We present a measurement of the charge-parity (CP) violating parameters in B0→π+π- decays. The results are obtained from the final data sample containing 772×106 BB̄ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain the CP violation parameters ACP(B0→π+π-)=+0.33±0.06(stat)±0.03(syst),SCP(B0→π+π-)=-0.64±0.08(stat)±0.03(syst),where ACP and SCP represent the direct and mixing-induced CP asymmetries in B0→π+π- decays, respectively. Using an isospin analysis including results from other Belle measurements, we find 23.8 <φ2<66.8 is disfavored at the 1σ level, where φ2 is one of the three interior angles of the Cabibbo-Kobayashi-Maskawa unitarity triangle related to Bu,d decays.
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - 19 Nov 2013|