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Analysis Questions

GENIE

Energy & Momentum Conservation

  • Asked by Janet
  • Assigned to XXX
  • At the interaction vertex, is momentum conserved? If not, why not? Is it because of a fake particle in the event? How are we handling this strictly from a kinematics point of view (not a model question)? Prove we handle missing energy properly when we move to different frames. If this is not handled right it will really screw up a lot of analyses, especially xsec analyses.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Boosting

  • Asked by Janet
  • Assigned to XXX
  • Are particles boosted correctly? I have been on experiments that did not have the correct boosts. So check it.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Protons boosting in MEC interaction

  • Asked by Janet
  • Assigned to XXX
  • Look at the protons produced in the MEC interaction – are these protons being boosted properly?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Neutron multiplicity

  • Asked by Janet
  • Assigned to XXX
  • Check the number of neutrons coming out. Tim has said he has seen an unphysical number. What does that mean? Prove you don’t have a mistake.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Beam flux

Beam rotation, width, parallax

  • Asked by Janet
  • Assigned to XXX
  • The solid angle of the detector is 5 mrads. Do we correct for this rotation in the simulation in order to match data? In fact, we need to think about beam width and parallax, because a neutrino with a 400 m travel distance actually has an opening angle of 6.25 mrads. Note that this will be flavor dependent. A consequence of not getting this right is that your muon angle distribution in the xsecs will be wrong. It also affects any analysis looking for transverse momentum or
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Geant4

dE/dx

  • Asked by Janet
  • Assigned to XXX
  • Check the dE/dx of the particles coming out against SRIM or any other data base. Prove it makes sense. I think it won’t because…
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Delta production threshold

  • Asked by Janet
  • Assigned to XXX
  • The deltas probably have too high of a threshold, since I can pick out data compared to MC in the DL LEE images from the amount of delta sparkle. Check this. This affects the multiple scattering energy measurement, all EM energy measurements, including the michels and also may explain the PIDA problem (and why truncated dQ/dx works better).
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Muon polarization and Michel spectrum

  • Asked by Janet
  • Assigned to XXX
  • The Michel energy and angle spectrum is surely wrong, since the MC does not include polarization. Explain to me why this doesn’t matter to your analysis.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Muon polarization and capture cross section

  • Asked by Janet
  • Assigned to XXX
  • Does muon polarization affect the capture cross section? (I don’t know the answer to this – I am just guessing that since capture is a weak process, it will).
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Stopped pi+ Bragg peak

  • Asked by Janet
  • Assigned to XXX
  • Are stopped pi+’s that decay making a Bragg peak in the simulation? They should.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Pi+ scattering cross section

  • Asked by Janet
  • Assigned to XXX
  • Use a particle gun to produce pi+’s and check the fraction of time they hard scatter given the energy. Is it right?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

CCpi0 analysis

Photon splitting/clustering

  • Asked by Janet
  • Assigned to XXX
  • There is a claim that the case of 2 EM blobs near a 1mu1p always corresponds to a pi0, so we don’t need to worry about the mass peak. Prove to me that a relatively high energy photon splitting into 2 blobs that do not cluster is rare.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Cosmic pi0 background

  • Asked by Janet
  • Assigned to XXX
  • How often do you get a pi0 from cosmic right on top of your CCQE event? According to Kazu, who has done a lot of scanning, about 1 in 3 BNBEXT has a pi0. There are so many more cosmics and so many more CCQE than CCpi0 that it seems very likely there will be some. If that isn’t right, please explain.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

pi+/pi0 charge exchange

  • Asked by Janet
  • Assigned to XXX
  • Check the rate of pi+/pi0 charge exchange – is it right? Is your CCpi0 analysis taking charge exchange into account properly?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

e+/e- conversion pair energies

  • Asked by Janet
  • Assigned to XXX
  • Check the energies of the e+e- conversion pair. Does the ratio in the simulation make sense?
  • Answer (by David C.): DocDB-12677, slide 4
  • Resolved: No

pi0 photons

  • Asked by Janet
  • Assigned to XXX
  • Check the energies of the two pi0 photons at truth level. Does the ratio make sense?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Hadronic invariant mass

  • Asked by Janet
  • Assigned to XXX
  • Check the invariant mass of the outgoing proton and pion in the resonant decays. Does it make sense? Yes, it will have smearing. Do a run with no Fermi motion as a cross check.
  • Answer (by Kirsty Duffy): DocDB-13705
  • Resolved: No

CPM analysis

Flash-matching affecting efficiency

  • Asked by Janet
  • Assigned to XXX
  • How does the flash-match requirements affect the efficiency, looked as a function of number of tracks?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Vertex-finding efficiency versus number of tracks

  • Asked by Janet
  • Assigned to XXX
  • How does vertex-finding efficiency vary with number of tracks?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Vertex-finding efficiency versus other vertex activity

  • Asked by Janet
  • Assigned to XXX
  • How does vertex finding efficiency vary with additional vertex activity other than tracks?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Track reconstruction efficiency versus number of tracks

  • Asked by Janet
  • Assigned to XXX
  • How does the number of reconstructable tracks vary with the number of tracks (is there confusion between tracks that causes a loss of efficiency?)
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Track reconstruction efficiency versus vertex activity other than tracks

  • Asked by Janet
  • Assigned to XXX
  • How does the number of reconstructable tracks vary with vertex activity?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Track-vertex association versus number of tracks

  • Asked by Janet
  • Assigned to XXX
  • I believe that tracks are associated with a vertex if they have some distance of closest approach (5 cm?) – does the efficiency vary a lot when this cutis slightly changed? This questions must be number-of-track dependent.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Short track reconstruction as a function of angle

  • Asked by Janet
  • Assigned to XXX
  • How does efficiency for multiple short tracks to be resolved vary with the angle from Z. As tracks go to higher angle, is there hitsharing? Do tracks remain distinct?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

Impact of reconstruction on dependence of multiplicity measurement on length cut

  • Asked by Janet
  • Assigned to XXX
  • The length cut is affecting the multiplicity measurement. How does the reconstruction affect this?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

General analysis questions

Beam windows in data and MC

  • Asked by Janet
  • Assigned to XXX
  • Does every single xsec analysis use the right beam windows for data and MC? Are you aware of the window-length difference when doing the BNBEXT subtraction? Can you prove this is right for every single xsec analysis by making a plot for each?
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

POT counting for exclusive samples

  • Asked by Janet
  • Assigned to XXX
  • Many xsec analyses will need exclusive samples. Is the POT counting for exclusive samples wrong? Prove it is right.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No

MC efficiency estimates

  • Asked by Janet
  • Assigned to XXX
  • Nearly all of the xsec analyses are making very tough cuts in order to get to a sample that is as pure as possible. When you do this, the error on the efficiency goes way up. How are you determining the error on your efficiency? Why should I think this is right? Prove to me it makes sense.
  • Answer (by XXX): DocDB-XXXX
  • Resolved: No