C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 /3 Oscillations Beyond Three-Neutrino Mixing Carlo Giunti INFN, Torino, Italy CNNP07 Conference on Neutrino and Nuclear Physics Catania, Italy, 5- October 07
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 /3 LSND [PRL 75 (995) 650; PRC 54 (996) 685; PRL 77 (996) 308; PRD 64 (00) 007] ν µ ν e 0 MeV E 5.8 MeV Well-known and pure source of ν µ p + target π + at rest µ + + ν µ 800 MeV µ + at rest e + + ν e + ν µ ν e + p n + e + Well-known detection process of ν e 3.8σ excess L 30 m m SBL 0. ev m ATM But signal not seen by KARMEN at L 8 m with the same method [PRD 65 (00) 00]
Beyond Three-Neutrino Mixing: Sterile Neutrinos C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 3/3 m. ν 5 ν 4. m SBL ν s ν s ev σ had [nb] 30 0 ALEPH DELPHI L3 OPAL average measurements, error bars increased by factor ν 3ν 4ν ν 3 ν ν m ATM m SOL ν e ν µ ν τ.5 3 ev 7.4 5 ev 0 86 88 90 9 94 E cm [GeV] N LEP ν active =.9840 ± 0.008 Terminology: means: a ev-scale sterile neutrino a ev-scale massive neutrino which is mainly sterile
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 4/3 Effective 3+ SBL Oscillation Probabilities Appearance (α β) ( ) m P SBL ( ) sin ϑ ν ( ) αβ sin 4 L α ν β 4E Disappearance ( ) m P SBL ( ) sin ϑ ν ( ) αα sin 4 L α ν α 4E sin ϑ αβ = 4 U α4 U β4 sin ϑ αα = 4 U α4 ( U α4 ) U e U e U e3 U e4 U µ U µ U µ3 U µ4 U = U τ U τ U τ3 U τ4 U s U s U s3 U s4 SBL 6 mixing angles 3 Dirac CP phases 3 Majorana CP phases CP violation is not observable in SBL experiments! Observable in LBL accelerator exp. sensitive to matm [de Gouvea et al, PRD 9 (05) 053005, PRD 9 (05) 0730, arxiv:605.09376; Palazzo et al, PRD 9 (05) 07307, PLB 757 (06) 4; Kayser et al, JHEP 5 (05) 039, JHEP 6 (06) ] and solar exp. sensitive to msol [Long, Li, CG, PRD 87, 3004 (03) 3004]
Gallium Anomaly C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 5/3 Gallium Radioactive Source Experiments: GALLEX and SAGE ν e Sources: e + 5 Cr 5 V + ν e e + 37 Ar 37 Cl + ν e E 0.75 MeV E 0.8 MeV Test of Solar ν e Detection: ν e + 7 Ga 7 Ge + e R =N exp N cal 0.7 0.8 0.9.0. GALLEX SAGE Cr Cr R = 0.84 ± 0.05 L GALLEX =.9 m GALLEX SAGE Cr Ar L SAGE = 0.6 m m SBL ev m ATM.9σ deficit [SAGE, PRC 73 (006) 045805; PRC 80 (009) 05807; Laveder et al, Nucl.Phys.Proc.Suppl. 68 (007) 344, MPLA (007) 499, PRD 78 (008) 073009, PRC 83 (0) 065504] 3 He + 7 Ga 7 Ge + 3 H cross section measurement [Frekers et al., PLB 706 (0) 34]
Reactor Electron Antineutrino Anomaly C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 6/3 [Mention et al, PRD 83 (0) 073006] New reactor ν e fluxes [Mueller et al, PRC 83 (0) 05465; Huber, PRC 84 (0) 0467] R = N exp N cal 0.70 0.80 0.90.00..0 Bugey 3 Bugey 4 Chooz Daya Bay Double Chooz Gosgen ILL Krasnoyarsk Nucifer 3 L [m].8σ deficit Palo Verde RENO Rovno88 R = 0.934 ± 0.04 Rovno9 SRP
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 7/3 P ν e νe 0.70 0.80 0.90.00..0 Bugey 4 Rovno9 E 4MeV sin ϑ ee = 0. m 4 = 0. ev m 4 = 0.5 ev m 4 =.0 ev Rovno88 Bugey 3 Gosgen ILL 3 L [m] Krasnoyarsk SRP Nucifer R DC DB DC R DB m SBL 0.5 ev m ATM SBL oscillations are averaged at the Daya Bay, RENO, and Double Chooz near detectors = no spectral distortion
