Stefano Gariazzo. Light sterile neutrino: the 2018 status. IFIC, Valencia (ES) CSIC Universitat de Valencia

Transcription

1 Stefano Gariazzo IFIC, Valencia (ES) CSIC Universitat de Valencia Light sterile neutrino: the 08 status The Magnificent CEνNS, Chicago, 03//08

2 Neutrino Oscillations - Some theory Electron (anti)neutrino disappearence 3 Muon (anti)neutrino disappearence 4 Electron (anti)neutrino appearence [ev ] m 4 Global Fit σ σ 3σ 5 Global fit 6 Sterile neutrinos and CEνNS 4 3 sin ϑ eµ = 4 U e4 U µ4 3σ Dis App 7 Conclusions

3 Neutrino Oscillations - Some theory Electron (anti)neutrino disappearence 3 Muon (anti)neutrino disappearence 4 Electron (anti)neutrino appearence 5 Global fit 6 Sterile neutrinos and CEνNS 7 Conclusions

4 The Standard Model of Particle Physics st nd 3rd generation standard matter unstable matter force carriers Goldstone bosons outside standard model 6 quarks (+6 anti-quarks) 6 leptons (+6 anti-leptons).3 umev up 4.8 MeV d down 5 ekev electron < ν ev e e neutrino R/G/B R/G/B /3 / /3 / / /.8 cgev R/G/B /3 charm / 95 smev /3 strange / 5.7 µ MeV muon ν < 90 kev µ µ neutrino R/G/B / / 73. GeV topt 4.7 GeV b bottom.777 τgev tau < ν8. MeV τ τ neutrino R/G/B R/G/B /3 / /3 / / / charge colors mass spin g gluon γ photon color 80.4 GeV ± 9. GeV W ± Z strong nuclear force (color) 5. GeV H Higgs electromagnetic force (charge) 0 weak nuclear force (weak isospin) graviton gravitational force (mass) fermions (+ anti-fermions) increasing mass 5 bosons (+ opposite charge W ) [D. Galbraith & C. Burgard, 0] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3

5 The Standard Model of Particle Physics st nd 3rd generation standard matter unstable matter force carriers Goldstone bosons outside standard model 6 quarks (+6 anti-quarks) 6 leptons (+6 anti-leptons).3 umev up 4.8 MeV d down 5 ekev electron < ν ev e e neutrino R/G/B R/G/B /3 / /3 / / /.8 cgev R/G/B /3 charm / 95 smev /3 strange / 5.7 µ MeV muon ν < 90 kev µ µ neutrino R/G/B / / 73. GeV topt 4.7 GeV b bottom.777 τgev tau < ν8. MeV τ τ neutrino R/G/B R/G/B /3 / /3 / / / charge colors mass spin g gluon γ photon color 80.4 GeV ± 9. GeV W ± Z strong nuclear force (color) 5. GeV H Higgs electromagnetic force (charge) 0 weak nuclear force (weak isospin) graviton gravitational force (mass) fermions (+ anti-fermions) increasing mass 5 bosons (+ opposite charge W ) [D. Galbraith & C. Burgard, 0] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3

6 Three Neutrino Oscillations ν α = 3 U αk ν k (α = e, µ, τ) k= U αk described by 3 mixing angles θ, θ 3, θ 3 and one CP phase δ CP Current knowledge of the 3 active ν mixing: [de Salas et al. (08)] NO: Normal Ordering, m < m < m 3 IO: Inverted Ordering, m 3 < m < m m = ( ) 5 ev m3 = (.50 ± 0.03) 3 ev (NO) = ( ) 3 ev (IO) sin (θ ) = sin (θ 3 ) = = sin (θ 3 ) = (NO) (IO) (NO) = (IO) First hints for δ CP 3/π χ χ sin θ 7 8 m [-5 ev ] sin θ 3 sin θ m 3 [-3 ev ] see also: S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3 δ/π

7 Two types of neutrinos flavor neutrinos ν α ν α = U αk ν k massive neutrinos ν k ν(t = 0) = ν α = U α ν + U α ν + U α3 ν 3 ν ν ν α ν 3 ν β source L detector ν(t > 0) = ν β = U α e ie t ν + U α e ie t ν + U α3 e ie 3t ν 3 ν α Ek = p + mk define t = L P να νβ (L) = ν α ν(l) = ( U βk U αku βju αj exp i m kj L ) E k,j m ij = m i m j S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 3/3

