PDF Neutrino Physics II - Benasque

(1)

Neutrino Physics II

Neutrino Phenomenology

Arcadi Santamaria

IFIC/Univ. València

TAE 2014, Benasque, September 19, 2014

(2)

Neutrino Physics II Outline

1 Neutrino oscillations phenomenology Solar neutrinos and KamLAND Atmospheric neutrinos and MINOS Results onθ₁₃and global fits

(Close) future: measurement ofsign(∆m₃₁² )andδ

2 Absolute Mass Scale Cosmological Bounds

Beta and double beta decays

3 Other neutrino properties Limit onN_ν

Sterileν’s, NSI and magnetic moments Supernova neutrinos

BAU from Leptogenesis

4 Summary of neutrino properties

5 Conclusions

(3)

Neutrino Physics II Outline

5 Conclusions

(4)

Neutrino Physics II Outline

5 Conclusions

(5)

Neutrino Physics II Outline

5 Conclusions

(6)

Neutrino Physics II Outline

4 Summary of neutrino properties Conclusions

(7)

1 Neutrino oscillations phenomenology Solar neutrinos and KamLAND Atmospheric neutrinos and MINOS Results onθ13and global fits

2 Absolute Mass Scale

3 Other neutrino properties

5 Conclusions

(8)

Solar neutrino experiments

Experiment Reaction Threshold

Homestake ν_e³⁷Cl→e³⁷Ar E>0.814 MeV SAGE, Gallex/GNO ν_e⁷¹Ga→e⁷¹Ge E>0.233 MeV Super-Kamiokande νe,xe→νe,xe E>5.5 MeV

SNO ES: νe,xe→νe,xe CC: νeD→ppe NC: νxD→νxpn

E>5.5 MeV

-1) -2 s 6 cm

× 10 e (

0 0.5 1 1.5 2 2.5φ 3 3.5

)-1 s-2 cm6 10× (τµφ

0 1 2 3 4 5 6

68% C.L.

CC φSNO

68% C.L.

NC φSNO

68% C.L.

ES φSNO

68% C.L.

ES φSK

68% C.L.

SSM φBS05

68%, 95%, 99% C.L.

τ µ φNC

(9)

Tests with reactor neutrinos: KamLAND

Terrestrial anti-neutrinos from nuclear reactors in Japan with E∼1 MeV and averageL∼180 Km (∆m₂₁² L/(4E)∼1) νep→e⁺n, E_ν_e=E_e++m_n−m_p

Measurement ofP(¯νe→¯νe) as a function of the energy!

(km/MeV)

!e 0/E L

20 30 40 50 60 70 80 90 100

Survival Probability

0 0.2 0.4 0.6 0.8 1

!e

Data - BG - Geo

Expectation based on osci. parameters determined by KamLAND

(10)

Global results

+

0.2 0.4 0.6 0.8

sin²e₁₂ 0

5 10 15

6m2 21 [ 10-5 eV2 ]

solar

KamLAND global 0

5 10 15 20

6r2

3m

90% CL

solar KamLAND solar + KamLAND

0 5 10 15 20

6r²

3m

90% CL

LMA MSW solution Oscillationsνe→νµ,τ

(11)

Atmospheric neutrino: SuperKamiokande

π⁺→µ⁺νµ→e⁺νeνµνµ. Same withπ⁻.

Ifν’s are not distinguished fromν¯⁰s:2ν_µ for eachνe

(12)

L∼10 Km to 10⁴Km andE∼0.1 GeV To 10 GeV.

Ideal to haveoscillations with∆m²∼10⁻³eV².

SuperKamiokandeνe_i+N→e_i+N⁰ detectse_i by Cherenkov:

It does not see the charge

It allows to obtain the direction ofνei its energy and the flavour

Results:

νeflux not changed and no dependence inL Oscillationsνµ →νx

x ∼τ (no much space for steriles orνdecays)

(13)

Test in accelerators

SuperK results confirmed by neutrinos produced in accelerators: MINOS, K2K,Opera

Opera: ν_µ→ν_τ L=732 Km E∼17 GeV K2K: ν_µ→ν_µ L=250 km E∼1 GeV MINOS: ν_µ→ν_µ L=735 km E∼3 GeV

(14)

★

0.3 0.4 0.5 0.6 0.7

sin²θ

23 1.5

2 2.5 3 3.5

∆m2 31 [ 10-3 eV2 ] ^{90,99% CL}

MINOS

T2K

global

Two solutions:

∆m²₃₁>0

Normal hierarchy (NH)

∆m²₃₁<0

Inverted hierarchy (IH) Octant ambiguity inθ₂₃

Oscillationsν_µ →ν_τ

(15)

Results on θ

₁₃

and δ

θ₁₃ has been measured since 2012 to be different from zero by using reactor anti-neutrino disappearance (Daya Bay and RENO) as well as accelerator appearance and disappearance (MINOS and T2K)

