Missing proton energy fake data effect on deltaCP DUNE LBL meeting - PowerPoint PPT Presentation

Missing proton energy fake data effect on deltaCP DUNE LBL meeting May 13 2019 Cristóvão Vilela

This is what we have presented before ● Mass-squared bias: ~0.04e-3 eV*eV ● sinsq(theta_23) bias: ~0.025 ● deltaCP bias: ~ 0.3 pi 2

These are the spectra we have showed before Background was not included on the nue samples (see next slide) 3

This is what the backgrounds look like Also, new selection and binning 4

DeltaCP = 1.5 pi 5

DeltaCP = 1.2 pi 6

Fake data fit with latest analysis tools Ignore error bars, look only at bias - these are just the gaussian-like uncertainties at the best-fit point 7

Same, without backgrounds 8

With th13 constrained 9

Appearance only, th13 unconstrained 10

All oscillation parameters fixed other than delta 11

All oscillation parameters fixed other than delta and th13 12

All oscillation parameters fixed other than delta and th23 13

All oscillation parameters fixed other than delta and dmsq32 14

15 years exposure all oscillation parameters fitted 7 years ND exposure 15

7 years exposure all oscillation parameters, NuFit constraint on all except deltaCP 16

Is this just a fluke? ● For a global energy scale transformation: ● From disappearance we get a biased mass-squared splitting: ○ Such that numu survival probability stays invariant ■ i.e., energy scale shift is absorbed by oscillation parameters 17

Is this just a fluke? ● Ignoring the solar term, can write the deltaCP dependence as: ● with ● Now apply energy scale transformation and use transformed : ○ ● Appearance probability is invariant under: ○ and To first order, deltaCP measurements are ● robust wrt energy scale in a joint LBL fit. ○ Disappearance parameter measurements are not. 18

So what about this? arXiv:1507.08560 “Since the atmospheric parameters are fixed to their current best-fit values, and we are only interested in the δ CP sensitivity,there is no need to include ν μ and ̄ ν μ disappearance channels in our analysis.” 19

Delta CP energy scale robustness - neutrinos 20

Delta CP energy scale robustness - antineutrinos 21

Delta CP energy scale robustness - neutrinos True atmospheric mass splitting known. 22

Delta CP energy scale robustness - antineutrinos True atmospheric mass splitting known. 23

Degeneracies Neutrinos ● Disappearance parameters can be degenerate with deltaCP. Made with Luke’s plotting tool. 24

Conclusions ● The missing proton fake data only induces a bias in delta CP if dmsq32 is fixed at nominal. ○ Otherwise, there is a nearly perfect trade-off between biasing deltaCP and dmsq32 and the data prefer a biased dmsq32, which is not surprising given its significant effect in the disappearance samples. ● Our fake data biases dmsq32, not deltaCP ○ To make a case for deltaCP probably need fake data that’s (more) different from a global energy scale shift… ○ Need ideas on how to present this in the short term. 25