Study of the K+ pi+ pi- Final State in B+ -> J/psi K+ pi+ pi- and B+ -> psi-prime K+ pi+ pi-

Understand

Using 535 x 10^6 B-meson pairs collected by the Belle detector at the KEKB e+ e- collider, we measure branching fractions of (7.16 +/- 0.10(stat) +/- 0.60(syst)) x 10^-4 for B+ -> J/psi K+ pi+ pi- and (4.31 +/- 0.20(stat) +/- 0.50(syst)) x 10^-4 for B+ -> psi-prime K+ pi+ pi-.

• We perform amplitude analyses to determine the resonant structure of the K+ pi+ pi- final state in B+ -> J/psi K+ pi+ pi- and B+ -> psi-prime K+ pi+ pi- and find that the K_1(1270) is a prominent component of both decay modes.
• There is significant interference among the different intermediate states, which leads, in particular, to a striking distortion of the rho line shape due to the omega.
• Based on the results of the fit to the B+ -> J/psi K+ pi+ pi- data, the relative decay fractions of the K_1(1270) to K rho, K omega, and K^*(892) pi are consistent with previous measurements, but the decay fraction to K_0^*(1430) is significantly smaller.