1 / 61

Solar Neutrinos: Current Implications and Future Possibilities

Solar Neutrinos: Current Implications and Future Possibilities. - Solar neutrinos - Reactor antineutrinos - Future Possibilities. SNO. KamLAND. solar neutrinos. b -decay. bb -decay. CENPA. J. F. Wilkerson March 20, 2003 Fermilab -- NUHORIZONS.

boyd
Download Presentation

Solar Neutrinos: Current Implications and Future Possibilities

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. Solar Neutrinos: Current Implications and Future Possibilities - Solar neutrinos - Reactor antineutrinos - Future Possibilities SNO KamLAND solar neutrinos b-decay bb-decay CENPA J. F. Wilkerson March 20, 2003 Fermilab -- NUHORIZONS Center for Experimental Nuclear Physics and Astrophysics

  2. SSM Energy Generation p + p 2H + e+ + e p + e- + p  2H + e 2H + p 3He +  3He + 3He 4He + 2p 3He + p  + e+ + e 3He +  7Be +  7Be + e- 7Li +  +e 7Be + p 8B +  7Li + p   +  8B  2  + e+ + e Our “accelerator” - the Sun 1854 von Helmholtz postulates gravitational energy 1920’s Eddington proposes p + p fusion “We do not argue with the critic who urges that the stars are not hot enough for this process; we tell him to go and find a hotter place.” 1938 Bethe & Critchfieldp + p 2H + e+ + ne

  3. SSM Energy Generation p + p 2H + e+ + e p + e- + p  2H + e 2H + p 3He +  3He + 3He 4He + 2p 3He + p  + e+ + e 3He +  7Be +  7Be + e- 7Li +  +e 7Be + p 8B +  7Li + p   +  8B  2  + e+ + e Using solar ns’ to probe the Sun 1946 Pontecorvo,1949 Alvarez 37Cl + ne37Ar + e-

  4. Using solar ns’ to probe the Sun 1946 Pontecorvo,1949 Alvarez 37Cl + ne37Ar + e- 1960’s Ray Davis, builds Chlorine detector John Bahcall, generates SSM & n flux predictions “…to see into the interior of a star and thus verify directly the hypothesis of nuclear energy generation in stars...”

  5. Solar n FluxMeasurement Results  n flux ~ 6.5 • 1010/cm2/s

  6. Hata and Langacker SSM Energy Generation p + p 2H + e+ + e p + e- + p  2H + e 2H + p 3He +  3He + 3He 4He + 2p 3He + p  + e+ + e 3He +  7Be +  7Be + e- 7Li +  +e 7Be + p 8B +  7Li + p   +  8B  2  + e+ + e Astrophysical Solutions? The data are incompatible with standard and non-standard solar models (For a model independent analysis see Heeger and Robertson, PRL 77 (1996) 3720 )

  7. +0.08 - 0.07 (106cm-2 s-1) • ES = 2.32± 0.03 • (stat) (sys.) Super-Kamiokande (hep-ex/0103032) Elastic Scattering:nx+e-nx+e- +0.016 - 0.014 • Data/SSM = 0.451± 0.005 • (stat) (sys.)

  8. Both Expts Performed n source tests 51Cr + e-51V + ne Gallium Measurements 71Ga + ne71Ge + e- Two independent experiments SAGE Data/SSM = 0.55± 0.05 GALLEX Data/SSM = 0.57± 0.05 Latest SAGE results (astro-ph/0204245) SSM

  9. Both Expts Performed n source tests 51Cr + e-51V + ne Gallium Measurements 71Ga + ne71Ge + e- Two independent experiments SAGE Data/SSM = 0.55± 0.05 GALLEX Data/SSM = 0.57± 0.05 Latest SAGE results (astro-ph/0204245) SSM

  10. Both Expts Performed n source tests 51Cr + e-51V + ne SAGE Source Test R(smea/sth)=0.95±.12±.03 Gallium Measurements 71Ga + ne71Ge + e- Two independent experiments SAGE Data/SSM = 0.55± 0.05 GALLEX Data/SSM = 0.57± 0.05 Latest SAGE results (astro-ph/0204245) SSM

  11. Beyond the Standard Model - n mass & mixing Vacuum Oscillations Small splittings in mass can lead to large observable phase differences in Q.M. amplitude.

