Dear Hiro,
I guess that the figure was made only
for events in which the BB and the TPM1 vertex
failed. If so the effect you see could be induced
by an (multiplicity dependent)
inefficency in the vertex algorithm of
these detectors. Could you please remake the
same plot for an unbiased sample of events from
the same run. Ideally that would be just ZDC triggers.
Yours Michael
Quoting Hironori Ito <hito@students.phsx.ukans.edu>:
> Well. I have another thought about fixing manually. I can not
> fix manually since I only use ZDC vertex when I do not have good vertex
> from BB or TPM1. This means that I can not fix ZDC since I do not have
> any other reference to fix ZDC Vertex.
>
> hiro
>
> On Fri, 16 Mar 2001, Hironori Ito wrote:
>
> > Hello. I have a question. I remember reading the e-mail about
> > ZDC_Vertex do not have Multiplicity dependence. Well, I think it is
> > there. Look at the figure "ZDC_TPM1_vertex.ps" in
> > "http://pii3.brahms.bnl.gov/~hito". The figure is produced from
> > run 2336. In this figure, the vertical scale is
> > ZDC vertex - TPM1 (cluster) vertex, and the horizontal scale is BB
> > Mult. Of cause, it is possible that BB Mult is wrong. But, if I use
> > other mult such as Si and Tile mult, I see the same thing.
> Furthermore, I
> > do not see this much dependence from BBVertex - TPM1 Vertex although
> > BBVertex have other problem. Can someone look at this? The fix is
> > needed since multiplicity in Si can easily is affected by 3-4 cm shift
> of
> > vertex. Until it is fixed, I will manually (in my own code) fix
> ZDCVertex
> > to align to TPM1 vertex.
> >
> > Hiro
> >
> >
>
Michael Murray, Cyclotron TAMU, 979 845 1411 x 273, Fax 1899
This archive was generated by hypermail 2b29 : Mon Mar 19 2001 - 10:58:44 EST