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Neutrino mass-mixing parameters and implications for single and double beta decay searches

Neutrino mass-mixing parameters and implications for single and double beta decay searches. Venice, March 8, 2007. Gianluigi Fogli. Gianluigi Fogli. Dipartimento di Fisica dell’Università di Bari & Sezione INFN - Bari.

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Neutrino mass-mixing parameters and implications for single and double beta decay searches

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  1. Neutrino mass-mixing parameters and implications for single and double beta decay searches Venice, March 8, 2007 Gianluigi Fogli Gianluigi Fogli Dipartimento di Fisica dell’Università di Bari & Sezione INFN - Bari Based on work done in collaboration with: E. Lisi, A. Marrone, A. Melchiorri, A. Palazzo, P. Serra, J. Silk, A. Slosar XII International Workshop on “Neutrino Telescopes”

  2. Outline • Oscillationsvs.absolute mass searches • An analysis of the3oscillation constraints • Constraints from non-oscillation data • A global analysis in the space of the observables • Conclusions Based on work done in collaboration with: E. Lisi, A. Marrone, A. Melchiorri, A. Palazzo, P. Serra, J. Silk, A. Slosar Mainly based on: hep-ph/0608060 (latest), hep-ph/0506083, hep-ph/0408045 See references therein for credits to experimental and theoretical works in  physics

  3. Oscillations vs. absolute mass searches Raffaello - Selfportrait

  4. Muon flavor non-conservation Electron flavor non-conservation Super-K KamLAND oscillations driven by m2~ 2.6 x 10-3 eV2 oscillations driven by m2 ~ 8.0 x 10-5 eV2 As we know, 2 different oscillation frequencies established: … but, in this way, no indication on absolute neutrino masses

  5. Tritium  decay: 3H 3He + e + e . e mass estimated from the end points of the Kurie plot all CP and Majorana phases disappear 1)Beta decay:time-honored search for the absolute mass of thene (Fermi 1934) Three main probes of absolute neutrino masses But e ≠ 1 (i.e. Ue1 ≠ 1), so what  decay probes (in 1st approximation) is an effective mass, the so-called “effective electron neutrino mass”, weighted by the e mixing with all i’s: mb2=åi ÷Uei÷2mi2

  6. n p e- ´ mn ni e- transition N(A, Z)  N(A, Z+2) + e- + e- n p K. Zuber at SUSSP 2006 2 effective Majorana mass m=åiUei mi CP and Majorana phases enter here 2)Neutrinoless Double Beta decay (if Majorana) Three main probes of absolute neutrino masses The electroweak part probes the so-called

  7. m = 0 eV m = 1 eV (E..g., Ma 1996) Neutrinos suppress the growth of fluctuations when they become non relativistic: a neutrino with mass of a fraction of eV would produce a significant suppression in the clustering on small cosmological scales m = 7 eV m = 4 eV Cosmological data mainly sensitive to the sum of the neutrino masses: = m1 + m2 + m3 3)Precision cosmology (a “modern” probe) Three main probes of absolute neutrino masses

  8.  decay a very good approximation, valid if energy smearing prevents observation of separate “Kurie plot kinks” 02 decay expression basically exact (as far as no RH currents or new physics interfere with light neutrino exchange) Cosmology leading sensitivity related to the sum of the masses; in the (far) future, maybe some weak sensitivity to mass spectrum hierarchy that depend on the parameters measured in  oscillations: Three absolute mass observables: m, m, 

  9. oscill. allowed m  Oscillations fix the mass2 splittings, and thus induce positive correlations between any pair of the three observables(m, m, ), e.g.: Interplay between oscillation - nonoscillation bounds i.e., if one observable increases, the other one (typically) must increase to match the mass2 splitting

  10. m oscill. allowed m  In the absence of new physics(beyond 3 masses and mixing), determinations of any two observables among(m, m, )are expectedtocross the oscillation band Interplay/2  This requirement provides either an important consistency check or, if not realized, an indication for new physics (barring expt. mistakes)  Analysis of established oscillation data is an important ingredient

