Attendees: Guang Yang (GY), Ciro Riccio (CR), Shih-Kai Lin (SKL), Abraham Meles Teklu (AT), David Last (DL), Andriaseta Sitraka (AS), Chang Kee Jung (CKJ), Wilf Shorrock (WS), David Martinez Caicedo (DMC), Rado Fanantenana Razakamiandra (RFR), Vittorio Paolone (VP), Eric Chong (EC), Michael Reh (MR), Sunwoo Gwon (SG), Clark McGrew (CMG), Christopher Mauger (CM)

Link to indico: https://indico.cern.ch/event/961465/

Data daily comparison - Andriaseta Sitraka

CK: What is the meaning of "half beam"? GY: Shutter was opened in the middle of the run.
CK: Did you check using XZ (slide 5)? AS: We didn’t check. CK: What is the beam condition here? GY: The same beam condition, but we are not sure about the upstream user condition. I will check that.
CK: slide 5, first plots on the left: what is causing this difference at low energies? GY&AS: We changed the selection and now we are more beam related activities. CK: Check what happens if you take XZ.
CK: Why you are saying that these differences do not change the cross-section measurement? I think it will.
DL: We are doing something in the middle here (between raw selection and fill reconstruction) and I agree we should check again when we have the full reconstruction.
CM: Out of beam events to cross-check the time variation we are observing.
CK: Do we have enough cosmic rays? GY: Martin with a student are working on the cosmic rays.
CR: Can we use proton data taken at CERN? CK: This will be difficult since it is a different kind of TB. GY: Anyway, worth to check with Dana.

Data analysis update - Abraham Meles Teklu

CK: Why 1 time tick or 8 ticks? AT: 1 tick can avoid ghost voxels but cut also cross-talk voxels, while 8 ticks can keep ghost and cross-talk voxels that can be cut out later. We are working to find the best compromise.
CM: Slide 13: real data or simulation? AT: Real data. CM: How do you compute the energy of two neutrons? AT: I sum up the energies. CM: You are summing two energies?AT: Yes. All: This is not correct.
CK: Slide 14: Low energy neutron is generating a lot of voxels, do you understand why? CM: Some low energy events are actually high energy or gamma flash from the next micropulse.
CM: Slide 14 Minimum energy 10 MeV. GY: Yes.
GY: Slide 14: Number of voxels can help in rejecting the wrap around.
CM: Slide 15: I’d suggest looking at the projection of this plot.
CM: On which data are we optimize those parameters? AT: They are optimized on MC.

Neutron interaction and Invisible scattering - Guang Yang

CM: Slide 3: Where did you find this plot? Does it come from a database? GY: From a paper where all the measurements are summarized.
CM: I am surprised to see the level of structure in this plot at these energies.
CM: Slide 6: Deuterons and protons are the final state products? GY: Yes. CM: Kerma factor is a cross-section basically? GY: Yes. CR: What is N0? GY: A normalization factor.
CK: Slide 6: What is the message here? GY: At low energies we do not see a lot of protons but more alphas.
CM: Making sure we have a good understanding of this effect.
CK: If elastic scattering is negligible we must demonstrate it.