Critical Review on Neutrino Anomalies Carlo Giunti INFN, Torino, - - PowerPoint PPT Presentation

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Critical Review on Neutrino Anomalies Carlo Giunti INFN, Torino, - - PowerPoint PPT Presentation

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Critical Review on Neutrino Anomalies Carlo Giunti INFN, Torino, Italy Neutrinos: the Quest for a New Physics Scale CERN, 27-31 March 2017 C. Giunti Review on Neutrino Anomalies Neutrinos: the Quest for a New Physics Scale 27 March

slide-1
SLIDE 1

Critical Review on Neutrino Anomalies Carlo Giunti

INFN, Torino, Italy

Neutrinos: the Quest for a New Physics Scale CERN, 27-31 March 2017

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 1/49
slide-2
SLIDE 2

Indications of SBL Oscillations Beyond 3ν

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 2/49
slide-3
SLIDE 3

LSND

[PRL 75 (1995) 2650; PRC 54 (1996) 2685; PRL 77 (1996) 3082; PRD 64 (2001) 112007]

¯ νµ → ¯ νe 20 MeV ≤ E ≤ 52.8 MeV

◮ Well-known and pure source of ¯

νµ p + target → π+

at rest

− − − → µ+ + νµ µ+ − − − →

at rest e+ + νe + ¯

νµ ¯ νe + p → n + e+ Well-known detection process of ¯ νe

◮ ≈ 3.8σ excess ◮ But signal not seen by KARMEN at

L ≃ 18 m with the same method

[PRD 65 (2002) 112001]

L ≃ 30 m

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 3/49
slide-4
SLIDE 4

10

  • 2

10

  • 1

1 10 10 2 10

  • 3

10

  • 2

10

  • 1

1 sin2 2θ ∆m2 (eV2/c4)

Bugey Karmen NOMAD CCFR 90% (Lmax-L < 2.3) 99% (Lmax-L < 4.6)

∆m2

SBL 3 × 10−2 eV2 ≫ ∆m2 ATM ≃ 2.5 × 10−3 eV2 ≫ ∆m2 SOL

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 4/49
slide-5
SLIDE 5

MiniBooNE

L ≃ 541 m 200 MeV ≤ E 3 GeV νµ → νe

[PRL 102 (2009) 101802]

LSND signal

¯ νµ → ¯ νe

[PRL 110 (2013) 161801]

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? ◮ CP violation? ◮ Low-energy anomaly!

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 5/49
slide-6
SLIDE 6

Gallium Anomaly

Gallium Radioactive Source Experiments: GALLEX and SAGE νe Sources: e− + 51Cr → 51V + νe e− + 37Ar → 37Cl + νe Test of Solar νe Detection: νe + 71Ga → 71Ge + e− E ≃ 0.75 MeV E ≃ 0.81 MeV

0.7 0.8 0.9 1.0 1.1

R = N exp N cal

Cr1 GALLEX Cr SAGE Cr2 GALLEX Ar SAGE

R = 0.84 ± 0.05

LGALLEX = 1.9 m LSAGE = 0.6 m ∆m2

SBL 1 eV2 ≫ ∆m2 ATM ≫ ∆m2 SOL

≈ 2.9σ deficit

[SAGE, PRC 73 (2006) 045805; PRC 80 (2009) 015807; Laveder et al, Nucl.Phys.Proc.Suppl. 168 (2007) 344, MPLA 22 (2007) 2499, PRD 78 (2008) 073009, PRC 83 (2011) 065504]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 6/49
slide-7
SLIDE 7

◮ Deficit could be due to overestimate of

σ(νe + 71Ga → 71Ge + e−)

◮ Calculation: Bahcall, PRC 56 (1997) 3391

71Ge

3/2− 1/2− 5/2− 3/2−

71Ga

0.175 MeV 0.500 MeV 0.233 MeV

◮ σG.S. from T1/2(71Ge) = 11.43 ± 0.03 days

[Hampel, Remsberg, PRC 31 (1985) 666]

σG.S.(51Cr) = 55.3 × 10−46 cm2 (1 ± 0.004)3σ

◮ σ(51Cr) = σG.S.(51Cr)

  • 1 + 0.669 BGT175

BGTG.S. + 0.220 BGT500 BGTG.S.

  • ◮ Contribution of excited states only 5%!
  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 7/49
slide-8
SLIDE 8

BGT175 BGTG.S. BGT500 BGTG.S. Krofcheck et al. PRL 55 (1985) 1051

71Ga(p, n)71Ge

< 0.056 0.126 ± 0.023 Haxton PLB 431 (1998) 110 Shell Model 0.19 ± 0.18 Frekers et al. PLB 706 (2011) 134

71Ga(3He, 3H)71Ge 0.039 ± 0.030 0.202 ± 0.016

◮ The 71Ga(3He, 3H)71Ge data confirm the contribution of the two excited states. ◮ Haxton: “The calculation predicts destructive interference between the (p, n)

spin and spin-tensor matrix elements”

◮ It is unlikely that the deficit is caused by an overestimate of the cross section. ◮ Possible explanations:

◮ Statistical fluctuations. ◮ Experimental faults. ◮ Short-baseline oscillations.