  12. 102 1 10-2 10-4 10-6 10-8 10-10 10-2 1 102 104 106 108 1010 Sensitivity of experiments to n oscillations Dm2 (eV2 ) Accelerator [~GeV] Reactor [~MeV] Atmospheric [~GeV] Solar [~MeV] L/E (km/GeV)

  13. Matter Enhanced Oscillations (MSW) 102 1 10-2 10-4 10-6 10-8 10-10 ns in matter can acquire an effective mass through scattering (analogous to index of refraction for light in transparent media) 10-2 1 102 104 106 108 1010 MSW Sensitivity of experiments to n oscillations Dm2 (eV2 ) Accelerator [~GeV] Reactor [~MeV] Atmospheric [~GeV] Solar [~MeV] L/E (km/GeV)

  14. Mikhevev, Smirnov, Wolfenstein Effect Matter Enhanced Oscillations e- e- e- ne Z W ns in matter can acquire an effective mass through scattering (analogous to index of refraction for light in transparent media) nx ne nx e- Normal Matter contains many electrons, but no muons or taus, so necan undergo both CC and NC scattering. Have QM two-state level crossing and flavor change. MSW Oscillations are dependent on the n energy and the density of the material, hence one can observe spectral energy distortions.

  15. Matter Enhanced n Oscillations MSW gives a dramatic extension of oscillation sensitivity to potential regions in Dm2 LMA SMA Solar n data are consistent with the MSW hypothesis. LOW • But only circumstantial evidence • Need definitive proof • Appearance measurement • Independent of SSM

  16. The SNO Collaboration G. Milton, B. Sur Atomic Energy of Canada Ltd., Chalk River Laboratories S. Gil, J. Heise, R.J. Komar, T. Kutter, C.W. Nally, H.S. Ng, Y.I. Tserkovnyak, C.E. Waltham University of British Columbia J. Boger, R.L Hahn, J.K. Rowley, M. Yeh Brookhaven National Laboratory R.C. Allen, G. Bühler, H.H. Chen* University of California, Irvine I. Blevis, F. Dalnoki-Veress, D.R. Grant, C.K. Hargrove, I. Levine, K. McFarlane, C. Mifflin, V.M. Novikov, M. O'Neill, M. Shatkay, D. Sinclair, N. Starinsky Carleton University T.C. Andersen, P. Jagam, J. Law, I.T. Lawson, R.W. Ollerhead, J.J. Simpson, N. Tagg, J.-X. Wang University of Guelph J. Bigu, J.H.M. Cowan, J. Farine, E.D. Hallman, R.U. Haq, J. Hewett, J.G. Hykawy, G. Jonkmans, S. Luoma, A. Roberge, E. Saettler, M.H. Schwendener, H. Seifert, R. Tafirout, C.J. Virtue Laurentian University Y.D. Chan, X. Chen, M.C.P. Isaac, K.T. Lesko, A.D. Marino, E.B. Norman, C.E. Okada, A.W.P. Poon, S.S.E Rosendahl, A. Schülke, A.R. Smith, R.G. Stokstad Lawrence Berkeley National Laboratory M.G. Boulay, T.J. Bowles, S.J. Brice, M.R. Dragowsky, M.M. Fowler, A.S. Hamer, A. Hime, G.G. Miller, R.G. Van de Water, J.B. Wilhelmy, J.M. Wouters Los Alamos National Laboratory J.D. Anglin, M. Bercovitch, W.F. Davidson, R.S. Storey* National Research Council of Canada J.C. Barton, S. Biller, R.A. Black, R.J. Boardman, M.G. Bowler, J. Cameron, B.T. Cleveland, X. Dai, G. Doucas, J.A. Dunmore, H. Fergani, A.P. Ferrarris, K. Frame, N. Gagnon, H. Heron, N.A. Jelley, A.B. Knox, M. Lay, W. Locke, J. Lyon, S. Majerus, G. McGregor, M. Moorhead, M. Omori, C.J. Sims, N.W. Tanner, R.K. Taplin, M.Thorman, P.M. Thornewell, P.T. Trent, N. West, J.R. Wilson University of Oxford E.W. Beier, D.F. Cowen, M. Dunford, E.D. Frank, W. Frati, W.J. Heintzelman, P.T. Keener, J.R. Klein, C.C.M. Kyba, N. McCauley, D.S. McDonald, M.S. Neubauer, F.M. Newcomer, S.M. Oser, V.L Rusu, S. Spreitzer, R. Van Berg, P. Wittich University of Pennsylvania R. Kouzes Princeton University E. Bonvin, M. Chen, E.T.H. Clifford, F.A. Duncan, E.D. Earle, H.C. Evans, G.T. Ewan, R.J. Ford, K. Graham, A.L. Hallin, W.B. Handler, P.J. Harvey, J.D. Hepburn, C. Jillings, H.W. Lee, J.R. Leslie, H.B. Mak, J. Maneira, A.B. McDonald, B.A. Moffat, T.J. Radcliffe, B.C. Robertson, P. Skensved Queen’s University D.L. Wark Rutherford Appleton Laboratory, University of Sussex R.L. Helmer, A.J. Noble TRIUMF Q.R. Ahmad, M.C. Browne, T.V. Bullard, G.A. Cox, P.J. Doe, C.A. Duba, S.R. Elliott, J.A. Formaggio, J.V. Germani, A.A. Hamian, R. Hazama, K.M. Heeger, K. Kazkaz, J. Manor, R. Meijer Drees, J.L. Orrell, R.G.H. Robertson, K.K. Schaffer, M.W.E. Smith, T.D. Steiger, L.C. Stonehill, J.F. Wilkerson University of Washington

