particle physics / standard model: neutrino mixing & susyuwer/lectures/... · particle physics...
TRANSCRIPT
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
..%[email protected])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∗)
..%[email protected])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.