Detec%on prospects for the Cosmic Neutrino Background using laser - - PowerPoint PPT Presentation

Detec%on prospects for the Cosmic Neutrino Background using laser interferometers

Mar$n Spinrath Na$onal Center for Theore$cal Sciences The 3rd KAGRA Interna$onal Workshop - 21/05/2017

Based on collabora$on with Valerie Domcke, arXiv:1703.08629

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

CNB Introduc$on

• Produced 1 s aXer Big Bang (CMB: 379k years)
• Number density: 330 cm-3
• Temperature: 1.9 K
• Energy: 0.16 meV
• Velocity: 10-3 - 1 c
• CNB cross sec$on to neutrons: 10-27 pb

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Mar$n Spinrath (NCTS) 21/05/17 - KIW3 CNB Detec$on Prospects

CNB wind l Interferometer d Pendulum θ

The Experiment

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• Pendulum in neutrino wind

• LIGO-like interferometers

• Einstein telescope maybe

[Domcke, MS '17]

aν 3 · 10−182

aν 10−162

aν g l d

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Theory: Magne$c Torque

• Neutrino background splits electron energy levels

(spin effect ➞ magne$c effect)

• For one flavour
• Caveats:
• Experimentally difficult (magne$c effect)
• Needs lepton asymmetry

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aR

GF =

NAV A mAV 2 √ 2 π GF β

⊕

γ R

• α=e,µ,τ

(nνα − n¯

να) gα A

aR

GF ≈ 4 · 10−29 n¯ νµ − nνµ

2 ¯ nν 2

[Domcke, MS ’17; see also Duda et al. '01]

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Theory: Scaeering I

• The basic formula
• Incoming flux:
• #nuclei in 1g test material:
• Neutrino-nucleus cross-sec$on:
• Coherence factor:
• Average momentum transfer:

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aG2

F = Φν

NAV A mAV Nc σν−A ∆p

NAV /(AmAV ) σν−A Nc ∆p Φν

[Domcke, MS ’17; see also Duda et al. '01]

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Theory: Scaeering II

• Neutrinos can come in three kinema$cs
• rela$vis$c (R)
• non-rela$vis$c non-clustered (NR-NC)
• non-rela$vis$c clustered (NR-C)
• Two important numbers
• The cross-sec$on:
• The coherence factor:

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σν−A ≈ 10−27 = 10−63 2

Nc = NAV A mAV ρ λ3

ν ∼ 1020 [Domcke, MS ’17; see also Duda et al. '01]

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Theory: Scaeering III

• Results for the three kinema$cal cases:


• Compare to experimental sensi$vity:

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aG2

F = nν

2 ¯ nν      3 · 10−33 2 , 5 · 10−31 (mν/0.1 c2) 2 , 2 · 10−27 (10−3/β) 2 ,

aν 10−162

[Domcke, MS ’17; see also Duda et al. '01]

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Other "Winds"

• Solar neutrinos
• Cold WIMP Dark Maeer (mX > 1 GeV)
• Light WIMP Dark Maeer (mX = 3.3 keV)

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a−ν ≈ 3 · 10−26 2

a ≈ 4 · 10−30 (A − Z)2 76 A σX−N 10−46 2 ρ 10−24 /3 βX 10−3 2 2

a ≈ Nc a ≈ 109 a

[Domcke, MS ’17; see also Duda et al. '01] [See also Graham et al. '15]

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Wind vs. Nudges I

• The scaeering rate
• Numbers for the CNB

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R = aG2

F

∆p

R ≈ 1 · 10−4 nν 2 ¯ nν −1 −1 R ≈ 0.02 nν 2 ¯ nν mν 0.1 c2 −1 −1 R ≈ 0.4 nν 2 ¯ nν 0.1 c2 mν 10−3 β 2 −1 −1

[Domcke, MS ’17]

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Wind vs. Nudges II

• Solar neutrinos
• Cold WIMP Dark Maeer (mX > 1 GeV)
• Light WIMP Dark Maeer (mX = 3.3 keV)


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R−ν ≈ 2 · 10−9 −1 −1

R ≈ 8 · 10−3 100 c2 mX σX−N 10−33 2 ρ 10−24 /3 βX 10−3

• −1 −1

R ≈ 4 · 105 3.3 c2 mX 4 σX−N 10−42 2 ρ 10−24 /3 βX 10−3

• −1 −1

[Domcke, MS ’17]

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Improvements and Alterna$ves

• Sensi$vity propor$onal to g factor
• Suspension
• Space
• Give up on pendulum setup
• free falling masses and wait
• Alterna$ves to mechanical force experiment
• Inverse beta decay (PTOLEMY)
• …

11 [Domcke, MS '17]

21/05/17 - KIW3 Mar$n Spinrath (NCTS) CNB Detec$on Prospects

Summary and Conclusions

• Cosmic Neutrino Background is interes$ng…
• … but difficult
• Laser interferometers cannot see the CNB…
• … but maybe other cosmic winds
• … or cosmic nudges

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Mar$n Spinrath (NCTS) 21/05/17 - KIW3 CNB Detec$on Prospects

Dream Big!

(but whom am I telling…)

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