E ( (Data - MC) / MC χ i ) 0. 0. 0 000 Reactor Antineutrino 5 MeV Bump 5000 E (Data - MC) / MC 0. 0. 0 Data / Predicted 0.5 MeV.4..0 Data No oscillation Reactor flux uncertainty Total systematic uncertainty Best fit: sin θ 3 0. 0. 0.8 0 3 4 5 6 7 8 3 4 5 6 7 8 0.6 Prompt Energy (MeV) 3 4 5 6 7 8 Prompt Energy Visible Energy (MeV) 4 [RENO, arxiv:5.05849] [Double Chooz, arxiv:406.7763] [Daya Bay, arxiv:508.0433] Cannot be explained by neutrino oscillations (SBL oscillations are averaged in Double Chooz, Daya Bay, RENO). It is likely due to theoretical miscalculation of the spectrum. 3% effect on total flux, but if it is an excess it increases the anomaly! No post-bump complete calculation of the neutrino fluxes. Saclay-Huber flux calculation uncertainty is about.5%. = 0.090 Entries / Ratio to Prediction (Huber + Mueller) contribution χ.. 0.9 0.8 4 Integrated 4 6 8 4 6 8 4 6 8 Prompt Energy (MeV) Increasing the flux uncertainty is a game that one can play, but there are only guesses, e.g. about 5%. [Hayes and Vogel, 06] Increasing the flux uncertainty decreases the statistical significance of the anomaly, but more anomaly is allowed in combined fits with other data! At the moment it is better to consider the calculated flux and uncertainties in order to predict the signal that must be tested in new experiments. C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 8/3 3 4 5 6 Local p-value ( MeV windows)
Daya Bay Reactor Fuel Evolution [Daya Bay, PRL 8 (07) 580 (arxiv:704.08)] Fission fraction (%) Reactor ν e flux produced by the β decays of the fission products of 35 U, 38 U, 39 Pu, 4 Pu. Effective fission fractions: 0 90 80 70 60 50 40 30 0 F 35, F 38, F 39, F 4. 35 U 39 Pu 38 U 4 Pu Others 0 0 5000 000 5000 0000 Burn-up (MWD/TU) Cross section per fission: σ f = F k σ f,k k=35,38,39,4 σ f,k = de ν φ k (E ν ) σ(e ν ) σ f / σ f SH 0.94 0.944 0.946 0.948 0.950 0.95 0.954 OSC 35+39 0.4 0.6 0.8 0.30 0.3 0.34 0.36 C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 9/3 F 39
σ39 [ 43 cm / fission] 5.5 5.0 4.5 4.0 3.5 3.0 Daya Bay Huber model w/ 68% C.L. σ38 = (. ±. 0) 43 σ4 = (6. 04 ± 0. 60) 43 C.L 68% 95% 99.7% 5. 5.6 6.0 6.4 6.8 7. σ35 [ 43 cm / fission] 9 χ 4 4 9 Best fit: mainly suppression of σ f,35 Equal fluxes suppression: χ /NDF = 7.9/ disfavored at.8σ Equal fluxes suppression corresponds to SBL oscillations, but theoretical flux uncertainties must be taken into account χ σ f,39 / σf,39 SH 0 4 6 8 0.80 0.85 0.90 0.95.00.05. 0.80 0.85 0.90 0.95.00 σ f,35 / σ f,35 SH σ σ 0 4 6 8 χ With theoretical flux uncertainties: Daya Bay χ min NDF GoF 35 U 3.8 7 80% OSC 9.5 7 % MC: OSC disfavored at.6σ [CG, X.P. Ji, M. Laveder, Y.F. Li, B.R. Littlejohn, arxiv:708.033] C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 /3