8 A large family In principle, previous discussion is valid for N neutrinos only constraint: there are exactly three flavor neutrinos in the SM [LEP, Phys. Rept. 47 (006) 57, arxiv:hep-ex/ ] N (Z) ν =.9840 ± through the measurement of the Z resonance e + e Z ν a ν a 0 a=e,µ,τ σ had [nb] 30 0 ALEPH DELPHI L3 OPAL neutrinos α > 3 must be sterile average measurements, error bars increased by factor ν 3ν 4ν E cm [GeV] sterile neutrino = SM singlet: no couplings with other SM particles S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 4/3

9 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 4/3 A large family In principle, previous discussion is valid for N neutrinos N N mixing matrix, N flavor neutrinos, N massive neutrinos ν e U e U e U e3 U e4. ν ν µ U µ U µ U µ3 U µ4 ν ν τ = U τ U τ U τ3 U τ4 ν 3 ν s U s U s U s 3 U s 4 ν

10 A large family In principle, previous discussion is valid for N neutrinos N N mixing matrix, N flavor neutrinos, N massive neutrinos ν e U e U e U e3 U e4. ν ν µ U µ U µ U µ3 U µ4 ν ν τ = U τ U τ U τ3 U τ4 ν 3 ν s U s U s U s 3 U s 4 ν Our case will be 3 (active)+ (sterile), a perturbation of 3 neutrinos case ν 6 angles m 4 m l ν l =,, 3 3 Dirac ν α ν 3 ν β CP phases m4 ev ν 4 m4 3 Majorana m43 CP phases L source detector S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 4/3

11 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 5/3 Short BaseLine (SBL) P να ν β (L) = ν α ν(l) = k,j U βk U αku βju αj exp ( i m kj L E ) If m 4 m l, faster oscillations ν 4 oscillations are averaged in most neutrino oscillation experiments Effect of 4th neutrino only visible as global normalization Short BaseLine (SBL) oscillations: m 4 L E At SBL, oscillations due to m and m 3 do not develop

12 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 5/3 Short BaseLine (SBL) P να ν β (L) = ν α ν(l) = k,j U βk U αku βju αj exp ( i m kj L E ) If m 4 m l, faster oscillations ν 4 oscillations are averaged in most neutrino oscillation experiments Effect of 4th neutrino only visible as global normalization Short BaseLine (SBL) oscillations: m 4 L E At SBL, oscillations due to m and m 3 do not develop APPearance (α β) ( ) ν α source of ( ) ν α ( ) ν β detect different flavor ( ) ν β

13 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 5/3 Short BaseLine (SBL) P να ν β (L) = ν α ν(l) = k,j U βk U αku βju αj exp ( i m kj L E ) If m 4 m l, faster oscillations ν 4 oscillations are averaged in most neutrino oscillation experiments Effect of 4th neutrino only visible as global normalization Short BaseLine (SBL) oscillations: m 4 L E At SBL, oscillations due to m and m 3 do not develop APPearance (α β) DISappearance ( ) ν α source of ( ) ν α ( ) ν β detect different flavor ( ) ν β ( ) ν α source of ( ) ν α ( ) ν s goes undetected

14 Short BaseLine (SBL) P να ν β (L) = ν α ν(l) = k,j U βk U αku βju αj exp ( i m kj L E ) If m 4 m l, faster oscillations ν 4 oscillations are averaged in most neutrino oscillation experiments Effect of 4th neutrino only visible as global normalization Short BaseLine (SBL) oscillations: m 4 L E At SBL, oscillations due to m and m 3 do not develop APPearance (α β) DISappearance ( ) ν α source of ( ) ν α ( ) ν β ( ) ν α ( ) detect different source ν s goes flavor ( ) ν β of ( ) ν α undetected CP violation cannot be observed in SBL experiments! S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 5/3

15 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 6/3 New mixings in the 3+ scenario 4 4 mixing matrix: U e U e U e3 U e4 U µ U µ U µ3 U µ4 U τ U τ U τ3 U τ4 U s U s U s 3 U s 4

16 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 6/3 New mixings in the 3+ scenario 4 4 mixing matrix: U e U e U e3 U e4 U µ U µ U µ3 U µ4 U τ U τ U τ3 U τ4 U s U s U s 3 U s 4 ϑ 4 ϑ 4 ϑ 34