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 8/49
slide-9
SLIDE 9

Reactor Electron Antineutrino Anomaly

[Mention et al, PRD 83 (2011) 073006]

New reactor ¯ νe fluxes

[Mueller et al, PRC 83 (2011) 054615; Huber, PRC 84 (2011) 024617]

L [m] R = N exp N cal

10 102 103 0.70 0.80 0.90 1.00 1.10 1.20

R = 0.940 ± 0.024

Bugey−3 Bugey−4 Chooz Daya Bay Double Chooz Gosgen ILL Krasnoyarsk Nucifer Palo Verde RENO Rovno88 Rovno91 SRP

≈ 2.5σ deficit

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 9/49
slide-10
SLIDE 10

L [m] Pνe→νe

1 10 102 103 0.70 0.80 0.90 1.00 1.10 1.20

DC DC DB DB R R E ≈ 4MeV − sin22ϑee = 0.1 ∆m41

2 = 0.1 eV2

∆m41

2 = 0.5 eV2

∆m41

2 = 1.0 eV2

Bugey−4 Rovno91 Rovno88 Bugey−3 Gosgen ILL Krasnoyarsk SRP Nucifer

∆m2

SBL 0.5 eV2 ≫ ∆m2 ATM ≫ ∆m2 SOL

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 10/49
slide-11
SLIDE 11

5 MeV Bump

Events / 0.2 MeV

5000 10000 15000

Data MC

Near (a)

Prompt Energy (MeV) 1 2 3 4 5 6 7 8

(Data - MC) / MC

0.1 − 0.1 0.2

Entries / 250 keV 5000 10000 15000 20000 Data Full uncertainty Reactor uncertainty ILL+Vogel Integrated Ratio to Prediction 0.8 0.9 1 1.1 1.2 (Huber + Mueller) Prompt Energy (MeV) 2 4 6 8 contribution

2

χ 4 − 2 − 2 4 )

i

χ ∼ ( (1 MeV windows) Local p-value

6 −

10

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10 1

[RENO, arXiv:1511.05849] [Daya Bay, arXiv:1508.04233]

◮ It is correlated with the reactor activity. ◮ Cannot be explained by neutrino oscillations. ◮ Very likely due to theoretical miscalculation of the spectrum. ◮ ∼ 3% effect on total flux. ◮ It seems to be an excess!

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 11/49
slide-12
SLIDE 12

NEOS

[arXiv:1610.05134]

1 2 3 4 5 6 7 8 Events /day/100 keV 10 20 30 40 50 60

ε

3 −

10

2 −

10

1 −

10 Neutrino Energy [MeV] 2 3 4 5 6 7 8 12 Prompt Energy [MeV] 1 2 3 4 5 6 7 10

Data signal (ON-OFF) Data background (OFF) (H-M-V) ν MC 3 (Daya Bay) ν MC 3

(a)

1 2 3 4 5 6 7 10 Data/Prediction 0.9 1.0 1.1 NEOS/H-M-V Systematic total

(b)

Prompt Energy [MeV] 1 2 3 4 5 6 7 10 Data/Prediction 0.9 1.0 1.1 NEOS/Daya Bay Systematic total , 0.050)

2

(1.73 eV , 0.142)

2

(2.32 eV

(c)

⋅ ⋅

◮ Hanbit Nuclear Power Complex in

Yeong-gwang, Korea.

◮ Thermal power of 2.8 GW. ◮ Detector: a ton of Gd-loaded

liquid scintillator in a gallery approximately 24 m from the reactor core.

◮ The measured antineutrino event

rate is 1976 per day with a signal to background ratio of about 22.

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 12/49
slide-13
SLIDE 13

14

θ 2

2

sin

2 −

10

1 −

10 1

]

2

[eV

41 2

m ∆

1 −

10 1

RAA allowed 90% CL 95% CL 99% CL Excluded NEOS 90% CL Bugey-3 90% CL

s

Daya Bay 90% CL

Raster Scan [NEOS, arXiv:1610.05134] Best Fits: ∆m2

41 = 1.7 eV2

sin2 2θ14 = 0.05 ∆m2

41 = 1.3 eV2

sin2 2θ14 = 0.04

sin22ϑee ∆m41

2 [eV2]

+

10−3 10−2 10−1 1 10−1 1 10

NEOS Spectrum 90% CL 95% CL 99% CL

2-D χ2 Analysis χ2

no osc. − χ2 min = 6.5

≈ 2.1σ anomaly

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 13/49
slide-14
SLIDE 14

Beyond Three-Neutrino Mixing: Sterile Neutrinos νe νµ ντ

∆m2

SOL

∆m2

ATM

. . . νs2 νs1 ∆m2

SBL

ν4 ν3 ν2 ν1 . . . ν5 m 1 eV2

≃ 2.5 × 10−3 eV2

≃ 7.4 × 10−5 eV2

Terminology: a eV-scale sterile neutrino means: a eV-scale massive neutrino which is mainly sterile

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 14/49
slide-15
SLIDE 15

Four-Neutrino Schemes: 2+2, 3+1 and 1+3

ν1 ν2 ∆m2

SOL

∆m2

SBL

ν4 ν3 ∆m2

ATM

m ∆m2

SBL

∆m2

SOL

ν1 ν2 ν4 ν3 ∆m2

ATM

m ν1 ν2 ν3 ν4 ∆m2

ATM

∆m2

SOL

∆m2

SBL

m ν3 ν2 ν4 ∆m2

ATM

∆m2

SBL

∆m2

SOL

ν1 m ∆m2

SBL

∆m2

ATM

ν1 ν2 ν3 ν4 ∆m2

SOL

m ∆m2

SBL

ν4 ∆m2

SOL

ν1 ν2 ν3 ∆m2

ATM

m

2+2 3+1 1+3

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 15/49
slide-16
SLIDE 16

2+2 Four-Neutrino Schemes

ν1 ν2 ∆m2

SOL

∆m2

SBL

ν4 ν3 ∆m2

ATM

m ∆m2

SBL

∆m2

SOL

ν1 ν2 ν4 ν3 ∆m2

ATM

m ◮ After LSND (1995) 2+2 was preferred to 3+1, because of the 3+1

appearance-disappearance tension

[Okada, Yasuda, IJMPA 12 (1997) 3669; Bilenky, CG, Grimus, EPJC 1 (1998) 247]

