probing neutrino flavor transition mechanism with ultrahigh energy astrophysical neutrinos...
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Probing neutrino flavor transition mechanism with ultrahigh energy
astrophysical neutrinos
Probing neutrino flavor transition mechanism with ultrahigh energy
astrophysical neutrinos
賴光昶賴光昶長庚大學通識中心長庚大學通識中心
賴光昶賴光昶長庚大學通識中心長庚大學通識中心
2014 海峡两岸粒子物理与宇宙学研讨会
黃山,安徽, May 9th, 2014
KCL, T.-C. Liu and G.-L. Lin, PRD 82, 103003KCL, T.-C. Liu and G.-L. Lin, PRD 82, 103003KCL, T.-C. Liu and G.-L. Lin, PRD 89, 033002KCL, T.-C. Liu and G.-L. Lin, PRD 89, 033002
Astrophysical neutrinoAstrophysical neutrino
Neutrino flavor transitionNeutrino flavor transition
Neutrino signals in neutrino telescopesNeutrino signals in neutrino telescopes
Test of transition modelsTest of transition models
ErnieErnieErnieErnie
Bert, Bert, 1.04PeV1.04PeV Ernie, Ernie, 1.14PeV1.14PeV
Astrophysical Astrophysical neutrinoneutrino
Astrophysical Astrophysical neutrinoneutrino
““AstrophysicalAstrophysical”” means means
QQ-representation-representation
Standard oscillationStandard oscillation
Neutrino decayNeutrino decay
QQuantum decoherenceuantum decoherence
Pseudo-Dirac neutrinoPseudo-Dirac neutrino
Flavor transitionFlavor transitionFlavor transitionFlavor transition
Q-representationQ-representationQ-representationQ-representation
neutrino on Earthneutrino on Earth→φ=Pφ→φ=Pφ00←←neutrino at the sourceneutrino at the sourceφφ00==((φφ00((νe), ), φφ00((νμ), ), φφ00((ντ))=1/3))=1/3VV11+a+aVV22+b+bVV33
φφ==ϰϰVV11++ϱϱVV22++λλVV33
((ϰϰ, , ϱϱ, , λλ))TT==QQ((11//3, a, b3, a, b))TT
⇒⇒Q≡AQ≡A-1-1PAPA
Tri-bimaximal matrix, eigenvectors of TBMTri-bimaximal matrix, eigenvectors of TBM::
Q-representationQ-representationQ-representationQ-representation
Standard oscillationStandard oscillationStandard oscillationStandard oscillation
Neutrino decayNeutrino decayNeutrino decayNeutrino decay
NormalNormalhierarchyhierarchy
InvertedInvertedhierarchyhierarchy
Neutrino decayNeutrino decayNeutrino decayNeutrino decayThe heaviest and The heaviest and
middle states decay middle states decay
into the lightest into the lightest
one(j=1 or 3).-one(j=1 or 3).-dec1dec1
The heaviest state The heaviest state
decays into the middle decays into the middle
and lightest ones.-and lightest ones.-dec2dec2{{
εε11==coscos2ϑ2ϑ2323--((√√2/3)sin2/3)sinϑϑ1313, , εε22=(1/2)=(1/2)coscos2ϑ2ϑ2323--εε11
Quantum Quantum decoherencedecoherence
Quantum Quantum decoherencedecoherence
distance dependentdistance dependent
γγ→0 or →0 or d→d→∞∞, , QQdcdc=Q=Qoscosc
∆∆mmii22: the mass-squared difference between active and sterile states.: the mass-squared difference between active and sterile states.
Pseudo-Dirac Pseudo-Dirac neutrinoneutrino
Pseudo-Dirac Pseudo-Dirac neutrinoneutrino
∆∆mmii22 =∆m =∆m22
In the limit of L(z)/4EIn the limit of L(z)/4Eνν≫1/≫1/∆m∆mii22, , QQpdpd=1/2 =1/2
QQoscosc
Neutrino eventsNeutrino eventsNeutrino eventsNeutrino events
125m corresponds to the decay 125m corresponds to the decay length of a 2.5 PeV tau lepton.-length of a 2.5 PeV tau lepton.-dist. between stringsdist. between strings ≈ ≈1km corresponds to the decay 1km corresponds to the decay length of a 25 PeV tau lepton.-length of a 25 PeV tau lepton.-size of IceCubesize of IceCube1054.51541054.5154
ObservablesObservablesObservablesObservables
Case I:Eν<33PeV
Case II:Eν>33PeV
RI=ϕ(νμ)/(ϕ(νe)+ϕ(ντ))SI= ϕ(νe)/ϕ(ντ)
RII=ϕ(νe)/(ϕ(νμ)+ϕ(ντ))
SII= ϕ(νμ)/ϕ(ντ)
RI: track-to-shower ratio; RII:shower-to-track ratio
ObservablesObservablesObservablesObservables
ϕ0=(ϕ(νe), ϕ(νμ), ϕ(ντ))=1/3 V1+aV2+bV3.
for non-ντ sources, a=-1/3+b and let RII≡R.
flux conservation assumed
For pion and damped-muon sources
Statistical analysisStatistical analysisStatistical analysisStatistical analysisWe consider: We consider: • i=π, only pion sourcei=π, only pion source• i=π and µ, both pion i=π and µ, both pion and damped-muon and damped-muon sourcesource• σσ=10% assumed=10% assumed
G. Fogli, et al., PRD 86, G. Fogli, et al., PRD 86, 013012013012
Statistical analysisStatistical analysisStatistical analysisStatistical analysis
Legend:Legend:
• ✕✕: oscillation: oscillation
• ▵▵: dec1-n, : dec1-n, ▴▴:dec1-i:dec1-i
• ○○ , , ◇◇, , ⃞⃞: dec2-n: dec2-n
• ••, , ◆◆, , ▪▪: dec2-i: dec2-i
Pion sourcePion sourcePion sourcePion source
11σ σ regionregion 33σ σ regionregion
Pion sourcePion sourcePion sourcePion source
11σ σ regionregion 33σ σ regionregion
Pion sourcePion sourcePion sourcePion source11σ σ regionregion 33σ σ regionregion
Pion and Muon Pion and Muon sourcessources
Pion and Muon Pion and Muon sourcessources
11σ σ regionregion 33σ σ regionregion
Pion and Muon Pion and Muon sourcessources
Pion and Muon Pion and Muon sourcessources
11σ σ regionregion 33σ σ regionregion
Pion and Muon Pion and Muon sourcessources
Pion and Muon Pion and Muon sourcessources
11σ σ regionregion 33σ σ regionregion
SummarySummarySummarySummary
Neutrino astronomy has begun.Neutrino astronomy has begun.
28 astrophysical events observed28 astrophysical events observed
Flavor transitions can be probed:Flavor transitions can be probed:
QQ-representation -representation
Observable definedObservable defined
𝜒𝜒22-analysis performed-analysis performed
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