Speaker
Description
The decay D → KSKS is among the most interesting modes for the understanding of CP violation in charm decays. It is a singly Cabibbo suppressed transition that involves the interference between cu (bar) → ss (bar) and cu (bar) → dd (bar) amplitudes, mediated by the exchange of a W boson at the tree level, that can generate CP asymmetries at the 1% level, even if the Cabibbo-Kobayashi-Maskawa phase is the only source of CP. Current experimental measurements of the CP asymmetry in D → KSKS decays are still limited by the statistical precision, with the best measurement performed by Belle experiment at an integrated luminosity of 921 fb−1: ACP (D → KSKS) = (−0.02 ± 1.53 ± 0.02 ± 0.17)%, where the first uncertainty is statistical, the second systematic and the third due to the CP asymmetry of the reference D → KS π0. ACP in D → K+K− is measured with 0.11% precision, Therefore, using D → K+K- as the control mode reduces the uncertainty due to the control mode and makes the analysis simpler. In this talk, we present the CP asymmetry in D → KSKS, using D → K+K− as the control mode with Belle and Belle II experiments. The full Belle data sample is used at integrated luminosity of 980 fb-1. For Belle II, the data collected before Long Shutdown 1 (LS1) is used and corresponds to an integrated luminosity of 420 fb−1.
| Track type | Collider and BSM Physics |
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