From: Peter H. L. Christiansen (pchristi@nbi.dk)
Date: Wed May 21 2003 - 11:54:39 EDT
Hi Mads
When I were using those data (qm data) for analysis I only used the
following runs :
fChain->Add("mrsDst/Ninety/B1000/mdst589*.root");
// 5901 and 5902 has bad matching cuts
fChain->Add("mrsDst/Ninety/B1000/mdst5903.root");
fChain->Add("mrsDst/Ninety/B1000/mdst5904.root");
fChain->Add("mrsDst/Ninety/B1000/mdst5908.root");
fChain->Add("mrsDst/Ninety/B1000/mdst591*.root");
fChain->Add("mrsDst/Ninety/B1000/mdst592*.root");
// for run 5931 and run 5932 there are no TPM2 tracks!!!!
fChain->Add("mrsDst/Ninety/B1000/mdst5937.root");
fChain->Add("mrsDst/Ninety/B1000/mdst5938.root");
fChain->Add("mrsDst/Ninety/B1000/mdst5939.root");
// 5940 has bad matching cuts
fChain->Add("mrsDst/Ninety/B1000/mdst5945.root");
fChain->Add("mrsDst/Ninety/B1000/mdst5946.root");
fChain->Add("mrsDst/Ninety/B1000/mdst5947.root");
fChain->Add("mrsDst/Ninety/B1000/mdst5948.root");
fChain->Add("mrsDst/Ninety/B1000/mdst595*.root");
// 5962,63,65,71,72,73,74 has bad matching cuts
// 5983 seems to have reversed polarity when I plot theta vs p
// fChain->Add("mrsDst/Ninety/B1000/mdst598*.root");
Bad matching cuts means that the correct track matching cuts are not
picked up and the default cuts are used. It is very easy to identify this
problem. Just look at the matched parameters and see if it is symmetric
for a given run. If not, I bet it uses default matching variables.
For the rest of the problems I think I have to know exactly what is on
your plot i.e. points to IP, status = 1, centrality = 0-20%, abs(vtx) <
15, valid slat hit. The last point is important, because not all the slats
are calibrated for all the runs, so for some of the runs the two outer
panels are not calibrated, so to compare and only have one map I cut those
out of all runs
Int_t slat = Int_t(tree->particles_fSlat[t]);
if (slat <=25 || slat >=103 || slat==31 || slat==76 || slat==92)
return 0;
I hope that helps.
Cheers
Peter
On Wed, 21 May 2003, Claus O. E. Jorgensen wrote:
>
> Hi Mads,
>
> First of all the back part of MRS was moved forward by 50 cm at run
> 588X, so that explains the first step in your plot. (I hope you are aware
> of this and use different maps for the different settings).
>
> When you make the track to vertex cut, is the sigma then calculated for
> each run? If not I guess that's where the second step comes from. Try to
> plot trkVtxZ-bbVtxZ and trkVtxY as function of events (instead of runs)
> to check if the width or the offset changes.
>
> It could of course also come from the matching in the magnet (check the
> MRS matching histograms) or the TOFW matching. In these cases you can
> either redo the DST from the new global tracking or just skip the runs
> where you know the offsets/widths are wrong.
>
> Cheers,
>
> Claus
>
> +------------------------------------------------------------+
> | Claus E. Jørgensen Phone : (+45) 33 32 49 49 |
> | Cand. Scient. (M. Sc.) Cell : (+45) 27 29 49 49 |
> | Office : (+45) 35 32 54 04 |
> | Niels Bohr Institute, Ta-2, Fax : (+45) 35 32 50 16 |
> | Blegdamsvej 17, DK-2100, E-mail : ekman@nbi.dk |
> | University of Copenhagen Home : www.nbi.dk/~ekman/ |
> +------------------------------------------------------------+
>
> On Wed, 21 May 2003, Mads Mikelsen wrote:
>
> >
> > Hello!
> >
> > I have taken a look at the Au data for the MRS. I have found problems
> > relating to one spectrometer setting in particular; 90degrees 1000B. (Runs
> > in aerea 5850 to 5990.) By
> > plotting the average number of tracks versus run-number I get a stair-case
> > like distribution. (Three flat plataus with sharp increases separating
> > them. Each increase is around 20-25%.) -- See attached plot.
> >
> > This indicates that something has happened with the detectors between
> > certain runs. (Tuning, triggers etc.)
> >
> > Only trig 6 events with <5% centrality and vertex between -5 and 5cm have
> > been counted. (And with ok zdc vtx.) And only primary tracks are counted.
> > (The number of identifiede pions etc. shows the same variation as primary
> > traks pr event.)
> >
> > Has anyone noticed this before? Or is there any explanation?
> > Shurly someone must have done theese tests before.
> >
> > I have not used the data from the latest reductions, since they are not
> > compatible with BDST. But Claus assured me that the QM data lockaded at
> > /brahms/data05/data/dst/MRS should be OK. (-- I do not expect that the
> > latest calibrations will give such a drastic effect.)
> >
> > I have cheked the shiftreports from the shifts around the runs where the
> > sharp increases are located but has not not found anything that can
> > explain this.
> >
> > I hope to get some comments soon as I plan to use the data for my thesis!
> > :-)
> >
> > Best regards
> > from Mads
>
--
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Peter H L Christiansen @ NBI
EMAIL : pchristi@nbi.dk
OFFICE : Tb1@NBI (353 25269)
HOME : Frimestervej 22, 1. tv
PHONE : 35824930/40840492
:-D --------------------------- \-:
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