Amplitude Analysis of the Decay B 0 → KS0 π+π- and First Observation of the CP Asymmetry in B 0 →k∗ (892)-π+

Abstract

The time-integrated untagged Dalitz plot of the three-body hadronic charmless decay B0→KS0π+π- is studied using a pp collision data sample recorded with the LHCb detector, corresponding to an integrated luminosity of 3.0 fb-1. The decay amplitude is described with an isobar model. Relative contributions of the isobar amplitudes to the B0→KS0π+π- decay branching fraction and CP asymmetries of the flavor-specific amplitudes are measured. The CP asymmetry between the conjugate B0→K∗(892)-π+ and B0→K∗(892)+π- decay rates is determined to be -0.308±0.062.