Search for neutral D meson mixing using semileptonic decays
Abstract (Summary)Based on a 87 fb-1 dataset, a search for D0 -DÃ?Â¯0 mixing is made using the semileptonic decay modes D *+ [arrow right] Ã? +D0 , D0 [arrow right] [K/K *]e Ã?Â½ (+c.c.) at the B -Factory facility at the Stanford Linear Accelerator Center. These modes offer unambiguous initial and final-state charm flavor tags, and allow the combined use of the D0 lifetime and D *+ - D0 mass difference (Ã?"M ) in a global likelihood fit. The high-statistics sample of reconstructed unmixed semileptonic D0 decays is used to model both the Ã?"M distribution and the time-dependence of mixed events directly from the data. Neural networks are used both to select events and to fully reconstruct the D0 . A result consistent with no charm mixing has been obtained, Rmix = 0.0023 Ã?Â± 0.0012(stat ) Ã?Â± 0.0004(sys ). This corresponds to an upper limit of Rmix < 0.0047 (95% C.L.) and Rmix < 0.0043 (90% C.L.). The lowest current published limit on semileptonic charm mixing is 0.005 (90% C.L.) (E791, E.M. Aitala et al. , Phys.Rev.Lett. 77 2384 (1996)). The current best published limit using any analysis technique on the total rate of charm mixing is 0.0016 (95% C.L.) (Babar K Ã? mixing, B. Aubert et al. , Phys.Rev.Lett. 91 171801 (2003)).
School Location:USA - Massachusetts
Source Type:Master's Thesis
Date of Publication:01/01/2004