The collection of a large number of B hadron decays to hadronic
final states at the CDF II detector is possible due to the presence of a
trigger that selects events based on track impact parameters. However,
the nature of the selection requirements of the trigger introduces a
large bias in the observed proper decay time distribution. A lifetime
measurement must correct for this bias and the conventional approach has
been to use a Monte Carlo simulation. The leading sources of systematic
uncertainty in the conventional approach are due to differences between
the data and the Monte Carlo simulation. In this paper we present an
analytic method for bias correction without using simulation, thereby
removing any uncertainty between data and simulation. This method is
presented in the form of a measurement of the lifetime of the B- using
the mode B- --> D0 pi+-. The B- lifetime is measured as tau_B- ñ.663
+/- 0.023 +/- 0.015 ps, where the first uncertainty is statistical and
the second systematic. This new method results in a smaller systematic
uncertainty in comparison to methods that use simulation to correct for
the trigger bias.
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Updated: Thursday, 2011 February 17 08:47:18 CST automatically from input from Carol Picciolo