DUNE Fitter Validation Daniel Cherdack Colorado State University - - PowerPoint PPT Presentation

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DUNE Fitter Validation

Daniel Cherdack Colorado State University DUNE LBPWG Meeting Monday July 3rd, 2017

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Motivation

• DUNE now has access to several Fitters

– GloBES/MGT – LOAF – VALOR – Cafana – Lfit

• Major benefit of many fitters is that they should validate each
• ther
• Plan: ensure validation though a series of fitter tests that check

each step in the fitting process

• Notes:

– This is a proposal that will be refined; all specific are up for debate – So far plan is for FD only fits – Going forward all public plots must be from ‘approved’ fitters

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Define the Baseline

• Compare all fitters to GloBES

– Most publicly used plots came from GloBES – Already the unofficial method

• Setup/Inputs:

– FD MC MMC7 with MVA cuts at 0.8 – 40 kt fiducial mass – 10 yrs @ 1.07 MW – Standard 1300 km baseline, and constant earth density used in CDR – Full CDR systematic treatment – Ability to propagate shape changing systematics

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Spectra Matching

• Produce the 4 (νµ,/νµ, νe/νe) oscillated reconstructed energy spectra

– Bins of 250 MeV from 0 to 10 GEV – Nufit v3 best fit osc param values (http://www.nu-fit.org/?q=node/139), and – δCP = [-π/2, 0, π/2]

• Spectra do not have to be identical, but should agree with some

reasonable (tbd) margin of error.

• Produce tables of bin contents by channel for easy comparison

– νe/νe appearance – νµ,/νµ disappearance – ντ,/ντ appearance – Intrinsic νe/νe – NC

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Systematic Error Propagation

• Choose a set of systematic uncertainty parameters, examples:

– A normalization parameter like the NC norm – A flux throw from the flux covariance matrix – A GENIE reweight parameter like Mares – A GENIE FSI parameter – An energy scale parameter

• Produce the a set of spectra and tables for each parameter

– Similar to those propsed on previous slide – Use only δCP = 0 – Set parameter values to +1σ (or ±1σ)

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χ2 Calculations

• Choose a few points in parameter space, examples:

– The nominal MC – The GLoBES BF point – Every parameter at +1σ

• Calculate the χ2
• Break down the contributions from

– Each of the 4 spectra – The penalty term for each parameter

• Assume a CDR configuration

– CDR Volume 2, page 3-44, top paragraph and table 3.9 – http://lbne2-docdb.fnal.gov/cgi-bin/RetrieveFile?docid=10688&filename

=DUNE-CDR-physics-volume.pdf&version=10

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χ2 Minimization

• Fit for CPV sensitivity with true δCP= [-π/2, 0 , π/2], and report:

– Best fit parameter values – 1σ uncertainty ranges for each fit parameter – Including nuisance parameters

• Fit a Mock Data samples

– TBD, but something other than the Asimov data – Report the same results.

• Assume a CDR configuration

– CDR Volume 2, page 3-44, top paragraph and table 3.9 – http://lbne2-docdb.fnal.gov/cgi-bin/RetrieveFile?docid=10688&fi

lename=DUNE-CDR-physics-volume.pdf&version=10

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CPV Sensitivity Plots

• Produce the standard set of CPV plots
• Assume a CDR configuration

– CDR Volume 2, page 3-44, top paragraph and table 3.9 – http://lbne2-docdb.fnal.gov/cgi-bin/RetrieveFile?docid=10688

&filename=DUNE-CDR-physics-volume.pdf&version=10

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Producing the GLoBES Baseline (per Elizabeth)

• Spectra matching: Ready
• Systematic error propagation:

– Can do norm/CDR style systematics – Requires MGT for more complex systematics

• χ2 Calculations:

– No existing code to do this, but should not be hard to implement – Penalty terms for each parameters may be difficult (might be in MGT)

• χ2 Minimization

– Similar issues reporting nuisance parameter values and errors

(might be in MGT)

• CPV Sensitivity: Ready