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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