We present a measurement of the top quark mass in the
all-hadronic channel (tt-bar --> bb-bar q_1 q-bar_2 q_3 q-bar_4)
using 943 pb-1 of pp-bar collisions at s**(1/2) ñ.96 TeV collected at
the CDF II detector at Fermilab (CDF). We apply the standard model
production and decay matrix-element (ME) to tt-bar candidate events.
We calculate per-event probability densities according to the ME
calculation and construct template models of signal and background.
The scale of the jet energy is calibrated using additional templates
formed with the invariant mass of pairs of jets. These templates form an
overall likelihood function that depends on the top quark mass and on the
jet energy scale (JES). We estimate both by maximizing this function.
Given 72 observed events, we measure a top quark mass of 171.1 +/- 3.7
(stat. + JES) +/- 2.1 (syst.) GeV/c2. The combined uncertainty on the
top quark mass is 4.3 GeV/c2.
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Updated: Tuesday, 2009 June 30 11:59:11 CDT automatically from input from carol picciolo