We report measurements of the branching fractions and direct CP asymmetries of the decays B0→K+π−, B+→K+π0, B+→K0π+, and B0→K0π0, and use these for testing the standard model through an isospin-based sum rule. In addition, we measure the branching fraction and direct CP asymmetry of the decay B+→π+π0 and the branching fraction of the decay B0→π+π−. The data are collected with the belle II detector from e+e− collisions at the Υ(4S) resonance produced by the SuperKEKB asymmetric-energy collider and contain 387×10^6 bottom-antibottom meson pairs. Signal yields are determined in two-dimensional fits to background-discriminating variables, and range from 500 to 3900 decays, depending on the channel. We obtain −0.03±0.13±0.04 for the sum rule in agreement with the standard model expectation of zero and with a precision comparable to the best existing determinations.
Measurement of branching fractions and direct CP asymmetries for B→Kπ and B→ππ decays at Belle II
Bettarini, S.;Casarosa, G.;Corona, L.;Forti, F.;Massaccesi, L.;Mondal, S.;Moneta, S.;Paladino, A.;Paoloni, E.;Rizzo, G.;Tenchini, F.;Zani, L.;
2024-01-01
Abstract
We report measurements of the branching fractions and direct CP asymmetries of the decays B0→K+π−, B+→K+π0, B+→K0π+, and B0→K0π0, and use these for testing the standard model through an isospin-based sum rule. In addition, we measure the branching fraction and direct CP asymmetry of the decay B+→π+π0 and the branching fraction of the decay B0→π+π−. The data are collected with the belle II detector from e+e− collisions at the Υ(4S) resonance produced by the SuperKEKB asymmetric-energy collider and contain 387×10^6 bottom-antibottom meson pairs. Signal yields are determined in two-dimensional fits to background-discriminating variables, and range from 500 to 3900 decays, depending on the channel. We obtain −0.03±0.13±0.04 for the sum rule in agreement with the standard model expectation of zero and with a precision comparable to the best existing determinations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.