2024-03-29T11:06:15Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/36362016-02-16T02:28:36Zcom_10261_61com_10261_4col_10261_314
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Jamin, Matthias
author
Pich, Antonio
author
Portolés, Jorge
author
2008-06-12
A theoretical description of the differential decay spectrum for the decay tau- -> nu_tau K_S pi-, which is based on the contributing K pi vector and scalar form factors F_+^{K pi}(s) and F_0^{K pi}(s) being calculated in the framework of resonance chiral theory (R$\chi$T), additionally imposing constraints from dispersion relations as well as short distance QCD, provides a good representation of a recent measurement of the spectrum by the Belle collaboration. Our fit allows to deduce the total branching fraction B[tau- -> nu_tau K_S pi-] = 0.427 ± 0.024 % by integrating the spectrum, as well as the K^* resonance parameters M_{K^*} = 895.3 ± 0.2 MeV and Gamma_{K^*} = 47.5 ± 0.4 MeV, where the last two errors are statistical only. From our fits, we confirm that the scalar form factor F_0^{K pi}(s) is required to provide a good description, but we were unable to further constrain this contribution. Finally, from our results for the vector form factor F_+^{K pi}(s), we update the corresponding slope and curvature parameters lambda'_+ = (25.2 ± 0.3)*10^{-3} and lambda''_+ = (12.9 ± 0.3)*10^{-4}, respectively.
Physics Letters B 664(1-2): 78-83 (2008)
http://hdl.handle.net/10261/3636
10.1016/j.physletb.2008.04.049
Decays of taus
Chiral symmetries
Dispersion relations
What can be learned from the Belle spectrum for the decay - tau- ---> nu(tau) K(S) pi-