Hadronic tau identification with track based approach: the $Z \to \tau\tau, W \to \tau\nu$ and dijet events from DC1 data samples

In this note we discuss algorithm for reconstruction and identification of true and fake hadronic $\tau$'s. Track-based approach is proposed to define a seed of reconstructed objects and energy-flow is used to define its energy scale. The single-prong and three-prong modes are discussed separately. Results are presented for the $q \bar q \to Z \to \tau \tau$, $q \bar q \to W \to \tau \nu$ and $gg, gq, q \bar q \to gg, gq, q \bar q$ events from DC1 data samples. It is shown, that proposed algorithm leads to very clean signal samples of low background for reconstructed candidates. Background suppression of identification selection is then rather moderate. Discussion is limited to the barrel region ($|\eta| < 1.5$) and is based on the DC1 events simulated without pile-up and electronic noise.