17 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 6/3 New mixings in the 3+ scenario 4 4 mixing matrix: U e U e U e3 U e4 U µ U µ U µ3 U µ4 U τ U τ U τ3 U τ4 U s U s U s 3 U s 4 ϑ 4 ϑ 4 ϑ 34 DISappearance ( ) m P SBL sin ϑ ( ) αα sin 4 L ν ( ) α ν α 4E sin ϑ αα = 4 U α4 ( U α4 ) ( ) ν e ( ) ν e U e4 = sin ϑ 4 reactor gallium ( ) ν µ ( ) ν µ accelerator atmospheric U µ4 = cos ϑ 4 sin ϑ 4

18 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 6/3 New mixings in the 3+ scenario 4 4 mixing matrix: U e U e U e3 U e4 U µ U µ U µ3 U µ4 U τ U τ U τ3 U τ4 U s U s U s 3 U s 4 ϑ 4 ϑ 4 ϑ 34 DISappearance ( ) m P SBL sin ϑ ( ) αα sin 4 L ν ( ) α ν α 4E sin ϑ αα = 4 U α4 ( U α4 ) ( ) ν e ( ) ν e U e4 = sin ϑ 4 ( ) ν µ ( ) ν µ U µ4 = cos ϑ 4 sin ϑ 4 reactor gallium accelerator atmospheric APPearance ( ) m P SBL sin ϑ ( ) ν ( ) αβ sin 4 L α ν 4E β sin ϑ αβ = 4 U α4 U β4 ( ) ν µ ( ) ν e sin ϑ eµ = 4 U e4 U µ4 quadratically suppressed! for small U e4, U µ4 LSND MiniBooNE KARMEN OPERA...

19 Neutrino Oscillations - Some theory Electron (anti)neutrino disappearence 3 Muon (anti)neutrino disappearence 3σ (solid dashed) Reactor Anomaly Gallium Anomaly 4 Electron (anti)neutrino appearence [ev ] m 4 5 Global fit 6 Sterile neutrinos and CEνNS 7 Conclusions NEOS+DANSS σ σ 3σ 3 sin ϑ ee

20 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 7/3 Gallium anomaly [SAGE, 006][Laveder, 007][Giunti&Laveder, 0] L.9 m L 0.6 m 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 In the detector: E 0.8 MeV ν e + 7 Ga 7 Ge + e 3/ 500 kev 3/ 7 Ga 5/ 75 kev / 7 Ge 3 kev cross sections of the transitions from [Krofcheck et al., PRL 55 (985) 5] [Frekers et al., PLB 706 (0) 34]

21 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 7/3 Gallium anomaly [SAGE, 006][Laveder, 007][Giunti&Laveder, 0] L.9 m L 0.6 m 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 In the detector: E 0.8 MeV ν e + 7 Ga 7 Ge + e Test detection of solar ν e 3/ 500 kev R =N exp N cal GALLEX SAGE Cr Cr R = 0.84 ± σ deficit GALLEX SAGE Cr Ar 3/ 7 Ga 5/ / 7 Ge 3 kev cross sections of the transitions from 75 kev [Krofcheck et al., PRL 55 (985) 5] [Frekers et al., PLB 706 (0) 34]

22 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 8/3 Reactor Antineutrino Anomaly (RAA) 0: new reactor ν e fluxes by Huber and Mueller+ (HM) [Huber, PRC 84 (0) 0467] [Mueller et al., PRC 83 (0) 05465] Previous reactor rates evaluated with new fluxes deficit [PRD 83 (0) ] R = N exp N cal Bugey 3 Bugey 4 Chooz Daya Bay Double Chooz Gosgen 3 L ILL Krasnoyarsk Nucifer [m] Palo Verde RENO Rovno88.8σ deficit R = ± 0.04 Rovno9 SRP Suppression at detector due to active-sterile oscillations?

