Search for D0 ? KS0 K-e+?e, D+ ? KS0 KS0 e+?e, and D+ ?k+K-e+?e

A search has been performed for the semileptonic decays D0?KS0K-e+?e, D+?KS0KS0e+?e, and D+?K+K-e+?e, using 7.9 fb-1 of e+e- annihilation data collected at the center-of-mass energy s=3.773 GeV by the BESIII detector operating at the BEPCII collider. No significant signals are observed, and upper limits are set at the 90% confidence level of 2.13×10-5, 1.54×10-5, and 2.10×10-5 for the branching fractions of D0?KS0K-e+?e, D+?KS0KS0e+?e, and D+?K+K-e+?e, respectively. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.