/\b Lifetime in /\b → /\c π Decays

This web page summarizes the results for the measurement of the /\b Lifetime in /\b → /\c π, based on a 1070 ± 60 pb-1 sample of data, collected using the CDF two displaced track trigger. It was approved by the CDF B group on 07/3/2008.
On April 16, 2009 the analysis was reblessed with the following changes:
  • The SVT modelling systematic uncertainty was updated using larger data samples which include all the run periods used in the /\b lifetime analysis. The resulting systematic uncertainty changed from 8.8 μm to 10.6 μm.
  • A small coding bug in the lifetime fit PDF was corrected which shifted the lifetime value from 422.8 μm to 420.1 μm.

The analysis employs a 2-step fit, first a binned fit of the /\b mass and second an unbinned maximum likelihood 2D fit of the decay length and its error distributions to extract the /\b lifetime. We measure

cτ(/\b) = 420.1 ± 13.7(stat.) ± 10.6 (syst.) μm

Using our measurement of the /\b lifetime and the PDG 2007 world average B0 lifetime, we obtain

&tau(/\b)/&tau(B0) = 0.916 ± 0.038

A more detailed summary of the results can be found here: PDF.

[/\b Decay Length Projection]

[Comparison with Other Experiments]

EPS and GIF Figures for Download: