2 The CDF Experiment at Fermilab Contents - Harvard University ...

58 Section 2: CDF Physics Analysis
Figure 28: Best t E/p distribution for W events. Top left and right: Best t E/p distribution
for Monte Carlo (histogram) with data overlayed (crosses), on a linear and log scale. Bottom:
the residuals of the top plot, data minus Monte Carlo. The errors on the bottom points
are the statistical errors associated with the data. Summing the squares over the points
divided by their errors gives 2 =dof = 1:15. The tracking resolution for the Monte Carlo
has (1=P T )=:00085 GeV ,1 . For 8% of the events, however, we use a second resolution of
(1=P T ) = :0026 GeV ,1 . This second resolution is needed to account for the low-end E/p
tail.