410 likes | 609 Views
Neutrino Masses and Mixings. Kenzo Ishikawa OMEGA 07 Department of Physics Hokkaido University. Topics. 1. Neutrino Parameters 2. Finite coherent length effects in “scattering of extremely high-energy charged particle with cosmic backgrond radiation “ (collaboration with Y. Tobita).
E N D
Neutrino Masses and Mixings Kenzo Ishikawa OMEGA07 Department of Physics Hokkaido University
Topics 1. Neutrino Parameters 2. Finite coherent length effects in “scattering of extremely high-energy charged particle with cosmic backgrond radiation “ (collaboration with Y. Tobita)
1. Neutrino parameters • Quarks and leptons of standard model Three familys of quarks and leptons
Particle table in the standard model Quarks Leptons
Three family of matter 1st generation e neutrino u-quark e d-quark 2nd generation μ-neutrino c-quark μ s-quark 3rd generation τ-neutrino t-quark τ b-quark
Masses of Quarks and Leptons Quarks and charged lepoton mass neutrino generations
Atmospheric Solar
Oscillation formula from mass eigenstate to flavor eigenstate Mass eigenstate From rest frame to laboratory frame Local coordinates Relativistic energy
Phase of mass eigenstate Flavour wave function Transition probability Physical units
distance vs energy (vacuum oscillation) |m1^2-m2^2|=1 ev^2 E(GeV) 0.1 1 10 100 L(Km)0.1 1 10 100 |m1^2-m2^2|=10^(-3) ev^2 E(GeV) 10^(-3)0.11 10 L(Km) 1 10^210^3 10^4 |m1^2-m2^2|=10^(-5) ev^2 E(GeV) 10^(-3) 0.1 1 10 L(Km) 10^2 10^3 10^5 10^6 R(earth)=6x10^4 Km , L(sun-earth)=1.4x10^8 Km
Quasi-two-neutrino oscillation here And
Matter MSW effect Electron neutrino has additional contribution from the charged elastic scattering and the finite electron density
Local positions • Neutrino oscillation amplitude is written by one particle wave function, because 1. neutrino interacts with matter weakly 2. production and detection positions are localy defined
Experiments 1 Sun; Davis ,SK(Super Kamioka),SNO 2 Atmosphere; K(Kamioka),SK 3 Accelarator ; K2K(KEK-Kamioka), 4 Reactor ; Kamland,
Solar neutrino summary groups targets unit expement expectation ex./SSM • Homestake 37Cl SNU 2.56±0.23 8.5 0.30±0.03 • SAGE 71Ga SNU 66.9±5.2 131 0.51±0.04 • GALLEX 71Ga SNU 69.3±5.5 131 0.53±0.04 • SKe- (water) 106/cm2/s 2.35±0.08 5.79 0.41±0.02 • SNO pure D2O 106/cm2/s 1.76±0.11 5.79 0.30±0.02 • SNO salt (D2O) 106/cm2/s 5.21±0.47 5.79 0.88±0.08 SNU = Solar Neutrino Unit = Events / 1036 atom / sec
SNO Detection of neutral current by Flux ratio of elastic event vs total neutrino evevts
2. Atmospheric neutrino Observe electron neutrino event and muon neutrino event . Find the deficit of muon neutrino flux
3. K2K(long base line exp.) Event Summary Nskobs systematics ~3% Fiducial volume 2% Reduction <1% Others <1% Nskobs Spectrum syst. (1 ring m) (dependent on the energy bin) Ring counting ~3~5% Fiducial volume 2% Particle Id <1% Energy scale ~2% Nskpred systematics Far/Near ~5% Normalization ~5%
Summary of masses and mixing 2 Atmospheric Solar+reactor(long distance) Reactor (short distance)
Mass hierarchy tau electron muon
Or inverted mass hierarchy ? (Mass)^2
Other (recent) experiments • T2K J-park (Tokai) > Sk(kamioka) Minos(USA), Borexino(Italy), Opera(Cern-Italy),Nova(USA),- - - Neutrino telescope Icecube(J), Goldstone(Moon),- - - - Other proposals.
Tokai 2 Korea may resolve hierarchy problem K.Hagiwara et al,hep-ph/0607255
Open problems • Absolute values of masses • Other components of mixing matrix U • Is neutrino Majorana or Dirac ? • neutrinoless double Beta decay • Can we use neutrino for astronimical observations ? • Implications and theory
Neutrino in the intermediate state beam target Asahara,KI,Shimomura,Yabuki,PTP113,2005
2. Finite coherent length effect in “scattering of extremely high-energy charged particle with cosmic backgrond radiation “ (collaboration with Y. Tobita) Ref. on wave packet K.I and T.Shimomura ,PTP114(2005)
Wave packet with finite coherent length • Wave packet size is semi-microscopic and its effect is normally negligible, because delta p( or E)(wave packet)<< delta p(orE )(exp.) However if wave packet effects are enhanced by aother mechanism, a finite wave packet effects is possible.
Extremely high energy particle • (p+q)^2=m1^2+m2^2+2p q =m1^2+m2^2+2 p0q0(1-a ) Delta q0(wave packet) << delta q(exp) However If p0 >> m, (extremely high energy) p0q0 >> (delta E(exp.))^2
Cosmic ray’s flux Ultara-high energy
GZK bound • High energy proton +2.7K Gamma > nuclean +pion GZK estimated pion production cross section due to Delta resonance(1236). Mean free path becomes about 10 Mpc, and cosmic rays beyond this threshold 10^20eV should be suppressed .(GZK bound)
AGASA Fly’sEye,PierreAugerColla.Tele.Arrays
Finite coherent length of cosmic gamma Wave packet Plank distribution Mean crossection
Comparisons of mean free path Wave packets Plane waves
Summary • New era on neutrino masses and mixing. • Masses and mixing parameteres are fundamental physical constants and it is important to know their precise values. • Neutrino masses and mixing would play key roles for the physics beyond the standard model. • Wave packet effects may be important in UHCR .