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 /3 Fuel Fractions of All Reactor Experiments F i 0.0 0. 0. 0.3 0.4 0.5 0.6 0.7 0.8 0.9.0 SRP 4 SRP 8 Krasnoyarsk99 34 Krasnoyarsk94 57 Krasnoyarsk87 9 Krasnoyarsk87 33 ILL Nucifer Daya Bay 0.5 Gosgen 38 Rovno88 I Rovno88 S Rovno88 S Rovno9 Daya Bay 0.74 Rovno88 I Palo Verde Daya Bay 0.87 Gosgen 46 Daya Bay 0.99 RENO Rovno88 S Daya Bay 0.3 Gosgen 65 Daya Bay 0.3 Bugey 3 95 Bugey 3 40 Bugey 3 5 Bugey 4 Daya Bay 0.33 Daya Bay 0.344 Double Chooz F 35 F 38 F 39 F 4 Chooz
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 /3 All Reactors χ min NDF GoF 35 U 5.3 3 79% OSC 3.0 3 85% σ f / σ f th 0.75 0.85 0.95.05.5 35 OSC MC: 35 U disfavored at.7σ L [m] 3 Bugey 4 Bugey 3 5 Rovno9 Rovno88 I Rovno88 I Rovno88 S Rovno88 S SRP 8 SRP 4 Rovno88 S Krasnoyarsk87 33 Krasnoyarsk99 34 Gosgen 38 Bugey 3 40 Gosgen 46 Krasnoyarsk94 57 Gosgen 65 Krasnoyarsk87 9 Bugey 3 95 RENO Double Chooz Daya Bay Palo Verde Chooz Nucifer ILL
ε C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 3/3 NEOS [PRL 8 (07) 80 (arxiv:6.0534)] Events /day/0 kev Data/Prediction Data/Prediction 60 50 40 30 0..0 (a) (b) Prompt Energy [MeV] Data signal (ON-OFF) Data background (OFF) MC 3ν (H-M-V) MC 3ν (Daya Bay) NEOS/H-M-V Systematic total 7 6 5 4 3 3 4 5 6 7 8 Neutrino Energy [MeV] 0.9. 3 4 5 6 7 (c) NEOS/Daya Prompt BayEnergy [MeV] Systematic total.0 (.73 ev, 0.050) (.3 ev, 0.4) 0.9 3 4 5 6 7 Prompt Energy [MeV] 3 Hanbit Nuclear Power Complex in Yeong-gwang, Korea. Thermal power of.8 GW. Detector: a ton of Gd-loaded liquid scintillator in a gallery approximately 4 m from the reactor core. The measured antineutrino event rate is 976 per day with a signal to background ratio of about.
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 4/3 NEOS Spectrum 90% CL 95% CL 99% CL [ev ] m 4 3 sin ϑ ee Best Fits: m4 =.7 ev sin θ 4 = 0.05 m4 =.3 ev sin θ 4 = 0.04 χ no osc. χ min = 6.5 χ distribution:.σ anomaly NEOS Monte Carlo:.σ anomaly
Global ν e and ν e Disappearance [Gariazzo, CG, Laveder, Li, JHEP 706 (07) 35 (arxiv:703.00860)] ν edis σ σ KARMEN+LSND ν e C [Conrad, Shaevitz, PRD 85 (0) 0307] [CG, Laveder, PLB 706 (0) 0] [ev ] σ Reactors Gallium ν ec Sun TK Solar ν e + KamLAND ν e [Li et al, PRD 80 (009) 3007, PRD 86 (0) 304] [Palazzo, PRD 83 (0) 303, PRD 85 (0) 07730] m 4 TK Near Detector ν e disappearance [TK, PRD 9 (05) 05] χ NO /NDF NO = 4./ 3. anom. sin ϑ ee Best Fit: m 4 =.7 ev L osc 4 = 4πE sin ϑ ee = 0.066 U e4 = 0.07 m4 χ min /NDF = 63.0/74 GoF = 7% In agreement with Dentler, Hernandez-Cabezudo, Kopp, Maltoni, Schwetz, arxiv:709.0494 C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 5/3
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 6/3 Tritium Beta-Decay: 3 H 3 He + e + ν e Q = M3 H M3 He m e = 8.58 kev dγ dt = (cosϑ C G F ) π 3 M F (E) p E K (T ) K (T ) Q T = k U ek (Q T ) m k θ(q T m k) m 4 m,,3 ( U e4 ) (Q T ) m β θ(q T m β) + U e4 (Q T ) m 4 θ(q T m 4) K(T) Q 3 mβ = U ek mk k= Q m 4 T Q m β
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 7/3 Mainz and Troitsk Limit on m 4 m 4 m 4 m,,3 = m 4 m 4 m m 4 [Kraus, Singer, Valerius, Weinheimer, EPJC 73 (03) 33] [Belesev et al, JPG 4 (04) 0500]
