XXVI DAE-BRNS High Energy Physics Symposium 2024

Measurement of Time-Dependent CP asymmetries in the decay channel B0→KS0ηγ at Belle and Belle II

Not scheduled

20m

Swatantrata Bhavan, Banaras Hindu University, Varanasi

Postar Beyond the standard model

Speaker

CHESHTA .

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 $B^0\to K_S^0\eta \gamma$ 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 $\mathrm{{\rm Y}}(4S)$ 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 $B^0\to K_S^0\eta \gamma$ decays from the Belle and Belle II experiments.