Alec Aivazis edited results.tex  over 9 years ago

Commit id: f2762a81401740ad56cc0be5fd8abfa6a0d7d6b5

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Since the mass of the decaying super symmetric top is unknown, many such analyses were performed assuming a different $m_\mathrm{stop}$ in order calculate a potential regime in which the data allows for a decay of the signature discussed in section \ref{sect:introduction}. For a summary of the total number of events predicted that match the signature for a particular $m_\mathrm{stop}$ see table \ref{table:nEvents} and a visualization of this data can be seen in figure \ref{fig:nEvents}.  Apart from raw event count, a plot of the average mass vs the difference in mass between the lepton/jet pair for each event provides a nice picture of the various final states present in the sample. The spread in $\Delta$M provides an graphical representation for the amount by which the two particles came from the same parent and the spread in $$ provides an understanding for the mass of the parent particle. As you can see in figure \ref{fig:money}, the data (left) shows that most events came from Z-bosons like the $dy$ process discussed in \ref{sect:backgrounds} \ref{sect:background}  as evident by the large collection of points centered around 90-100 GeV. Comparing this to a few of the same plots with only signal Monte Carlo (right), the data plot does not seem to contain a substaintial number of events that match our signature in any of the mass regions. From table \ref{table:nEvents}, there is a $m_\mathrm{stop}$ where the data could contain enough events that match the target signature to count as evidence for the target decay. In order to investigate this, upper limit on the cross section was calculated based on the number of events in each signal region. This plot was overlayed with the cross section used during signal simulation and a cut-off point is extracted. See fig \ref{fig:brazil} for more information. From this, a lower limit on the mass of the supersymmetric top is set to around 750 GeV.