23 Can we trust the HM fluxes? Data / Predicted 0.5 MeV.4..0 Data No oscillation Reactor flux uncertainty Total systematic uncertainty Best fit: sin θ 3 = Fast neutron (a) Accidental Li/ He [Double Chooz, arxiv: ] Events / 0. MeV (Data - MC) / MC Near Visible Energy (MeV) Prompt Energy Data [Daya Bay, arxiv: ] MC Prompt Energy (MeV) Events / 0. MeV 04: bump in the spectrum around 5 MeV! (b) cannot be explained Li/ He 5 Cf by SBL oscillations Prompt 6 Energy 7 (MeV) 8 [RENO, arxiv: ] (Data - MC) / MC Fast neutron Accidental (averaged at the observed distances) Prompt Energy 0 Far Data many attempts of MC possible explanations, how to clarify the issue? Prompt Energy (MeV) S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 9/3

24 Can we trust the HM fluxes? Data / Predicted 0.5 MeV.4..0 Data No oscillation Reactor flux uncertainty Total systematic uncertainty Best fit: sin θ 3 = Fast neutron (a) Accidental Li/ He [Double Chooz, arxiv: ] Events / 0. MeV (Data - MC) / MC Near Visible Energy (MeV) Prompt Energy Data [Daya Bay, arxiv: ] MC Prompt Energy (MeV) Events / 0. MeV 04: bump in the spectrum around 5 MeV! (b) cannot be explained Li/ He 5 Cf by SBL oscillations Prompt 6 Energy 7 (MeV) 8 [RENO, arxiv: ] (Data - MC) / MC Fast neutron Accidental (averaged at the observed distances) Prompt Energy 0 Far Data many attempts of MC possible explanations, how to clarify the issue? Model independent information! (i.e. take ratio of spectra at 3 different 4 5 distances) Prompt Energy (MeV) S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 9/3

25 NEOS Single detector experiment ε [PRL 8 (07) 80] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3 Events /day/0 kev (a) Prompt Energy [MeV] Data signal (ON-OFF) Data background (OFF) MC 3ν (H-M-V) MC 3ν (Daya Bay) Neutrino Energy [MeV] 3 Data/Prediction..0 (b) NEOS/H-M-V Systematic total Data/Prediction (c) NEOS/Daya Prompt BayEnergy [MeV] Systematic total.0 (.73 ev, 0.050) (.3 ev, 0.4) Prompt Energy [MeV] Ratio to DayaBay measurement to be model independent

26 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3 Ratio Bottom/Top DANSS Single movable detector [arxiv: ] σ preference for 3+ oscillations Positron energy, MeV Detector can be at.5,.5 or.5 m from reactor core [D.Svirida@NOW08]

27 Model-independent fit of ( ) ν e DIS [SG et al., PLB 78 (08) 3] σ DANSS NEOS NEOS + DANSS [ev ] m 4 The NEOS and DANSS region perfectly overlap at m 4.3 ev sin ϑ ee 0.05 NEOS+DANSS σ σ 3σ 3 sin ϑ sin ϑ ee S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3

28 Model-independent fit of ( ) ν e DIS [SG et al., PLB 78 (08) 3] DANSS + NEOS + RAA + Gallium 3σ (solid dashed) Reactor Anomaly Gallium Anomaly [ev ] m 4 DANSS + NEOS do not agree with Gallium and RAA NEOS+DANSS σ σ 3σ 3 sin ϑ ee S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3

29 Model-independent fit of ( ) ν e DIS [SG et al., PLB 78 (08) 3] 3σ (solid dashed) NEOS+DANSS All data: [ev ] m 4 Fit dominated by DANSS + NEOS MIν e Dis σ σ 3σ 3 sin ϑ ee S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3

30 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 3/3 More to come... [STEREO, arxiv: ] = current DANSS+NEOS best fit [SG et al., PLB 78 (08) 3] [PROSPECT, arxiv: ] 4 [ev ] m m 4 (ev ) RAA 95% C.L. RAA 99% C.L. RAA: Best fit STEREO Exclusion Sensitivity (66 days) : 90% C.L. STEREO Exclusion (66 days) : 90% C.L. sin (θee) [Neutrino-4, arxiv:809.56] PROSPECT Exclusion, 95% CL PROSPECT Sensitivity, 95% CL SBL + Gallium Anomaly (RAA), 95% CL sin θ 4 [SoLiD, arxiv: ]

31 Neutrino Oscillations - Some theory Electron (anti)neutrino disappearence 3 Muon (anti)neutrino disappearence 4 Electron (anti)neutrino appearence 5 Global fit 6 Sterile neutrinos and CEνNS 7 Conclusions [ev ] m 4 99% CL CDHSW (984) CCFR (984) ATM SB MB ν µ (0) SB MB ν µ (0) IceCube (06) MINOS (06) MINOS+ (07) 3 U µ4

