1 / 11

Can we be fooled at 1e20?

Can we be fooled at 1e20?. Jenny Thomas UCL. Preview. Explanation of Quick Fit Method Potential pitfalls Statistics P.O.T Calibration FD MC/Data Conclusion. Explanation of Method. Basic ‘know nothing’ approach Use ND data in combination with MC to get predicted, unoscillated spectrum

weylin
Download Presentation

Can we be fooled at 1e20?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Can we be fooled at 1e20? Jenny Thomas UCL

  2. Preview • Explanation of Quick Fit Method • Potential pitfalls • Statistics • P.O.T • Calibration • FD MC/Data • Conclusion

  3. Explanation of Method • Basic ‘know nothing’ approach • Use ND data in combination with MC to get predicted, unoscillated spectrum • Encompass ND data/MC discrepancy as error bars in predicted spectrum • Add in beam uncertainty estimate for uncertainty in acceptance • Use simple c2 minimization with MINUIT to see effect on parameter measurement • Point is an independent cross-check of parameter measurement and useful tool for systematic studies

  4. Explanation of Method • This is an overestimate of errors if: • Due to detector modelling • Light in scintillator • GEANT • Beam related (different from other) • This is reasonable if • ND/FD different • Slicing • Calibration • P.O.T • This could be an underestimate if • FD MC/Data totally different

  5. Explanation of Method • Assumes all nm oscillated to nt • Etrue is oscillated and returned to Ereco • NC and CC events in sample but cuts applied to reduce NC • Pseudo runs study effect of statistics: • Nearest integer of • #nt+ran(sqrt(#nt) + #nm+ran(sqrt(#nm)) • For each bin in Ereco is calculated

  6. Example of results

  7. Potential Pitfalls at 1e20 • Using 100 pseudo-experiments • MINUIT calculates errors on parameters • Can check these are reasonable

  8. Potential Pitfalls at 1e20 0.0022eV2 0.005eV2

  9. Protons on Target • Errors in #P.O.T can give false information: fitting within limits as an extra parameter solves this • Plots to right have a 10% P.O.T miscalibration

  10. Calibration +5% • Difference between ND and FD calibration can be studied • Effects worse at low Dm2 • Again, extra parameter can alleviate this problem

  11. Conclusion • Effects of calibration and normalization should not hurt us at 1e20 • FD Data/MC differences are the only comparison which isn’t taken into account in this method • At what value of Dm2 do we decide to raise the beam energy?

More Related