Combination of ttbar cross section measurements and constraints on the mass of the top quark and its decays into charged Higgs bosons

TL;DR

This paper combines top quark pair production measurements to refine the top quark mass estimate and set limits on charged Higgs boson decays, providing insights into potential new physics beyond the Standard Model.

Contribution

It presents a combined analysis of multiple top quark cross section measurements to improve the top quark mass determination and constrain charged Higgs boson decay modes.

Findings

Measured ttbar cross section at 8.18 pb for 170 GeV top mass.

Set upper limits on charged Higgs decay branching fractions.

Estimated top quark mass from combined cross section data.

Abstract

We combine measurements of the top quark pair production cross section in ppbar collisions in the l+jets, ll and tau-l final states (where l is an electron or muon) at a center of mass energy of sqrt(s)=1.96 TeV in 1fb^{-1} of data collected with the D0 detector. For a top quark mass of 170 GeV, we obtain sigma_ttbar=8.18^{+0.98}_{-0.87} pb. In addition, the ratios of ttbar cross sections in different final states are used to set upper limits on the branching fractions B(t -> H^{+}b -> tau nu b) and B(t -> H^{+}b -> c sbar b) as a function of charged Higgs boson mass. Based on predictions from higher order quantum chromodynamics, we extract a mass for the top quark from the combined ttbar cross section.