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*+→K0Sπ+ 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 A^Im_T=−1.27±0.52±0.12, and the K* transverse asymmetry to be A^(2)_T=0.52±0.53±0.11, with FL and A^Re_T 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.
Angular analysis of B→K*e+e- in the low-q2 region with new electron identification at Belle
Tenchini, F.;
2024-01-01
Abstract
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*+→K0Sπ+ 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 A^Im_T=−1.27±0.52±0.12, and the K* transverse asymmetry to be A^(2)_T=0.52±0.53±0.11, with FL and A^Re_T 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.