Search for 𝐷0 meson decays to 𝜋+𝜋−𝑒+𝑒− and 𝐾+𝐾−𝑒+𝑒− final states

Physical Review D - Particles, Fields, Gravitation and Cosmology. 2025. Vol. 111. No. 9. Article L091101.

Aaij R., Abdelmotteleb A. S., Abellan Beteta C., Abudinén F., Ackernley T., Adefisoye A. A., Adeva B., V. Bocharnikov, A. Boldyrev, Derkach D., F. Ratnikov, A. Ryzhikov

A search for 𝐷0 meson decays to the 𝜋+⁢𝜋−⁢𝑒+⁢𝑒− and 𝐾+⁢𝐾−⁢𝑒+⁢𝑒− final states is reported using a sample of proton-proton collisions collected by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6  fb−1. The decay 𝐷0 →𝜋+⁢𝜋−⁢𝑒+⁢𝑒− is observed for the first time when requiring that the two electrons are consistent with coming from the decay of a 𝜙 or 𝜌0/𝜔 meson. The corresponding branching fractions are measured relative to the 𝐷0 →𝐾−⁢𝜋−⁢[𝑒+⁢𝑒−]𝜌0/𝜔 decay, where the two electrons are consistent with coming from the decay of a 𝜌0 or 𝜔 meson. No evidence is found for the 𝐷0 →𝐾+⁢𝐾−⁢𝑒+⁢𝑒− decay and world-best limits are set on its branching fraction. The results are compared to, and found to be consistent with, the branching fractions of the 𝐷0 →𝜋+⁢𝜋−⁢𝜇+⁢𝜇− and 𝐷0 →𝐾+⁢𝐾−⁢𝜇+⁢𝜇− decays recently measured by LHCb and confirm lepton universality at the current precision.

Keywords: particle physics, физика частиц

Publication based on the results of: Development of theoretical foundations and methods of generative artificial intelligence and their application to heterogeneous domain area (2025)