| We present a measurement of the Cabibbo-Kobayashi-Maskawa CP -violating phase gamma with a Dalitz analysis of neutral D-meson decays to the K0S pi+pi- final state occurring in B+/- → D(*) K+/- decays. The data sample consists of 347 million e+e - → Upsilon(4S) → BB events collected by the BABAR detector at the Stanford Linear Accelerator Center's PEP-II asymmetric-energy e+ e- collider. We measure gamma = (92+/-41+/-11+/-12)°, where the first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the Dalitz model uncertainty. For the ratios r*B of the magnitudes of the amplitudes A (B- → D (*)0K-) and A (B- → D -(*)0K-) we obtain the one standard deviation intervals [0; 0.14] and [0.02; 0.20], respectively. We also present a study of the Dalitz plot in the decay D 0 → K0S pi+pi- using approximately 250000 events collected by the BABAR detector. We characterize the S-wave (spin-0) component of the pi+pi- system using the K-matrix formalism, which is needed to describe the broad overlapping resonance structure in this decay. The results are compared and discussed with the traditional two-body (isobar) model, which is used in the determination of the CKM angle gamma from charged B decays. |
