Neutrino mass and mixing: 2006 Status 1 NOW 2006 Conca Specchiulla, Otranto Neutrino mass and mixing: 2006 Status Antonio Palazzo University of Oxford and INFN, Bari based on work done in collaboration with: G.L. Fogli, E.Lisi, A. Marrone (Bari) A. Melchiorri, P. Serra (Rome) J. Silk , A. Slosar (Oxford)

• Introduction: The 3 framework 2 Outline • Introduction: The 3 framework • Constraints on oscillation parameters • Constraints on absolute  masses • Combination of world n data (when feasible) • Conclusions

Mass spectrum Mixing Sensitivities 3 Mass spectrum Norm. Hier. Inv. Hier. n3 n2 m2 - Absolute mass scale not probed by  oscillations n1 ? +Dm2 -Dm2 n2 - Hierarchy unknown m2 n1 n3 Mixing Sensitivities leading 2 S12 ~ 0.31 - Solar, KamLAND (dm2, q12, q13) sub-leading 2 S23 ~ 0.45 - ATM, K2K, MINOS (Dm2, q23, q13) S13 < few% 2 - CHOOZ (Dm2, q13) * Hint for a third DM2 ~O(eV2) from LSND: waiting for MiniBoone (dis)confirmation .

leading “solar” parameters 4 Constraints on the leading “solar” parameters

Consistency among four LMA essentially determined by 5 2n Solar constraints Consistency among four different experiments LMA essentially determined by SNO + SK sensitive to high energy 8B n’s

LMA solution confirmed by KamLAND 6 LMA solution confirmed by KamLAND Disappearance Spectral distortions 2 4 6 8

2n Solar + KamLAND contraints 7 2n Solar + KamLAND contraints Very high level of consistency KamLAND dominates dm2 constraints q12 range determined by solar data

Matter effects with standard size confirmed 8 Matter effects with standard size confirmed V(x) = 2 GF Ne(x) V(x) aMSW V(x) (dm2,q12) marginalized

leading “atmospheric” parameters 9 Constraints on the leading “atmospheric” parameters (pre-MINOS)

Super-Kamiokande Evidence for atmospheric nm-> nt oscillations 10 Super-Kamiokande Evidence for atmospheric nm-> nt oscillations angle dependence in zenith distributions oscillatory pattern no osc. in high L/E resolution analysis

confirmed by K2K: The first LBL accelerator experiment 11 confirmed by K2K: The first LBL accelerator experiment K2K energy spectrum No oscillation Best fit Both nm disappearance and spectral distortion observed No oscillation (normalized to data) Number of events En (GeV)

Constraints from the 2n analysis 12 Constraints from the 2n analysis Stringent constraints from SK Perfect agreement with K2K Dm2 range determined with a 24% accuracy (2s) Contours at 1, 2, 3  (1 dof)

13 Limits on 13

CHOOZ and the upper bound on q13 14 CHOOZ and the upper bound on q13 Non observation of ne disappearance exclusion plot in the (m2, 13) plane m2 scale set by SK+K2K+(MINOS) Upper limit on q13 Anti-correlation between 13 upper limit and m2

stable for unconstrained 13 Mild anti-correlation 15 3n CHOOZ + (SK + K2K) constraints Strong upper bound on q13 Leading parameters stable for unconstrained 13 Mild anti-correlation between Dm2 and q13

3n Solar + KamLAND constraints 16 3n Solar + KamLAND constraints Solar and KamLAND prefer q13 = 0 Leading parameters stable for unconstrained 13 Upper limit on q13 dominated by solar data …

Gallium-SNO : tension for q13 = 0 17 Gallium-SNO : tension for q13 = 0 SNO and Gallium: 3n constraints (1s) perfect agreement for q13 = 0 spoiled for increasing q13 See also Goswami & Smirnov , Phys.Rev.D 72 053011 (2005) (hep-ph/0411359)

18 Impact of MINOS

MINOS first results: Corroborate SK and K2K 19 MINOS first results: Corroborate SK and K2K 735 Km MINOS energy spectrum (hep-ex/0607088)

…and improve parameters’ determination 20 …and improve parameters’ determination POST - MINOS PRE - MINOS Dm2 noticeable improvement from 24% to 15% (2s) q23 still dominated by atmospheric (SK) q13 upper bound slightly improved

Overview of the global analysis constraints 21 Overview of the global analysis constraints

up-to-date numerical ±2 ranges 22 up-to-date numerical ±2 ranges

Constraints on absolute  masses 23 Constraints on absolute  masses

Current limits: (Mainz + Troitsk) upper bound m < 1.8eV (2s) 24  decay: mi  0 can affect the spectrum endpoint Observable: “effective electron neutrino mass” Current limits: (Mainz + Troitsk) upper bound m < 1.8eV (2s)

Observable: “effective Majorana mass” 25 Neutrinoless double b decay (02) : possible if mi  0 and n = n (Z, A)  (Z+2, A) + 2e- Q 22b n p e- = W 02b Observable: “effective Majorana mass” Majorana phases No signal in all experiments, except for the claim of Klapdor et al. (Heidelberg-Moscow) claim accepted, m in the range [0.43-0.81] eV (2s)* claim rejected, m < 0.81eV * Theoretical input for nuclear matrix elements taken from Rodin et al. (2006).

Sensitivity up to S < 0.17eV (2s) 26 Cosmology: mi  0 can affect LSS and CMB massive n’s suppress the formation of small scale structures mn = 0 1 eV 7 eV 4 eV Observable: sum of neutrino masses Current limits: depend on the dataset considered. Sensitivity up to S < 0.17eV (2s) Ma, 1996

Results from the analysis of cosmological data 27 Results from the analysis of cosmological data Bounds obtained with seven different data sets data set 2s limit 1- WMAP 2.3 eV 2- WMAP + SDSS 1.2 eV 3- WMAP + SDSS + SN + HST + BBN 0.78 eV 4- WMAP + LSS + SN 0.75 eV 5- WMAP + LSS + SN + BAO 0.58 eV 6- WMAP + LSS + SN + Ly-a 0.21 eV 7- WMAP + LSS + SN + BAO + Ly-a 0.17 eV

superposed constraints on (mb, m, ) 28 superposed constraints on (mb, m, ) n oscillations - Significant correlations - Partial overlap of NH and IH - Large m spread - Lower bound on S b decay Irrelevant in all cases except when combined with the less stringent cosmo data set (1) Tension between Cosmology and 0n2b claim …

0n2b claim with cosmological bounds 29 combination of 0n2b claim with cosmological bounds not feasible most “aggressive” data set (7) we disregard most of the cosmological data and consider only the WMAP results … unless

Only an another 0n2b experiment with higher sensitivity 30 However, we should not be too hasty in concluding that : “cosmological data rule out the claim of Klapdor et al.,” since: - The 0n2b signal might be due to new physics beyond light Majorana n’s - Astrophysical data may be still affected by unknown systematics - Bounds on S unavoidably depend on assumptions on the Cosmological Model Only an another 0n2b experiment with higher sensitivity can (dis)prove such claim

absolute neutrino masses 31 Conclusions flavor oscillations - All the existing data* fit perfectly within a 3n framework - Basic parameters determined with a [10-30]% accuracy - Latest major improvement coming from MINOS (24%  15% on Dm2) absolute neutrino masses - Cosmology most sensitive probe at the moment providing sub-eV upper bounds - Tension with the Heidelberg-Moscow claim requires further scrutiny in both fields - b decay: promising (KATRIN) * Except for LSND