  11. An analysis of the 3 oscillation constraints Marc Chagall - Selfportrait

  12. …final results of our global analysis of world neutrino oscillation searches (with solar, atmospheric, accelerator, reactor neutrino beams)*, in terms of, e.g.,2ranges(= 95 % C.L.): To make a long story short … *Debated LSND result (a 4th sterile neutrino?) excluded here (more info later today by M. Shaevitz) Determination ofsin213  e32is one of the most urgent problems with implications also for CP and hierarchy determination

  13. MINOS not included MINOS included (A detail: Impact of MINOS 2006 data) 2 error on m2 reduced from 24% to 15% no significant impact elsewhere

  14. Degenerate (overlap) Inverted Normal Bands overlap when mass splittings are small with respect to the absolute masses: Bands from oscillation datafornormalandinvertedhierarchy

  15. Oscillation results Concerningm There is a large intrinsic uncertainty due to the unknown Majorana phases constructive/destructive interference of channels

  16. Constraints from non-oscillation data Antonio Canova - Selfportrait

  17. e.g., if… Dreaming about future precise non-oscillation data … Data = green “dot” in the figure, then … in principle, one might, with some luck: Check the overall consistency between oscill./nonoscill. data … Identify the hierarchy … (inverted, in this case) Probe the Majorana phase(s) … (i.e., reduce vertical spread in m)

  18.  decay: no signal so far. Mainz & Troitsk expts:m < O(eV) 02 decay, no signal in all experiments, except in the most sensitive one to date(Heidelberg-Moscow). Rather debated claim. • Claim accepted: m in sub-eV range (with large uncertainties) • Claim rejected: m < O(eV) Cosmology. Upper bounds: < eV/sub-eV range,depending on the adopted data inputs and priors. E.g., Ly- data crucial to probe sub-eV region deeply (but: systematics?) … Back to real life! Info from non-oscillation experiments:

  19. Half-life results can be transformed in bounds on mif nuclear matrix element (and its uncertainty) are known  6 signalclaimed by (part of) the experimental collaboration. Still debated. 02 Heidelberg-Moscow result

  20. Basic relation: Logs to linearize error propagation: Then, the claim by Klapdor et al. implies (at 95% C.L.): 02 Heidelberg-Moscow result/2 We take matrix element(s) and uncertainties from the recent work: Rodin, Faessler, Simkovic & Vogel, NPA 766, 107 (2006). If claim is rejected: Just remove lower bound (accept only upper bound)

  21. ν fν = in terms of m Bounds on  for increasingly rich data sets (assuming flat CDM model): Power Spectrum of density fluctuations Limits depend on the input data sets: • CMB (WMAP3y + others) • Sloan Digital Sky Survey (SDSS) • Type Ia Supernovae (SN) • Big Bang Nucleosynthesis (BBN) • Large Scale Structure (LSS) • Hubble Space Telescope (HST) • Baryon Acoustic Oscillations (BAO) • Lyman-(Ly-) Cosmology

  22. Constraints from Cosmology standard deviations  (eV) Constraints on  from Cosmology Case 1: most “conservative” (only 1 data set: WMAP 3y) Case 7: most “aggressive” (all available cosmological data) Upper limits range from ~2 to ~0.2 eV at 95% C.L., but no consensus on a specific value yet

  23. A global analysis in the space of the observables Giorgione - La tempesta

  24. Different choices Different possiblecombinations (and implications) •  oscillation data •  decay • 02 decay • cosmology Superposition of all constraints in the space (m, m, )

  25. Restrict cosmo data to WMAP 3y butaccept claim by Klapdor et al. In this case, a global combination is allowed (thick black wedge in the upper part of the figure) Implications (at 95% C.L.):   1.8  0.6 eV m  0.6  0.2 eV m  0.6  0.2 eV “Conservative” case: Degenerate spectrum, with m 0.6  0.2 eV (2) for each neutrino

