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KATRIN and the Cosmic Neutrino Background
Amand FaesslerUniversity of Tuebingen
Germany
Amand Faessler, Rastislav Hodak, Sergey Kovalenko, Fedor Simkovic:
arXiv: 1304.5632 [nucl-th] 20. April 2013.
Cosmic Microwave Background Radiation
(Photons in the Maximum 2 mm)
Decoupling of the photons from matter about 300 000 years after the Big Bang,when the electron are captured by the protons and He4 nuclei and the
universe gets neutral. Photons move freely.
Penzias and Wilson;Bell Telephon
Nobel Price 1978
Planck Satellite Temperature FluctuationsComic Microwave Background (March 21. 2013)
6
Curvature of the Univers
flat
xx x
1 1 1
WMAP 2002 :
1.00 0.02
We know the size of the hot spots.
The Universe is flat. The
density has the critical
value: W = 1.00+-
0.02
We can only see till the
sphere of the the last photon-electron
scattering:~14 x1012 light years
Black body radiation.
Temperature adjusted
(pdg 2012):T=2.7255(6) K
Experiment
Microwave Background Radiation
T = 2.7255(6) Kelvin
The relative number abundance of the light
nuclei formed in the big bang allows to
determine the absolute baryon
density and relative to the critical density (flat
universe).
WBaryon = rBaryon/rcritical = 0.02h-2 = 0.04
nB = 0.22 m-3
eB = 210 MeV/m-3
h = 0.71h2 = 0.5
Hubble-Konstant=H = 100 h [km/(sec Mpc)]
WBh2 = 0.02
Planck‘s Black Body Radiation
Decoupling of Photons and Neutrinos from Matter
„Re“-combination of Electrons with Protons and a-Particles (1 g out of 1.7x109 from upper tail) 3000 Kelvin; 300 000 years after Big Bang;
e- + p neutral Hydrogen-Atom 2e- + a neutral Helium-Atom
Photons move freely since 14x1012 years.
Last sphere of scattering: Radius = 14x1012 light years. Today Tg = 2.7255(6) Kelvin independent of the direction.
Neutrino Decoupling and Cosmic Neutrino Background
For massless-massive Neutrinos:
Estimate of Neutrino Decoupling
Universe Expansion rate: H=(da/dt)/a ~ n Interaction rate: = G ne-e+<svrelative>
H = \sqrt{8 p G rtotal /3} = \sqrt{8 p r/(3 MPlanck2)} =
= O(T2) [1/time]
G ~ T3 <GF2 p2 c=1> = T3 GF
2 T2 = GF2 T5 [Energy = 1/time]
hbar = h/(2p) = c = 1
Neutrino Decoupling
G/H = ( kB T/ 1MeV)3 ~ 1 T(Neutrinos)decoupl ~ 1MeV ~ 1010 Kelvin; Today: 1.95 K
Time after Big Bang: 1 Second
T(Photons)decoupling = 3000 Kelvin; heute: 2.7255 K Time(Photons)decoupling = 300 000 years
Below T = 1 MeV:
(Energy=Mass)-Density of the Universe
log r
a(t)~1/T
Radiation dominated: r ~ 1/a4 ~ =Stefan-Boltzmann
Matter dominated: r ~ 1/a3 ~ T3
Dark Energy
1/Temp1 MeV1sec n
dec.
1 eV3x104y heute
3000 K300 000 y
g dec.
8x109 y Tg = 2.7255 KTn = 1.95 K
Hamburg, March 3. 2008.
Tranformation from Mass to Flavor Eigenstates
Mass of the Electron Neutrino?Tritium decay (Mainz + Troisk)
With:
Hamburg, March 3. 2008.
Measurement of the upper Limit of the Neutrino Mass in Mainz: mn < 2.2 eV 95% C.L.
Kurie-Plot
Q = 18.562 keV
mn 2>0 mn2 <0 Electron Energy
Eur. Phys. J. C40 (2005) 447
Negatives Squares of the Measured Neutrino Masses
Ch. Kraus, B. Bornschein, L.
Bornschein, J. Bonn, B. Flatt, A. Kovalik,
B. Ostrick, E. W. Otten, J. P. Schall,
Th. Thümmler, Ch Weinheimer: Eur. Phys. J. C40 (2005) 447-468.
nrelic
DGZK=50Mpc
NeutrinoE = 4x1022 eVEnergy Momentum
conservation:n1(GZK,4x1022 eV)
+ n2(CB) Z0(4x1022eV)burst 10p0, 2 nucleons, 17 p+-
Anihilation of Relic Neutrinos with extreme High Energy Neutrinos > 1022 eV
Z0
Above GZK
Anihilation below Greisen-Zatsepin-Kuzmin
Radius of 50 Mpc
Cosmic Radiation from Z-Burst expected at 1021 -1022eV
Free magnetic floating cylinder with half n absorbing material
Permanent Magnet
SuperconductingMagnet
Cylinder shaped
One half n
absorbing,the other
sterile. Balanced.
The system rotates 90 degrees.
Thomas Müller pointed this out to me.
A. Ringwald: arXiv:hep-ph/031157v1; 2003.
Search for Cosmic Neutrino Background CnB by Beta decay (KATRIN): Tritium
Kurie-Plot of Beta and induced Beta Decay: n(CB) + 3H(1/2+) 3He (1/2+) + e-
Electron Energy
2xNeutrino Masses
Emitted electron
Q = 18.562 keV
Infinite good resolution
Resolution Mainz: 4 eV mn < 2.3 eV
Resolution KATRIN: 0.93 eV mn < 0.2 eV 90% C.L.
