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A. Yu. Smirnov

Neutrinos:. Towards new phase of the field. A. Yu. Smirnov. International Centre for Theoretical Physics, Trieste, Italy Institute for Nuclear Research, RAS, Moscow, Russia. Outline. 10 years after discovery of oscillations. Quiet period?.

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A. Yu. Smirnov

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  1. Neutrinos: Towards new phase of the field A. Yu. Smirnov International Centre for Theoretical Physics, Trieste, Italy Institute for Nuclear Research, RAS, Moscow, Russia

  2. Outline 10 years after discovery of oscillations. Quiet period? New generation of neutrino experiments will start in 2009 – 2010 Future programs are under consideration time to think... Standard neutrino scenario Understanding neutrino mass and mixing Beyond the standard scenario Future which we know Future which we can imagine

  3. Standard neutrino scenario

  4. 1. Neutrino interactions are described by the Standard (electroweak) model. 2. There are only 3 types of light neutrinos: three flavors and three mass states. 3. Neutrinos are massive. Neutrino masses are in the sub-eV range - much smaller than masses of charge leptons and quarks. 4. Neutrinos mix. There are two large mixings angles and one small or zero angle; mixing strongly differs from that of quarks. 5. Masses and mixing have pure vacuum origin; they are generated at the EW and probably higher mass scales.

  5. Spectrum ne nm nt ? n3 n2 Dm221 n1 ? mass mass Dm223 Dm232 n2 Dm221 n1 n3 Inverted mass hierarchy Normal mass hierarchy nf = UPMNSnmass UPMNS = U23 Id U13 I-d U12

  6. Standard scenario ``neutrino time’’ 106 105 104 103 102 101 100 10-1 10 -2 me Pauli Fermi Result of work of several generations of neutrino physicists mn , eV Bergkvist collective efforts of experimentalists and theoreticians ITEP Zurich Los Alamos Troitzk, Mainz Our conquest territory. Basis and Starting point for further advance. Reference scenario KATRIN 2008 Summary of results of the first phase of studies of neutrino mass and mixing

  7. Interactions Gauge interactions are well known (SM) and well checked Yukawa couplings with Higgs boson(s) - related to existence of the RH neutrinos are unknown; they are relevant for leptogenesis Interaction with complex systems, nucleons and nuclei, nN-, nA: open questions problem of strong interactions. axial mass, single-pion forward production In some cases - neutrinos are unique: provide axial vector current  axial vector anomaly  interactions of Z, g, w (for MiniBooNE ) J Harley, C.T. Hill, R. Hill Nuclear physics for bb-decay Rare neutrino processes relevant for astrophysics, nn- pair production, etc.

  8. Propagation Theory of n-oscillations in vacuum: still some discussions ``Eternal Questions’’ • momentum vs. energy • stationary source approximation • relevance of the wave packets • coherence Paradoxes of n- oscillations matters for oscillations of ``Mossbauer neutrinos’’ In medium: oscillations at extreme conditions - high densities temperatures, magnetic fields, etc.. Neutrinos in neutrino gases: effects of the nn-scattering, collective, non-linear effects

  9. Phenomenology of the scenario Long baseline Solar Atmospheric neutrinos experiments neutrinos Supernova Cosmic neutrinos neutrinos To large extend phenomenology of standard scenario has been elaborated; in some cases - in great details Relic neutrinos Reactor Still some areas exist (cosmic, supernova neutrinos) where active research continues now neutrinos Few spots are not covered yet

  10. Comments Comprehensive description of neutrino conversion; very precise analytic results Solar From experimental side - detection of - the earth matter effect (day-night asymmetry, zenith angle dependence of signal); - upturn of spectrum (see recent BOREXINO result); - N,O, pep- neutrinos; - pp-neutrinos (??) neutrinos Atmospheric Comprehensive description of physical processes in terms of oscillograms of the Earth neutrinos Structures of oscillograms: - generalized amplitude condition - generalized phase condition CP- domains given by grids on magic lines and lines of the interference phase condition

  11. Oscillograms of the Earth 1 - Pee E. Akhmedov M. Maltoni A.S.

  12. CP-violation domains P(d) – P(0) formed by grids of magic lines and lines of interference phase DP

  13. Supernova neutrinos Further studies of collective effects: m = 2 GFnn can change whole picture of conversion w = Dm2/2E exact adiabatic solution Spectral splits (swaps) n1 H. Duan, G. Fuller, J. Carlson, Y. Z. Qian G. G. Raffelt, A.S. n2 Pw B initial spectrum final spectrum adiabatic G. Raffelt, A.S. exact

