu })b\bar{b}$ production are compared to calculations in the narrow width approximation, where the production of a top quark pair is calculated at NLO and combined with three different descriptions of the top quark decay: leading order, next-to-leading order and via a parton shower. The different theory predictions then enter the calibration of template fit functions, which are used for a fit to pseudo-data. The offsets in the top quark mass resulting from the fits based on the various theoretical descriptions are determined.

Comments: 39 pages, 25 figures, v3: version published in JHEP