We check the stability of our and measurements under different reconstruction methods in two ways. First, we use the standard direction vectors instead of the improved vectors. We see no appreciable systematic due to the choice of direction vectors, as illustrated by the `nots' (no target silicon) point in sc_mass:method_sys.
As a second check, we use the standard momentum values instead of the values. This does give a systematic error. In fact it is the dominant error in this study of reconstruction and fitting methods, as evidenced by the `notrk' point in sc_mass:method_sys.
Neither of these checks apply to the case since there is no tracking information for the .