From Global fits some indirect information onδ

(16)

The two mass orderings

sin²Θ13

1 2 3

sin²Θ12 sin²Θ23

1 -1 1 -1 1 -1 cos∆ =

NORMAL

Νe ΝΜ ΝΤ

NeutrinoMassSquared

Fractional Flavor Content varying cos∆ Dmsol2

Dmatm2

ÈsinΘ13È ÈsinΘ13È

sin²Θ13 1 2

3

cos∆ =

1 -1 1 -1

1 -1 sin²Θ23

sin²Θ12

INVERTED Dmsol2

Dmatm2

ÈsinΘ13È ÈsinΘ13È

∆m₂₁² = 7.6×10⁻⁵eV² (2.5%

∆m₃₁² =

( 2.48×10⁻³eV²

−2.38×10⁻³eV² (2.5%)

sin²θ₁₂=0.32(4%) sin²θ₂₃=0.57(11%) sin²θ₁₃=0.021(5%) Octant ambiguity inθ₂₃

still not well determinded from the fits but a hint for ≈3π/2

(17)

(Close) future: measurement of sign(∆m

₃₁²

) and δ

Noνa (ν_µ→νe Andν¯_µ→ν¯e):

sign(∆m²₃₁)(Earth MSW effects)

δ (νevsν¯e)

Strong dependece onθ23

Also: ν-Factories (NF), Super Beams (SB), Beta Beams (BB) Direct CP asymmetry

A^CP

α β ≡(P(ν_α→ν_β)−P(¯να→ν¯_β))/(P(να→ν_β) +P(¯να→ν¯_β)) difficult: depends onJ=s₁₂c₁₂s₂₃c₂₃s₁₃c²₁₃sinδ and the two mass differences∆m²₂₁and∆m₃₁²

(18)

1 Neutrino oscillations phenomenology

5 Conclusions

(19)

Cosmic Neutrino Background

ν’s decouple atT_f ∼1MeVand presentνdensity is n_ν= 3ζ(3)g_ν

4π² T_ν³≈112 cm⁻³, kT_ν∼10⁻⁴eV ifm_ν6=0,ν’s contribute to the mass density of the universe

Ω_ν_i =n_ν_im_ν_i ρc

→Ω_νh²=∑im_ν_i

94eV ,^h∼0.7,−→^Ω.0.3

∑

i

m_ν_i.14eV

Refined using CMB and LSS (depends on hypothesis)

∑

i

m_ν_i <0.2–2eV

(20)

Beta decay

β decay of tritium: ³H→³He+e⁻+νe

Very little available energy (order few keV) very sensitive tom_ν dN

dE =

∑

^|U^ei^|²^Γ(m²^νi,E) =hΓ(m²_ν,E)i ≈Γ(hm_ν²i,E) m²_ν

e≡ hm_ν²i=|U_ei|²m²_ν

i= (M_ν^†M_ν)ee=c₁₃² (m²₁c₁₂² +m²₂s²₁₂)+m₃²s₁₃²

99%CLH1 dofL

Bound from MAINZ and TROITSK

Sensitivity of KATRIN

disfavouredbycosmology

Dm₂₃² <0

Dm₂₃² >0

10^-3 0.01 0.1 1

0.01 0.1 1

0.003 0.03 0.3 3

lightest neutrino mass in eV mΝeineV

(21)

Neutrinoless 2β decay

2ν β β observed withT_{2ν β β}∼10²⁰ year 0ν β β requires Majoranaνmasses (does not conserve LN)

Suppressed bym_ν but enhanced by phase space

A0ν β β∝G_F²m_{β β}

q² , q∼100MeV

m_{β β} =

∑

^V^ei²^mⁱ⁼

VM_diagV^T

ee

=

M_ν^†

ee

=

c₁₃² (m₁c₁₂² +m₂s²₁₂e^2iα) +m₃s²₁₃e^2i(β−δ)

(22)

Present limits (HM,IGEX) givem_{β β}.0.3–0.4 eV.

Improved recently by KamLAND-Zen (and EXO-200) m_{β β} .0.12–0.25 eV

Future

(KamLAND2-Zen,nEXO,Majorana,GERDA2,CUORE,. . . ):

m_{β β} ∼0.01 eV

(23)

Future

m_{β β} ∼0.01 eV

(24)

Future

m_{β β} ∼0.01 eV

(25)

Future

m_{β β} ∼0.01 eV

(26)

5 Conclusions

(27)

Limit on N

_ν

N_ν=2.982±0.008 Light (m_ν .45 GeV) Active (fullZ couplings)

Any other light particle coupling to the Z will contribute

A fourth generation withm_ν₄ <45GeV:∆N_ν=1 (excluded) Triplet majorons (Y =1): ∆N_ν =2 (excluded)