  14. Cosmic neutrinos New level of studies AGN GRBs Sources: E ~ 1 GeV – 104 TeV core-collapse supernovae Detailed computations of the neutrino yield (output) at different conditions SN remnants microquasars Related to developments of g-astronomy blasars for maximal 2-3 mixing and 2 : 1 : 0 original ratio flavor equilibration: 1 : 1 : 1 Vacuum oscillations Propagation: Conversion in matter of source deviations from 1 : 1 : 1 studies of various non-standard effects • n production mechanism • - q23= p /4

  15. Neutrinos from astrophysical sources flavor conversion in He-, H- envelopes n thick source Measurements of deviation of 2-3 mixing from maximal acceleration of protons in relativistic jets by the inner shocks Sensitivity to 1-3 mixing, type of mass hierarchy, CP - phase pp -, pn - collisions  neutrinos flavor conversion in outer layers  breaking flavor equilibration O. Mena, et al

  16. Long baseline experiments Physics is well understood (see oscillograms) LBL industry output d input s hierarchy E q13 L Lindner & Co sensitivities

  17. Masses and Mixing Right handed components of neutrinos exist Standard scenario Smallness of mass is due to some mechanism, that involves the EW scale and probably some higher scale(s) of nature In general: mn = mhard + msoft(E,n) medium-dependent soft component Bounds on msoft Neutrinos are Majorana particles? In the context of the see-saw mechanism: MR(heaviest) ~ MGUT is an interesting possibility Difference of the quark and lepton mass spectra and mixing patterns is related to the smallness of neutrino mass

  18. Where are we in understanding neutrino mass & mixing?

  19. Whole the excitement was that neutrino mass and mixing are manifestations of physics beyond the standard model! Dramatically, after many years and many trials the underlying physics hasn’t been identified. Certain problems have been realized. Nevertheless, we should further pursue the search, asking how the progress can be achieved

  20. Bottom-up Quark-lepton Tri-bimaximal Quark-Lepton universality mixing complementarity Gatto-Sartory-Tonin With different implications: ``bi-maximal - CKM'' QLCn VCKM+Vbm QLCl Vbm+VCKM Flavor symmetry The same principle as in quark sector Quark-lepton symmetry, GUT Extension to quarks ? Large mixing is related to weak mass hierarchy of neutrinos structure which produces bi-maximal mixing – symmetry? • subject of RGE • no relation to masses? • additional ambiguities • (CP-phases)

  21. Disentangling possibilities q12 ,q13 QLC n TBM q13 35.40, 9o 35.2o, 0 q12 ,q13 q12 QLC TBM: 23-mixing should be zero or very small l 32.2o, 1.5o

  22. 1-2 mixing Precision & benchmarks QLCl p/4 -qC tbm QLCn 2s SK, 2008 KamLADN + SNO, 2008 1s 3s Schwetz et al., 2008 * * 2s 1s 3s SNO (2008) 2s 1s Strumia-Vissani 99% 90% Fogli et al 2008** 3s Gonzalez-Garcia, Maltoni 2008 1s q12 29 31 33 35 37 39 q12+ qC ~p/4 UQLC1 = UC Ubm Utbm = Utm Um13 give almost the same 12 mixing

  23. 1-3 mixing ** - after n-2008 T2K Double CHOOZ QLCn Dm212/Dm322 qC QLCl Schwetz et al., 2008 * * 3s 2s 1s Gonzalez-Garcia, Maltoni 2008 1s 3s 99% Strumia-Vissani 90% Fogli et al 2008** 2s 1s sin2q13 0 0.01 0.02 0.03 0.04 0.05 * Non-zero central value (Fogli, et al): Atmospheric neutrinos, SK spectrum of multi-GeV e-like events * MINOS lead to stronger the bound on 1-3 mixing (G-G, M.)