  17. p - n + d  + p + e CC e n +  + + n NC d p n x x ES - - +  + n e n e x x The Sudbury Neutrino Observatory • Good sensitivity to ne energy spectrum • Weak directional sensitivity 1-1/3cos(q) • ne only. • Measure total 8B n flux from the sun. • Equal cross section for all n types • 2.2 MeV Threshold, Integrated E > Eth • Low Statistics • Dominant contribution (5/6) from ne,, smaller (`1/6) contributions from n & n • Strong directional sensitivity

  18. Fcc ne = Fnc ne +nm+ nt Fday Fnight vs Key signatures for unexpected n Flavors Measure total flux of solar neutrinos vs. the pure ne flux Fcc ne June 2001 = Direct Evidencefor n flavor change Fes ne + 0.154(nm+ nt) April 2002 Potential signal For n oscillations April 2002

  19. The SNO Detector during Construction

  20. The SNO Detector during Construction

  21. The SNO Detector during Construction

  22. The SNO Detector during Construction

  23. n +  + + - CC d p e e n +  + + n NC d p n x x ES - - +  + n e n e x x  Reactions in SNO p Produces Cherenkov Light Cone in D2O • Good measurement of ne energy spectrum • Weak directional sensitivity 1-1/3cos(q) • ne only. D2O Only Phase n captures on deuteron 2H(n, g)3H Observe 6.25 MeV g • Measure total 8B n flux from the sun. • Equal cross section for all n types • 2.2 MeV Threshold, Integrated E > Eth Produces Cherenkov Light Cone in D2O • Low Statistics • Mainly sensitive to ne,, some sensitivity to n and n • Strong directional sensitivity

  24. Extraction of CC, ES, NC Signals To extract the CC, ES, NC signal SNO performs a Max-likelihood statistical separation of these signals based on distributions of the SNO observables.

  25. First result Eth of 6.75 MeV CC 1967.7 #EVENTS +61.9 +26.4 +49.5 +60.9 +25.6 +48.9 ES 263.6 NC 576.5 Shape Constrained Signal Extraction Results

  26. Fsno = 5.09 +1.01 Fssm= 5.05 -0.81 +0.44 +0.46 -0.43 -0.43 SNO NC in D2O Conclusions ~ 2/3 of initial solar ne are observed at SNO to be nm,t Rule out null hypothesis - no flavor change - at 5.3 s level.

  27. 2.0 1.5 Fes(ne) = 2.39 x106 cm-2s-1 Fcc(ne) = 1.76 x106 cm-2s-1 FNC(ne) = 5.09 x106 cm-2s-1 Neutrino Signal (SSM BP00) 1.0 0.5 0.0 +0.06 +0.12 +0.44 +0.46 +0.24 +0.09 -0.12 -0.23 -0.09 -0.43 -0.43 -0.05 SNO Signal Extraction inFCC, FNC, FESEtn = 5 MeV June 2001 Elastic Scattering (ES) Neutral Current (NC) Charged Current (CC) 8B from CCSNO+ESSK CC shape constrained ESSNO CCSNO SSM April 2002 5.3  NCSNO ESSNO CC shape unconstrained CCSNO e e+ + e+ 0.15 (+)

  28. SNO Conclusions nucl-ex/0204008, nucl-ex/0204009 • First NC flux measurements - clear evidence that the majority of e produced in the Sun are transformed to  and/or  • Null hypothesis - “No Weak Flavor Mixing” ruled out at 5.3 s • Lowest Detection threshold yet for a real-time solar n detector • Total 8B flux measurement agrees well with Solar Models • Data in good agreement with previous SNO - SK CC/ES result • First measurements of the Day-Night Asymmetries • SNO Data consistent with MSW oscillation interpretation • combined with global solar neutrino data favors LMAsolution • “Dark side” solutions not allowed, indicating mn2 > mn1 Combining All Experimental and Solar Model information

