Particle Physics / Standard Model: Neutrino Mixing & SUSY

1J. Pawlowski / U. Uwer

1

Physics beyond the Standard Model

1.Neutrino Mixing

2.Supersymmetry

3.Extra Dimensions

2

1. Neutrino Oscillation

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛⋅⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛=

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛

3

2

1

321

331

321

ννν

ννν

τττ

µµµ

τ

µ

UUUUUUUUU eeee

For massive neutrinos one could introduce in analogy to the quark mixing a mixing matrix describing the relation between mass and flavor states:

332211 νννν eeee UUU ++=

Constant for massless ν: mixing is question of convention

βββ

αααννν tiE

ii

iitiE

ii

ii eUUeUt −− ∑∑ == *

,)0()(

→ there will be a mixing of the flavor states with time.

Massive neutrinos develop differently in time.

)2

(2

)0()0()( i

ii

i pmpi

itiE

ii eet+−

− == νννfor masses mi<<Ei:

i

iiiii p

mpmpE2

222 +=+=

Particle Physics / Standard Model: Neutrino Mixing & SUSY

2J. Pawlowski / U. Uwer

3

Mixing probability:

⎥⎦⎤

⎢⎣⎡ −−==→ tEEttP

2cos1)sin(cos2)(),( 12222

θθνννν αββα

⎟⎟⎠

⎞⎜⎜⎝

⎛ ∆⋅=⎟⎟

⎠

⎞⎜⎜⎝

⎛ ∆=→ ][

][4][27.1sin2sin

4sin2sin),(

222

222 kmL

GeVEeVmL

EmtP θθνν βα

1.1 Mixing in the 2 neutrino case

⎟⎟⎠

⎞⎜⎜⎝

⎛⋅⎟⎟⎠

⎞⎜⎜⎝

⎛−

=⎟⎟⎠

⎞⎜⎜⎝

⎛

2

1

cossinsincos

νν

θθθθ

νν

β

α

( ) LEmtEE

Em

pmmEE

pmpmpE i

ii

2

:1w/L/tsame) the is p (assuming

22

2

2

12

i

222

21

12

222

∆=−

≈=

∆≈

−=−

+=+=

ββ

Definite momentum p; same for all mass eigenstate components

Time development for an initially pure |να> beam:

[ ][ ] β

α

α

νθθ

νθθ

νθνθν

⋅−+

⋅+=

+=

−−

−−

−−

)(sincos

sincos

sincos)(

21

21

21

22

21

tiEtiE

tiEtiE

tiEtiE

ee

ee

eet

4

• Disappearance:(I) With known neutrino flux: Measurement of flux at distance L: reactor experiments (sun).

(II) Measure neutrino flux at position 1 and verify flux after distance L.

• Appearance:Use neutrino beam of type A and search at distance L for neutrinos of type B.

⎟⎟⎠

⎞⎜⎜⎝

⎛ ∆=→ L

EmtP

4sin2sin),(

222 θνν βα

How to search for neutrino oscillation ?

Solar neutrinos, atmospheric neutrinos

Reactor neutrinos

Particle Physics / Standard Model: Neutrino Mixing & SUSY

3J. Pawlowski / U. Uwer

5

1.2 Atmospheric neutrinos

Cosmic radiation: Air shower

)()(

)(,,

µµ

µµ

ννννµ

ννµππ

++→

+→

→+

±±

±±±

±±

eee

KKNp

2=++

=ee

Rνννν µµ

Exact calculation: R=2.1 (Eν<1GeV)

(For larger energies R>2.1)

6

Neutrino detection with water detectors [Eν~O(GeV)]Water = “active target” (Cherenkov effect)

Elastic scattering ES

CherenkovLight

Experiments: (Super)-Kamiokande

Detection of Cherenkov photons: Photo multiplier

xν xν

−e −e

Z

Charged current CCKinematical limit for νµ: Eν>mµµν ,e

−− µ,e

pn

W

eν e

−e eν

W

Particle Physics / Standard Model: Neutrino Mixing & SUSY

4J. Pawlowski / U. Uwer

7

Super-Kamiokande

• Largest artificial water detector (50 kt)

