The first evidence of D mixing has recently been reported by the B factories in two independent analyses. D mixing is the only neutral-meson oscillation involving up-type quarks, making it sensitive to new processes that cannot contribute to K and B mixing. A percent-level asymmetry in the D widths has been found, and the mass asymmetry may be similar, but is less constrained.
These results are consistent with Standard Model predictions that include long-distance contributions.
I will discuss how these results were obtained and interpret several other recent analyses in context. I will also include an outlook for continued progress in this area and the implications for new physics searches at the LHC.