◮ This is not a perturbation of 3-ν Mixing =

⇒ Large active–sterile

  • scillations for solar or atmospheric neutrinos!
  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 16/49
slide-17
SLIDE 17

2+2 Schemes are Strongly Disfavored

0.2 0.4 0.6 0.8 1

ηs

10 20 30 40 50

∆χ

2 99% CL (1 dof)

solar + KamLAND s

  • l

a r s

  • l

a r ( p r e S N O s a l t ) 0.2 0.4 0.6 0.8 1

ηs

χ

2 PG

χ

2 PC

atm + K2K + SBL global solar + KamLAND

Solar: Matter Effects + SNO NC Atmospheric: Matter Effects ηs = |Us1|2 + |Us2|2 = 1 − |Us3|2 + |Us4|2 99% CL: ηs < 0.25 (Solar + KamLAND) ηs > 0.75 (Atmospheric + K2K)

[Maltoni, Schwetz, Tortola, Valle, New J. Phys. 6 (2004) 122]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 17/49
slide-18
SLIDE 18

3+1 and 1+3 Four-Neutrino Schemes

ν1 ν2 ν3 ν4 ∆m2

ATM

∆m2

SOL

∆m2

SBL

m ν3 ν2 ν4 ∆m2

ATM

∆m2

SBL

∆m2

SOL

ν1 m ∆m2

SBL

∆m2

ATM

ν1 ν2 ν3 ν4 ∆m2

SOL

m ∆m2

SBL

ν4 ∆m2

SOL

ν1 ν2 ν3 ∆m2

ATM

m

3+1 1+3

◮ Perturbation of 3-ν Mixing:

|Ue4|2, |Uµ4|2, |Uτ4|2 ≪ 1 |Us4|2 ≃ 1

◮ 1+3 schemes are disfavored by cosmology (ΛCDM):

3

  • k=1

mk 0.2 eV

[Planck, Astron. Astrophys. 594 (2016) A13 (arXiv:1502.01589)]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 18/49
slide-19
SLIDE 19

Effective 3+1 SBL Oscillation Probabilities

Appearance (α = β)

PSBL

(−)

να→

(−)

νβ

≃ sin2 2ϑαβ sin2 ∆m2

41L

4E

  • sin2 2ϑαβ = 4|Uα4|2|Uβ4|2

Disappearance

PSBL

(−)

να→

(−)

να

≃ 1 − sin2 2ϑαα sin2 ∆m2

41L

4E

  • sin2 2ϑαα = 4|Uα4|2

1 − |Uα4|2

U = Ue1 Ue2 Ue3 Ue4 Uµ1 Uµ2 Uµ3 Uµ4 Uτ1 Uτ2 Uτ3 Uτ4 Us1 Us2 Us3 Us4               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 ∆m2

ATM

[de Gouvea et al, PRD 91 (2015) 053005, PRD 92 (2015) 073012, arXiv:1605.09376; Palazzo et al, PRD 91 (2015) 073017, PLB 757 (2016) 142; Gandhi et al, JHEP 1511 (2015) 039] and solar exp. sensitive to ∆m2

SOL

[Long, Li, CG, PRD 87, 113004 (2013) 113004]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 19/49
slide-20
SLIDE 20

Reactor ¯ νe Disappearance

Reactor Rates

sin22ϑee ∆m41

2 [eV2]

10−4 10−3 10−2 10−1 10−1 1 10

+

Rea:Rat 1σ 2σ 3σ

sin22ϑee ∆m41

2 [eV2]

10−4 10−3 10−2 10−1 10−1 1 10

+

2σ Bugey−3 Spectrum NEOS Spectrum Rea:Spe 1σ 2σ 3σ

Reactor Spectra

sin22ϑee ∆m41

2 [eV2]

10−4 10−3 10−2 10−1 10−1 1 10

+

2σ Reactor Rates Reactor Spectra Rea:Rat+Spe 1σ 2σ 3σ

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860]

Reactor Rates + Spectra

◮ ∆χ2

NO = 10.6 ⇒ ≈ 2.8σ anomaly

◮ Best Fit:

∆m2

41 = 1.7 eV2

sin2 2ϑee = 0.060 ⇔ |Ue4|2 = 0.015

◮ χ2

min/NDF = 94.1/108 ⇒ GoF = 83%

◮ χ2

PG/NDFPG = 7.8/2 ⇒ GoFPG = 2%

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 20/49
slide-21
SLIDE 21

Reactor ¯ νe + Gallium νe Disappearance

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860] sin22ϑee ∆m41

2 [eV2]

10−2 10−1 10−1 1 10

+

2σ Reactors Gallium

Rea+Gal 1σ 2σ 3σ

◮ ∆χ2

NO = 14.6 ⇒ ≈ 3.4σ anomaly

◮ Best Fit:

∆m2

41 = 3.0 eV2

sin2 2ϑee = 0.13 ⇔ |Ue4|2 = 0.034

◮ χ2

min/NDF = 107.3/112 ⇒ GoF = 61%

◮ χ2

PG/NDFPG = 5.4/2 ⇒ GoFPG = 7%

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 21/49
slide-22
SLIDE 22

Global νe and ¯ νe Disappearance

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860]

sin22ϑee ∆m41

2 [eV2]

10−2 10−1 1 10

+

2σ Reactors Gallium νeC Sun T2K

νeDis 1σ 2σ 3σ

◮ KARMEN+LSND νe–12C

[Conrad, Shaevitz, PRD 85 (2012) 013017] [CG, Laveder, PLB 706 (2011) 20]

◮ Solar νe + KamLAND ¯

νe

[Li et al, PRD 80 (2009) 113007, PRD 86 (2012) 113014] [Palazzo, PRD 83 (2011) 113013, PRD 85 (2012) 077301]