  29. + p  n + e n + e Reactor ne oscillation searches 1956 Reines & Cowan Chooz hep-ex/9907037 Disappearance experiments

  30. Solar neutrino LMA implication Reactor experiments optimum at ~180 km Solar LMA best fit prediction

  31. KamLAND Collaboration G.A.Horton-Smith, R.D.McKeown, J.Ritter, B.Tipton, P.Vogel California Institute of Technology C.E.Lane, T.Miletic Drexel University Y-F.Wang IHEP, Beijing T.Taniguchi KEK B.E.Berger, Y-D.Chan, M.P.Decowski, D.A.Dwyer, S.J.Freedman, Y.Fu, B.K.Fujikawa, K.M. Heeger, K.T.Lesko,K-B.Luk, H.Murayama, D.R.Nygren, C.E.Okada, A.W.Poon, H.M.Steiner, L.A.Winslow LBNL/UC Berkeley S.Dazeley, S.Hatakeyama, R.C.Svoboda Louisiana State University J.Detwiler, G.Gratta, N.Tolich, Y.Uchida Stanford University K.Eguchi, S.Enomoto, K.Furuno, Y.Gando, J.Goldman, H.Ikeda, K.Ikeda, K.Inoue, K.Ishihara, T.Iwamoto, T.Kawashima, Y.Kishimoto, M.Koga, Y.Koseki, T.Maeda, T.Mitsui, M.Motoki, K.Nakajima, H.Ogawa, K.Oki, K.Owada, I.Shimizu, J.Shirai, F.Suekane, A.Suzuki, K.Tada, O.Tajima, K.Tamae, H.Watanabe Tohoku University L.DeBraeckeleer, C.Gould, H.Karwowski, D.Markoff, J.Messimore, K.Nakamura, R.Rohm, W.Tornow, A.Young TUNL J.Busenitz, Z.Djurcic, K.McKinny, D-M.Mei, A.Piepke, E.Yakushev University of Alabama P.Gorham, J.Learned, J.Maricic, S.Matsuno, S.Pakvasa University of Hawaii B.D.Dieterle University of New Mexico M.Batygov, W.Bugg, H.Cohn, Y.Efremenko, Y.Kamyshkov, Y.Nakamura University of Tennessee

  32. KamLAND - Kamioka LiquidScintillator Anti-NeutrinoDetector 16 complexes - 10% of world’s nuclear power 3 GW reactor: ~8 • 1020 ne/s L ~140 - 210 km

  33. KamLAND - Kamioka LiquidScintillator Anti-NeutrinoDetector 16 complexes - 10% of world’s nuclear power 3 GW reactor: ~8 • 1020 ne/s L ~140 - 210 km

  34. KamLAND first results (hep-ex/0212021) • Data summary • 145.1 live days • Observed: 54 • Expected: 86.8 ± 5.6 • Background 1 ± 1 Measured survival probability differs from 1 by 4.1  Probability that result is consistent with no oscillation hypothesis < 0.05%

  35. Evidence of neoscillations Global fit (de Holanda and Smirnov) KamLAND with LMA shown CL: 1s, 90%, 95%, 99%, 3s CL: 95% hep-ex/0212021 hep-ph/0212270

  36. Current situation • Atm. n, Solar n, & KamLAND provide compelling evidence for oscillations. • LSND awaits confirmation by miniBoone. • Big surprise - unlike quark sector (CKM), lepton sector has large mixing angles. • Osc. Results yield a LOWER BOUND on mn ; tritium beta decay, astrophysical data set UPPER BOUND _ _ nmnsne nmnt Solar n & KamLAND nenmt What’s next?

  37. n physics - issues & questions • accurate determinations of qij, Dm2ij • especially q13 • CP violation phases • Majorana/Dirac character of the neutrinos • absolute scale of neutrino mass • magnetic and other neutrino moments • existence of, constraints on sterile neutrinos • inverted or regular hierarchy? • role of neutrinos in nucleosynthesis, supernova explosions, BBN • lepton number violation • baryogenesis via leptogenesis

  38. Non-accelerator n physics - future possibilities • Solar neutrinos • More accurate determination of q12 • potential independent observation of oscillations • day/night effect • low energy 7Be & pp shape effects • Astrophysics (pp flux, CNO cycle) • Single b-decay(endpoint measurement) • absolute scale of neutrino mass • 0 nbb-decay • Majorana/Dirac character of the neutrinos • absolute scale of neutrino mass • inverted or regular hierarchy? • Atmospheric neutrinos - covered by Kearns • Reactor neutrinos - will be covered by Gratta

