EVO meeting at 3 pm central time Look under Universe for DM Task Force, with password “depth” or connect by phone at 1 626 395 2112 with ID = 446 1036# and Pwd 8461#

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• Presentation by Anthony.
• Discussion.

• New MC at Homestake with G4 4.9.5 + Mu-nuc + MUSUN muons (parameterized muon spectrum) - Chao
• Input files (Angie) and first comparison with Homestake parameterization (Chao)
• Comparing Livetimes & benchmark numbers: Fill in the TABLE below BEFORE the meeting so we can discuss. We will start with quick presentation of what you did, in order to interpret the numbers. If you want to include a few slides with pictures or explanations, you can plug them into these first four bullet points.

1. LZ geometry with G4 4.9.3 P02 (good mu-nuc + shielding list) - Angie
2. LZ geometry with isotropic M&H thrown - Monica
3. LZ geometry at Brown with Angie's files - David, Monica
4. LZ geometry at Homestake with parametrization Chao's Presentation

We will refer to these “methods” by the following numbers and letters. Numbers refer to particle files, letters to parametrizations.

• 1. “Groom” Parametrization of muons at Homestake depth, propagated through rock using GEANT4 v4.9.3 P02 with new mu-nuclear to produce neutrons and all secondaries. Assumes a flat overburden, but has a good angular distribution of incoming neutrons. Uses “Soudan” rock.
• 2. Muons generated via MUSUN, taking account of the geography and geology of the Homestake site. Muons then propagated through rock using GEANT4 v4.9.5 to produce neutrons and all secondaries. Not yet generated by Chao.
• 3. Muons generated via MUSUN, taking account of the geography and geology of the Soudan site. Muons then propagated through rock using GEANT4 v4.9.3 P02 with new mu-nuclear to produce neutrons and all secondaries. Done by Angie, not yet filtered for Melinda
• A. The LZ Monte Carlo (4850 level) with isotropic angular distribution on a sphere
• B. The Neutron Multiplicity Meter (2100 mwe) with cosnθ distribution (partly derived from existing flux measurements)
• C. Muons generated via MUSUN, taking account of the geography and geology of the Homestake site. Neutron parametrization created from this. Done by Chao.

Fill these out by referring to the method. Fill out numbers and put links to spectra. Templates are included for the first few entries. Please replace with the correct numbers.

• 4.4 E-5 (File 1 on LZ geometry - Angie) Explicitly tied to M&H rate.
• 4.4 E-5 (Method A - Monica) Uses M&H muon flux rate at Homestake.
• 6.46 E-5 (Method C - Chao) Deduced by MUSUN+GEANT4

• 7.3 E-6 (File 1 on LZ geometry - Angie)
• 4.4 E-5 (Method A - Monica) Uses M&H muon flux rate at Homestake.
• 1.84 E-5 (Method C - Chao) Deduced by MUSUN+GEANT4

• 1.9 E -6 (File 1 on LZ geometry - Angie)
• 1.7 E-6 (Method A - Monica) Uses M&H muon-induced neutron flux rate at Homestake and accounts for top and bottom of the water tank.
• 2.91 E-6 (Method C - Chao) MUSUN+GEANT4

• 2.4 E -6 (File 1 on LZ geometry - Angie)
• 3.6 E-6 (Method A - Monica) Uses M&H muon-induced neutron flux rate at Homestake.
• 1.13 E-6 (Method C - Chao) MUSUN+GEANT4

• 5.9 E -7 (File 1 on LZ geometry - Angie)
• 3.4 E -10 (Method A - Monica) This value though has the caveat that there must be some energy deposition (NR or ER) in the liquid Xe since we did not store all events that pass into the detector.
• 1.00 E-8 (Method C - Chao) MUSUN+GEANT4

• 4.9 E -5 (File 1 on LZ geometry - Angie)
• 5.44 E -8 (Method A - Monica) for NR_dep > 5 keV_r; 5.42 E -8 for NR_dep > 10 keV_r
• 2.56 E -9 (Method C - Chao) MUSUN+GEANT4 → Secondary neutron only

• 5.9 E -7 (File 1 on LZ geometry - Angie)
• 1.1 E -10 (Method A - Monica) for NR_dep > 5 keV_r & Single Scatter cut; 1.0 E -10 for NR_dep > 10 keV_r
• < 4.26e-12 (Method C - Chao) MUSUN+GEANT4 → Secondary neutron only

• 3.2 E -12 (Method A - Monica) see slides;

• 69:2 (Method A - Monica) single NR corresponds to NR > 5 keV_r and single scatter cut. Veto corresponds to applying all cuts (NR cut, Single Scatter, Elastic, and Fiducial)

• 33506:10 (Method A - Monica) multiple NR corresponds to NR > 5 keV_r. Veto corresponds to applying NR, Elastic, and Fiducial cut

• Status of filtered files - Melinda, Angie
• Livetime numbers: 6e7 muons → 35 days → ~60k events with neutrons hitting the N detector geometry