Speaker
Description
The measurement of time-dependent CP asymmetries in radiative penguin decays of $B^0$ mesons allows us to search for signs of New Physics through new particles in the loop, which can enhance the contribution of right-handed polarized photons. The decay channel $B^0 \rightarrow K_S^0 \eta \gamma$ is one such example, where a photon is emitted through loop-level processes involving virtual particles. This analysis targets a larger dataset, including the complete Belle data of 772 million events and nearly 700 million events from Belle II (expected 2025 dataset) collected at the $\Upsilon(4S)$ resonance, providing significant potential to improve upon previous results. To enhance the sensitivity of the analysis, we have integrated an upgraded Graph Neural Network-based flavor tagger and plan to use a more robust fit model along with certain other analysis improvements for background rejection to obtain more precise measurements of CP violation parameters. We present the latest status of time-dependent measurements of these parameters in $B^0 \rightarrow K_S^0 \eta \gamma$ decays from the Belle and Belle II experiments.
| Field of contribution | Experiment |
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