[d2n-analysis-talk] BB/LHRS tracks

[Brad Sawatzky]

Repost.

On Tue, 20 Apr 2010, Brad Sawatzky wrote:

> 
> On Mon, 19 Apr 2010, posik at jlab.org wrote:
> 
> > I have just finished implementing my proton cuts for selecting good
> > events in the LHRS looking at the 1-pass H2 runs that we took
> > (1258-1262). Here is a list of the cuts that I have used:
> > 
> >  tg_y ="(abs(L.tr.tg_y)<0.04)";
> > 
> >  tg_ph ="(abs(L.tr.tg_ph)<0.02)";
> > 
> >  tg_th ="((L.tr.tg_th>-0.035)&&(L.tr.tg_th<0.05))";
> 
> Does the structure in LHRS target theta make sense?  (I really don't know,
> but I hadn't expected it...  See what Zein-Eddine thinks.)
> 
> >  tg_dp ="(abs(L.tr.tg_dp)<0.035)";
> > 
> >  ex_tg_p="((ExTgtCor_L.p<0.9)&&(ExTgtCor_L.p>0.83))";
> > 
> >  triggers = "((DL.evtypebits&1<<5)==(1<<5)&&(DL.edtpl==0))";
> 
> Are these DL (DecData class) variables arrays?  If so, you'll want to put a
> [0] index on them.  If they're scalars, then you're fine.
> 
> >  energy="L.prl2.asum_c+L.prl1.asum_c)<100&&(L.prl2.asum_c+L.prl1.asum_c)>10)";
> 
> Why such a small slice in energy?  What are the particles in the peak
> between channel 150--300?
> 
> >  prl="((L.prl2.asum_c>0)&&(L.prl1.asum_c>0))";
> 
> I think protons will probably dump all their energy in the first layer and
> you won't see much at all in prl2.  This cut is OK.
> 
> [ . . . ]
> > Taking the ratio of BB reconstructed one tracks with proton cuts and the
> > LHRS reconstructed one tracks with proton cut we get 0.93 So 93% of the
> > reconstructed one tracks in LHRS for a good proton show up in the BB
> > reconstructed one track.
> 
> 93% is encouraging.  The energy cut above (in particular) strikes me as a
> little odd though.
> 
> -- Brad
> 
-- 
Brad Sawatzky, PhD <brads at jlab.org>  -<>-  Jefferson Lab / Hall C / C111
Ph: 757-269-5947  -<>-  Fax: 757-269-5235  -<>- Pager: brads-page at jlab.org
The most exciting phrase to hear in science, the one that heralds new
  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov