[Clas12_verystrange] slides and meeting

[dan watts]

Hi Lei

The resolution of the forward tagger is quoted in the TDR as

sigma_E/E <= (2% /  sqrt(E(GeV)) + 1%

This is taking a 10 MeV single crystal threshold in the calorimeter 
crystals.

Cheers,
Dan


On 11/06/2013 15:40, Lei Guo 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
> 212                       /  /
>        /    \ |             Miami, FL
> 33199        /                       /  /
>       /  I_/ \  ____ USA _____ /______/__________/  /
>      /   /
> L
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>     /   /                       /              /              /                       /  /
>    /_/__________/______/______/__________/_/
> /_/__________/______/______/__________/_/
> 305-348-0234(o)
>
> **************************************
>
>
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>
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>
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