2008/03/12 by Matthias Jamin, Antonio Pich, J. Portolés +1 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-ph
paper · pdf · doi:10.1016/j.physletb.2008.04.049
published as Phys.Lett.B664:78-83,2008 · 15 pages, 2 figures
arxiv created 2008/03/12 · openalex publication_date 2008/04/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/02
A theoretical description of the differential decay spectrum for the decay τ−→ντKSπ−, which is based on the contributing Kπ vector and scalar form factors F+Kπ(s) and F0Kπ(s) being calculated in the framework of resonance chiral theory (RχT), 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[τ−→ντKSπ−]=0.427±0.024% by integrating the spectrum, as well as the K∗ resonance parameters MK∗=895.3±0.2 MeV and ΓK∗=47.5±0.4 MeV, where the last two errors are statistical only. From our fits, we confirm that the scalar form factor F0Kπ(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+Kπ(s), we update the corresponding slope and curvature parameters λ+′=(25.2±0.3)×10−3 and λ+″=(12.9±0.3)×10−4, respectively.