1 / 43

Unofficial Summary of Long Baseline Neutrino Experiment Workshop

This summary presents discussions from the LBNE physics workshop regarding the study of neutrinos, detector options, physics goals, and hierarchy determination potential. Key topics include detection possibilities, event requirements for hierarchy resolution, and detector configuration considerations for optimal performance in neutrino physics research. Detailed analyses and comparisons between Water Cherenkov and Liquid Argon detectors are provided, offering insights into spectral features and statistical significance in neutrino studies.

june
Download Presentation

Unofficial Summary of Long Baseline Neutrino Experiment Workshop

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. Unofficial* summary of the Long Baseline Neutrino Experiment (LBNE) physics workshopSeattle, Aug 9 to Aug 11 David Webber August 24, 2010 *Many studies/plots are preliminary. These slides are a representation of the workshop’s discussion. An official report is in preparation by the collab.

  2. Why Study Neutrinos? • Neutrinos are half the known stable particles in the universe • n1, n2, n3, p, e, g • Neutrinos are a major component of the universe • ~300 n/cm3, roughly same as CMB photons • nucleons and electrons are ~10-7/cm3 • Neutrinos allow for the study of particle physics, without the complications of strong and electromagnetic forces. Svoboda

  3. Neutrino Physics Goals Svoboda

  4. neutrino Svoboda

  5. Svoboda

  6. Svoboda

  7. Svoboda

  8. Svoboda

  9. Svoboda

  10. Svoboda

  11. Far Detector Options Water • 100 kTfiducial module. • 4850 ft depth. • 15% or 30% HQE PMT coverage? • Gadolineum or not? • 1,2,3 modules? • More signal! • Larger volume Liquid Argon • 17 kTfiducial module. • 300, 800, 4850 ft depth? • 3, 4, 5 mm wire spacing? • Probably will be 3 mm • photon trigger? • 1,2,3 modules? • Less background! • Better p0 identification 100 kT water ~= 17 kT liquid Ar for beam physics sensitivity

  12. Far Detector Configurations

  13. Long Baseline Physics:CP violation and neutrino hierarchy

  14. 300 kT water ~= 50 kT liquid Ar for beam physics sensitivity Svoboda

  15. LBNE could push to 3-4 x 10-3 (see talk by Zeller)

  16. Svoboda

  17. Proton Decay

  18. Svoboda

  19. Galactic Supernova Burst

  20. Scholberg

  21. Neutrino hierarchy determination from a galactic supernova burst David Webber August 20, 2010

  22. Neutrino energies at infinity(1 second late-time slice of 10-second burst spectrum) H. Duan and A. Friedland, http://arxiv.org/abs/1006.2359

  23. Consider 3 detector possibilities • Water Cherenkov (WC) with 30% phototube coverage and high quantum-efficiency tubes • This is roughly equivalent to Super-K’s coverage • WC, 15% coverage, HQE • Liquid Argon

  24. n reaction cross-sections Water Argon Dominant reaction: Dominant reaction: https://wiki.bnl.gov/dusel/index.php/Event_Rate_Calculations

  25. Normal Hierarchy: Observed Spectra(accounts for detector acceptance) n flux at detector WC 30% coverage WC 15% coverage Liquid Ar

  26. Inverted Hierarchy: Observed Spectra(accounts for detector acceptance) n flux at detector WC 30% coverage WC 15% coverage Liquid Ar

  27. How many events are needed to distinguish normal from inverted hierarchy in water? Normal Hierarchy Inverted Hierarchy 102 events indistinguishable 105 events clearly distinguishable • Water Detector • 30% PMT coverage • HQE tubes • IBD reaction • c2 shown for “wrong” fit

  28. How many events for 3 sigma exclusion? • Note: c2is not the same as Gaussian • “3 sigma” = 99.73% confidence • 99.73% confidence is… • c2/NDF of 1.6 for 57 degrees of freedom • c2/NDF of 1.8 for 34 degrees of freedom

  29. c2 vs. events, WC, 30% coverage Normal fit Inverted fit Normal hierarchy Inverted hierarchy • Water Detector • 30% PMT coverage • HQE tubes • IBD reaction ~103.5-3.6 = 3200-4000 events are needed

  30. c2 vs. events, WC, 15% coverage Normal fit Inverted fit Normal hierarchy Inverted hierarchy • Water Detector • 15% PMT coverage • HQE tubes • IBD reaction ~103.5-3.6 = 3200-4000 events are needed

  31. How many events are needed to distinguish normal from inverted hierarchy in argon? Normal Hierarchy Inverted Hierarchy 102 events indistinguishable 105 events clearly distinguishable • Liquid Argon • c2 shown for “wrong” fit

  32. c2 vs. events, liquid argon Normal fit Inverted fit Normal hierarchy Inverted hierarchy ~102.7-2.8 = 500-630 events are needed

  33. Normal and inverted hierarchy neutrino spectra for 99.7% confidence. Normal Hierarchy Inverted Hierarchy Water Cherenkov 30% PMT coverage 4000 events Liquid Argon 630 events

  34. Summary • WC phototube coverage has little impact on resolving the hierarchy. • 15% is as good as 30% • To resolve the hierarchy… • ~4000 events must be observed in water, or • ~630 events must be observed in argon • If a SNB occurs at 8.5 kpc… • Need 18.3 kT water • Need 7.6 kTAr • a 100kT water module would have better statistics than a 17 kTLAr module • The LAr module would show more interesting spectral features This study was based on repository revision 754 Volume estimates based on http://arxiv.org/abs/astro-ph/0701081

  35. Confidence vs. Events See other slides • SNB Hierarchy study improvements: • Allow more parameters to fit in my study to allow for spectral shifts and broadening, eg. E --> E_0 + m*E • Perform a multi-module simultaneous for Argon (nue) and Water (nuebar).

  36. LBNE Workshop Summary • Choice of far detector is currently undecided • There are many choices • Liquid Argon has not been attempted at this size • possibility for something new • technical risk • Details of each detector are still under consideration

  37. Far Detector Options Water • 100 kTfiducial module. • 4850 ft depth. • 15% or 30% HQE PMT coverage? • Gadolineum or not? • 1,2,3 modules? • More signal! • Larger volume Liquid Argon • 17 kTfiducial module. • 300, 800, 4850 ft depth? • 3, 4, 5 mm wire spacing? • Probably will be 3 mm • photon trigger? • 1,2,3 modules? • Less background! • Better p0 identification 100 kT water ~= 17 kT liquid Ar for beam physics sensitivity

  38. References • http://www.int.washington.edu/talks/WorkShops/int_10_2b/, Aug 9-10

More Related