1 |
Tau candidates in all CMS tau identification algorithms are seeded by
|
2 |
reconstructed jets. After particle-flow reconstruction, particle candidates
|
3 |
are clustered into collections by the iterativeCone5 jet algorithm. The
|
4 |
efficiencies for jet seed reconstruction are described in~\cite{PFT08001} and are near
|
5 |
unity for both signal and background. Quality cuts (see
|
6 |
~\ref{table:pftau_q_cuts} are are then applied to the constituents in the jets.
|
7 |
The remaining particles are then considered a ``tau candidate.''
|
8 |
|
9 |
\begin{table}
|
10 |
\centering
|
11 |
\caption{Quality cuts on tau seed jet constituents}
|
12 |
\begin{tabular}{l r}
|
13 |
Particle flow charged hadron candidates & \\
|
14 |
\hline
|
15 |
Minimum transverse momentum & 0.5 GeV/$c$ \\
|
16 |
Minimum tracker hits & 3 \\
|
17 |
Maximum tracker $\chi^2$ & 100 \\
|
18 |
Maximum track transverse impact parameter & 0.03cm \\
|
19 |
\hline \hline
|
20 |
Particle flow gamma candidates & \\
|
21 |
\hline
|
22 |
Minimum transverse energy & 0.5 GeV \\
|
23 |
\end{tabular}
|
24 |
\end{table}
|
25 |
|
26 |
The constituents of tau candidate seed jets are then divided into two
|
27 |
collections, called ``signal'' and ``isolation'' collections as the method at
|
28 |
this stage is identical to the process for defining the isolation annulus.
|