[Halld-physics] Physics Working Group Meeting: Tuesday, October 16 @ 11:15 am

Tue Oct 23 14:50:06 EDT 2018

Sure, Sean, I know that

There is a perfect agreement between g12 by Kunkel and g1c by Dugger in the
case of overlap.
Specifically that Dugger (sorry, they both Mikes) made his analysis to
select outcoming proton
while Kunkel selected e+e- from pi0 decay

Cheers, igor

-----
Igor Strakovsky, SAID INS The George Washington University
Tel: 571-553-8344(VC),202-994-4742(FB),Skype: igors1945_2,
Cell: 703-728-5627,Emails: igor at gwu.edu, igor at jlab.org

On Tue, Oct 23, 2018 at 2:43 PM Sean Dobbs <sdobbs at fsu.edu> wrote:

> Hi Igor,
>
> Just one more comment, I made these estimates with comparing to CLAS
> measurements (including the data you sent me) in mind.
>
> Cheers
> Sean
>
> On Tue, Oct 23, 2018 at 3:22 AM Igor Strakovsky <igor at gwu.edu> wrote:
>
>> Hi Justin,
>>
>> Plan looks great.  I have two small comments
>>
>> - The min Eg is still unclear.  So, if one can possible to go a little
>> bit below 3 GeV then CLAS
>> g1c data for pi0 is reachable [DUGGER, PRC76, 025211(2007)]: Eg
>> = 2875, 2825, 2775 and so on
>>
>> - I would not use  previous measuremen
>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__halldweb.jlab.org_DocDB_0008_000809_002_GlueX-5Fdoc-5F809.pdf&d=DwMFaQ&c=HPMtquzZjKY31rtkyGRFnQ&r=bxTPW7N21WY8eJ2MkW85CQ&m=1O1CO8HBnkAzX_0rBMir1hYatCH9geOY0aILsSyuhEo&s=jOyUpUcxA4ygMm4nUGJcQB4JT4TC-2jTVaMFmt2YlZ8&e=>as the
>> source to compare with because most of data
>> came from brem Bonn measurements which systematics is out the control.
>>
>> Cheers, igor
>>
>> -----
>> Igor Strakovsky, SAID INS The George Washington University
>> Tel: 571-553-8344(VC),202-994-4742(FB),Skype: igors1945_2,
>> Cell: 703-728-5627,Emails: igor at gwu.edu, igor at jlab.org
>>
>>
>> On Tue, Oct 23, 2018 at 7:54 AM Justin Stevens <jrsteven at jlab.org> wrote:
>>
>>> Hi Igor, All,
>>>
>>> Yes, as we discussed at the Physics WG meeting last week, there are 2
>>> possibilities for low energy measurements which correspond to your bullets
>>> below.  The priority was given to proposing a run plan for this Fall, since
>>> time is limited.  Thanks to Sean for collecting the relevant data and rate
>>> estimates for this Fall’s proposal at
>>> https://halldweb.jlab.org/wiki-private/index.php/2018_Low_energy_measurements
>>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__halldweb.jlab.org_wiki-2Dprivate_index.php_2018-5FLow-5Fenergy-5Fmeasurements&d=DwMFaQ&c=HPMtquzZjKY31rtkyGRFnQ&r=bxTPW7N21WY8eJ2MkW85CQ&m=1O1CO8HBnkAzX_0rBMir1hYatCH9geOY0aILsSyuhEo&s=qKz1F8vW7uaYtr4qsZe3ELkzY4KlLhx9PAsepkinRgA&e=>.
>>> The short summary is that we would like to propose a ~5 day run with a
>>> lower PS field setting to give statistical errors <10% on cross sections
>>> for comparison to previous measurements, and this is on the agenda for
>>> today’s bi-weekly meeting.
>>>
>>> This Fall’s proposal of course does not preclude running in Summer 2019,
>>> but would give us some data in the short term to compare with previously
>>> measured cross sections.  To make a decision on Summer 2019 running, we
>>> would need a similar proposal with the stated goals, rate estimates, and
>>> required running time.
>>>
>>> -Justin
>>>
>>> On Oct 17, 2018, at 4:34 PM, Igor Strakovsky <igor at gwu.edu> wrote:
>>>
>>> Hi Justin,
>>>
>>> According to my understanding there are two different run periods
>>>
>>> - this fall which will allow to cover 4-9 GeV or so.  CLAS6 does not
>>> have pol measurements
>>>
>>> - next summer which is a low energy run which you spelled out. that is
>>> different story
>>>
>>> Cheers, igor
>>>
>>>
>>> On Wed, Oct 17, 2018 at 1:15 PM Justin Stevens <jrsteven at jlab.org>
>>> wrote:
>>>
>>>> Hi Igor,
>>>>
>>>> Thanks for your feedback.  My understanding is the accelerator would
>>>> run at half energy (Ee ~ 5.5 GeV), and as usual we could choose to set the