32 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 4/3 IceCube and DeepCore IceCube 4 High energy µ events 30 GeV < E < 0 TeV O( km) L O( 4 km) 0 m 4 /ev IceCube 99% CL Exclusions IC86 rate+shape IC86 shape only (blind result) IC59 result 0 sin θ 4 [PRL 7 (06) 0780]

33 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 4/3 IceCube and DeepCore IceCube 4 High energy µ events 30 GeV < E < 0 TeV O( km) L O( 4 km) IceCube string DeepCore string DeepCore Corridor 00 m DeepCore 0 m 4 /ev IceCube 99% CL Exclusions IC86 rate+shape IC86 shape only (blind result) IC59 result 0 Depth [ m ] m Veto cap DOMs m vertical spacing Dust layer bad optical properties DeepCore 50 HQE DOMs 7 m vertical spacing sin θ [PRL 7 (06) 0780] Absorption [ / m ]

34 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 4/3 m 4 /ev IceCube and DeepCore IceCube 4 High energy µ events 0 30 GeV < E < 0 TeV O( km) L O( 4 km) Uτ4 = sin θ34 cos θ ln L DeepCore 5 3 tracklike events 6 GeV E 60 GeV SK, NO (05), 90 % C.L. SK, NO (05), 99 % C.L. 99% C.L. 90% C.L. IceCube, NO (06), 90 % C.L. IceCube, NO (06), 99 % C.L. IceCube, IO (06), 90 % C.L. IceCube, IO (06), 99 % C.L. 90% C.L. 99% C.L. IceCube 99% CL Exclusions IC86 rate+shape IC86 shape only (blind result) IC59 result 0 sin θ 4 [PRL 7 (06) 0780] Uµ4 = sin θ4 [PRD 95 (07) 0] Both also constrain U τ ln L

35 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 5/3 ν µ ) MINOS & MINOS+ µ P(ν Near (ND, 500 m) and far (FD, 800 km) detector Reconstructed energy (GeV) ND CC ν µ FD GeV E 40 GeV, peak at 3 GeV ν s ) µ - P(ν ND NC FD 3-flavor prob. m4 = 0.05 ev m4 = 0.50 ev m4 = 5.00 ev L / E (km / GeV) [PRL 7 (06) 5803]: far-to-near ratio [arxiv: ]: full two-detectors fit 0

36 ν µ ) MINOS & MINOS+ µ P(ν Near (ND, 500 m) and far (FD, 800 km) detector Reconstructed energy (GeV) ND CC ν µ FD GeV E 40 GeV, peak at 3 GeV Systematics: ν s ) µ - P(ν ND NC FD 3-flavor prob. m4 = 0.05 ev m4 = 0.50 ev m4 = 5.00 ev ) 4 (ev m 90% C.L. Sensitivity Statistics only Energy Scale Hadron Production Cross Sections Backgrounds Other Systematics Total Systematics L / E (km / GeV) [PRL 7 (06) 5803]: far-to-near ratio [arxiv: ]: full two-detectors fit POT MINOS POT MINOS+ ν µ mode simulation 3 sin (θ 4 ) [arxiv: ] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 5/3

37 ν µ ) MINOS & MINOS+ µ P(ν Near (ND, 500 m) and far (FD, 800 km) detector Reconstructed energy (GeV) ND CC ν µ FD GeV E 40 GeV, peak at 3 GeV Sensitivity and exclusion limit: POT MINOS POT MINOS+ ν µ mode ν s ) µ - P(ν ND NC FD 3-flavor prob. m4 = 0.05 ev m4 = 0.50 ev m4 = 5.00 ev ) 4 (ev m L / E (km / GeV) [PRL 7 (06) 5803]: far-to-near ratio [arxiv: ]: full two-detectors fit MINOS & MINOS+ data 90% C.L. 90% C.L. Sensitivity (σ and σ) 3 sin (θ 4 ) [arxiv: ] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 5/3