◮ T2K Near Detector νe disappearance

[T2K, PRD 91 (2015) 051102]

◮ ∆χ2

NO = 13.3 ⇒ ≈ 3.2σ anomaly

◮ Best Fit:

∆m2

41 = 1.7 eV2

sin2 2ϑee = 0.066 ⇔ |Ue4|2 = 0.017

◮ χ2

min/NDF = 162.5/174 ⇒ GoF = 72%

◮ χ2

PG/NDFPG = 13.8/7 ⇒ GoFPG = 6%

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 22/49
slide-23
SLIDE 23

Tritium Beta-Decay: 3H → 3He + e− + ¯ νe

dΓ dT = (cosϑCGF)2 2π3 |M|2 F(E) p E K 2(T) Kurie function: K(T) =

  • (Q − T)
  • k

|Uek|2

  • (Q − T)2 − m2

k

1/2 Q = M3H − M3He − me = 18.58 keV

Q − m2 T Q − m1 K(T) Q

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 23/49
slide-24
SLIDE 24

Mainz and Troitsk Limit on ∆m2

41 ≃ m2 4

m4 ≫ m1, m2, m3 = ⇒ ∆m2

41 ≡ m2 4 − m2 1 ≃ m2 4

[Kraus, Singer, Valerius, Weinheimer, EPJC 73 (2013) 2323] [Belesev et al, JPG 41 (2014) 015001]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 24/49
slide-25
SLIDE 25

Global νe and ¯ νe Disappearance + β Decay

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860]

sin22ϑee ∆m41

2 [eV2]

10−2 10−1 1 10 102

+

3σ νeDis β

νeDis+β 1σ 2σ 3σ

◮ Best Fit:

∆m2

41 = 1.7 eV2

sin2 2ϑee = 0.065 ⇔ |Ue4|2 = 0.016

◮ 2 cm

Losc

41

E [MeV] 8 m at 3σ

◮ 0.0033 sin2 2ϑee 0.22

at 3σ

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 25/49
slide-26
SLIDE 26

The Race for νe and ¯ νe Disappearance

sin22ϑee ∆m41

2 [eV2]

10−3 10−2 10−1 1 10−1 1 10 102 103

+

νeDis+β 1σ 2σ 3σ CeSOX shape (95% CL) CeSOX rate (95% CL) CeSOX rate+shape (95% CL) BEST (1σ) IsoDAR@KamLAND (5yr, 3σ) IsoDAR@C−ADS (5yr, 3σ) KATRIN (90% CL)

sin22ϑee ∆m41

2 [eV2]

10−3 10−2 10−1 1 10−1 1 10 102 103

+

νeDis+β 1σ 2σ 3σ DANSS (1yr, 95% CL) Neutrino−4 (1yr, 95% CL) PROSPECT phase 1 (3yr, 3σ) PROSPECT phase 2 (3yr, 3σ) SoLiD phase 1 (1yr, 95% CL) SoLiD phase 2 (3yr, 3σ) STEREO (1yr, 95% CL)

CeSOX (Gran Sasso, Italy) 144Ce → ¯ νe

BOREXINO: L ≃ 5-12m [Vivier@TAUP2015]

BEST (Baksan, Russia) 51Cr → νe L ≃ 5-12m [PRD 93 (2016) 073002] IsoDAR@KamLAND (Kamioka, Japan)

8Li → ¯

νe L ≃ 16m [arXiv:1511.05130] IsoDAR@C-ADS (Guangdong, China)

8Li → ¯

νe L ≃ 15m [JHEP 1601 (2016) 004] DANSS (Kalinin, Russia) L ≃ 10-12m [arXiv:1606.02896] Neutrino-4 (RIAR, Russia) L ≃ 6-11m [JETP 121 (2015) 578] PROSPECT (ORNL, USA) L ≃ 7-12m [arXiv:1512.02202] SoLid (SCK-CEN, Belgium) L ≃ 5-8m [arXiv:1510.07835] STEREO (ILL, France) L ≃ 8-12m [arXiv:1602.00568] KATRIN (Karlsruhe, Germany) 3H → ¯ νe [Drexlin@NOW2016]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 26/49
slide-27
SLIDE 27

DANSS

[Danilov, Moriond EW 2017]

✾

DANSS Preliminary Const/R2 DANSS Preliminary Const/R2

¨M2=2.3eV2, Sin2(2Ä)=0.14 Î2=59 (NDF=30) Prob.=0.003

Positron

tions in:

sults ectrum

more to atics

DANSS Preliminary 95%CL

Compilation of allowed regions from arxiv:1512.02202

See talk C.Giunti for new regions

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 27/49
slide-28
SLIDE 28

¯ νµ → ¯ νe and νµ → νe Appearance

sin22ϑeµ ∆m41

2 [eV2]

+

10−3 10−2 10−1 1 10−2 10−1 1 10 102

99% CL LSND MiniBooNE KARMEN NOMAD BNL−E776 ICARUS OPERA νµ → νe 90% CL 95% CL 99% CL

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 28/49
slide-29
SLIDE 29

νµ and ¯ νµ Disappearance

sin22ϑµµ ∆m41

2 [eV2]

10−2 10−1 1 10−1 1 10

99% CL CDHSW: νµ (1984) ATM: νµ + νµ SciBooNE−MiniBooNE: νµ (2012) SciBooNE−MiniBooNE: νµ (2012) MINOS: νµ CC+NC (2016) IceCube: νµ + νµ (2016)

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 29/49
slide-30
SLIDE 30

3+1 Appearance-Disappearance Tension

νe DIS sin2 2ϑee ≃ 4|Ue4|2 νµ DIS sin2 2ϑµµ ≃ 4|Uµ4|2 νµ → νe APP sin2 2ϑeµ = 4|Ue4|2|Uµ4|2 ≃ 1

