2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/113637We report first observations of the decays B- to Ds(*)+ K- pi-, using 292 fb^-1 of data collected at Upsilon(4S) resonance energy by the BaBar detector at the PEP II e+ e- collider. The branching fractions are measured to be B(B- to Ds+ K- pi-) = (1.88 +- 0.13 +- 0.41) x 10^-4 and B(B- to Ds*+ K- pi-) = (1.84 +- 0.19 +- 0.40) X 10^-4.Submitted to the 33rd International Conference on High-Energy Physics, ICHEP 06, 26 July - 2 August 2006, Moscow, RussiaHigh Energy Physics - Experimenttext