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 8/3 Global ν e and ν e Disappearance + β Decay [Gariazzo, CG, Laveder, Li, JHEP 706 (07) 35 (arxiv:703.00860)] ν edis+β σ σ ν edis β Best Fit: m 4 =.7 ev sin ϑ ee = 0.066 U e4 = 0.07 [ev ] m 4 cm Losc 4 7 m at E [MeV] 0.0050 sin ϑ ee 0.3 at sin ϑ ee
The Race for ν e and ν e Disappearance C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 9/3 3 CeSOX shape (95% CL) CeSOX rate (95% CL) CeSOX rate+shape (95% CL) KATRIN (90% CL) ν edis+β σ σ 3 DANSS (yr, 95% CL) Neutrino 4 (yr, 95% CL) PROSPECT phase (3yr, ) PROSPECT phase (3yr, ) SoLiD phase (yr, 95% CL) SoLiD phase (3yr, ) STEREO (yr, 95% CL) ν edis+β σ σ [ev ] m 4 [ev ] m 4 3 3 sin ϑ ee sin ϑ ee CeSOX (Gran Sasso, Italy) 44 Ce ν e BOREXINO: L 5-m [Vivier@TAUP05] KATRIN (Karlsruhe, Germany) 3 H ν e [Drexlin@NOW06] DANSS (Kalinin, Russia) L -m [arxiv:606.0896] Neutrino-4 (RIAR, Russia) L 6-m [JETP (05) 578] PROSPECT (ORNL, USA) L 7-m [arxiv:5.00] SoLid (SCK-CEN, Belgium) L 5-8m [arxiv:5.07835] STEREO (ILL, France) L 8-m [arxiv:60.00568]
ν µ ν e and ν µ ν e Appearance 99% CL LSND MiniBooNE KARMEN NOMAD BNL E776 ICARUS OPERA [ev ] m 4 ν µ ν e 90% CL 95% CL 99% CL 3 sin ϑ eµ C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 0/3
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 /3 MiniBooNE L 54 m ν µ ν e [PRL (009) 80] 00 MeV E 3 GeV ν µ ν e [PRL (03) 680] LSND signal LSND signal Purpose: check LSND signal. Different L and E. Similar L/E (oscillations). No money, no Near Detector. LSND signal: E > 475 MeV. Agreement with LSND signal? Low-energy anomaly MicroBooNE Pragmatic Approach: E > 475 MeV.
ν µ and ν µ Disappearance [ev ] m 4 99% CL CDHSW: νµ (984) ATM: νµ + νµ SciBooNE MiniBooNE: νµ (0) SciBooNE MiniBooNE: νµ (0) MINOS: νµ CC+NC (06) IceCube: νµ + νµ (06) sin ϑ µµ C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 /3
[ev ] m 4 3+ Appearance-Disappearance Tension ν e DIS sin ϑ ee 4 U e4 ν e Dis ν µ Dis Dis App ν µ ν e APP ν µ DIS sin ϑ µµ 4 U µ4 sin ϑ eµ = 4 U e4 U µ4 4 sin ϑ ee sin ϑ µµ [Okada, Yasuda, IJMPA (997) 3669; Bilenky, CG, Grimus, EPJC (998) 47] 4 3 sin ϑ eµ PrGlo6A σ σ ν µ ν e is quadratically suppressed! PrGlo6A = 06 data except MINOS and [Gariazzo, CG, Laveder, Li, JHEP 706 (07) 35] IceCube χ NO /NDF NO = 48.3/3 6.4σ anom. Best Fit: m 4 =.6 ev U e4 = 0.06 U m4 = 0.03 χ min /NDF = 6.0/44 GoF = 0% χ PG /NDF PG = 3.8/ GoF PG = 5% Similar tension in 3+, 3+3,..., 3+N s [CG, Zavanin, MPLA 3 (05) 650003] C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 3/3
Effects of MINOS and IceCube PrGlo6A PrGlo6A + MINOS PrGlo6A + IceCube PrGlo6A + MINOS + IceCube = PrGlo6B m 4 [ev ] MINOS IceCube sin ϑ µµ IceCube effect in agreement with Collin, Arguelles, Conrad, Shaevitz, PRL 7 (06) 80 Best Fit: m 4 =.6 ev U e4 = 0.030 U µ4 = 0.0 χ min /NDF = 530.3/59 GoF = 36% χ PG /NDF PG = 4.7/ GoF PG = 9.7% More tension! C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 4/3
Effects of NEOS C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 5/3 m 4 [ev ] PrGlo6A PrGlo6B PrGlo7 sin ϑ ee Best Fit: m 4 =.7 ev U e4 = 0.00 U µ4 = 0.05 χ min /NDF = 595./579 GoF = 3% χ PG /NDF PG = 7./ GoF PG =.7% More tension!
