Measurements of the Top Anti-Top Cross Section and the Top Quark Mass in the Hadronic tau + Jets Decay Channel at CDF

TL;DR

This paper reports the first measurement of the top-antitop cross section and top quark mass in the hadronic tau plus jets decay channel using data from the CDF experiment, employing likelihood methods for extraction.

Contribution

It introduces the first exclusive analysis of ttbar decays involving hadronic tau and jets, providing new measurements in this decay channel.

Findings

Measured ttbar cross section in tau+jets channel

Determined top quark mass using likelihood fit

Demonstrated feasibility of tau+jets channel analysis

Abstract

We present the first exclusive observation of the ttbar to hadronic tau + jets decay channel. Using these events from 1.96 TeV ppbar collisions at CDF, we measure the ttbar cross section as well as the top quark mass. Events require a single hadronic tau, large missing transverse energy, and exactly 4 jets of which at least one must be tagged as a b jet. The cross section measurement is extracted from a Poisson likelihood function based on the observed number of events and the predicted number of signal and background events for a given ttbar cross section. The mass is extracted from a likelihood fit based on per-event probabilities calculated from leading-order signal (ttbar) and background (W+jets) matrix elements.