4 sin2 2ϑee sin2 2ϑµµ

[Okada, Yasuda, IJMPA 12 (1997) 3669; Bilenky, CG, Grimus, EPJC 1 (1998) 247] sin22ϑeµ ∆m41

2 [eV2]

10−4 10−3 10−2 10−1 1 10−1 1 10

+ +

10−4 10−3 10−2 10−1 1 10−1 1 10

Glo16A 1σ 2σ 3σ 3σ νe Dis νµ Dis Dis App

◮ νµ → νe is quadratically suppressed! ◮ Glo16A = 2016 data except MINOS and

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860]

IceCube

◮ ∆χ2

NO = 51.9 ⇒ ≈ 6.4σ anomaly

◮ Best Fit:

∆m2

41 = 1.6 eV2

|Ue4|2 = 0.025 |Um4|2 = 0.015

◮ χ2

min/NDF = 288.3/249 ⇒ GoF = 4%

◮ χ2

PG/NDFPG = 13.4/2 ⇒ GoFPG = 0.1%

◮ Similar tension in 3+2, 3+3, . . . , 3+Ns

[CG, Zavanin, MPLA 31 (2015) 1650003]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 30/49
slide-31
SLIDE 31

Effects of MINOS and IceCube

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860] sin22ϑµµ ∆m41

2 [eV2]

+

10−2 10−1 1 10

3σ Glo16A Glo16A + MINOS Glo16A + IceCube Glo16A + MINOS + IceCube = Glo16B 3σ MINOS IceCube

sin22ϑeµ ∆m41

2 [eV2]

+

10−3 10−2 1 10

3σ Glo16A Glo16A + MINOS Glo16A + IceCube Glo16A + MINOS + IceCube = Glo16B

◮ Glo16B = Glo16A + MINOS + IceCube

∆χ2

NO = 50.7 ⇒ ≈ 6.3σ anomaly

◮ Best Fit:

∆m2

41 = 1.6 eV2

|Ue4|2 = 0.027 |Uµ4|2 = 0.014

◮ χ2

min/NDF = 556.9/525 ⇒ GoF = 16%

◮ χ2

PG/NDFPG = 14.5/2 ⇒ GoFPG = 0.07%

← Strong tension!

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 31/49
slide-32
SLIDE 32

Another Analysis of SBL + IceCube

[Collin, Arguelles, Conrad, Shaevitz, PRL 117 (2016) 221801 (arXiv:1607.00011)]

SBL SBL + IceCube → Red: 90% CL Blue: 99% CL

3+1 ∆m2

41 |Ue4| |Uµ4| |Uτ4| Nbins

χ2

min

χ2

null

∆χ2 (dof) SBL 1.75 0.163 0.117

  • 315

306.81 359.15 52.34 (3) SBL+IC 1.75 0.164 0.119 0.00 524 518.59 568.84 50.26 (4) IC 5.62

  • 0.314
  • 209

207.11 209.69 2.58 (2)

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 32/49
slide-33
SLIDE 33

Effects of NEOS

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860] sin22ϑee ∆m41

2 [eV2]

+

10−2 10−1 1

3σ Glo16A Glo16A + MINOS + IceCube = Glo16B Glo16A + MINOS + IceCube + NEOS = Glo17 3σ NEOS

sin22ϑeµ ∆m41

2 [eV2]

+

10−3 10−2 1

3σ Glo16A Glo16A + MINOS + IceCube = Glo16B Glo16A + MINOS + IceCube + NEOS = Glo17

◮ Glo17 = GLO16B + NEOS

∆χ2

NO = 50.8 ⇒ ≈ 6.3σ anomaly

◮ Best Fit:

∆m2

41 = 1.7 eV2

|Ue4|2 = 0.020 |Uµ4|2 = 0.016

◮ χ2

min/NDF = 621.7/585 ⇒ GoF = 14%

◮ χ2

PG/NDFPG = 17.3/2 ⇒ GoFPG = 0.02%

← Strong tension!

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 33/49
slide-34
SLIDE 34

MiniBooNE Low-Energy Anomaly

νµ → νe

[PRL 102 (2009) 101802]

LSND signal

¯ νµ → ¯ νe

[PRL 110 (2013) 161801]

LSND signal

◮ Fit of MB Low-Energy Excess requires small ∆m2

41 and large sin2 2ϑeµ, in

contradiction with disappearance data PSBL

(−)

νµ→

(−)

νe

= sin2 2ϑeµ sin2 ∆m2

41L

4E

  • ◮ MB low-energy excess is the main cause of bad APP-DIS GoFPG = 0.06%

◮ Pragmatic Approach: discard the Low-Energy Excess because it is likely not

due to oscillations

[CG, Laveder, Li, Long, PRD 88 (2013) 073008]

◮ MicroBooNE is crucial for checking the MiniBooNE Low-Energy Anomaly and

the consistency of different short-baseline data

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 34/49
slide-35
SLIDE 35

sin22ϑeµ ∆m41

2 [eV2]

10−4 10−3 10−2 10−1 1 10−2 10−1 1 10 102

νeDIS νµDIS νe&νµDIS ICARUS OPERA ATM+SUN

* + + +

MiniBooNE 3σ

−0.2 0.0 0.2 0.4 0.6 0.8

E [MeV] Excess Events / MeV

200 400 600 800 1000 1200 1400 3000

200 400 600 800 1000 1200 1400 −0.2 0.0 0.2 0.4 0.6 0.8 MiniBooNE − νe Data − Expected Background sin22ϑ = 0.98, ∆m2 = 0.04 eV2 (bf) sin22ϑ = 0.0017, ∆m2 = 0.5 eV2 sin22ϑ = 0.0022, ∆m2 = 0.9 eV2 sin22ϑ = 0.0023, ∆m2 = 3 eV2

No fit of low-energy excess for realistic sin2 2ϑeµ 3 × 10−3

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 35/49
slide-36
SLIDE 36

Neutrino energy reconstruction problem?

