[Clas12_verystrange] slides and meeting

[Igor Strakovsky]

Sorry, Lei, I missed today meeting.  Students, students...

But there is no attachment yet

I will write you my thoughts on Ulrike's report in several hours.
She was in Peniscula when I reported VS task.  She asked more or
less the same questions and got my answers

igor

On Tue, 11 Jun 2013 11:40:54 -0400, Lei Guo <lguo at jlab.org> wrote:

> Hi, All,
> 
> Attached are four slides I picked from Igor's presentation, and made  
> some small modifications.
> I've also received comments from one PAC reader Ulrike Thoma:
> 
> * You are discussing ~4000 reconstructed Omega^- and several
>  million of Cascade states which will become observable
> 
>  - with 4000 reconstructed Omega^- events, do you really
>    expect to see something like excited states ?
>    I would assume that in this case an determination of
>    the quantum numbers would not be possible, correct ?
> 
>    Do I then understand correctly that the main issue in
>    the Omega^- sector is to understand the production mechanism
>    of the groud state Omega^- ?
> 
> 
> * You are discussing that the observation of the Omega^- in
>  gamma p environment is of specific interest.
>  It did not become entirely clear to me why ? Do you relate this
>  to the strangeness content in the proton ?
>  Or what can I learn about physics or other processes if I
>  have understood the production mechanism of the omega^-
>  in photoproduction ?
>  (Sorry if I have missed something in the proposal)
> 
> 
> * What is the mass resolution you expect to get for the
>  Cascade^0 and Cascade^- ground states ?
>  Which systematic error do you expect ?
> 
> 
> * One page 13 you are discussing the reaction gamma p -> K^+ K^0 X
>  and you are mentioning the since the strangeness of the K^0 is
>  not defined background from pions misidentified as kaons might
>  be significant : I would assume that a cut on the detached
>  K^0->pi+pi- vertex should solve this problem ?
> 
> 
> * I got confused with your coordinate systems. Do you have a
>  figure which defines your coordinate system and the naming
>  you are using for the different planes ?
>  (e.g. related to Fig.7)
> 
> 
> * Fig.12(right) : why is the band-like vertical structure
>  not running through the complete phase space area ?
>  Is this an area of reduced acceptance ?
>  Is yes, why do I see events in the same area in the left figure ?
> 
> 
> * Forward tagger: how are the crystals read out in this high rate
>  environment ?  Are they operated at room temperature ?
> 
>  Which energy dependent resolution is expected to be reached
>  with the forward tagger ?
> 
> 
> 
> * Fig.21 shows all particles of the events at the same time but
>  what is the probability that one of the particles in an event
>  has a momentum above 2 GeV (and is therefore misidentified)?
> 
> 
> * How realistic is the FASTMC in respect to momentum resolution ?
>  Are in the FASTMC the tracks really reconstructed or is just
>  some smearing of the momentum done ?
> 
>  You are not considering an uncertainly in l, why ?
> 
> 
> * What kind of reactions are included in the 100k Pythia background
>  events ?  (sorry for not knowing this but I never used Pythia so far)
> 
> 
> * Are the simulations done using the half or full magnetic field ?
>  I understood that at least parts of them are done at half field,
>  while the measurement will take place at full field ...
> 
> 
> * I am missing a study which tells me how well the quantum numbers
>  of the resonances can be determined from the obtained data.
> 
>  How many good events are needed above background to allow
>  for a quantum number determination ?
> 
>  Which part of the multidimensional phase space is covered ?
>  Are there e.g. areas in cos(theta) of the hyperons where the
>  recoil polarization cannot be determined.
> 
>  It is very difficult to judge based on the proposals what the
>  restrictions of the PWA might later be due to uncovered regions
>  in phase space.
> 
> 
> * The baryon resonances can also be studied using GlueX. What are
>  the advantages doing this with CLAS12 relative to GlueX ?
> **************************************
>        @
>       /    *
>      /   ___  ___  Lei Guo _______________________
>     L_O_/ ____ Florida International University____/_/
>         \   |             Physics Dept., CP  
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> 
> 
> 
> 
> 
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Igor Strakovsky, SAID CNS The George Washington University
Tel: 703-726-8344(NV),202-994-4742(FB),Skype: igors1945_2
Fax: 202-994-3001(FB),Emails: igor at va.gwu.edu, igor at jlab.org