Measurements of the Branching Fraction and CP-Violation Asymmetries in B0→f0(980)KS0

We present measurements of the branching fraction and CP-violating asymmetries in the decay B0→f0(980)KS0. The results are obtained from a data sample of 123×106 Υ(4S)→BB̅ decays. From a time-dependent maximum likelihood fit, we measure the branching fraction B(B0→f0(980)(→π+π-)K0)=(6.0±0.9±0.6±1.2)×10-6, the mixing-induced CP violation parameter S=-1.62-0.51+0.56±0.09±0.04, and the direct CP violation parameter C=0.27±0.36±0.10±0.07, where the first errors are statistical, the second systematic, and the third due to model uncertainties. We measure the f0(980) mass and width to be mf0(980)=(980.6±4.1±0.5±4.0)   MeV/c2 and Γf0(980)=(43-9+12±3±9)   MeV/c2, respectively.