Detachment ()

The detachment cut is the most powerful cut in most charm analyses. By requiring a significance of separation between the primary and secondary vertices, short lived hadronic background is effectively removed. The detachment cut requires that be greater than some value where L is the measured distance between the two vertices and $\sigma_L$ is the error on that measurement. This requirement is illustrated in select:charm_decay where the errors on vertex positions are shown using ellipses. (The error in the longitudinal direction is typically several hundred per vertex while the errors in the transverse directions are only a few .)