Difference between revisions of "Pi0 Polarizability Meeting Mar 6, 2020"
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#* Assessment of nuclear coherent background (Elton) | #* Assessment of nuclear coherent background (Elton) | ||
#** What is the t-dependence of the sigma (500)? | #** What is the t-dependence of the sigma (500)? | ||
+ | # [[Media:NPP Theory Appendix.pdf|Theory Appendix from Jose]] | ||
# Other business | # Other business | ||
# Next meeting | # Next meeting | ||
= Minutes = | = Minutes = | ||
+ | Note: I am writing these notes from memory without good notes and memory might not be accurate. <br> | ||
+ | ''Attending: Jose, Mark, Elton, Ilya, Rory | ||
+ | |||
+ | # Announcements | ||
+ | #* Goal is to have a all input to the draft proposal by next Wednesday so it can be reviewed and submitted by next Friday. | ||
+ | # Action Items | ||
+ | # Theory update | ||
+ | #* Update to theory section of proposal. Expect to have a draft of an appendix with more details by next Wed. | ||
+ | # Experiment update | ||
+ | #* [[Media:Screen Shot 2020-03-12 at 4.22.53 PM.png | Signal cross sections]] (Ilya) | ||
+ | #* Ilya has used the FF taken from single pi0 calculations and used to estimate cross sections for 2pi0. Replace longitudinal momentum transfer qL ~ mpi -> 2mpi, and scattering of pi0 in final state -> 2x scattering for 2 pi0. | ||
+ | #* Calculation of FF shows oscillations that require increased precision and Ilya has increased granularity and computing time. Glauber calculation includes final-state absorption and computes real and imaginary part of FF. | ||
+ | #* Comparing to Elton's estimate (in the draft): Elton's estimate was 345 nb at 6 GeV. Using pi0 FF, Jose's sigma(gg-pi0pi0) and 5.5-6 GeV range Ilya gets sigma=200 nb -> at 6 GeV sigma=212 nb -> Use Elton's sigma(gg->pi0pi0) sigma=270 nb. Remaining difference is due to FF. Average for the proposal; use the estimate of 300 +/- 50 nb. | ||
+ | # Updates to proposal | ||
+ | #* Ilya added a section on the Primex-eta analysis | ||
+ | #* Rory added a paragraph describing the state-of-the-art polarizability measurements (proton and pi+), which was added to the introduction | ||
+ | #* The theory support is added separately from other authors on the collaboration list | ||
+ | #* Added Sergey and Lingyung to the theory list (in addition to Jose, Svetlana and Aleks) They were happy to be included. | ||
+ | #* Added title CPP/NPP to table of run conditions | ||
+ | #* Added comment that the cross section is model dependent | ||
+ | #* Corrected typo in sensitivity section | ||
+ | #* Modified precision goals in abstract to agree with sensitivity and summary | ||
+ | #* [[Media:NPP Theory Appendix.pdf|Theory Appendix from Jose]] | ||
+ | # Other business | ||
+ | # Next meeting |
Latest revision as of 16:25, 12 March 2020
Contents
Meeting Information
Meeting Time And Location
10:00 am ET (JLab time)
CC F228
Connecting
You can connect using BlueJeans Video conferencing (ID: 949 429 419). (Click "Expand" to the right for details -->):
- Make sure you have created a BlueJeans account via your JLab CUE account using this link:
- http://jlab.bluejeans.com (You should only need to do this once)
- Meeting ID: 949 429 419
- (you may need to type this in, depending how you connect)
- If connecting via Web Browser: click this link (no passcode is needed):
- If connecting via iOS or Android App:
- Use your JLab e-mail address to log in and then enter the meeting ID given above to join the meeting
- If connecting via Phone: Dial one of the following numbers and then enter the meeting ID above and hit "#" or "##"
- Dial: (408) 740-7256 (US or Canada only)
- or, List of International Numbers
- If connecting via Polycom unit:
- Dial 199.48.152.152 or bjn.vc
- Enter meeting ID above
Action Items
- ChiPT calculation to one loop with Coulomb photon (Svetlana and Aleks)
Tentative Agenda
- Announcements
- Action Items
- Theory update
- Experiment update
- Work list for the draft proposal to collaboration
- Clarification to questions from the PAC where possible
- Update to theory section (Jose and Mark)
- Sensitivity of cross section to polarizabilities
- Jose: The sensitivity is determined by extrapolating into the kinematic region for polarizabilities and will take effort. For now, we will use the estimates from Dai/Pennington.
- Initial optimization of experiment (e.g. target position)
- This item will not be attempted for the proposal draft.
- Analysis of PRIMEX data (Ilya)
- Assessment of nuclear coherent background (Elton)
- What is the t-dependence of the sigma (500)?
- Theory Appendix from Jose
- Other business
- Next meeting
Minutes
Note: I am writing these notes from memory without good notes and memory might not be accurate.
Attending: Jose, Mark, Elton, Ilya, Rory
- Announcements
- Goal is to have a all input to the draft proposal by next Wednesday so it can be reviewed and submitted by next Friday.
- Action Items
- Theory update
- Update to theory section of proposal. Expect to have a draft of an appendix with more details by next Wed.
- Experiment update
- Signal cross sections (Ilya)
- Ilya has used the FF taken from single pi0 calculations and used to estimate cross sections for 2pi0. Replace longitudinal momentum transfer qL ~ mpi -> 2mpi, and scattering of pi0 in final state -> 2x scattering for 2 pi0.
- Calculation of FF shows oscillations that require increased precision and Ilya has increased granularity and computing time. Glauber calculation includes final-state absorption and computes real and imaginary part of FF.
- Comparing to Elton's estimate (in the draft): Elton's estimate was 345 nb at 6 GeV. Using pi0 FF, Jose's sigma(gg-pi0pi0) and 5.5-6 GeV range Ilya gets sigma=200 nb -> at 6 GeV sigma=212 nb -> Use Elton's sigma(gg->pi0pi0) sigma=270 nb. Remaining difference is due to FF. Average for the proposal; use the estimate of 300 +/- 50 nb.
- Updates to proposal
- Ilya added a section on the Primex-eta analysis
- Rory added a paragraph describing the state-of-the-art polarizability measurements (proton and pi+), which was added to the introduction
- The theory support is added separately from other authors on the collaboration list
- Added Sergey and Lingyung to the theory list (in addition to Jose, Svetlana and Aleks) They were happy to be included.
- Added title CPP/NPP to table of run conditions
- Added comment that the cross section is model dependent
- Corrected typo in sensitivity section
- Modified precision goals in abstract to agree with sensitivity and summary
- Theory Appendix from Jose
- Other business
- Next meeting