Measurement of the Top-Quark Mass in All-Hadronic Decays in p pbar Collisions at CDF II

TL;DR

This paper reports a measurement of the top-quark mass in all-hadronic decay channels using proton-antiproton collision data from the CDF II detector, employing a likelihood method to analyze six-jet final states.

Contribution

It introduces a likelihood-based analysis for top-quark mass measurement in all-hadronic decays with detailed jet-parton assignment, improving precision over previous methods.

Findings

Measured top-quark mass: 177.1 ± 4.9 (stat) ± 4.7 (syst) GeV/c^2

Analyzed 290 events with a multi-jet trigger at 1.96 TeV

Utilized 90 jet-to-parton assignment possibilities per event

Abstract

We present a measurement of the top-quark mass, $M_{\mathrm{top}}$, in the all-hadronic decay channel $t\bar{t} \to W^+b W^- \bar{b} \to q_1\bar{q}_2 b q_3 \bar{q}_4 \bar{b}$. The analysis is performed using 310 pb$^{-1}$ of $\sqrt{s}$=1.96 TeV $p\bar{p}$ collisions collected with the CDF II detector using a multi-jet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value of $M_{\mathrm{top}}$=177.1 $\pm$ 4.9 (stat.) $\pm$ 4.7 (syst.) GeV/$c^2$.