10/09/2019

Minutes of the 10/09/2019 HD-GDH meeting

Present: A. Deur, M. Dalton, D. Florjancic, S. Sirca, J. Stevens.

• A. Deur is working on setting up a GDH in Hall D wikipage

• A. Deur reported on possible polarized backgrounds (see questions in previous minutes). Based on discussion with C. Keith,
  • There should not be any polarized Compton background because the electrons of the ¹⁶O and ¹² nuclei making the butanol of the target are all spin-paired. The unpaired electrons of the hydrogens should also be unpolarized because each is shared with the ¹⁶O in the OH bound. In principle, there might be a slight polarization of the electrons of ¹⁶O and ¹²C if some those get ionized. The lone remaining electrons will then fully polarized in the direction of the solenoid field. However, this is estimated to be no more than the 10⁴ level
  • There will be no polarized hadronic background because all nucleons in ¹⁶O and ¹² nuclei are spin-paired.

• Discussion on steps that needs to be done with the simulation:
  • Put the target in
  • Set-up MC wrapper
  • run MC from the web page
  • David analyzes the data, to answer our list of questions (see e.g. Justin's document)
  • Based on the results, optimized the experimental set-up.

• Benefit of an additional tagger for low photon energy: Mark Dalton asked about the quality of the data at low energy, since the photon beam polarization will be low. (To justify constructing an additional tagger, these data should be of good enough quality.)
  • Alexandre will look into the figue of merit of the experiment in this region.

• Next meeting will be Monday Oct. 23rd, 8am (JLab time) in room A110.