>>>> coherent peak as we prefer.  The hodoscope in this case would cover Eg ~
>>>> 1.5 GeV to the endpoint, although it will still be only half instrumented
>>>> (sampling) between 1.5 and 3.5 GeV.  So data below Eg = 4 GeV could be
>>>> possible in this scenario, but at a lower efficiency.
>>>>
>>>> -Justin
>>>>
>>>> On Oct 15, 2018, at 3:11 PM, Igor Strakovsky <igor at gwu.edu> wrote:
>>>>
>>>> Hi Justin,
>>>>
>>>> It would be good to spell out a possible Eg range and our goals for
>>>> summer of 2019.  Then all depends.
>>>>
>>>> I reported twice that if our range is limited by 4 - 6 GeV and our main
>>>> goal is diff cross sections then
>>>> g12 from CLAS6 will work for us.  There are no CLAS pol measurements in
>>>> this case.  So, we have
>>>> gp-->pi0p cross sections published several month ago and Volker's
>>>> analyses for gp-->etap and
>>>> gp-->omegap are under the HW group review now.
>>>>
>>>> If one can possible to go below 3 GeV then we will have more options
>>>> including polarized
>>>> measurements. Additional benefit will come from the ability to use the
>>>> PWA technology to evaluate
>>>> new data and possibility to provide "good" event generators for MC.
>>>> See my slides at DB
>>>>
>>>> Cheers, igor
>>>>
>>>>
>>>>
>>>> -----
>>>> Igor Strakovsky, SAID INS The George Washington University
>>>> Tel: 571-553-8344(VC),202-994-4742(FB),Skype: igors1945_2,
>>>> Cell: 703-728-5627,Emails: igor at gwu.edu, igor at jlab.org
>>>>
>>>>
>>>> On Mon, Oct 15, 2018 at 12:50 PM Justin Stevens <jrsteven at jlab.org>
>>>> wrote:
>>>>
>>>>> Hi All,
>>>>>
>>>>> There’s been a proposal to have a short discussion about a potential
>>>>> low-energy run in Summer 2019 during tomorrow’s physics meeting.  To frame
>>>>> the discussion: the accelerator plans to run at ~half energy during
>>>>> June/July 2018 and GlueX could potentially run parasitically during this
>>>>> period.
>>>>>
>>>>> We had some discussion about the potential usefulness of low-energy
>>>>> running earlier this year (comparison to cross section measurements from
>>>>> CLAS, energy-dependence of polarization observables, etc.), but that was in
>>>>> a different context of using the full energy electron beam with lower
>>>>> coherent peak settings (see
>>>>> https://halldweb.jlab.org/wiki-private/index.php/Aug_7,_2018,_Physics_Working_Group
>>>>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__halldweb.jlab.org_wiki-2Dprivate_index.php_Aug-5F7-2C-5F2018-2C-5FPhysics-5FWorking-5FGroup&d=DwMFaQ&c=HPMtquzZjKY31rtkyGRFnQ&r=bxTPW7N21WY8eJ2MkW85CQ&m=1O1CO8HBnkAzX_0rBMir1hYatCH9geOY0aILsSyuhEo&s=k-u9QGAIL1MkAy0QcTRZX7uRIHyi0N_j9auSkJx475M&e=>
>>>>> ).
>>>>>
>>>>> If you have something you would like to contribute to the discussion,
>>>>> please let me know.
>>>>>
>>>>> -Justin
>>>>>
>>>>> On Oct 14, 2018, at 1:46 PM, Justin Stevens <jrsteven at jlab.org> wrote:
>>>>>
>>>>> Hi All,
>>>>>
>>>>> Our next Physics WG meeting we be Tuesday, October 16 at 11:15 am,
>>>>> https://halldweb.jlab.org/wiki-private/index.php/Oct_16,_2018,_Physics_Working_Group
>>>>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__halldweb.jlab.org_wiki-2Dprivate_index.php_Oct-5F16-2C-5F2018-2C-5FPhysics-5FWorking-5FGroup&d=DwMFaQ&c=HPMtquzZjKY31rtkyGRFnQ&r=bxTPW7N21WY8eJ2MkW85CQ&m=1O1CO8HBnkAzX_0rBMir1hYatCH9geOY0aILsSyuhEo&s=W_9cfqYD3IiiFCrQK_scYgrcuEMuqTKEdbR9Zn2L9vo&e=>.
>>>>> Please let me know if you have something you would like to present.
>>>>>
>>>>> -Justin
>>>>> _______________________________________________
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>>>>>
>>>>>
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>>>>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__mailman.jlab.org_mailman_listinfo_halld-2Dphysics&d=DwMFaQ&c=HPMtquzZjKY31rtkyGRFnQ&r=bxTPW7N21WY8eJ2MkW85CQ&m=1O1CO8HBnkAzX_0rBMir1hYatCH9geOY0aILsSyuhEo&s=9mZJww8FzlxjiVc2da-1WkkKp5daCVj6V2l4zMCqbMY&e=>
>>>>
>>>>
>>>>
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