Top mass shift resulting from the recalibration of flavor-dependent jet energy corrections in the D{\O} lepton+jets top mass measurement

TL;DR

This paper investigates how recalibrating flavor-dependent jet energy corrections impacts the top quark mass measurement at DØ, revealing shifts that suggest the need for re-evaluation of calibration procedures.

Contribution

It provides a detailed analysis of the effects of different $F_{Corr}$ calibrations on top mass results, highlighting potential biases in previous measurements.

Findings

Recalibration shifts top mass from 174.95 to 173.16 GeV with Pythia6.

Using Herwig7 calibration further shifts mass down to 171.84 GeV.

Results indicate the importance of re-reviewing jet energy correction procedures.

Abstract

We review the possible effects of the miscalibration of the flavor-dependent Jet Energy Corrections ($F_{\mathrm{Corr}}$) on the D{\O} lepton+jets top mass measurement. The work is based on a previous study, where the D{\O} $F_{\mathrm{Corr}}$ calibration procedure was repeated based on the release of the internal D{\O} notes after a 5-year moratorium. The cited study was motivated by the extraordinary precision claimed by D{\O} in their top mass measurement. Using a Pythia6-based $F_{\mathrm{Corr}}$ recalibration, the $m_t$ result was shifted from 174.95 to 173.16 GeV. Moreover, utilizing a Herwig7-based $F_{\mathrm{Corr}}$ calibration (not accounted for in D{\O} studies), a shift down to 171.84 GeV was observed. We find this both convincing and specific evidence for re-reviewing a part of the $F_{\mathrm{Corr}}$ calibration process. However, D{\O} has been unwilling to open such studies or to provide other convincing counter-evidence.