[Martini, Ericson, Chanfray, PRD 85 (2012) 093012; PRD 87 (2013) 013009]

◮ Effect due to multinucleon interactions whose signal is indistinguishable

from that due to quasielastic charged-current scattering νe + n → p + e− ¯ νe + p → n + e+

◮ In the MiniBooNE analysis the reconstructed neutrino energy is

(EB ≃ 25 MeV) E QE

ν

= 2 (Mi − EB) Ee −

  • m2

e − 2MiEB + E 2 B + ∆M2 if

  • 2 (Mi − EB − Ee + pe cos θe)

◮ The MiniBooNE collaboration took into account:

◮ Fermi motion of the initial nucleon ◮ Charged-current single charged pion production events in which the pion is

not observed (e.g. νe + n → ∆+ + e− → n + π+ + e− with π+ absorbed by a nucleus)

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 36/49
slide-37
SLIDE 37

10 20 30 40 50 60 0.5 1 1.5 2 2.5 d N / d E_reconstructed E_reconstructed ( GeV ) quasi-elastic component multinucleon component 0.4 * pion component qe + mn + 0.4*pi 5 10 15 20 25 30 0.5 1 1.5 2 2.5 d N / d E_reconstructed E_reconstructed ( GeV ) quasi-elastic component multinucleon component 0.4*pion component qe + mn + 0.4*pi

MiniBooNE νµ → νe full transmutation Monte Carlo events

0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0

MiniBooNE − νe E ν [GeV] E ν

rec [GeV]

→

0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0

MiniBooNE + multinucleon − νe E ν [GeV] E ν

rec [GeV]

[Ericson, Garzelli, CG, Martini, PRD 93 (2016) 073008]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 37/49
slide-38
SLIDE 38

−0.2 0.0 0.2 0.4 0.6 0.8

Eν

rec [MeV]

Excess Events / MeV

200 400 600 800 1000 1200 1400 3000

MiniBooNE − νe Data − Expected Background sin22ϑ = 1.00, ∆m2 = 0.04 eV2 (bf) sin22ϑ = 0.01, ∆m2 = 0.4 eV2 sin22ϑ = 0.003, ∆m2 = 0.7 eV2 sin22ϑ = 0.003, ∆m2 = 4 eV2

→

−0.2 0.0 0.2 0.4 0.6 0.8

Eν

rec [MeV]

Excess Events / MeV

200 400 600 800 1000 1200 1400 3000

MB + multinucleon − νe Data − Expected Background sin22ϑ = 0.98, ∆m2 = 0.04 eV2 (bf) sin22ϑ = 0.01, ∆m2 = 0.4 eV2 sin22ϑ = 0.003, ∆m2 = 0.7 eV2 sin22ϑ = 0.003, ∆m2 = 4 eV2 sin22ϑ ∆m2 [eV2] 10−4 10−3 10−2 10−1 10−2 10−1 1 10

+ + + +

2 4 6 8

∆χ2

2 4 6 8

∆χ2

MiniBooNE 68.27% CL 90.00% CL 95.45% CL 99.00% CL 99.73% CL MiniBooNE 68.27% CL 90.00% CL 95.45% CL 99.00% CL 99.73% CL

→

sin22ϑ ∆m2 [eV2] 10−4 10−3 10−2 10−1 10−2 10−1 1 10

+ + + +

2 4 6 8

∆χ2

2 4 6 8

∆χ2

MB + multinucleon 68.27% CL 90.00% CL 95.45% CL 99.00% CL 99.73% CL MB + multinucleon 68.27% CL 90.00% CL 95.45% CL 99.00% CL 99.73% CL

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 38/49
slide-39
SLIDE 39

sin22ϑeµ ∆m41

2 [eV2]

10−3 10−2 1

+

10−3 10−2 1

+

3+1−GLO 1σ 2σ 3σ 3σ APP DIS

→

sin22ϑeµ ∆m41

2 [eV2]

10−3 10−2 1

+

10−3 10−2 1

+

3+1−GLO 1σ 2σ 3σ 3σ APP DIS

GoF = 7% PGoF = 0.2% GoF = 7% PGoF = 0.2%

◮ Multinucleon interactions can decrease slightly the MiniBooNE

low-energy anomaly

◮ Multinucleon interactions cannot solve the APP-DIS tension ◮ MicroBooNE is crucial for checking the MiniBooNE low-energy anomaly ◮ If confirmed it is a real problem

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 39/49
slide-40
SLIDE 40

Global → Pragmatic

[CG, arXiv:1609.04688]

sin22ϑeµ ∆m41

2 [eV2]

10−4 10−3 10−2 10−1 10−1 1 10

3σ DIS APP−GLO APP−PrGLO

◮ APP-GLO: all MiniBooNE data ◮ APP-PrGLO: only MiniBooNE E > 475 MeV data (Pragmatic)

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 40/49
slide-41
SLIDE 41

Pragmatic Global 3+1 Fit

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860] (−)

νµ →

(−)

νe

sin22ϑeµ ∆m41

2 [eV2]

10−3 10−2 1 10

+ +

PrGlo17 1σ 2σ 3σ 3σ App Dis

(−)

νe →

(−)

νe

sin22ϑee ∆m41

2 [eV2]

10−2 10−1 1 1 10

+

PrGlo17 1σ 2σ 3σ 3σ νe Dis Dis

(−)

νµ →

(−)

νµ

sin22ϑµµ ∆m41

2 [eV2]

10−2 10−1 1 10

+

PrGlo17 1σ 2σ 3σ 3σ νµ Dis Dis

◮ ∆χ2 NO = 46.5 ⇒ ≈ 6.0σ anomaly ◮ Best Fit:

∆m2

41 = 1.7 eV2

|Ue4|2 = 0.019 |Uµ4|2 = 0.015

◮ χ2 min/NDF = 594.8/579 ⇒ GoF = 32% ◮ χ2 PG/NDFPG = 7.4/2 ⇒ GoFPG = 3%

← Mild tolerable tension!