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 6/3 The Race for the Light Sterile ( ) ν e ( ) ν e PrGlo7 σ σ PrGlo7 σ σ [ev ] [ev ] m 4 m 4 DANSS (yr, 95% CL) Neutrino 4 (yr, 95% CL) PROSPECT phase (3yr, ) PROSPECT phase (3yr, ) SoLiD phase (yr, 95% CL) SoLiD phase (3yr, ) STEREO (yr, 95% CL) sin ϑ ee CeSOX shape (95% CL) CeSOX rate (95% CL) CeSOX rate+shape (95% CL) KATRIN (90% CL) sin ϑ ee
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 7/3 ( ) ν µ ( ) ν e ( ) ν µ ( ) ν µ SBN (3yr, ) nuprism () JSNS () SBN (3yr, ) KPipe (3yr, ) [ev ] [ev ] m 4 m 4 PrGlo7 σ σ 4 3 sin ϑ eµ PrGlo7 σ σ sin ϑ µµ
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 8/3 New Bound from MINOS & MINOS+ [arxiv:7.06488, today!] 3 0.56 POT MINOS 0 5.80 POT MINOS+ ν µ mode ) 4 (ev m 3 MINOS & MINOS+ data 90% C.L. MINOS 90% C.L. IceCube 90% C.L. Super-K 90% C.L. CDHS 90% C.L. CCFR 90% C.L. SciBooNE + MiniBooNE 90% C.L. Gariazzo et al. (06) 90% C.L. 4 4 3 sin (θ 4 )
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 9/3 Neutrinoless Double-Beta Decay m ββ = U e m + U e e iα m + U e3 e iα 3 m 3 + U e4 e iα 4 m 4 χ 0 3 4 5 6 7 8 9 PrGlo7 99.73% 99% 95.45% 90% 68.7% (4) m ββ [ev] m (k) ββ = U ek m k m m 4 m (4) ββ U e4 m 4 warning: possible cancellation with m (3ν) ββ [Barry, Rodejohann, Zhang, JHEP 07 (0) 09] [Li, Liu, PLB 706 (0) 406] [Rodejohann, JPG 39 (0) 4008] [Girardi, Meroni, Petcov, JHEP 3 (03) 46] [CG, Zavanin, JHEP 07 (05) 7]
Normal 3ν Ordering ν4 Inverted 3ν Ordering σ σ σ σ Ue m Ue4 m4 [ev] [ev] Ue4 m4 Uek mk Uek mk ν4 σ σ σ σ Ue m Ue m Ue3 m3 3 3 Ue3 m3 Ue m 4 4 4 3 Lightest mass: m 4 [ev] 3ν () 3+ () [ev] KamLAND Zen, PRL 7 (06) 08503 90% C.L. UPPER LIMIT [ev] mββ [ev] m3 Inverted 3ν Ordering KamLAND Zen, PRL 7 (06) 08503 90% C.L. UPPER LIMIT mββ Lightest mass: Normal 3ν Ordering 3ν () 3+ () 3 3 3 4 4 4 3 Lightest mass: m [ev] 4 3 Lightest mass: m3 [ev] C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 30/3
C. Giunti Oscillations Beyond Three-Neutrino Mixing CNNP07 9 October 07 3/3 Conclusions Exciting indications of sterile neutrinos (new physics!) at the ev scale: LSND ν µ ν e signal (caveat: single experimental signal). Gallium ν e disappearance (caveat: overestimated detector efficiency?). Reactor νe disappearance (caveat: flux calculation dependence). Vigorous experimental program to check conclusively in a few years: ν e and ν e disappearance with reactors and radioactive sources. ν µ ν e transitions with accelerator neutrinos. ν µ disappearance with accelerator neutrinos. Independent tests through effect of m 4 in β-decay and ββ 0ν -decay. Cosmology: strong tension with N eff = and m 4 ev. It may be solved by a non-standard cosmological mechanism. Possibilities for the next years: Reactor and source experiments νe and ν e observe SBL oscillations: big excitement and explosion of the field. Otherwise: still marginal interest to check the LSND appearance signal. In any case the possibility of the existence of sterile neutrinos related to New Physics beyond the Standard Model will continue to be studied (e.g kev sterile neutrinos).