Ho, good people.
With the ClusterVertex class, there has always been an issue of what cuts
to use on the gauss-fit to select only "well-determined" vertices. I
presented my "best" values at the last collab.meeting and improved them
somewhat before QM, but for diverse reasons they have never been made
default in the class. Now that the class is beeing used by different
people, I should long ago have checked this in so that the clustervertex
may me used "blindly" - sorry about the slackness there. I have a version
ready for checkin, but before I do so I want to ask if this messes up
anything for anyone. What will happen is that instead of ClusterVertex
returning a vertex whenever it is able to fit something to its data, it
will only return a vertex when the fit is better than some
(settable!) cuts. This will reduce the number of vertices but _greatly_
increase the vertex precision.
For reference, the planned default cuts are:
BrVertex *cvtx = some_event_node->GetObject("Cluster VtxData");
if (cvtx->GetVertexZSigma()<2.0 &&
sqrt(cvtx->GetVarianceZ())<1.0) {OK!}
If there are no comments, I'll check this in by the end of the week.
Ping :-)
------------------------------------------------
Bjorn H. Samset
Master-student in Heavy Ion physics
Mob: +47 92 05 19 98 Office: +47 22 85 77 62
Adr: Kri 2A709 Sognsveien 218 0864 Oslo
This archive was generated by hypermail 2b29 : Wed Feb 28 2001 - 12:28:25 EST