  24. 12- and 13- mixings T. Schwetz et al., 0808..2016 G.L. Fogli, et al 0805.2517, v3 x x x

  25. Theta 1-3 Solar neutrinos: degeneracy of 1-2 and 1-3 mixing S. Goswami, A.S. sin2q13 = 0.017+/- 0.26

  26. Hint of non-zero 1-3 mixing? Fogli et al ., 0806.2649 • difference of 1-2 mixing from solar data and Kamland • atmospheric: excess of sub-GeV e-like events sin2q13 = 0.016 +/- 0.010

  27. 2-3 mixing SK: sin22q23 > 0.93, 90% C.L. T2K maximal mixing QLCn QLCl Schwetz et al., 2008 ** (without 1-2) 1s Gonzalez-Garcia, Maltoni, 2008 3s 1s SK (3n, one mass scale) 90% 3s Gonzalez-Garcia, Maltoni, A.S. 2s 1s Fogli et al 2008** 0.2 0.3 0.4 0.5 0.6 0.7 sin2q23 * in agreement with maximal, though all complete 3n - analyses show shift * shift of the bfp from maximal is small * still large deviation is allowed: (0.5 - sin2q23)/sin q23 ~ 40% 2s

  28. Flavor symmetries Fundamental symmetry Effective symmetries: Flavor features of various symmetry groups have been explored • No symmetry (or some other • symmetry) at the fundamental level. - Required symmetry appears at the effective level after decoupling of heavy degrees of freedom Discrete groups: A4 (subg. SO3) - many studies T7 (Frobenius) (subg. SU3) looks promising Partially realized in some models ``See-saw symmetry'' Deriving the group from observations S C Lam: Along with this line: ``Symmetries from mass hierarchies’’ TBM  S4 minimal symmetry Ferretti , S. King, A. Romanino,

  29. Real or accidental? Tri-bimaximal mixing Q-L-complementarity Maximal 2-3 mixing Very small 1-3 mixing Koide relation Accidental: interplay of different independent factors / contributions Real: immediate ``one step’’ Discovery of degenerate neutrino mass spectrum would be convincing evidence of existence of symmetry KATRIN Heidelberg-Moscow Degenerate spectrum and TBM are not related ?

  30. GeV Planck scale mechanisms Energy many O(100) RH neutrinos MPl 1018 M3 ~ MGUT MGUT GUT scale mechanisms scales 1015 1012 of new MRH scale of RH neutrino masses Intermediate Scale mechanisms 109 physics 106 LHC 103 VEW EW scale mechanisms mP 100 Low scale mechanisms 10-3 me kev-GeV scale mechanisms? 10-6 Physics behind neutrino masses is not identified 10-9 Neutrino masses 10-12

  31. Flavor & GUT Generic problem: difference of mass and mixing pattern GUT’s: unification of quarks and leptons difference of flavor properties Relate this difference to spontaneous breaking of GUT symmetry No 126H SO(10) flavons Non-renormalizable operators C Hagedorn M. Schmidt A.S. Singlet fermions Geometrical hierarchy of the up quark masses SO(10) + singlets + discrete flavor symmetries relates Nearly maximal 2-3 mixing

  32. The best scenario Minimal number of assumptions: Assumption 1: cos2q13 = 1 Assumption 2: 1/sin2q23 = 2 Assumption 3: 1/sin2q12 = 3 Plus possible small corrections… Any model with smaller number of assumptions?

  33. Koide relation Y. Koide, Lett. Nuov. Cim. 34 (1982), 201 me + mm + mt = 2/3 ( me + mm + mt )2 with accuracy 10-5 all three families are involved: no perturbation approach! was obtained in attempt to explain mm - me tanqC = 3 2 m t - mm - me mi = m0 (zi + z0)2 Both relations can be reproduced if Si zi = 0, z0 = Si zi2/3 C A Brannen Non-abelian flavor symmetry, VEV alignment Neutrinos, hierarchical spectrum Related to TBM?

  34. for neutrinos m1 + m2 + m3 C A Brannen, (2006) = 2/3 (- m1 + m2 + m3 )2 minus sign is crucial Neutrinos have hierarchical spectrum with m1 = 3.9 x 10-4 eV Related to TBM?

  35. From the bottom & from the top Data String theory menu * Existence of a number O(100) of singlets of SM and GUT symmetry group * GUT no simple relations between masses and mixing  can not be described in terms of few parameters * Several U(1) gauge factors * Discrete symmetries * Heavy vector-like families * Non-renormalizable interaction * Selection rules for interactions * Explicit violation of symmetry * Incomplete GUT multiplets No simple ``one-step’’ explanations How one can get from this complicated structure so simple pattern we observed at low energies?  data look complicated  data look too simple

  36. Beyond the standard scenario Two aspects: Searches for new physics Tests of the standard scenario

  37. Classifying possibilities New physics Neutrino motivated by anomalies other fields related to Various extensions of the standard model: SUSY, LR-symmetry, GUT extraD were driving force of the developments for more than 40 years explanation of neutrino masses Recall, 10 - 20 years ago ``standard’’ would be: - zero mass, - zero mixing… Unmotivated

