Angular analysis of B → Ke+e- in the low- q2 region with new electron identification at Belle

We perform an angular analysis of the B → K*e+e- decay for the dielectron mass squared, q2 , range of 0.0008–1.1200 GeV2/c4 using the full Belle dataset in the K*0 → K+π- and K*+ → KS0π+ channels, incorporating new methods of electron identification to improve the statistical power of the dataset. This analysis is sensitive to contributions from right-handed currents from physics beyond the Standard Model by constraining the Wilson coefficients C 7 ( ′ ) . We perform a fit to the B → K*e+e- differential decay rate and measure the imaginary component of the transversality amplitude to be ATIm=-1.27±0.52±0.12 , and the K* transverse asymmetry to be AT ( 2 ) =0.52±0.53±0.11 , with FL and ATRe fixed to the Standard Model values. The resulting constraints on the value of C 7′ are consistent with the Standard Model within a 2σ confidence interval.