Experimental HEP Seminar

Kaon Spectroscopy with B-Mesons

Hulya Guler

McGill University & Université de Montréal

I will show an analysis of the K⁺ π⁺ π^- final state in the decays B⁺ &rarr J/ψ K⁺ π⁺ π^- and B⁺ &rarr ψ^' K⁺ π⁺ π^- based on 535M B-meson pairs collected by the Belle detector at the KEKB e⁺e^- collider. To determine the resonant substructure of this final state, an amplitude analysis is performed in the three dimensions M²(K⁺ π⁺ π^-), M²(K⁺ π^-), and M²(π⁺ π^-). The K₁(1270) is found to be the dominant contribution in both J/ψ and ψ^' decay modes. Interference among the different intermediate states is significant and is particularly spectacular between the K⁺ ρ and K⁺ ω decay modes of the K₁(1270). An additional fit in which the mass and width of the K₁(1270) are floated provides an improved measurement of these quantities.