  38. Anomalies: unresolved and new Seeds of new developments? feature: possible interpretation name: excess of e+-events LSND see separate slide excess of events at low energies MiniBooNE NuTeV value of sin qW low signal, tension with other data mixing with very light sterile neutrino Homestake - neutrino magnetic moment, - periodicity of energy release time variations of solar neutrino signals? Unnamed SN 1987A angular, time distributions LSD signal Astrophysics? Z0 -width Hadron physics? Nn < 3 modulation of exponential decay Nothing to do with neutrinos? New GSI

  39. LSND after MiniBooNE or MiniBooNE after LSND True or fake… triggered a number of developments Two sterile neutrinos with CP? M. Maltoni, T. Schwetz (Exotics)^2 Light vector boson + 3 sterile nu A. Nelson, J Walsh CPT violation + sterile neutrinos V. Barger, D. Marfatia, K. Whisnant Y. Farzan, T. Schwetz, A.S. Soft decoherence Reconstruct from data its L and E dependence, Something very exotic not connected to known physics processes checks of consistency = Mechanism X or LSND-effect

  40. New Physics New NSI New dynamics neutrino states Violation Of fundamental Symmetries: CPT Lorentz invariance Pauli principle Non-Standard Interactions Sterile neutrinos Vector, U(1)’ Tensor Unparticle Scalar physics Light particles Heavy

  41. Non-standard interactions Motivation: new physics at the EW and terascale; various extensions of SM Z’, SUSY, KK, light particles standard Rich phenomenology - propagation - detections Pee High energies where usual mixing is suppressed … q13 = 8o eet ~ - 0.5 sin2b white: strong transition Checks at LHC, Rare processes with L-violation M. Blennow, T. Ohlsson, 0805.2301

  42. General picture M S SO(10) A S Standard Model S S S S S u d n l nR S S L L A uR dR S S S lR S S S S S Hidden sector with certain symmetries S S S s Planck scale physics

  43. Sterile Neutrinos Contours of constant induced mass and bounds bb0n thermalization line: above if S are in equilibrium CMB For benchmark parameters S were thermalized X-rays Bounds - in non-equilibrium region LSS reactors atmospheric R. Zukanovic-Funchal, A.S.

  44. Unparticles H. Georgi Hidden sector (HS) e.g., gauge theory with fermions and coupling g g scale invariance Particles of HS couple with SM particles via exchange of messenger field(s) with mass M OU OUV g* infrared fixed point dUV - dU LU Mk 1 Mk OSMOUV C OSMOU C ~ 1 E Lu If g* >> 1  appearance of composite (confined) states of the HS particles (described by operators OU ) N. Krasnikov M. A. Stepanov hadrons  quarks Key difference: Scale invariance  continuous mass spectrum of confined states, Each has infinitesimal coupling with SM particles. Integral is finite Individual (mass) modes: negligible effect

  45. Unparticle effects Effects in solar neutrinos Neutrino decay: ni nj U ne- scattering L. Anchordoqui, H. Goldberg Shun Zhou Unparticle exchange: modifies matter potential and effective neutrino mass  modify survival probability M.C. Gonzalez-Garcia, P.C. de Holanda, R. Zukanovich-Funchal M – mass of messenger dH - dimension of operator in hidden sector, d – dimension of unparticle operator LU - infrared fixed point

  46. Future which we know

  47. Accomplish reconstruction of the neutrino mass and mixing spectrum • - 1-3 mixing • deviation of 2-3 mixing • from maximal • - CP-phase • mee, nature of neutrinos • absolute scale • - Majorana phases The program emerged more that 10 years ago well motivated and elaborated Reconstruction of neutrino mass matrix May not reconstruct completely 20 - 30 years?

  48. Leptonic unitarity triangle sin q13 = 0.15 em - triangle today in future - illustration - method to measure d , test of unitarity? Y. Farzan

  49. Another approach? Large atmospheric neutrino detectors 100 LAND NuFac 2800 0.005 CNGS 0.03 0.10 10 LENF E, GeV MINOS ~ 2000 events in Multi- megaton detector T2KK T2K 1 Degeneracy of parameters 0.1

  50. Searches for new physics beyond standard scenario improving bounds …. Precision measurements in neutrino physics One expects interesting interplay LHC other colliders Cosmology Cosmology Neutrino results Astrophysical data Rare processes Precision measurements

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