deletions | additions       diff --git a/section_Week_4_5_During__.tex b/section_Week_4_5_During__.tex  index e7b3501..4c3152a 100644  --- a/section_Week_4_5_During__.tex  +++ b/section_Week_4_5_During__.tex 
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\begin{itemize}  \item For each track, calculate the IP and its significance by dividing the IP by the resolution signif = $\frac{IP}{\sigma} $  \item For each track calculate the "track probability", that is the probability that if the track comes from a zero-lifetime hadron (that means that the IP value is entirely due to the experimental resolution) I measured an IP (hence a significance) that is equal or larger than what I actually measured. We expect this distribution to be flat between 0 and 1 for tracks coming from zero-lifetime hadrons and to be peaked at 0 for tracks containing lifetime.  \item Put some quality cuts on the tracks: requiring for instance to be good measured tracks or IP not too large to avoid long lifetime particles like K0.  \item After this selection calculate the combine probability of a set of tracks (basically a jet), that is the probability that, if the jet doesn't contain lifetime, I observed a set of track probabilities that are equal or larger than those I have actually measured. \\  It is expected that the distribution of this variable is almost flat for light quarks jets (only almost because of the presence of V0 particles, like K0, $\Lambda$ and so on which actually contain lifetime) and that is squezed at 0 for c and b jets.  \item This probability is a tag for the jet, and giving a cut purity and efficiency of the selected sample could be study.  \end{itemize}