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 — preprints:2006:ttp06-01 [2016/03/17 11:03] (current) Line 1: Line 1: + ====== TTP06-01 Tau-Decays to Five Mesons in TAUOLA ====== + + + <​hidden TTP06-01 ​ Tau-Decays to Five Mesons in TAUOLA > The $\tau$-decay library TAUOLA has gained popularity over the last decade. + ​However,​ with the continuously increasing precision of the data, some of its + ​functionality has become insufficient. + One of the requirements is the implementation of decays + into five mesons plus a neutrino with a realistic decay amplitude. This note + ​describes a step into this direction. + For the $2\pi^-\pi^+2\pi^0$ mode the three decay chains + ​$\tau^- \to a_1^- \nu \to + ​\rho^-(\to \pi^-\pi^0) \omega (\to \pi^-\pi^+\pi^0) ​ \nu$, + ​$\tau^- \to a_1^- \nu \to + ​a_1^-(\to 2\pi^-\pi^+) f_0 (\to 2\pi^0) ​ \nu$, and + ​$\tau^- \to a_1^- \nu \to + ​a_1^-(\to \pi^-2\pi^0) f_0 (\to \pi^+\pi-) ​ \nu$ are introduced + with simple assumptions about the couplings and propagators of the + ​various resonances. Similar amplitudes (without the + ​$\rho\omega$ contributions) are adopted for the $\pi^-4\pi^0$ + and $3\pi^-2\pi^+$ modes. + + The five-pion amplitude is thus based on a simple model, + ​which,​ however, can be considered as a first realistic ​ example. + ​Phase-space generation includes the possibility of + ​presampling the $\omega$ and $a_1$ resonances, in one channel only, however. + This is probably sufficient for the time being, both for physics applications + and for tests. + + The technical test of the new part of the generator + is performed by  comparing Monte Carlo and analytical results. + To this end a non-realistic,​ but easy to calculate,​ + ​purely scalar amplitude for the decay into five massless pions was used. + ​ + |**Johann H. Kuehn and Z. Was**  | + |**  Acta Phys.Polon. ​ B39 147-158 2008  **  | + | {{preprints:​2006:​ttp06-01.pdf|PDF}} {{preprints:​2006:​ttp06-01.ps|PostScript}} [[http://​arxiv.org/​abs/​hep-ph/​0602162|arXiv]] ​  | + | |