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Impact of NSI on sterile neutrino searches at IceCube Danny - - PowerPoint PPT Presentation
Impact of NSI on sterile neutrino searches at IceCube Danny - - PowerPoint PPT Presentation
Impact of NSI on sterile neutrino searches at IceCube Danny Marfatia with Jiajun Liao (1602.08766, PRL) LSND e Baseline: 30 m Maximum energy: 53 MeV m 2 1 eV 2 L/E 1 km / GeV = mass MiniBooNE
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MiniBooNE
νµ → νe
Baseline: 500 m Average energy: 800 MeV
¯ νµ → ¯ νe
LSND+MiniBooNE anomaly has 6.1 sigma significance
L/E ∼ 1 km/GeV
= ⇒ ∆m2 ∼ 1 eV2
Oscillation amplitude from global analysis:
sin2 2θ14 sin2 θ24 ∼ 0.1 sin2 θ24
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IceCube
crust mantle core !
Focus on (anti)muon neutrino survival probabilities
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Resonant 3+1 atmospheric neutrino oscillations
Oscillation maximum in vacuum: Resonance condition in earth matter: ∆m2 eV2 L 103 km TeV E ∼ 1 Resonance occurs in antineutrino channel ∆m2
41 cos 2θ24 ' ⌥ 1 eV2
E 5 TeV
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Model independent bounds from neutrino oscillation data allow large diagonal NSI parameters with O(1) differences between them COHERENT bounds obtained using contact approx don’ t apply for mediators lighter than 50 MeV
Nonstandard interactions in matter
LNSI = 2 √ 2GF ✏fC
αβ [⌫αρPL⌫β]
⇥ ¯ fρPCf ⇤ + h.c.
α, β = e, µ, τ, C = L, R, f = u, d, e
✏αβ ≡ X
f,C
✏fC
αβ
Nf Ne
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1805.04530
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Bottomline:
Adapted from 1602.08766, 1703.00860, 1710.06488, 1803.10661
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Simplifications
For E > 500 GeV , electron flavor can be neglected Mass splittings between active neutrinos negligible Assume all phases in the mixing matrix are zero Assume all NSI parameters are real
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3+1 oscillations with NSI
H = ∆m2
41
2Eν s24s34 s24c34 s24s34 s2
34
s34c34 s24c34 s34c34 c2
34
+ ˆ A ✏µµ ✏µτ ✏µτ ✏ττ +O(s2
14, s2 24) ,
ˆ A = 2 p 2GF NeEν ∆m2
41
κ = Nn 2Ne ' 0.5
Special case: If the submatrix of NSI parameters is proportional to the identity, the NSI interaction can be attributed entirely to the sterile neutrino
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3+1 oscillations with NSI
Pνµνµ = 1 − 4 X
j<k
|U 0
µj|2|U 0 µk|2 sin2(λk − λj)∆m2 41L
4Eν
j = 1, 2, 3
U 0
µ1 ' 1
U 0
µ2 ' 2[s24 sin(✓34 ⇠) + ✏µτ ˆ
A cos ⇠] 2 1 U 0
µ3 ' 2[s24 cos(✓34 ⇠) + ✏µτ ˆ
A sin ⇠] 3 1
⇠ = 1 2 arctan sin 2✓34 cos 2✓34 + ( − ✏ττ) ˆ A
1 ' 0 2,3 ' 1 2 h 1 + ( ✏ττ) ˆ A ⌥ q 1 + 2 cos 2✓34( ✏ττ) ˆ A + ( ✏ττ)2 ˆ A2
- For antineutrinos, ˆ
A → − ˆ A For |✏µτ|, |✏ττ ✏µµ|, s24 ⌧ 1,
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Notes and expectations
IC data are consistent with 3-neutrino oscillations, for which survival probability is unity above 500 GeV Deviations from unity will be mainly governed by mixing matrix elements, not oscillation frequencies will be constrained to be close to 0 Large values of suppress the mixing matrix elements, and will be consistent with IC data
∴ ✏µτ
✏ττ
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sin2 2θ24 = 0.25 ∆m2
41 = 0.63 eV2
✏µµ = −6.26 ✏ττ = −6.4
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Muon energy proxy
Although the energy loss observed in the detector is only loosely connected to the true neutrino energy, it is a useful statistical tool
1507 .04005
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2-year IceCube upgoing atmospheric data
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Analysis
Fix Marginalize over atmospheric flux normalization, for each point in the plane θ34 = 0 ✏µτ = 0
✏µµ, ✏ττ
(sin2 2θ24, ∆m2
41)
(best fit to reactor neutrino disappearance data) since IC is not sensitive to this parameter to weaken the IC signal (i.e. relax the exclusion) to weaken the IC signal sin2 θ14 = 0.01
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Results:
Adapted from 1602.08766, 1703.00860, 1710.06488, 1803.10661
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Adapted from 1602.08766, 1703.00860, 1710.06488, 1803.10661
sin2 θ14 = 0.023
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The shading shows the effect of NSI on 3+1 oscillations
1602.08766
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