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 41/49
slide-42
SLIDE 42

(−)

νµ →

(−)

νe

sin22ϑeµ ∆m41

2 [eV2]

+

10−3 10−2 1

3σ Glo16A Glo16B Glo17 PrGlo17

(−)

νe →

(−)

νe

sin22ϑee ∆m41

2 [eV2]

+

10−2 10−1 1

3σ Glo16A Glo16B Glo17 PrGlo17

(−)

νµ →

(−)

νµ

sin22ϑµµ ∆m41

2 [eV2]

+

10−2 10−1 1

3σ Glo16A Glo16B Glo17 PrGlo17

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 42/49
slide-43
SLIDE 43

Bounds on |Uτ4|2

0. 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 101 100 101 UΤ4

2

m 41

2 eV2

99 MINOS MINOS atm MB disapp CDHS

best phases worst phases best phases worst phases

[Kopp et al, JHEP 1305 (2013) 050]

τ µ

θ 2

2

sin

  • 4

10

  • 3

10

  • 2

10

  • 1

10 1

)

2

(eV

41 2

m ∆

  • 4

10

  • 3

10

  • 2

10

  • 1

10 1 10

2

10

3

10

90% CL OPERA NH OPERA IH CHORUS NOMAD

νµ → ντ

[OPERA, JHEP 1506 (2015) 069]

2

|

4 µ

|U

  • 3

10

  • 2

10

  • 1

10 1

2

|

4 τ

|U

0.2 0.4 0.6 0.8 1 [Super-Kamiokande, PRD 91 (2015) 052019]

10−3 10−2 10−1 |Uµ4|2 = sin2 θ24 0.00 0.05 0.10 0.15 0.20 0.25 0.30 |Uτ4|2 = sin2 θ34 · cos2 θ24

SK (2015), 90 % C.L. SK (2015), 99 % C.L. IceCube (2016), 90 % C.L. IceCube (2016), 99 % C.L.

2 4 6 8 −2∆LLH

90% C.L. 99% C.L.

0 2 4 6 8 −2∆LLH

90% C.L. 99% C.L.

[IceCube DeepCore, arXiv:1702.05160]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 43/49
slide-44
SLIDE 44

[Collin et al, PRL 117 (2016) 221801]

90% CL ϑ34 < 6◦ for ∆m2

41 ≈ 6 eV2

ϑ34 < 80◦ for ∆m2

41 ≈ 2 eV2

[Gariazzo, CG, Laveder, Li, arXiv:1703.00860] |U τ4|2 ∆χ2

68.27% CL 90% CL 95.45% CL 99% CL 99.73% CL

10−3 10−2 10−1 1 2 3 4 5 6 7 8 9 10

Glo16B Glo17 PrGlo17

90% CL Glo16A + MINOS: ϑ34 < 27◦ Glo16A + IceCube: ϑ34 < 7.3◦ Glo16B: ϑ34 < 7.3◦ Glo17: ϑ34 < 5.6◦ PrGlo17: ϑ34 < 6.0◦

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 44/49
slide-45
SLIDE 45

The Race for the Light Sterile

sin22ϑeµ ∆m41

2 [eV2]

10−4 10−3 1

+

PrGlo17 1σ 2σ 3σ SBN (3yr, 3σ) nuPRISM (3σ) JSNS2 (3σ)

sin22ϑµµ ∆m41

2 [eV2]

10−2 10−1 1

+

PrGlo17 1σ 2σ 3σ SBN (3yr, 3σ) KPipe (3yr, 3σ)

sin22ϑee ∆m41

2 [eV2]

10−2 10−1 1

+

PrGlo17 1σ 2σ 3σ DANSS (1yr, 95% CL) Neutrino−4 (1yr, 95% CL) PROSPECT phase 1 (3yr, 3σ) PROSPECT phase 2 (3yr, 3σ) SoLiD phase 1 (1yr, 95% CL) SoLiD phase 2 (3yr, 3σ) STEREO (1yr, 95% CL)

sin22ϑee ∆m41

2 [eV2]

10−2 10−1 1

+

PrGlo17 1σ 2σ 3σ CeSOX shape (95% CL) CeSOX rate (95% CL) CeSOX rate+shape (95% CL) BEST (1σ) IsoDAR@KamLAND (5yr, 3σ) IsoDAR@C−ADS (5yr, 3σ) KATRIN (90% CL)

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 45/49
slide-46
SLIDE 46

Effects of light sterile neutrinos should also be seen in:

◮ β Decay Experiments

[Hannestad et al, JCAP 1102 (2011) 011, PRC 84 (2011) 045503; Formaggio, Barrett, PLB 706 (2011) 68; Esmaili, Peres, PRD 85 (2012) 117301; Gastaldo et al, JHEP 1606 (2016) 061]

◮ Neutrinoless Double-β Decay Experiments

[Rodejohann et al, JHEP 1107 (2011) 091; Li, Liu, PLB 706 (2012) 406; Meroni et al, JHEP 1311 (2013) 146, PRD 90 (2014) 053002; Pascoli et al, PRD 90 (2014) 093005; CG, Zavanin, JHEP 1507 (2015) 171; Guzowski et al, PRD 92 (2015) 012002]