38 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 6/3 Global fit of ( ) ν µ DIS [SG+, preliminary] [ev ] m 4 99% CL CDHSW (984) CCFR (984) ATM SB MB ν µ (0) SB MB ν µ (0) IceCube (06) MINOS (06) MINOS+ (07) 3 U µ4 MINOS(+) dominates at small m 4

39 Neutrino Oscillations - Some theory Electron (anti)neutrino disappearence 3 Muon (anti)neutrino disappearence 4 Electron (anti)neutrino appearence [ev ] m 4 σ LSND MiniBooNE KARMEN NOMAD BNL E776 ICARUS OPERA 5 Global fit 6 Sterile neutrinos and CEνNS Combined σ σ 3σ 4 3 sin ϑ eµ = 4 U e4 U µ4 7 Conclusions

40 LSND Beam Stop Overburden [PRD 64 (00) 07] ν µ ν e, 0 E/(MeV) m well known source of ν µ : p + target π + at rest µ + + ν µ µ + at rest e + + ν e + ν µ L 30 m ν e + p n + e + No signal seen in KARMEN (L 8 m) [PRD 65 (00) 0] LSND Detector Water Plug and Veto System Beam Excess Electronics Caboose Beam Excess p(ν _ µ ν_ e,e+ )n p(ν _ e,e+ )n other 3.8σ L/E ν (meters/mev) S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 7/3

41 MiniBooNE purpose: check LSND signal L 54 m, 00 MeV E 3 GeV ) (ev m no money, no near detector LSND 90% CL 68% CL 90% CL 95% CL 99% CL 3σ CL 4σ CL KARMEN 90% CL OPERA 90% CL Excess Events/MeV Events/MeV ν sample Data (stat err.) ν from µ +/- e +/- ν e from K 0 ν e from K π 0 misid Nγ dirt other Constr. Syst. Error Best Fit QE E ν (GeV) [arxiv:805.8] 0 ν e :.84 0 ν e :.7 POT POT ν + ν excess 3 LSND 99% CL sin θ QE E ν (GeV) S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 8/3

42 MiniBooNE purpose: check LSND signal L 54 m, 00 MeV E 3 GeV ) (ev m no money, no near detector LSND 90% CL 68% CL 90% CL 95% CL 99% CL 3σ CL 4σ CL KARMEN 90% CL OPERA 90% CL Excess Events/MeV Events/MeV ν sample Data (stat err.) ν from µ +/- e +/- ν e from K 0 ν e from K π 0 misid Nγ dirt other Constr. Syst. Error Best Fit QE E ν (GeV) [arxiv:805.8] MicroBooNE will check 0 ν e :.84 POT 0 low energy ν e :.7 excess POT ν + ν excess 3 LSND 99% CL sin θ QE E ν (GeV) S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 8/3

43 Global fit of ( ) ν µ ( ) ν e APP [SG+, preliminary] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 9/3 [ev ] m 4 σ LSND MiniBooNE KARMEN NOMAD BNL E776 ICARUS OPERA ICARUS and OPERA exclude MiniBooNE best fit LSND and MiniBooNE only partially in agreement Combined σ σ 3σ 4 3 sin ϑ eµ = 4 U e4 U µ4 KARMEN cuts part of LSND region

44 Neutrino Oscillations - Some theory Electron (anti)neutrino disappearence 3 Muon (anti)neutrino disappearence 4 Electron (anti)neutrino appearence [ev ] m 4 Global Fit σ σ 3σ 5 Global fit 6 Sterile neutrinos and CEνNS 4 3 sin ϑ eµ = 4 U e4 U µ4 3σ Dis App 7 Conclusions

45 APPearance - DISappearance tension Without 08 data: [SG+, preliminary] [ev ] m 4 Global Fit σ σ 3σ 4 3 sin ϑ eµ = 4 U e4 U µ4 3σ ν e Dis ν µ Dis Dis App S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 0/3

46 [ev ] m 4 APPearance - DISappearance tension Without 08 data: Status after Neutrino 08: [SG+, preliminary] Global Fit σ σ 3σ Global Fit σ σ 3σ 4 3 sin ϑ eµ = 4 U e4 U µ4 3σ ν e Dis ν µ Dis Dis App [ev ] m sin ϑ eµ = 4 U e4 U µ4 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 0/3 3σ Dis App