• 11000 PMTs (50 cm tubes!): 40% of surface covered with photo-cathode

8

Stopped Muon

)1(42

1cos

==⇔

=

βθ

βθ

o

n

Cherenkov cone:

Experiment can distinguish electron and muon events, can measure energy

stoppedµνµ →

Particle Physics / Standard Model: Neutrino Mixing & SUSY

5J. Pawlowski / U. Uwer

9

Oscillation pattern from atmospheric neutrinose µ

L~15 km

L~13000 km

w/o oscillationw/ oscillation

Theoretical predicton

νµ deficit depends on angle

νe flux okay

Oscillation: νµ↔ ντ

10

Oscillation pattern of atmospheric neutrinos

νµ↔ ντ mixing of atmos. neutrinos

..%90@92.02sineV10)4.04.2(

2

32

LCm

>

×±=∆ −

θ

allowed

Neutrino 2004

Particle Physics / Standard Model: Neutrino Mixing & SUSY

6J. Pawlowski / U. Uwer

11

1.3 Solar Electron Neutrino Problem

Neutrino production

12

Neutrino energy spectrum

2-body decays

Cl2 detectors νe + 37Cl → 37Ar + e, 37Ar → 37Cl (EC) Eν>0.8 MeV

Ga detectors νe + 71Ga → 71Ge + e Eν>0.2 MeV

H2O detectors Elastic scattering: νe + e → νe +e Eν>5 MeV (detection)

Neutrino experiments:

HomestakeSage, Gallex

Particle Physics / Standard Model: Neutrino Mixing & SUSY

7J. Pawlowski / U. Uwer

13

Radio-chemical experiments: Homestake, SAGE, GALLEX

SSM prediction

• Homestake mine, 1400 m underground

• 615 t of C2Cl4 (perchloroethilene) = 2.2x1030 atoms of 37Cl

• Use 36Ar and 38Ar to carry-out the few atoms of 37Ar (~ 1 atom/day)

• Count radioactive 37Ar decays

Homestake Cl2 experiment

14

Eν>0.8 MeV

Eν>0.2 MeVEν> 5 MeV Eν> 5 MeV

CC CCES +CC ES+CC

Neutrino disappearance

Can one measure the oscillated neutrinos ??

Solar Neutrino Problem: Experimental summary

Particle Physics / Standard Model: Neutrino Mixing & SUSY

8J. Pawlowski / U. Uwer

15

The Nobel Prize in Physics 2002

Riccardo GiaconiMasatoshi KoshibaRaymond Davis Jr.

"for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos"

"for pioneering contributions to astrophysics, which have led to the discovery of cosmic X-ray sources"

16

Sudbury Neutrino Observatory

• 6 m radius transparent acrylic vessel

• 1000 t of heavy water (D2O)

• 9456 inward looking photo multipliers

• Add 2 t of NaCl to detect neutrons

Try to measure the “oscillated” neutrinos

Particle Physics / Standard Model: Neutrino Mixing & SUSY

9J. Pawlowski / U. Uwer

17

Solar Neutrino ( 8B) detection with SNO

)()()(154.0

τµ νσνσνσ=

=⋅ e

Charged current

xν xν

−e −e

Z

eν e

−e eν

W

eν −e

pn

W

xν xν

nn

Z

Elastic scattering

Neutral current

CherenkovLight

CherenkovLight

Neutron)()()( τµ νσνσνσ ==e

0)()( == τµ νσνσ

Cl),(Cl 3635 γn

eCC νφφ =

6/)(τµ ννν φφφφ ++=

eES

τµ ννν φφφφ ++=eNC

(kinematics)

18

How to distinguish CC, ES and NC events:

Particle Physics / Standard Model: Neutrino Mixing & SUSY

10J. Pawlowski / U. Uwer

19

SNO Evidence for Neutrino Oscillation

Electron neutrino flux is too low:

Total flux of neutrinos is correct!!Interpreted as νe ↔ νµ or ντ oscillation

)%235( ±=eeP νν

ecc νφφ =

6/)(τµ ννν φφφφ ++=

eES

τµ ννν φφφφ ++=eNC

But in case of simple “vacuum oszillation”: %502sin211 2 ≥−≥ θνν eeP ?

