ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2004, vol. 70, p. 091102-1
Search for D0-D̄0 mixing using semileptonic decay modes
Based on an 87-fb-1 data set collected by the BABAR detector at the PEP-II asymmetric-energy B Factory, a search for D0- D̄0 mixing has been made using the semileptonic decay modes D*+ → π+D0, D0 → K(*)eν (+c.c.). The use of these modes allows unambiguous flavor tagging and a combined fit of the D0 decay time and D*+-D0 mass difference (ΔM) distributions. The high-statistics sample of unmixed semileptonic D0 decays is used to model the ΔM distribution and time dependence of mixed events directly from the data Neural networks are used to select events and reconstruct the D0. A result consistent with no charm mixing has been obtained, Rmix = 0.0023 ± 0.0012 ± 0.0004. This corresponds to an upper limit of Rmix < 0.0042 (90% C.L.).