  26. In this case, a signal should be clearly seen in the (Karlsruhe Tritium Neutrino) beta-decay experiment KATRIN Expected range formwould be m = 0.42-0.84 eV(2) well withinKATRIN sensitivity (~0.3 eV)

  27. A long way from Fermi’s table-top experimental proposal… KATRIN spectrometer during transportation ( , november 2006)

  28. detail MT = 5.87 (kg 130Te) x y b = 0.18  0.02 c/keV/kg/y (Jul 2005) DBD Energy [keV] (Fig. from E. Fiorini talk at NOW 2006) Current Cuoricino half-life limit for 130Te: Range predicted from previous scenario (2): T > 2 x 1024 y T = 3-19 x 1024 y E.g., signal might be seen also in Cuoricino,the 130Te double-betadecayexperiment at Gran Sasso (with more statistics and some luck) Also, 02 signal should emerge in other nuclei …

  29.  < 0.17 eV m< 0.06 eV m< 0.06 eV (i.e., deeply in sub-eV range) Conversely, assume ALL cosmo data at face value “Aggressive” case In this case, a global combination with the claimed double beta signal is not possible Implications (at 95% C.L.) if Klapdor’s claim is rejected: Much smaller absolute masses; life much harder, especially if mass hierarchy is normal

  30. Implications for (m, m, ) in “extreme” and “intermediate” case Implications/1 Cases withcosmo data = WMAP 3yorWMAP 3y + SDSScan be probed, at least in part, by KATRIN.Other cases (including more constraining cosmological data) are beyond KATRIN sensitivity.

  31. Corresponding implications for neutrinoless double-beta half-lives in different nuclei (using Faessler et al. matrix elements and errors) Implications/2 Note: Klapdor et al. claim is not compatible with WMAP+X data (where X = any additional cosmo data).

  32. Q.: Can one say that “cosmological data” rule out Klapdor’s claim? A.: NO. Several reasons: A question A laboratory result needs a laboratory - not only an astrophysical - test Claimed signal might be due to new physics (RH currents, SUSY …) Cosmological constraints are still very much affected by assumptions and by systematics We should never forget that the “standard” cosmological model contains mostly unknown sources of gravity (~0.75 dark energy, ~0.20 dark matter), while the known neutrinos are a tiny fraction One can turn the question around, and ask: If we assume that both Klapdor’s signal (as due to Majorana neutrinos) and cosmological data are correct, what should one alter in the standard cosmological model to fit the data? Several possible solutions …

  33. While, up to now, dark energy scenario is consistent with a true cosmological constant, with equation of state w = -1 combining cosmological data with the 02 result of Heidelberg-Moscow (+ osc.) leads to - 1.67 < w < -1.05 at 95% C.L. so excluding a cosmological constant. … e.g., one could allow a “non-standard” equation of state for dark energy, ruling out a cosmological constant …[astro-ph/0608351] [astro-ph/0608351]

  34. 33 95% C.L. 68% C.L. S a … or one could assume “mass-varying neutrinos”…[astro-ph/0611227] [astro-ph/0611227] Assuming a linear parametrization of the evolution of  in terms of the scale factor a ( being the parameter denoting the time-varying effect)  = 0[1 + (1-a)] If the Heidelberg-Moscow result is included together with cosmological data, mass-varying neutrinos are favored at about 3 But other possibilities will certainly be explored in future papers!

  35. Conclusions Giorgione - Le maraviglie dell’arte

  36. 38 2 m oscillations cosmology  Conclusions In the (long) process of cornering the neutrino mass … Conclusions/1 …neutrino oscillationscurrently provide very stable and reliable constraints, … … which are expected to be followed by progress onnon-oscillation searchesin the next years …

  37. 39 2 m oscillations cosmology  … future nightmares, which can’t be excluded, might include non-convergent situations (partly realized now?) … Conclusions/2 ? … but we should never forget that such situations might eventually “converge” if something even more exciting happens:

  38. 2 oscillations cosmology  Conclusions/3 m + new physics ! ? … with the “convergence” induced by the advent of New Physics !

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