Search for the Cosmic Neutrino Background and the Nuclear Beta Decay .

1. Search fortheCosmicNeutrino Background andtheNuclear Beta Decay. Amand Faessler University of Tuebingen Germany Publication: Amand Faessler, RastislavHodak, Sergey Kovalenko, Fedor Simkovic: arXiv: 1304.5632 [nucl-th] 20. April 2013.

2. CosmicMicrowave Background Radiation (Photons in the Maximum 2 mm) Decouplingofthephotonsfrom matter about 300 000 years after the Big Bang, whentheelectronsarecapturedbytheprotonsand He4 nucleiandtheuniversegets neutral. Photons movefreely. Today: ~550 Photons /cm3 (~340 Neutrinos/cm3)

3. Planck SatelliteTemperatureFluctuationsComic Microwave Background (Release March 21. 2013) e(f) = (8ph/c3) f3df/[exp(hf/kBT)-1][Energy/Volume]

4. Neutrino Decoupling and Cosmic Neutrino Background Formassless-massive Neutrinos:

5. Estimateof Neutrino Decoupling Universe Expansion rate: H=(da/dt)/a; a ~ 1/T; (today, Planck)  H =67km/(sec*Mpc) ~ n Interaction rate: G= ne-e+<svrelative>

6. Neutrino Decoupling • G/H = ( kB T/ 1MeV)3 ~ 1 • T(Neutrinos)decoupl ~ 1MeV ~ 1010 Kelvin; • today: Tn = 1.95 K • Time after Big Bang: 1 Second

7. (Energy=Mass)-DensityoftheUniverse Radiation dominated: r ~ 1/a4 ~ =Stefan-Boltzmann log r Matter dominated: r ~ 1/a3 ~ T3 Dark Energy a(t)~1/T 1/Temp 8x109 y 1 MeV 1sec ndec. g 2.7255 K n 1.95 K 3000 K 300 000 y gdec. 1 eV 3x104y today

8. Mass of the Electron Neutrino?Tritium decay (Mainz + Troisk) With: Hamburg, March 3. 2008.

9. Measurement oftheupper Limit ofthe Neutrino Mass in Mainz: mn < 2.2 eV 95% C.L. Kurie-Plot Eur. Phys. J. C40 (2005) 447 mn2 <0 mn2>0 ElectronEnergy Q = 18.562 keV

10. SearchforCosmic Neutrino Background CnBby Beta decay: Tritium Kurie-Plot of Beta andinduced Beta Decay: n(CB)+ 3H(1/2+)  3He (1/2+) + e- Infinite goodresolution Q = 18.562 keV Resolution Mainz: 4 eV  mn < 2.3 eV Emittedelectron Resolution KATRIN: 0.93 eV  mn < 0.2 eV 90% C. L. ElectronEnergy Fit parameters: mn2andQ valuemeV Additional fit: onlyintensityofCnB 2xNeutrino Masses

11. Neutrino Capture: n(relic) + 3H 3He + e- 20 mg(eff) of Tritium  2x1018 T2-Molecules: Nncapture(KATRIN) = 1.7x10-6nn/<nn> [year-1] Every 590 000 years a count!! for <nn> = 56 cm-3

12. Two Problems Numberof Events withaverage Neutrino Densityofnne= 56 [ Electron-Neutrinos/cm-3] Katrin: 1 Count in 590 000 Years Gravitational Clustering of Neutrinos!!!??? 2. Energy Resolution (KATRIN) DE ~ 0.93 eV Kurie-Plot Emittedelectron Resolution KATRIN: 0.93 eV  mn < 0.2 eV 90% C.L. ElectronEnergy Fit parameters: mn2andQ valuemeV Additional fit: onlyintensityofCnB 2xNeutrino Masses

13. Gravitational Clustering of Neutrinos Light neutrinos: Gravitateonly on 50 Mpc (GalaxyCluster) scale: nn/<nn> ~ nb/<nb> ~ 103 – 104; <nb>= 0.22 10-6 cm-3 R.Lazauskas,P. Vogel andC.Volpe, J. Phys.g. 35 (2008) 025001; A. Ringwald and Y. Wong: Vlasovtrajectorysimulations. Clustering on GalacticScalepossible (30 kpcto 1 Mpc) nn/<nn> = nb/<nb> ~ 106 ; (R = 30 kpc) Nncapture(KATRIN) = 1.7x10-6nn/<nn> (year-1)= 1.7 [counts per year] Effective Tritium Source: 20 microgram 2 milligram Nncapture(KATRIN*) = 1.7x10-4nn/<nn> (year-1)= 170 [countsperyear]; See also: B. Monreal, J. A. Formaggio, Phys. Rev. D80 (2009) 051301 „Relativisticcyclotronradiationdetectionoftritiumdecayelectrons“

14. Summary 1 • The CosmicMicrowave Background allowstostudytheUniverse 300 000 year after the BB. • The Cosmic Neutrino Background 1 sec after the Big Bang (BB): Tn(today) = 1.95 Kelvin

15. Summary 2 Average Density: nne= 56 [ Electron-Neutrinos/cm-3] Katrin: 1 Count in 590 000 Years Gravitational Clustering of Neutrinosnn/<nn> < 106  1.7 counts per year (2 milligram3H 170 per year) 2. Measureonly an upperlimitofnn Kurie-Plot Emittedelectron ElectronEnergy THE END 2xNeutrino Masses