Measurement of CP asymmetry in D0→KS0KS0 decays with Run 3 data

Abstract

A measurement of CP asymmetry in D0→KS0KS0 decays is reported, based on a data sample of proton-proton collisions collected with the LHCb detector in 2024 at a centre-of-mass energy of 13.6 TeV, corresponding to an integrated luminosity of 6.2 fb−1. The D0→KS0π+π− decay is used as calibration channel to cancel residual detection and production asymmetries. The time-integrated CP asymmetry for the D0→KS0KS0 mode is measured to be (Formula presented.) where the first uncertainty is statistical, and the second is systematic. This measurement represents the most precise single-experiment determination of this quantity to date.