  39. Future Possibilities for Solar Neutrinos Solar neutrinos - immediate future • SNO entering precision phase of experiment • Salt measurements underway since June 2001 • 3He proportional neutral current detectors (Fall 2003) • Some possibility of observing day/night effect - and hence direct oscillation signature

  40. SNO - Current Status and Future Plans Neutral Current Detectors The Salt Phase n35Cl 36Cl g …  e (Eg = 8.6 MeV) n3He  p  t • Event by event separation • Different systematics • Higher n-capture efficiency • Higher event light output • Event isotropy differs from e- • Running since June 2001

  41. Impact of precision SNO • Improved NC/CC measure-ment will yield an improved q12 value (red ---- lines) • D2O: unconstrained ~30% • Salt: perhaps 10-15% • NCD: potentially ~5 % • Note KamLAND should improve on Dm12 • Possible chance to observe Day/Night asymmetry and hence direct oscillation siganl de Holanda and Smirnov hep-ph/0212270

  42. Ax = 2*(FN,X – FD,X) (FN,X + FD,X) MSW and Day-Night Fluxes Certain MSW oscillation solutions predict ns can change flavor while passing through the earth Define Asymmetry

  43. Signal Extraction in FCC, FNC, FES. • Anc = -20.4 16.9 • Acc = 14.0 6.3 +1.5 +2.0 +2.4 +1.3 -2.5 -1.4 -1.2 -1.7 + + + + - - - - • Ae = 7.0 4.9 • Aesk = 5.3 3.7 SNO Ae and Atot Measurements Signal Extraction in Fe, Ftotal,+ Atotal = 0

  44. Impact of precision SNO • Improved NC/CC measure-ment will yield an improved q12 value (red ---- lines) • D2O: unconstrained ~30% • Salt: perhaps 10-15% • NCD: potentially ~5 % • Note KamLAND should improve on Dm12 • Possible chance to observe Day/Night asymmetry and hence direct oscillation siganl (blue -- lines) • limited by statistics • Depends on real solution de Holanda and Smirnov hep-ph/0212270

  45. Future Possibilities for Solar Neutrinos Solar neutrinos - immediate future • SNO entering precision phase of experiment • Salt measurements underway since June 2001 • 3He proportional neutral current detectors (Fall 2003) • Some possibility of observing day/night effect - and hence direct oscillation signature • KamLAND solar n and Borexino (2004?) real-time 7Be ( KamLAND initial backgrounds look promising for solar n measurements) • Independent confirmation of LMA solution • Confirmation of solar model, slight improvement on CNO limit Next generation experiments (pp in real-time)

  46. Next generation Solar Neutrinos Charged-Current Experiments: LENS, MOON Goal: Measure ne component of p-p (7Be) with 1-3% (2-5%) accuracy Elastic Scattering Experiments: CLEAN, HERON, TPC XMASS (Japan) Goal: Measure ne / nm, nt component of p-p (7Be) with 1-3% (2-5%) accuracy Projected

  47. Future Possibilities for Solar Neutrinos Solar neutrinos - immediate future • SNO entering precision phase of experiment • Salt measurements underway since June 2001 • 3He proportional neutral current detectors (Fall 2003) • Some possibility of observing day/night effect - and hence direct oscillation signature • KamLAND solar n and Borexino (2004?) real-time 7Be ( KamLAND initial backgrounds look promising for solar n measurements) • Independent confirmation of LMA solution • Confirmation of solar model, slight improvement on CNO limit Next generation experiments (pp in real-time) • q12 to 1% • CPT- potentially more sensitive than kaon system • ~10 x improvement on neutrino magnetic moment sensitivity • Confirmation of solar model, slight improvement on CNO limit “…to see into the interior of a star and thus verify directly the hypothesis of nuclear energy generation in stars...”

  48. The absolute scale of n masses • Addresses key issues in particle physics • hierarchical or degenerate neutrino mass spectrum • understanding the scale of new physics beyond SM • potential insight into origin of fermion masses • Impacts cosmology and astrophysics • early universe, relic neutrinos (HDM), structure formation, anisotropies of CMBR • supernovae, r-process, origin of elements • potential insight on understanding the origin of UHE cosmic rays

  49. sub-eV absolute n mass measurements hierarchical degenerate Given the surprise of large mixing in the lepton sector, there is limited theoretical insight into which scenario occurs in nature.

  50. Probes of absolute n mass • Indirect methods • Cosmology • CMB • Galaxy clusters • Lyman-a forest • Galaxy large scale structure • Astrophysics • UHE cosmic-rays • Supernovae generation mechanisms • Neutrinolessbb-decay • Direct techniques • time of flight (supernovae) • particle decay kinematics

More Related