Testing Lorentz Invariance with Atmospheric Neutrinos and AMANDA-II - PowerPoint PPT Presentation

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Testing Lorentz Invariance with Atmospheric Neutrinos and AMANDA-II

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  1. Testing Lorentz Invariance with Atmospheric Neutrinos and AMANDA-II John Kelley for the IceCube CollaborationUniversity of Wisconsin, Madison CPT ‘07, Bloomington, Indiana August 9, 2007

  2. The IceCube Collaboration Sweden: Uppsala Universitet Stockholm Universitet USA: Bartol Research Institute, Delaware Pennsylvania State University UC Berkeley UC Irvine Clark-Atlanta University University of Maryland University of Wisconsin-Madison University of Wisconsin-River Falls Lawrence Berkeley National Lab. University of Kansas Southern University and A&M College, Baton Rouge University of Alaska, Anchorage Germany: Universität Mainz DESY-Zeuthen Universität Dortmund Universität Wuppertal Humboldt Universität zu Berlin MPI Heidelberg RWTH Aachen UK: Oxford University Netherlands: Utrecht University Japan: Chiba University Belgium: Université Libre de Bruxelles Vrije Universiteit Brussel Universiteit Gent Université de Mons-Hainaut New Zealand: University of Canterbury 29 institutions, ~250 members http://icecube.wisc.edu John Kelley, UW-Madison, CPT '07

  3. Array of optical modules on cables in ice or water (“strings” or “lines”) • High energy muon (~TeV) from charged current  interaction • Good angular reconstruction from timing of Cherenkov cone • Rough  energy estimate from muon energy loss • OR, look for cascades (e, , NC )

  4. AMANDA-II • The AMANDA-II neutrino telescope is buried in deep, clear ice, 1500m under the geographic South Pole • 677 optical modules: photomultiplier tubes in glass pressure housings • Muon direction can be reconstructed to within 2-3º optical module

  5. Amundsen-Scott South Pole Research Station IceCube South Pole Station AMANDA-II skiway Geographic South Pole John Kelley, UW-Madison, CPT '07

  6. Atmospheric Production Cosmic rays (mostly p+) produce muons, neutrinos through pion / kaon decay Even with > km overburden, atm. muon events dominate over  by ~106 Neutrino events: reconstruct direction + use Earth as filter, or look only for UHE events Figure from Los Alamos Science 25 (1997) John Kelley, UW-Madison, CPT '07

  7. Current Experimental Status • No detection (yet) of • point sources or other anisotropies • diffuse astrophysical flux • transients (e.g. GRBs, AGN flares, SN) • Astrophysically interesting limits set • Large sample of atmospheric neutrinos • AMANDA-II: >4K events, 0.1-10 TeV A. Achterberg et al., astro-ph/0611063 Opportunity for particle physics with high-energy atmospheric  John Kelley, UW-Madison, CPT '07

  8. Violation of Lorentz Invariance (VLI) • Effective field-theoretic approach by Kostelecky, Colladay, et al. (SME: hep-ph/9809521; +, hep-ph/0403088) Addition of renormalizable VLI and CPTV+VLI terms; encompasses a number of interesting specific scenarios John Kelley, UW-Madison, CPT '07

  9. *see Kostelecky & Mewes, PRD 69 016005 (2004) VLI Phenomenology • Effective Hamiltonian (seesaw + leading order VLI+CPTV)*: • To narrow possibilities we consider: • rotationally invariant terms (only time component) • only cAB00 ≠ 0 (leads to interesting energy dependence…) John Kelley, UW-Madison, CPT '07

  10. VLI Oscillations • Equivalent to modified dispersion relation: • Different maximum attainable velocities ca (MAVs) for different particles*: E ~ (c/c)E • For neutrinos: MAV eigenstates not necessarily flavor or mass eigenstates  mixing  VLI oscillations *see, e.g., Glashow and Coleman, PRD 59 116008 (1999) John Kelley, UW-Madison, CPT '07

  11. VLI Oscillations (continued) • For atmospheric , conventional oscillations turn off above ~50 GeV (L/E dependence) González-García, Halzen, and Maltoni, hep-ph/0502223 • VLI oscillations turn on at high energy (n=1 above; L E dependence), depending on size of c/c, and distort the zenith angle / energy spectrum John Kelley, UW-Madison, CPT '07

  12. Atmospheric Survival Probability c/c = 10-27

  13. 2000-2003 AMANDA-II Data • Quality selection criteria used to separate neutrinos from background atmospheric muons • Bad OMs, electrical crosstalk, and mis-reconstructed muons eliminated • Total livetime is 807.2 days • 3401 neutrino candidate events survive the selection criteria Number of OMs hit (energy estimator) J. Ahrens, Ph.D. thesis, Univ. of Mainz John Kelley, UW-Madison, CPT '07

  14. Analysis Method function parametrizing sys. errors 4 bins: 2 zenith  2 Nch VLI parameter space systematic errors:  = flux normalization(30%)  = K /  ratio(6%)  = OM sensitivity(11.5%) John Kelley, UW-Madison, CPT '07

  15. Results • No evidence for alternative oscillations found • 90% CL limit set on VLI and VEP parameter for maximal mixing angle: c/c, 2|| ≤ 5.3  10-27 • Result comparable to other experiments • MACRO: c/c < 2.5  10-26 (90% CL)Battistoni et al., hep-ex/0503015 • SuperK + K2K: c/c < 2.0  10-27González-García & Maltoni, PRD 70 033010 (2004) John Kelley, UW-Madison, CPT '07

  16. Future Sensitivity (maximal mixing) • AMANDA-II: sensitivity of c/c ~ 10-27 (7 years)with full likelihood analysis technique (JK, astro-ph/0701333) • Analysis will also test for quantum decoherence, LE2, LE3, rotation? • IceCube: sensitivity of c/c ~ 10-28up to 700K atmospheric  in 10 years(González-García, Halzen, and Maltoni, hep-ph/0502223) John Kelley, UW-Madison, CPT '07

  17. 1.2 km IceTop IceCube: 22 strings deployed 450 m AMANDA-II IceCube 1 km 2500m deep hole!

  18. IceCube Sensitivity potential IceCube exclusion (10 yr) VLI / VEP parameter VLI mixing angle John Kelley, UW-Madison, CPT '07

  19. Summary • Neutrino telescopes provide a large sample of HE atmospheric  — probe of new physics • AMANDA-II 2000-03 VLI limit in neutrino sector: c/c ≤ 5.3  10-27 (maximal mixing) • Improvements on the way with more AMANDA-II data, IceCube John Kelley, UW-Madison, CPT '07