Doublet majorons, light sneutrinos:∆N_ν =1/2 (excluded) Light esterile (singlet) neutrinos are allowed

(28)

Sterile ν ’s, NSI and magnetic moments

Sterile neutrinos

LSND and MiniBoone see evidence of transitionsν_µ→ν_ewith

∆m_LSND² >∆m²_ATM(Also hints from reactor, Gallium anomalies and from cosmology (N_s=1,2))

Experimental situation not completely clear Difficult to adjust everything

Necessary, at least, a fourth neutrino (sterile givenΓ_Z) Non-standar interactions (NSI)

LNSI=−ε^fC

α β2√

2G_F2 ν¯αγ^µP_Lν_β ¯fγ^µP_L,R¯f

,affectνcross sections and oscillations. Not very strong limits, typicallyε_α_β <0.01−10 depending on the flavours.

Neutrino magnetic moments

Changeνe→νecross section (µ_ν.10⁻¹⁰µ_B) and contribute to the energy loss of stars because plasmon decayγP→ν ν. From red giant stars

< × ⁻¹² < '

(29)

Supernova neutrinos

Energy released in a SN explosion∼3×10⁵³ erg mainly neutrinos (99%)

E_ν ∼few MeV.∆t∼10s. The 3 types of neutrinos are emitted.

SN1987A observed: 24¯νin a 13sinterval.

Limit on the masses:m_ν <16 eV Restrictions on the neutrino velocities

Restrictions on non-standard cooling mechanisms

Oscillation to steriles sin²2θs.10⁻⁸

Magnetic moments of neutrinos

(30)

BAU from leptogenesis

We exist!:η_B≡(n_baryons−nantibaryons)/n_γ∼6×10⁻¹⁰. Sakharov:

a)∆B6=0, b) out of equilibrium c)∆C6=0 &∆(CP)6=0 Possible in the SM but not enough. In seesawL→B

ε1=Γ(N₁→Φ`)−Γ(N₁→Φ¯`) Γ(N₁→Φ`) + Γ(N1→Φ¯`)

N1

l Φ

+ N1

Φ l

N Φ

l +

l Φ N1 N

l Φ

|ε1|=

− 3 16π

∑

i

Im{(˜λ_ν^†λ˜_ν)²_i1} (˜λ^†˜λ)11

M₁ M_i

≤ 8 16π

M₁

v²|∆m_atm² |^1/2 Sphalerons conserveB−Lbut violateBwith∆L= ∆B

η =10⁻²ε κ→M ≥10⁹GeV

(31)

5 Conclusions

(32)

Summary of parameters

∆m²₃₁∼ ±2.4×10⁻³eV² θ₂₃∼45^◦ Atmos,K2K,MINOS

∆m²₂₁∼7.6×10⁻⁵eV² θ₁₂∼35^◦ Solar, KamLAND θ₁₃∼9^◦ T2K,MINOS,Double Chooz

Daya Bay,RENO

N_ν (active and light) 3 LEP

m_{β β}=∑i|V_ei²m_ν_i| .0.2eV KamLAND-Zen,EXO,HM,IGEX,. . . m_ν_e=∑i|V_ei|²m²_ν_i <2.2eV Mainz and Troitsk

∑im_ν_i .1eV Cosmology

sign(∆m²₃₁) ? Noνa,NF,BB,SB,. . .

CP,δ 3π/2 ? Noνa,NF,BB,SB,. . .

Dirac or Majorana? (α,β) ? HM?,0ν β β

N_s(light sterile) 1,2 ? LSND,MiniBooNE,Cosmology µ_ν/µ_B <10⁻¹⁰,10⁻¹² σ_ν, red giants

NSI ε.0.01–10 Sun,Atm,LSND,NF,. . .

LFV (µ→eγ,· · ·) <5.7×10⁻¹³ MEG,COMET/Mu2e,. . .

(33)

Unknowns

m_lightestnot known (it could be zero) Mass ordering (sign(∆m²₃₁)) now known Is there CP violation (δ)?

Is LN conserved in 2β decays? Is it due to Majoranaν masses?

Is there LFV in the charged sector (µ →eγ,τ →µ γ,µ-econversion,· · ·)

Are there sterileν’s, NSI or magnetic moments?

Whyνmasses are so small?

Why the structure of masses and mixings is so different from the quark sector?

(34)

5 Conclusions

(35)

Conclusions

We have learned a lot on the neutrino properties in the last years but there isstill a lot to be learned

We do not have a “Standard Model” of neutrino masses but havemany interesting ideas

Fortunatelly, we havemany proposed experimentswhich can refine our knowledge on the neutrino properties and guide us in our way to a“Standard Model of Neutrino Masses”

(36)

Conclusions

(37)

Conclusions

(38)

Thank you

Thanks for your attention It has been a pleasure!