Vacuum oscillation effect is enhanced by matter inside the sun: MSW effect.

20

1.4 Status of oscillation measurements

Atmosνµ→νx

Solar+KamLANDνe→νx

LMA = large mixing angle + matter

effect : MSW effect∗)

..%90@92.02sineV10)4.04.2(

2

32

LCm

>

×±=∆ −

θ

83.02sineV10)6.02.8(

2

52

≈

×±=∆ −

θ

m

Long baseline “many”reactors experiment

Different oscillation pattern for different neutrinos – what can we learn about the masses ??

allowed

allowed

excluded

*) Mikhaev, Smirnov (1986), Wolfenstein (1976)

Particle Physics / Standard Model: Neutrino Mixing & SUSY

11J. Pawlowski / U. Uwer

21

1.5 Neutrino masses

25eV102.8~ −⋅

23eV104.2~ −⋅

25eV102.8~ −⋅

23eV104.2~ −⋅

Absolute neutrino masses are not known !

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛

−−−−−−=

132313231223121323122312

132313231223121323122312

1313121312

ccscsscsccsscssssccssccs

scsccU

ijijijij sc θθ sin,cos where ==

solθθ ≡12 atmθθ ≡23 013 ≈θ

Outlook:

CP Violation in Neutrino Mixing ?

22

2. SUSY

Particle Physics / Standard Model: Neutrino Mixing & SUSY

12J. Pawlowski / U. Uwer

23

SUSY Multiplets

Mixing of “inos”

24

Extended Higgs sector:

⎟⎟⎠

⎞⎜⎜⎝

⎛−d

d

HH0

⎟⎟⎠

⎞⎜⎜⎝

⎛ +

0u

u

HHTwo doublets:

d

u

υυβ =tanVacuum expectation

values (VEV):

R-Parity:

After electroweak symmetry breaking:

h, H, H±, A (5 physical states), mh<~130 GeV

To avoid proton decay: 0π+→ epNew conserved quantum number:

SLBR 2)(3)1( +−−=R-Parity:

Particle Physics / Standard Model: Neutrino Mixing & SUSY

13J. Pawlowski / U. Uwer

25

Constraint Minimal Supersymmetric Standard Model (CMSSM)

MSSM has 105 new parameters: Use models (e.g. mSUGRA) to relate parameters at very high scale. 5 parameters left:

µβ sign,tan,,, 02/10 Amm

26

2.1 SUSY Production at LHC

mostly through gluino and squark production

Particle Physics / Standard Model: Neutrino Mixing & SUSY

14J. Pawlowski / U. Uwer

27

Missing ET as signature of new physics

GeV360GeV60)3(

GeV140)2(GeV330)1(

==

==missTT

TT

EE

EE Model: Gluino = 600 GeV

Neutralino = 100 GeV

CMS

Large uncertainties

MC simulation

28

ATLAS

Properties of SUSY Particles

Ti

iTeff EEM /+= ∑=

4

1,

4 jet events + missing ET

Effective mass approximates SUSY particle mass scale.

Endpoint of di-lepton mass:

MC simulationMC simulation

Particle Physics / Standard Model: Neutrino Mixing & SUSY

15J. Pawlowski / U. Uwer

29

2.2 Prospects for SUSY discovery at LHC

If exist, SUSY particles up to a mass scale of 1 – 2 TeV will be discovered.

Blaising et al, 2006

ATLAS

30

3. Search for Extra Dimensions at LHC

Clear signature:

• High-energetic monojet

• + missing energy

Gravitons leave our 3D-brane and are not detected,

Consequences of extra-dimensions: mini black holes.