Difference between revisions of "Pi0 Polarizability Meeting Dec 6, 2019"

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== Action Items ==
 
== Action Items ==
−
# ChipT calculation to one loop with Coulomb photon (Svetlana and Aleks)
+
# ChiPT calculation to one loop with Coulomb photon (Svetlana and Aleks)
 
# Formulate questions for Serguei (Elton and Ilya)
 
# Formulate questions for Serguei (Elton and Ilya)
−
# Look at gp->pi0pi0 from empty target runs (Alex)
+
# <strike> Look at gp->pi0pi0 from empty target runs (Alex) </strike> See meeting notes
 
# Contact theorists:
 
# Contact theorists:
−
#* Lingyun Dai, Hunan University: Changsha, Hunan, CN (dailingyun@hnu.edu.cn)
+
#* <strike> Lingyun Dai, Hunan University: Changsha, Hunan, CN (dailingyun@hnu.edu.cn) </strike>
  
 
== Tentative Agenda ==
 
== Tentative Agenda ==
Line 53: Line 53:
 
# Action Items
 
# Action Items
 
# Theory update
 
# Theory update
−
## [[File:NOTES-JOSE.pdf Notes Jose 12/6/2019]]
+
## [[Media:NOTES-JOSE.pdf | Notes Jose 12/6/2019]]
 
# Experiment update
 
# Experiment update
 +
## Empty target run 51556 (Fall 2018): [https://halldweb.jlab.org/wiki/images/thumb/d/d4/Vertex_2tracks.png/800px-Vertex_2tracks.png], [https://halldweb.jlab.org/wiki/images/thumb/8/86/Vertex_p2pi0.png/800px-Vertex_p2pi0.png], [https://halldweb.jlab.org/wiki/images/thumb/d/d6/Pi0_p2pi0.png/800px-Pi0_p2pi0.png]
 
# Other business
 
# Other business
 
# Next meeting
 
# Next meeting
  
 
=Minutes=
 
=Minutes=
−
''Attending:
+
''Attending: Elton, Beni, Alex, Jose, Mark, Rory, Phil Martel , Lingyun Dai
 +
 
 +
# Announcements
 +
#* Svetlana and Aleks are in Chile
 +
#* Accelerator is restarting operations. Will run till May with a break for Christmas.
 +
# Action Items
 +
# Theory update
 +
## [[Media:NOTES-JOSE.pdf | Notes Jose 12/6/2019]]
 +
##* Update on amplitudes: A and B remain, but amplitude C is zero by current conservation.
 +
##* Formulation goes back to Morgan and Pennington (1986) using Donahue and Holstein (1992-93) to model A and B. These should be sufficient for simulating the experiment. Specifics involve how to deal with final state interactions and they choose to keep s-channel s-waves and vector mesons in the t and u channels.
 +
##* Dispersion relation is for P_I(s), which is related to form factors f_0 and f_2.
 +
##* Parameterization of s-waves is needed. Elton has a reference that he will share with Jose.
 +
##* Lingyun. He has parameterizations of the partial waves and showed the I=0 S=0 phase shift. Offline discussions with Jose to develop a set to use for this experiment.
 +
# Experiment update
 +
## Empty target run 51556 (Fall 2018): [https://halldweb.jlab.org/wiki/images/thumb/d/d4/Vertex_2tracks.png/800px-Vertex_2tracks.png], [https://halldweb.jlab.org/wiki/images/thumb/8/86/Vertex_p2pi0.png/800px-Vertex_p2pi0.png], [https://halldweb.jlab.org/wiki/images/thumb/d/d6/Pi0_p2pi0.png/800px-Pi0_p2pi0.png]
 +
##* Alex showed empty target distributions for one run using charged tracks. GlueX has taken about 15 already
 +
##* The target windows are Kapton (C_22H_10N_20_5). Target distribution was shown for gA->p pi0 pi0 events, where the vertex is taken from a (measured) recoil proton.
 +
##* These runs may be useful to investigate various characteristics of the data.
 +
# Discussion
 +
#* The location of the target should be studied for this experiment. Locating it upstream makes sense to enhance acceptance at low angles. It could be that an optimum location may be even farther upstream than for CPP.
 +
#* Beni: If it is placed sufficiently upstream, one may wish to remove the CDC. (In any case we anticipate using Flashes from the CDC for the muon chambers).
 +
# Other business
 +
# Next meeting
 +
#* We will meet on Fri Dec 20, 10 am.

Latest revision as of 13:06, 6 December 2019

Meeting Information

Meeting Time And Location

10:00 am ET (JLab time)

CC F228

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Action Items

  1. ChiPT calculation to one loop with Coulomb photon (Svetlana and Aleks)
  2. Formulate questions for Serguei (Elton and Ilya)
  3. Look at gp->pi0pi0 from empty target runs (Alex) See meeting notes
  4. Contact theorists:
    • Lingyun Dai, Hunan University: Changsha, Hunan, CN (dailingyun@hnu.edu.cn)

Tentative Agenda

  1. Announcements
  2. Action Items
  3. Theory update
    1. Notes Jose 12/6/2019
  4. Experiment update
    1. Empty target run 51556 (Fall 2018): [1], [2], [3]
  5. Other business
  6. Next meeting

Minutes

Attending: Elton, Beni, Alex, Jose, Mark, Rory, Phil Martel , Lingyun Dai

  1. Announcements
    • Svetlana and Aleks are in Chile
    • Accelerator is restarting operations. Will run till May with a break for Christmas.
  2. Action Items
  3. Theory update
    1. Notes Jose 12/6/2019
      • Update on amplitudes: A and B remain, but amplitude C is zero by current conservation.
      • Formulation goes back to Morgan and Pennington (1986) using Donahue and Holstein (1992-93) to model A and B. These should be sufficient for simulating the experiment. Specifics involve how to deal with final state interactions and they choose to keep s-channel s-waves and vector mesons in the t and u channels.
      • Dispersion relation is for P_I(s), which is related to form factors f_0 and f_2.
      • Parameterization of s-waves is needed. Elton has a reference that he will share with Jose.
      • Lingyun. He has parameterizations of the partial waves and showed the I=0 S=0 phase shift. Offline discussions with Jose to develop a set to use for this experiment.
  4. Experiment update
    1. Empty target run 51556 (Fall 2018): [4], [5], [6]
      • Alex showed empty target distributions for one run using charged tracks. GlueX has taken about 15 already
      • The target windows are Kapton (C_22H_10N_20_5). Target distribution was shown for gA->p pi0 pi0 events, where the vertex is taken from a (measured) recoil proton.
      • These runs may be useful to investigate various characteristics of the data.
  5. Discussion
    • The location of the target should be studied for this experiment. Locating it upstream makes sense to enhance acceptance at low angles. It could be that an optimum location may be even farther upstream than for CPP.
    • Beni: If it is placed sufficiently upstream, one may wish to remove the CDC. (In any case we anticipate using Flashes from the CDC for the muon chambers).
  6. Other business
  7. Next meeting
    • We will meet on Fri Dec 20, 10 am.
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