MCC11 Smearing Matrices and Energy Resolution Erin Conley January - PowerPoint PPT Presentation

MCC11 Smearing Matrices and Energy Resolution Erin Conley January 23, 2019 SNB/LE Working Group Meeting

Outline • Introduction • MCC11 smearing matrices: – Using truth deposited energy – Using different charge quantification – Applying drift correction • Fractional energy resolution • Takeaways 2

Introduction • Hack Days 2018: produced the right-hand smearing matrix for MCC11 MARLEY with strange behavior Many issue(s): • – Comparing to MCC10 shows biggest differences in low-energy bins – Charge distributions show double bumps, shoulders, negative charge – Determined that different files contain different charge distributions • See SNB meeting from November 14 for more information 3 1/23/19

Different Charge Quantification MARLEY Smearing Matrix (No Drift Correction) MARLEY Smearing Matrix (No Drift Correction) Calculated reconstructed • 100 Reconstructed Energy (MeV) energy for smearing matrix 0.16 90 using reco hits (Hit::Integral) 0.14 80 Smoothed, columns • 70 0.12 60 normalized 0.1 50 0.08 Filled in missing energy level • 40 0.06 by averaging neighboring 30 0.04 columns 20 0.02 10 Less wiggly! • 0 0 0 10 20 30 40 50 60 70 80 90 100 Truth Neutrino Energy (MeV) 4 1/23/19

Applying Drift Correction No Drift Correction Reco Drift Correction MARLEY Smearing Matrix, Drift Corrected (Reco) MARLEY Smearing Matrix, Drift Corrected (Reco) MARLEY Smearing Matrix (No Drift Correction) MARLEY Smearing Matrix (No Drift Correction) 100 Reconstructed Energy (MeV) 100 Reconstructed Energy (MeV) 0.16 90 0.16 90 80 0.14 80 0.14 70 70 0.12 0.12 60 60 0.1 0.1 50 50 0.08 0.08 40 40 0.06 0.06 30 30 0.04 0.04 20 20 0.02 0.02 10 10 0 0 0 0 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 Truth Neutrino Energy (MeV) Truth Neutrino Energy (MeV) Less spread when drift correction is applied! 5 1/23/19

Fractional Energy Resolution • Considered five different smearing matrices with different “reconstructed energy” quantifications (see backup) • For a given !true : – Distribution of !reco values – Calculated the fractional difference, !reco − !true /!true – Found standard deviation, RMS of fractional difference values – Plotted vs neutrino energy 6

Fractional Energy Resolution Plot Notes: • Truth kinetic energy at zero due to cut-off energy in MARLEY modeling; also see backup • Truth information has better resolution than reco • Our resolution is worst for reco charge, but improves with drift correction 7

Fractional Energy Resolution Plot Notes: Same overall trends as • standard deviation plot Truth information has • better resolution than reco Our resolution is worst for • reco charge, but improves with drift correction See backup for more • information 8

Takeaways • We now have MCC11 smearing matrices! – Alternative charge quantification with reco Hits resolves the wiggly behavior seen using RawDigit objects • Applying drift correction reduces the spread in the smearing matrix • RMS and standard deviation of fractional energy quantifies the resolution/spread in the smearing matrices 9

Backup Slides 10

Toy Smearing Matrix (MARLEY + %) Used truth deposited energy • from the LArSoft simulation for the reconstructed energy • Smeared with different Gaussian resolutions using SNOwGLoBES (0-20%) Filled in missing energy level • by averaging neighboring columns • Use these matrices to reproduce plots in spectral parameter fitting 11 1/23/19

Applying Drift Correction No Drift Correction Truth Drift Correction MARLEY Smearing Matrix (No Drift Correction) MARLEY Smearing Matrix (No Drift Correction) MARLEY Smearing Matrix, Drift Corrected (Truth) MARLEY Smearing Matrix, Drift Corrected (Truth) 100 100 Reconstructed Energy (MeV) Reconstructed Energy (MeV) 0.2 0.16 90 90 0.18 0.14 80 80 0.16 70 70 0.12 0.14 60 60 0.1 0.12 50 50 0.1 0.08 40 40 0.08 0.06 30 30 0.06 0.04 20 20 0.04 0.02 10 10 0.02 0 0 0 0 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 Truth Neutrino Energy (MeV) Truth Neutrino Energy (MeV) Less spread when drift correction is applied! 12 1/23/19

Reco Drift Correction • Applied drift correction: ! = ! # exp '0 ) * ! : Truth charge – – ! # : Observed charge – ) * : Electron lifetime – '0 : Reco interaction start time • Find '0 using photon flash, reco hit information (used longest track as reco electron track) • Effect of correction: narrower reco energy distribution 13 1/23/19

Comparing Event Rates: MCC10 vs. MCC11 Notes: Used GVKM flux • Cutoff at 5 MeV due • to post-smearing efficiency model We see energy loss • between MCC11, other two smearing matrices See backup for more • event rates! 14

Comparing Event Rates: MCC11 Notes: Used GVKM flux • Cutoff at 5 MeV due • to post-smearing efficiency model Applying drift • correction reduces energy loss in MCC11 See backup for more • event rates! 15

Standard Deviation Plot For a given !true : • – Distribution of !reco values – Calculated the fractional difference for each !reco,i value using Efrac,i = !reco,i − !true /!true for event i Standard deviation: • 7 !frac,i − 6 5 ∑ 234 !frac 0frac = 8 − 1 – 8 : number of events for a given !true – 6 !frac : mean of all Efrac,i values Plotted standard deviation vs neutrino energy • 16

RMS Plot For a given !true : • – Distribution of !reco values – Calculated the fractional difference for each !reco,i value using Efrac,i = !reco,i − !true /!true for event i RMS: • 8 1 9 Erms = 3 4 Efrac,i 567 – 3 : number of events for a given !true Plotted RMS vs neutrino energy • 17

How the two quantities are related (From Wikipedia) • For ! "frac as the mean and 'frac as the standard deviation: • * + 'frac * ! * "rms = "frac If ! "frac = 0 , then standard deviation and RMS are ~ same • If ! "frac ≠ 0 , then we don’t expect the values to be the same • I believe the truth kinetic energy curve for RMS is nonzero below 10 • MeV due to relationship between ' frac and E rms 18

Example fractional energy distributions Notes: The reason why 6.25 and • 12.25 MeV peaks are lower than the others is due to less simulated events for those particular energy levels We see a nonzero mean • for all the energy levels All events for ! true < • 10 MeV are contained in a singular peak; we expect % frac = 0 for those energy levels Energy levels above 10 • MeV are not a singular peak (see red arrows) 19

Backup Slides SMEARING MATRICES 20

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