Re: Strange looking Au data

From: Marco Germinario (germina@hilux03.nbi.dk)
Date: Wed May 21 2003 - 12:20:56 EDT

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    Hi,
    I also used for my coalescence analysis the runs indicated by Peter.
    Marco
    
    
    On Wed, 21 May 2003, Peter H. L. Christiansen wrote:
    
    > 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
    > > 
    > 
    > 
    
    -- 
    
                                 Marco Germinario
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