◮ Long-baseline Neutrino Oscillation Experiments

[de Gouvea et al, PRD 91 (2015) 053005, PRD 92 (2015) 073012, arXiv:1605.09376; Palazzo et al, PRD 91 (2015) 073017, PLB 757 (2016) 142, JHEP 1602 (2016) 111, JHEP 1609 (2016) 016, arXiv:1605.04299; Gandhi et al, JHEP 1511 (2015) 039; Pant et al, NPB 909 (2016) 1079, Choubey, Pramanik, PLB 764 (2017) 135]

◮ Solar neutrinos

[Dooling et al, PRD 61 (2000) 073011, Gonzalez-Garcia et al, PRD 62 (2000) 013005; Palazzo, PRD 83 (2011) 113013, PRD 85 (2012) 077301; Li et al, PRD 80 (2009) 113007, PRD 87, 113004 (2013), JHEP 1308 (2013) 056; Kopp et al, JHEP 1305 (2013) 050]

◮ Atmospheric neutrinos

[Goswami, PRD 55 (1997) 2931; Bilenky et al, PRD 60 (1999) 073007; Maltoni et al, NPB 643 (2002) 321, PRD 67 (2003) 013011; Choubey, JHEP 0712 (2007) 014; Razzaque, Smirnov, JHEP 1107 (2011) 084, PRD 85 (2012) 093010; Gandhi, Ghoshal, PRD 86 (2012) 037301; Barger et al, PRD 85 (2012) 011302; Esmaili et al, JCAP 1211 (2012) 041, JCAP 1307 (2013) 048, JHEP 1312 (2013) 014; Rajpoot et al, EPJC 74 (2014) 2936; Lindner et al, JHEP 1601 (2016) 124; Behera et al, arXiv:1605.08607]

◮ Supernova neutrinos

[Caldwell, Fuller, Qian, PRD 61 (2000) 123005; Peres, Smirnov, NPB 599 (2001); Sorel, Conrad, PRD 66 (2002) 033009; Tamborra et al, JCAP 1201 (2012) 013; Wu et al, PRD 89 (2014) 061303; Esmaili et al, PRD 90 (2014) 033013]

◮ Cosmic neutrinos

[Cirelli et al, NPB 708 (2005) 215; Donini, Yasuda, arXiv:0806.3029; Barry et al, PRD 83 (2011) 113012]

◮ Indirect dark matter detection [Esmaili, Peres, JCAP 1205 (2012) 002] ◮ Cosmology [see: Wong, ARNPS 61 (2011) 69; Archidiacono et al, AHEP 2013 (2013) 191047]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 46/49
slide-47
SLIDE 47

Neutrinoless Double-Beta Decay

mββ = |Ue1|2 m1 + |Ue2|2 eiα21 m2 + |Ue3|2 eiα31 m3 + |Ue4|2 eiα41 m4

mββ

(4) [eV]

∆χ2 KamLAND−Zen 2016 90% CL 10−2 10−1 1 2 3 4 5 6 7 8 9 10

68.27% 90% 95.45% 99% 99.73%

PrGlo17

m(k)

ββ = |Uek|2mk

m1 ≪ m4 ⇓ m(4)

ββ ≃ |Ue4|2

  • ∆m2

41

surprise: possible cancellation with m(3ν)

ββ

[Barry et al, JHEP 07 (2011) 091] [Li, Liu, PLB 706 (2012) 406] [Rodejohann, JPG 39 (2012) 124008] [Girardi, Meroni, Petcov, JHEP 1311 (2013) 146] [CG, Zavanin, JHEP 07 (2015) 171]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 47/49
slide-48
SLIDE 48

Lightest mass: m1 [eV] |Uek|2mk [eV] 10−4 10−3 10−2 10−1 1 10−4 10−3 10−2 10−1 1 |Ue1|2m1 |Ue2|2m2 |Ue3|2m3 |Ue4|2m4

Normal 3ν Ordering 1σ 2σ 3σ ν4 1σ 2σ 3σ

Lightest mass: m1 [eV] |mββ| [eV] 90% C.L. UPPER LIMIT 10−4 10−3 10−2 10−1 1 10−4 10−3 10−2 10−1 1

Normal 3ν Ordering − 3σ 3ν 3+1

Lightest mass: m3 [eV] |Uek|2mk [eV] 10−4 10−3 10−2 10−1 1 10−4 10−3 10−2 10−1 1 |Ue1|2m1 |Ue2|2m2 |Ue3|2m3 |Ue4|2m4

Inverted 3ν Ordering 1σ 2σ 3σ ν4 1σ 2σ 3σ

Lightest mass: m3 [eV] |mββ| [eV] 90% C.L. UPPER LIMIT 10−4 10−3 10−2 10−1 1 10−4 10−3 10−2 10−1 1

Inverted 3ν Ordering − 3σ 3ν 3+1

[CG, Zavanin, JHEP 07 (2015) 171]

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 48/49
slide-49
SLIDE 49

Conclusions

◮ Exciting indications of light sterile neutrinos at the eV scale:

◮ LSND ¯

νµ → ¯ νe signal.

◮ Gallium νe disappearance. ◮ Reactor ¯

νe disappearance.

◮ Vigorous experimental program to check conclusively in a few years:

◮ νe and ¯

νe disappearance with reactors and radioactive sources.

◮ νµ → νe transitions with accelerator neutrinos. ◮ νµ disappearance with accelerator neutrinos.

◮ Independent tests through effect of m4 in β-decay and ββ0ν-decay. ◮ Cosmology: strong tension with ∆Neff = 1 and m4 ≈ 1 eV. It may be

solved by a non-standard cosmological mechanism.

◮ Possibilities for the next years:

◮ Reactor and source experiments νe and ¯

νe 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).

  • C. Giunti − Review on Neutrino Anomalies − Neutrinos: the Quest for a New Physics Scale − 27 March 2017 − 49/49