47 [ev ] m 4 APPearance - DISappearance tension Without 08 data: Global Fit 4 3 sin ϑ eµ = 4 U e4 U µ4 3σ ν e Dis ν µ Dis Dis App [ev ] m 4 ithout 08 data: 3σ ν e σdis σ ν µ 3σDis Dis App µ4 [ev ] m 4 Status after Neutrino 08: 4 3 sin ϑ eµ = 4 U e4 U µ4 ] [SG+, preliminary] Global Fit S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 0/3 3σ σ σ 3σ Dis App

48 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3 May something be wrong? [Dentler+, JHEP 08 (08) 0] (03 data from MiniBooNE)

49 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3 May something be wrong? [Dentler+, JHEP 08 (08) 0] (03 data from MiniBooNE) No improvements if MiniBooNE is not considered

50 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3 May something be wrong? [Dentler+, JHEP 08 (08) 0] (03 data from MiniBooNE) ( ) ν µ DIS also constrain U e4, while ( ) ν e DIS do not constrain U µ4

51 May something be wrong? [Dentler+, JHEP 08 (08) 0] (03 data from MiniBooNE) Only removing LSND or all ( ) ν µ constraints the fit is almost acceptable No reason to do so! S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3

52 Neutrino Oscillations - Some theory Electron (anti)neutrino disappearence 3 Muon (anti)neutrino disappearence 4 Electron (anti)neutrino appearence 5 Global fit 6 Sterile neutrinos and CEνNS 7 Conclusions

53 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3 Present and future... [Papoulias+, PRD 97 (08) ] COHERENT: 4.57 kg CsI m %C.L. full syst. simple syst. 0 sin θ new Assumption: all DIS mixing angles are equal sin ϑ ee = sin ϑ µµ = sin θ new not competitive (yet)

54 m 4 Present and future... [Papoulias+, PRD 97 (08) ] 0 COHERENT: 4.57 kg CsI 90%C.L. full syst. simple syst. 0 sin θ new Assumption: all DIS mixing angles are equal sin ϑ ee = sin ϑ µµ = sin θ new R m 4 (ev ) [Cañas+, PLB 776 (08) 45].05 E = 4 MeV E = 6.5 MeV MINER m MINER 3m MINER 5m RED0 5m RED0 9m Texono CONNIE L (m) 0% eff, Q f =.0 50% eff, Q f =.0 50% eff, Q f = 0. + not competitive (yet) TEXONO-like reactor experiment sin θ ee S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /3

55 Neutrino Oscillations - Some theory Electron (anti)neutrino disappearence 3 Muon (anti)neutrino disappearence 4 Electron (anti)neutrino appearence 5 Global fit 6 Sterile neutrinos and CEνNS 7 Conclusions

56 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 3/3 Conclusions first model-independent hints from reactors ( ) ν e DIS, some discrepancy with Gallium anomaly and RAA 3 nothing seen in ( ) ν µ DIS strong upper bounds on U µ4, but also first constraints on U τ4 strong APP-DIS tension What are LSND and MiniBooNE observing? Systematics or LSν or new physics? 4 incoming CEνNS experiments will enter the game!

57 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 3/3 Conclusions first model-independent hints from reactors ( ) ν e DIS, some discrepancy with Gallium anomaly and RAA 3 nothing seen in ( ) ν µ DIS strong upper bounds on U µ4, but also first constraints on U τ4 strong APP-DIS tension What are LSND and MiniBooNE observing? Systematics or LSν or new physics? 4 incoming CEνNS experiments will enter the game! Thank you for the attention!

58 8 LSν Constraints from oscillation experiments 9 Cosmological constraints

59 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /6 Fraction of 5 MeV excess (%) Fuel evolution Reactor fluxes produced by decay fissions of 35 U 38 U 39 Pu 4 Pu Can we use time evolution to identify source of 5 MeV bump? F Data Constant 5 MeV excess Best fit F 35 [RENO, arxiv: ] 0.5 F39 Fi Fuel fractions in reactors change with time 0.4 EH EH Year F35 F38 F39 F F 39 [Daya Bay, PRL 8 (07) 580]

