Re: 22GeV update

From: Michael Murray (murray@CyclotronMail.tamu.edu)
Date: Tue Dec 04 2001 - 11:46:04 EST

  • Next message: Stephen J. Sanders: "Re: 22GeV update"

        Dear Bjorn,
                 the distribution looks as one might expect. We are
    inefficent for low multiplicity events. Did you just use BB 
    triggers in your sample or also ZDC ones. I think it would be
    better to analysis them  as two separate data sets since the
    ZDCs and BB counters will have different efficencies.
         Anyway, keep up the good work. I have asked Zi-wei Lin
    to give us "predictions" for this run. By the way I think we
    should stop calling it 22GeV since in fact the momentum was
    9.47. So I get sqrt{s_nn}=19GeV.
                   Yours Michael
    
    > I've looked at the different responses of the global detectors using
    > what
    > calibrations I have (for run 4640, mostly), and the only one that looks
    > more or less reasonable at first glance is the Si array hits:
    > 
    > http://folk.uio.no/bjornhs/brahms/22GeV/SiArrayHits_22GeV.ps
    > 
    > I use this response "blindly" to select "most central" events - if this
    > is
    > a very bad thing to do I'd appreciate some feedback.
    > 
    > Again using the geant BB response (assuming 100% tube efficiency) to
    > normalize the number of events, but now doing a much better job of the
    > background subtraction:
    > 
    > http://folk.uio.no/bjornhs/brahms/22GeV/dvf_z_fit.ps
    > 
    > ...I get the following:
    > 
    > dNdEta (eta=0) = 313
    > 
    > Getting closer. There are still some parts of the TPC-specific code that
    > I
    > need to look into more closely, but I'd very much like to hear from
    > Steve/Hiro on the Si response - is this curve usable the way I'm doing
    > -
    > i.e. just using the 200GeV calib blindly?
    > 
    > Ping :-)
    > 
    > --
    > Bjorn H. Samset                           Phone: 22856465/92051998
    > PhD student, heavy ion physics            Adr:   Schouterrassen 6
    > Inst. of Physics, University of Oslo             0573 Oslo
    >                               \|/
    > ----------------------------> -*- <-----------------------------
    >                               /|\
    > 
    
    
    
    Michael Murray, Cyclotron TAMU, 979 845 1411 x 273, Fax 1899
    



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