Fit parameters: mn
2 and Q value meVAdditional fit: only
intensity of CnB
Search for Cosmic Neutrino Background CnB by Beta decay: 187Re
Kurie-Plot of beta and induced beta Decay: n(CB) + 187
75Re112(5/2+) 18776Os111(1/2-) + e-
Electron Energy
2xNeutrino Masses
Emitted electron
Q = 2.460 keV
Infinite good resolution
MARE-Genova: DE ~ 11 eV mn ~ 2 eV 90% C.L. Milano-Bicocca:DE ~24 eV mn ~ 3-4 eV
Fit parameters: mn
2 and Q value meVAdditional fit: only
intensity of CnB
Tritium Beta Decay: 3H 3He+e-+nce
Neutrino Capture: n(relic) + 3H 3He + e-
20 mg(eff) of Tritium 2x1018 T2-Molecules: Nncapture(KATRIN) = 1.7x10-6 nn/<nn> [year-1]
Every 590 000 years a count!! for <nn> = 56 cm-3
Kaboth, Formaggio, Monreal: Phys. Rev. D82 (2010) 062001
66 mg(eff) of Tritium 6.6x1018 T2-Molecules:Nncapture(KATRIN) =5.5x10-6 nn/<nn> (year-1)Every 180 000 years a count. (For nn = <nn>)
Faessler et al.: J. Phys. G38 (2011) 075202
50mg(eff) of Tritium 5x1018 T2-MoleculesNncapture(KATRIN) = 4.2x10-6 nn/<nn>(year-1)Every 240 000 years a counts.(For nn= <nn>)
Drexlin April 2013: 20mg(eff) of Tritium 2x1018 T2-MoleculesNncapture(KATRIN) = 1.7x10-6 nn/<nn>(year-1)Every 590 000 years a counts.(For nn= <nn>)
Kurie-Plot
Electron Energy
2xNeutrino Masses
Emitted electron
Resolution KATRIN: 0.93 eV mn < 0.2 eV 90% C.L.
Fit parameters: mn
2 and Q value meVAdditional fit: only
intensity of CnB
Two Problems1. Number of Events with average Neutrino Density
of nne = 56 [ Electron-Neutrinos/cm-3] Katrin: 1 Count in 590 000 Years Gravitational Clustering of Neutrinos!!!???2. Energy Resolution (KATRIN) DE ~ 0.93 eV
Gravitational Clustering of Dark Matter and Neutrinos in Galaxies
Was kompensiert die Zentrifugalkraft?
Dunkle Materie
?Faktum
erwartet
Gravitational Clustering of NeutrinosA. Ringwald, Y. Wong: arXiv:hep-ph/0408241; solved Vlasov eq. for n; Dark Matter from Navarro et al. Ap J490 (1997) 493
Circles: 1h-1 kpc; Pentagons: 10h-1 kpc; Squares: 100h-1 kpc; Triangles 1000h-1 kpc. h-1 = 1.4 The solar system is 8 kpc = 24 000 ly from the galactic center.
Virial Mass:Mvir = 5v2R/G;v = velocity in sight
Gravitational Clustering of NeutrinosR.Lazauskas,P. Vogel and C.Volpe, J. Phys.g. 35 (2008) 025001;
Light neutrinos: Gravitate only on Mpc (50 Mpc Galaxy Cluster) scale: nn/<nn> ~ nb/<nb> ~ 103 – 104; <nb>= 0.22 10-6 cm-3
A. Ringwald and Y. Wong: Vlasov trajectory simulations
Clustering on Galactic Scale possible nn/<nn> = nb/<nb> ~ 106 ; (R = 30 kpc)Nncapture(KATRIN) = 1.7x10-6 nn/<nn> (year-1)
= 1.7 (170 for 2 milligram) [counts per year]
R. Wigmans, Astroparticle Physics 19 (2003) 379 discusses up to: nn/<nn> = 1013 but for us unrealistic.
n Capture: ne(relic) + 18775Re(5/2)+187
76Os(1/2)- + e-
MARE Genova and Milano
760 grams of AgReO4 Nncapture(MARE) = 6.7x10-8 nn/<nn> [year-1]
For nn = <nn>: Every 15 Million years a count.For: nn/<nn> = 106: Every 15 years a count. (KATRIN: 1.7 per year)
Main Contribution: n s(1/2); e- p(3/2)
Summary 1• The Cosmic Microwave Background allows to
study the Universe 300 000 year after the BB.
• The Cosmic Neutrino Background 1 sec after the Big Bang (BB): Tn(today) = 1.95 Kelvin.
• Extremly difficult to detect: Small Cross Section and low Density 56 n‘s/cm3 and low Energies (1.95 Kelvin = 2x10-4 eV).
2xNeutrino Masses
Emitted electron
Resolution KATRIN: .93 eV mn < 0.2 eV 90% C.L.
Fit parameters: mn
2 and Q value meVAdditional fit: only
intensity of CnB
Kurie-Plot
Electron Energy
Summary 21. Average Density: nne = 56 [ Electron-Neutrinos/cm-3] Katrin (20 mg eff. mass 3H): 1 Count in 590 000 Years Gravitational Clustering of Neutrinos nn/<nn> < 106
1.7 counts (2 milligram of 3H 170 counts) per year.2. Measure only an upper limit of nn
ENDE