I see. good news is later versions of codes have all outer detector hits
booked in DST, so we don't loose tof hits because of missing tracks. but
this only started when we use v3_3 (bats problem as a side effect).
On Tue, 28 Sep 2004, vitaliy ziskin wrote:
> Well, I think I know what happened. This "neutron" peak in hydrogen
> went away when I cut on the trigger type. This means that a lot of
> trigger 1 events that supposed to have tof hits in the right chamber
> (definition of a trigger 1) all of a sudden did not have tofs. I think
> the explanation lies in the the fact that we only record tof hits when
> there is a valid track linked to it /in the dst/. So no track, no tof
> hit. By doing it this way we rely purely on the wire chamber
> reconstruction (not hits) to do the veto (85% efficient only). Thus,
> huge proton background. Thank G-d we kept trigger type in the dst. I
> still have a sizable proton background and it would be nice to somehow
> get at the raw wire chamber info for a given event number of a given
> run. Does anyone have such code.
>
> Vitaliy
>
> Tancredi Botto wrote:
>
> >which goes back to the issue raised last week, that you should not use
> >"tracks" for the veto but only wch hits. There will be always be a
> >tracking inefficiency and therefore holes in your veto if the analysis
> >does not ground itself on raw wch hits.
> >
> >
> >
> >
> >>Vitaliy,
> >>
> >>one thing comes to my mind. We increased the low-momentum cutoff to
> >>150MeV/c (=proton kinetic energy of 12 MeV). Assuming 50MeV/c tolerance
> >>to account for resolution effects, means 200 MeV/c (or 21 MeV).
> >>
> >>Supposedly a proton track with kinetic energy < 25 MeV is likely not
> >>assigned to a track, but may still be recognized as a neutron when it
> >>still fired a neutron counter and no ToF.
> >>
> >>Regards,
> >>
> >> Michael
> >>
> >>
> >>
> >>On Tue, 28 Sep 2004, vitaliy ziskin wrote:
> >>
> >>
> >>
> >>>To back up my point. I include a picture of an unpol hydrogen runs
> >>>normalized to charge. These data sets have different runs in them since
> >>>no all hydrogen runs have been recrunched. In black is the latest
> >>>recrunch and in read is the data before the recrunch. Do I need to say
> >>>anything else. What went wrong?
> >>>
> >>>
> >>>Vitaliy
> >>>
> >>>
> >>>vitaliy ziskin wrote:
> >>>
> >>>
> >>>
> >>>>Well, for whatever it is worth, the recrunched hydrogen runs show a
> >>>>huge increase in the "neutron" rate, factor of 2.5 where as neutron
> >>>>yield increased by about 1.5 probably mostly due to misidentified
> >>>>"protons". I now even see a nice missing mass peak in the hydrogen
> >>>>runs. Is it possible that we are no assigning more hits to the
> >>>>neutron detector than before or not assigning enough to the tofs. Or
> >>>>maybe bats somehow get in the way. Please... I need your help.
> >>>> Cheers,
> >>>>Vitaliy
> >>>>
> >>>>Chris Crawford wrote:
> >>>>
> >>>>
> >>>>
> >>>>>hi eugene,
> >>>>> you can always do a joint analysis from dst and raw data. just open
> >>>>>both filetypes together, and loop through them in sync.
> >>>>>--chris
> >>>>>
> >>>>>Eugene J. Geis wrote:
> >>>>>
> >>>>>
> >>>>>
> >>>>>>lrd is not generating new lr-#### ntuples as well as flr and dst? I
> >>>>>>notice none
> >>>>>>in the recrunch directory. Is there potentially a new entry with
> >>>>>>all wire
> >>>>>>chamber hits per event regardless of a link to a track? Could be quite
> >>>>>>important for the neutrons... -eg
> >>>>>>
> >>>>>>
> >>>>>>Quoting Michael Kohl <kohlm@mit.edu>:
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>Vitaliy,
> >>>>>>>
> >>>>>>>Chi mentioned to me that in this BlastLib version the dst header
> >>>>>>>information is not copied over. Maybe this is related to your
> >>>>>>>problem?!
> >>>>>>>
> >>>>>>>Look at the yields for each spin state separately if your asymmetries
> >>>>>>>are inconclusive.
> >>>>>>>
> >>>>>>>Regards,
> >>>>>>>
> >>>>>>> Michael
> >>>>>>>
> >>>>>>>
> >>>>>>>--
> >>>>>>>
> >>>>>>>+-------------------------------------+--------------------------+
> >>>>>>>| Office: | Home: |
> >>>>>>>|-------------------------------------|--------------------------|
> >>>>>>>| Dr. Michael Kohl | Michael Kohl |
> >>>>>>>| Laboratory for Nuclear Science | 5 Ibbetson Street |
> >>>>>>>| MIT-Bates Linear Accelerator Center | Somerville, MA 02143 |
> >>>>>>>| Middleton, MA 01949 | U.S.A. |
> >>>>>>>| U.S.A. | |
> >>>>>>>| - - - - - - - - - - - - | - - - - - - - - -|
> >>>>>>>| Email: kohlm@mit.edu | K.Michael.Kohl@gmx.de |
> >>>>>>>| Work: +1-617-253-9207 | Home: +1-617-629-3147 |
> >>>>>>>| Fax: +1-617-253-9599 | Mobile: +1-978-580-4190 |
> >>>>>>>| http://blast.lns.mit.edu | |
> >>>>>>>+-------------------------------------+--------------------------+
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>--------------------------------------------------------------------------
> >>>>>>
> >>>>>>Eugene Geis
> >>>>>>PhD Student, Physics Department, ASU
> >>>>>>Research Affiliate, MIT-Bates Laboratory of Nuclear Science
> >>>>>>eugene.geis@asu.edu
> >>>>>>--------------------------------------------------------------------------
> >>>>>>
> >>>>>>-------------------------------water is
> >>>>>>good------------------------------
> >>>>>>--------------------------------------------------------------------------
> >>>>>>
> >>>>>> ** Check Out the Phatty Acidz @ http://www.phattyacidz.com **
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>
> >>>
> >>
> >>
>
>
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