[G14_run] Simulation

Fri May 26 03:36:54 EDT 2017

We did several studies for acceptance effects on the determination of the E observable and we saw no significant systematic effects. My main goal for the simulation is to show that with the cuts we apply we remove all background events and understand the source of the band in lower missing masses that we talked about a couple of weeks ago.

-N 

> On 25 May 2017, at 22:29, Reinhard Schumacher <schumacher at cmu.edu> wrote:
> 
> Hi Franz,
> 
> Yes, I was referring only to the circular polarization runs, specifically pi- p.   But also for Janie’s analysis, detecting the decay of the Sigma- hyperons cannot, I believe, depend significantly on the CLAS acceptance.   The weak decay asymmetry factor of the Sigma- is -0.068, which is not too far from isotopic.   In any case, our statistics are pretty low, so I think we can argue that a full Monte Carlo is not needed.    It would be a different story if we were detecting the Sigma+, which is a huge weak decay asymmetry.
> 
> Of course, we will need the GSIM work you did for the analysis of the linearly polarized beam data that Haiyun is doing!
> 
> Reinhard
> _____________________________________________________________
> Reinhard Schumacher         Department of Physics, 5000 Forbes Ave.
> Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.
> phone: 412-268-5177           web: www-meg.phys.cmu.edu/~schumach <https://urldefense.proofpoint.com/v2/url?u=http-3A__www-2Dmeg.phys.cmu.edu_-7Eschumach&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=S2ZLWreG80lNvNTOLF-ZWA&m=rfl8fcnuJcvU8vJMbiKNqdCEunzchKagUXmr5WFR72I&s=9F9Hwf-gkjf2RpzhH-BBV1Sj0_8zt0x-BHwW4O9qJ78&e=>
> _____________________________________________________________
> 
> 
> 
>> On May 25, 2017, at 2:05 PM, Franz Klein <fklein at jlab.org <mailto:fklein at jlab.org>> wrote:
>> 
>> Sorry, folks: this should have been sent to the whole group ...
>> 
>> 
>> ----- Forwarded Message -----
>> From: "Franz Klein" <fklein at jlab.org <mailto:fklein at jlab.org>>
>> 
>> Reinhard,
>> 
>> this is actually not true: we set up the simulations for Dao - and it seems that the wire efficiencies I put into the GPP map were reasonably well reproducing the detector response (I admit that we did not look into all the details, e.g. TAG, ST, SC).
>> As I wrote Nick already earlier today, the files (+script to have compatible settings in gsim's ffread and recsis' tcl + to run the sequence) are in $CLAS_PACK/tests/frost (for frost and HD). I updated some environment settings as these files in the clasg14 account this morning (there were some minor changes missing to run root on ifarm1101 (centos6) as well as ifarm140x (centos7)).
>> Flaws in the detector performance are almost completely cancelling out for E in pi- p, the but the situation might be different when it comes to the separation of the Sigma flavors in Jamie's analysis. Simulations are very likely required for hyperon channels when the observable depends on the azimuthal angle.
>> 
>> Greetings,
>> Franz
>> 
>> ----- Original Message -----
>> From: "Reinhard Schumacher" <schumacher at cmu.edu <mailto:schumacher at cmu.edu>>
>> To: "Nicholas Zachariou" <nickzachariou at gmail.com <mailto:nickzachariou at gmail.com>>
>> Cc: "g14 run" <g14_run at jlab.org <mailto:g14_run at jlab.org>>
>> Sent: Thursday, May 25, 2017 1:02:06 PM
>> Subject: Re: [G14_run] Simulation
>> 
>> Hi Nick, 
>> 
>> Jamie’s analysis was for the “E” observable. To a good (enough?) approximation, all acceptance issues cancel when forming this quantity from the CLAS data. For the recently published data for the pi- p reaction, there were no GSIM calculations done by any of the three parallel analysis efforts. We explicitly assumed that the cancellation approximation is sufficient. And further, recall that g14 was the last hurrah for the CLAS spectrometer, and in many ways it was in miserable shape: many many dead channels. I do not recall that we have even tried to itemize and model all the flaws for Monte Carlo study. 
>> 
>> Cheers, 
>> Reinhard 
>> _____________________________________________________________ 
>> Reinhard Schumacher Department of Physics, 5000 Forbes Ave. 
>> Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A. 
>> phone: 412-268-5177 web: www-meg.phys.cmu.edu/~schumach <https://urldefense.proofpoint.com/v2/url?u=http-3A__www-2Dmeg.phys.cmu.edu_-7Eschumach&d=DwMFaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=S2ZLWreG80lNvNTOLF-ZWA&m=rfl8fcnuJcvU8vJMbiKNqdCEunzchKagUXmr5WFR72I&s=9F9Hwf-gkjf2RpzhH-BBV1Sj0_8zt0x-BHwW4O9qJ78&e=> 
>> _____________________________________________________________ 
>> 
>> 
>> 
>> 
>> 
>> 
>> On May 25, 2017, at 6:00 AM, Nicholas Zachariou < nickzachariou at gmail.com <mailto:nickzachariou at gmail.com> > wrote: 
>> 
>> Hi all, 
>> 
>> I have generated some signal and background data for Jamies Analysis and wanted to run them through GSIM to illustrate that with our cuts minimal background events survive and do a quick study of the weird structure below the missing-mass of signal events that I think comes from kaons that decay. I was wondering if you can point to me the following: 
>> g14-approved version of GSIM 
>> ffread card to use 
>> appropriate run num for constants 
>> gpp variables 
>> and cook tcl file for user_ana 
>> 
>> Cheers, 
>> Nick 
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