60 σ39 [ 43 cm / fission] Fuel evolution Fit bump amplitude as a function of flux normalizations Daya Bay Huber model w/ 68% C.L. σ38 = (. ±. 0) 43 σ4 = (6. 04 ± 0. 60) 43 C.L 68% 95% 99.7% σ 35 [ 43 cm / fission] 9 4 χ 4 9 [Daya Bay, PRL 8 (07) 580] χ / fission] cm -43 [ 39 y Normalization of 35 U flux smaller than prediction! 99.7% C.L. 95.5% C.L. 68.3% C.L y cm / fission] χ [ 35 Model RENO [RENO, arxiv: ] Again, we need model-independent information! take ratios at different distances to avoid normalization dependency S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /6

61 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /6 Gallium anomaly and RAA revisited [SG et al., PLB 78 (08) 3] detection efficiencies in Gallium experiments fit with free parameters: normalization of spectra of reactor fuels

62 S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 /6 Gallium anomaly and RAA revisited [SG et al., PLB 78 (08) 3] detection efficiencies in Gallium experiments fit with free parameters: normalization of spectra of reactor fuels χ Reactor spectra: r 35 r 38 r r k 99.73% 99% 95.45% 90% 68.7% 35 U flux normalization smaller than at σ χ η S Gallium efficiencies: η G MIν edis σ σ 3σ χ SAGE efficiency η S smaller than at σ

63 8 LSν Constraints from oscillation experiments 9 Cosmological constraints

64 [to be precise: N eff is slightly smaller at CMB decoupling, when the LSν starts to be non-relativistic] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 3/6 LSν thermalization Using SBL best-fit parameters for the LSν ( m 4, θ s): [Hannestad et al., JCAP 07 (0) 05] [Mirizzi et al., PRD 86 (0) ] (colors coding N eff ) (L: lepton asymmetry) Unless L O( 3 ), N eff See also: [Saviano et al., PRD 87 (03) ], [Hannestad et al., JCAP 08 (05) 09]

65 LSν constraints from cosmology CMB+local: [Planck Collaboration, 08] Neff H0 [km s Mpc ] [Archidiacono et al., JCAP 08 (06) 067] N eff ΛCDM+N eff +m s : TT ΛCDM+N eff +m s : TT+HST ΛCDM+N eff +m s : TT+HST+BAO m s [ev] H0 [km/s/mpc] mν, eff sterile [ev] { Neff < 3.9 < 0.65 ev m eff s (Planck8+BAO) [m s < ev] free N dataset eff [m s < ev] N eff = (TT) N eff < 3.5 m s < 0.66 ev (+H 0) N eff < 3.9 m s < 0.55 ev (+BAO) N eff < 3.8 m s < 0.53 ev BBN constraints: N eff =.90 ± 0. (BBN+Y p ) [Peimbert et al., 06] Summary: N eff = from LSν incompatible with m s ev! Planck8=Planck 08 TT,TE,EE + lowe + lensing All the constraints are at σ CL S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 4/6

66 Incomplete Thermalization Active-sterile oscillations in the early Universe: mixing parameters from SBL data = N eff [Hannestad et al., 0] [Mirizzi et al., 0] Many probes constrain N eff <. Do we need a mechanism to suppress oscillations and full thermalization of ν s? to compensate N eff = with additional mechanisms in Cosmology? Some ideas (an incomplete list!): large lepton asymmetry [Foot et al., 995; Mirizzi et al., 0; many more] new neutrino interactions [Bento et al., 00; Dasgupta et al., 04; Hannestad et al., 04; Saviano et al., 04; Archidiacono et al. 06; many more] entropy production after neutrino decoupling [Ho et al., 03] very low reheating temperature [Gelmini et al., 004; Smirnov et al., 006] time varying dark energy components [Giusarma et al., 0] larger expansion rate at the time of ν s production [Rehagen et al., 04] freedom in the Primordial Power Spectrum (PPS) of scalar perturbations from inflation compensate damping due to N eff [SG et al., 05] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 5/6

67 Solving both σ 8 and H 0 Tension? [Planck Collaboration, 05] S. Gariazzo Light sterile neutrino: the 08 status The Magnificent CEνNS, 03//08 6/6 Planck TT+lowP +lensing +lensing+bao ΛCDM 0.9 +Neff +Neff+Σmν +Neff +Neff+Σmν σ Σmν +Neff+m eff ν, sterile +Σmν +Neff+m eff ν, sterile σ Ω m Ω m H H 0 dashed: local measurements ΛCDM model, ΛCDM + ν a,s models: full cosmological dataset H 0 increases σ 8 increases (and viceversa)! The correlations do not help.