sin2ϕ1 MEASUREMENT IN b -> {cbar {c}s} MODES FROM BELLE

An angular analysis for B decays into two vector mesons gives parameters that are sensitive to new physics. They are the decay amplitudes of the three helicity states, the asymmetry in the triple product, and the CP violating parameters. In this paper, we present measurements of these quantities for the decay of B⁰ → J/ψK*⁰ based on a 275 × 10⁶Bbar {B} pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e⁺e^- collider.