Angular analysis of $B^0 \to K^\ast(892)^0 \ell^+ \ell^-$

摘要: We present a measurement of angular observables, P′4, P′5, P′6, P′8, in the decay B0→K∗(892)0ℓ+ℓ−, where ℓ+ℓ− is either e+e− or μ+μ−. The analysis is performed on a data sample corresponding to an integrated luminosity of 711 fb−1 containing 772×106 BB¯ pairs, collected at the Υ(4S) resonance with the Belle detector at the asymmetric-energy e+e− collider KEKB. Four angular observables, P′4,5,6,8 are extracted in five bins of the invariant mass squared of the lepton system, q2. We compare our results for P′4,5,6,8 with Standard Model predictions including the q2 region in which the LHCb collaboration reported the so-called P′5 anomaly.