[Clas_hadron] [G14_run] Draft slides for my talk on NSTAR2013

Tue May 21 11:16:00 EDT 2013

Hello Andy,
	I was not suggesting that Tsuneo ought to change the co-planarity cut 
at this time.  But some outside viewer of the talk might ask how that 
cut was justified.  So he ought to have an answer ready, that is all.

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
___________________________________________________________________

On 05/21/2013 11:06 AM, A.M. Sandorfi wrote:
> Igor,
> Regarding Fermi motion, while the peak in deuterium is 50 MeV/c, deuterium
> has a known large high-energy tail that becomes small only above about 200
> MeV/c. (See Hamada and Johnston, Nucl Phys 34 (62)382.) That's the
> motivation for the location of the cut in Tsuneo's slide 13.
>
> Tsuneo is working on adding to slide 13 a histogram of the missing momentum
> before the co-planarity cut - the difference is quite dramatic. The two
> different cuts make similar physics selections.
>
> Reinhard,
> The side peaks in the co-planarity plot, or rather the dips, are created by
> holes in the CLAS azimuthal acceptance. I suspect it's premature to double
> the width of the cut to include multiple sectors until we get farther along
> with the DC calibrations.
>
> Andy
>
>
>
> On 5/21/13 10:26 AM, "Igor Strakovsky"<igor at va.gwu.edu>  wrote:
>
>> Thank you, Eugene, for your clarification.  Now it works (more or less) for
>> me
>>
>> Cheers, Igor
>>
>> On Tue, 21 May 2013 10:16:02 -0400 (EDT), Eugene Pasyuk<pasyuk at jlab.org>
>> wrote:
>>
>>> Igor,
>>>
>>> Coplanarity cut and missing proton (spectator) momentum cut are used for
>>> "quasi-free" reaction selection. pi- threshold is to large extent irrelevant
>>> for selection of "quasi-free" events. It only affects accessible kinematic
>>> range. Nobody argues that these cuts do not remove all FSI.
>>>
>>> -Eugene
>>>
>>> ----- Original Message -----
>>>> From: "Igor Strakovsky"<igor at va.gwu.edu>
>>>> To: "Eugene Pasyuk"<pasyuk at jlab.org>
>>>> Cc: "g14 run"<g14_run at jlab.org>, "CLAS Hadron Spectroscopy"
>>>> <clas_hadron at jlab.org>
>>>> Sent: Tuesday, May 21, 2013 9:45:54 AM
>>>> Subject: Re: [Clas_hadron] [G14_run] Draft slides for my talk on NSTAR2013
>>>>
>>>> Eugene,
>>>>
>>>> If g14 analysis is using pi- to get gn-->pi-p from gd-->pi-pp then it
>>>> is difficult task but that is doable for specific kinematics.
>>>>   Meanwhile
>>>> there is a cut-of for charged pions as well, say 100 MeV/c - please
>>>> correct if I am wrong
>>>>
>>>> igor
>>>>
>>>>
>>>> On Tue, 21 May 2013 09:30:41 -0400 (EDT), Eugene Pasyuk
>>>> <pasyuk at jlab.org>
>>>> wrote:
>>>>
>>>>> Igor,
>>>>>
>>>>> Your statement about threshold for proton would be correct if we
>>>>> would
>>>>> attempt to detect spectator proton.
>>>>> We don't do that, spectator is reconstructed as a missing particle.
>>>>> For
>>>>> missing particle there is no threshold problem. If you look at the
>>>>> spectrum
>>>>> you will see it starts at 0.
>>>>>
>>>>> -Eugene
>>>>>
>>>>> ----- Original Message -----
>>>>>> From: "Igor Strakovsky"<igor at va.gwu.edu>
>>>>>> To: "Reinhard Schumacher"<schumacher at cmu.edu>, "Tsuneo Kageya"
>>>>>> <kageya at jlab.org>
>>>>>> Cc: "g14 run"<g14_run at jlab.org>, "CLAS Hadron Spectroscopy"
>>>>>> <clas_hadron at jlab.org>
>>>>>> Sent: Tuesday, May 21, 2013 9:25:23 AM
>>>>>> Subject: Re: [G14_run] Draft slides for my talk on NSTAR2013
>>>>>>
>>>>>> Dear Reinhard,
>>>>>>
>>>>>> I am afraid to try to correct you but the "select quasi-free
>>>>>> neutrons"
>>>>>> condition is not possible for CLAS.  CLAS cannot make a deal with
>>>>>> proton
>>>>>> with p<  200 MeV/c - there is a cut-off.  The 'quasi-free neutron'
>>>>>> term
>>>>>> is applying to the protons for p = 50 MeV/c or less.
>>>>>>
>>>>>> Best, Igor
>>>>>>
>>>>>> On Tue, 21 May 2013 09:18:49 -0400, Reinhard Schumacher
>>>>>> <schumacher at cmu.edu>
>>>>>> wrote:
>>>>>>
>>>>>>> Hello Tsuneo,
>>>>>>> I took a look at your slides for NSTAR2013 and have a few
>>>>>>> suggestions
>>>>>>> about them.  Overall, they look to be in good shape.
>>>>>>>
>>>>>>> Slide 11:  the position of the coplanarity cuts seems quite
>>>>>>> arbitrary.
>>>>>>> I would ask:  how does the result change if you double the width
>>>>>>> of
>>>>>>> the cut?
>>>>>>>
>>>>>>> Slide 13: For this slide you state the energy range as 1.1 to
>>>>>>> 1.3,
>>>>>>> whereas the previous two slides had 0.7 to 1.3.  For
>>>>>>> consistency,
>>>>>>> maybe
>>>>>>> keep the energy range the same?  Also, on this slide you have
>>>>>>> the
>>>>>>> phrase
>>>>>>> "excludes bound neutrons".  This is needlessly obscure and not
>>>>>>> strictly
>>>>>>> correct.  Maybe you want to say "select quasi-free neutrons"
>>>>>>>
>>>>>>> Have a great trip.
>>>>>>>
>>>>>>> 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
>>>>>>> ___________________________________________________________________
>>>>>>>
>>>>>>> On 05/20/2013 11:12 PM, Tsuneo Kageya wrote:
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>>    I would like to get some comments and suggestions for my
>>>>>>>>    slides
>>>>>>>>    on
>>>>>>>> NSTAR2013.
>>>>>>>> My talk is related to the preliminary double spin asymmetries
>>>>>>>> on
>>>>>>>> g14
>>>>>>>> experiments.
>>>>>>>> I have 20 minutes including the discussion.
>>>>>>>> I got comments from Volker and others when I showed slides and
>>>>>>>> tried talking
>>>>>>>> about this this Monday.
>>>>>>>> I modified based on their comments, but I have still homework
>>>>>>>> to
>>>>>>>> do; page
>>>>>>>> 10, need to show the graph
>>>>>>>> with colors.   Most of others have been changed.
>>>>>>>>
>>>>>>>>    Some of you may have different aspects; please let me know,
>>>>>>>>    if
>>>>>>>>    you have
>>>>>>>> comments.
>>>>>>>> A pdf file is attached.
>>>>>>>>
>>>>>>>>          Regards, Tsuneo Kageya.
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