ABRACADABRA: Detecting axion dark matter 0902.1089 Fermi (NASA) Ben Safdi 1406.0507 MIT / University of Michigan Y. Kahn, B.S., J. Thaler, PRL 2016 ABRA-10 cm collaboration 2017 I QCD gives a mass: f 1016 GeV m π m 10−9 eV a ≈ f π ≈ f a a I Axion couples to QED 1 µν αEM = gaγγaFµνF~ gaγγ L −4 / fa I Axion (field) can make up all of dark matter Axions -22 -12 -3 9 12 27 log10(ma/eV) I Axion solves strong CP problem (neutron EDM) 2 a g ~µν axion = 2 GµνG L −fa 32π Peccei, Quinn 1977; Weinberg 1978; Wilczek 1978 I Axion couples to QED 1 µν αEM = gaγγaFµνF~ gaγγ L −4 / fa I Axion (field) can make up all of dark matter Axions -22 -12 -3 9 12 27 log10(ma/eV) I Axion solves strong CP problem (neutron EDM) 2 a g ~µν axion = 2 GµνG L −fa 32π I QCD gives a mass: f 1016 GeV m π m 10−9 eV a ≈ f π ≈ f a a Peccei, Quinn 1977; Weinberg 1978; Wilczek 1978 I Axion (field) can make up all of dark matter Axions -22 -12 -3 9 12 27 log10(ma/eV) I Axion solves strong CP problem (neutron EDM) 2 a g ~µν axion = 2 GµνG L −fa 32π I QCD gives a mass: f 1016 GeV m π m 10−9 eV a ≈ f π ≈ f a a I Axion couples to QED 1 µν αEM = gaγγaFµνF~ gaγγ L −4 / fa Peccei, Quinn 1977; Weinberg 1978; Wilczek 1978 Axions -22 -12 -3 9 12 27 log10(ma/eV) I Axion solves strong CP problem (neutron EDM) 2 a g ~µν axion = 2 GµνG L −fa 32π I QCD gives a mass: f 1016 GeV m π m 10−9 eV a ≈ f π ≈ f a a I Axion couples to QED 1 µν αEM = gaγγaFµνF~ gaγγ L −4 / fa I Axion (field) can make up all of dark matter Peccei, Quinn 1977; Weinberg 1978; Wilczek 1978 Motivation PDG • Search for 10-14-10-6 eV pseudoscalar (ALP) dark matter • Motivated by Strong CP Problem and String Theory • Created via realignment mechanism • Couples weakly to E&M: 1 g aF F˜µ⌫ L ⊃−4 aγγ µ⌫ Reyco Henning PATRAS 2017 — May 16,2017 ABRACADABRA !3 Motivation PDG • Search for 10-14-10-6 eV pseudoscalar (ALP) dark matter • Motivated by Strong CP Problem and String Theory • Created via realignment mechanism • Couples weakly to E&M: 1 g aF F˜µ⌫ L ⊃−4 aγγ µ⌫ Reyco Henning PATRAS 2017 — May 16,2017 ABRACADABRA !3 Motivation PDG • Search for 10-14-10-6 eV pseudoscalar (ALP) dark matter • Motivated by Strong CP Problem and String Theory • Created via realignment mechanism • Couples weakly to E&M: 1 g aF F˜µ⌫ L ⊃−4 aγγ µ⌫ Reyco Henning PATRAS 2017 — May 16,2017 ABRACADABRA !3 Motivation PDG • Search for 10-14-10-6 eV pseudoscalar (ALP) dark matter • Motivated by Strong CP Problem and String Theory • Created via realignment mechanism • Couples weakly to E&M: 1 g aF F˜µ⌫ L ⊃−4 aγγ µ⌫ Reyco Henning PATRAS 2017 — May 16,2017 ABRACADABRA !3 I Magnetoquasistatic approximation: new electric current that follows B-field lines @a B = g B r × aγγ @t 1 2 2 I Locally: a(t) a sin(m t) and m a = ρ ≈ 0 a 2 a 0 DM I Jeff = gaγγ 2 ρDMB sin(mat) p Axion dark matter modifies Maxwell’s equations I Recall axions also couple to QED: 1 µν αEM = gaγγaFµνF~ gaγγ L −4 / fa 1 2 2 I Locally: a(t) a sin(m t) and m a = ρ ≈ 0 a 2 a 0 DM I Jeff = gaγγ 2 ρDMB sin(mat) p Axion dark matter modifies Maxwell’s equations I Recall axions also couple to QED: 1 µν αEM = gaγγaFµνF~ gaγγ L −4 / fa I Magnetoquasistatic approximation: new electric current that follows B-field lines @a B = g B r × aγγ @t Axion dark matter modifies Maxwell’s equations I Recall axions also couple to QED: 1 µν αEM = gaγγaFµνF~ gaγγ L −4 / fa I Magnetoquasistatic approximation: new electric current that follows B-field lines @a B = g B r × aγγ @t 1 2 2 I Locally: a(t) a sin(m t) and m a = ρ ≈ 0 a 2 a 0 DM I Jeff = gaγγ 2 ρDMB sin(mat) p Axion dark matter generates magnetic flux Y. Kahn, B.S., J. Thaler, PRL 2016 Superconducting pickup loop R r a h B0 Two readout strategies Broadband Resonant M Δω M L L i Lp L p C L R Li Better at low frequency Better at high frequency f [Hz] 102 103 104 105 106 107 108 109 8 10− 10 CAST 10− IAXO ] 12 1 10− − [GeV ADMX γγ a g 14 10− 16 10− KSVZ 12 11 10 9 8 7 6 5 10− 10− 10− 10− 10− 10− 10− 10− ma [eV] ABRA-10 cm (happening now!) f [Hz] 102 103 104 105 106 107 108 109 8 10− ABRA-10cm (Broad.) 10 CAST 10− IAXO ] 12 1 10− − Broadband Resonant [GeV M Δω ADMX M γγ a g 14 10− L L i Lp L p C L R Li 16 10− 1 month Better at low frequency Better at high frequency B = 1 T KSVZ 12 11 10 9 8 7 6 5 10− 10− 10− 10− 10− 10− 10− 10− ma [eV] ABRA-10 cm (happening now!) f [Hz] 102 103 104 105 106 107 108 109 8 10− ABRA-10cm (Broad.) ABRA-10cm (Res.) 10 CAST 10− IAXO ] 12 1 10− − Broadband Resonant [GeV M M ADMX γγ Δω a g 14 10− L L i Lp L p C L R Li 16 10− Better at low frequency Better at high frequency 1 month B = 1 T KSVZ 12 11 10 9 8 7 6 5 10− 10− 10− 10− 10− 10− 10− 10− ma [eV] ABRA-Gen2 f [Hz] 102 103 104 105 106 107 108 109 8 10− ABRA-10cm (Broad.) ABRA-100cm (Broad.) ABRA-300cm (Broad.) CAST 10 10 − ABRA-10cm (Res.) ABRA-100cm (Res.) ABRA-300cm (Res.) IAXO ] 12 1 10− − [GeV ADMX γγ a g 14 10− 16 10− 1 year B = 5 T KSVZ 12 11 10 9 8 7 6 5 10− 10− 10− 10− 10− 10− 10− 10− ma [eV] The MIT prototype: ABRACADABRA-10 cm I ABRACADABRA: A Broadband/Resonant Approach to Cosmic Axion Detection with an Amplifying B-field Ring Apparatus I People (LNS+CTP, PSFC, Princeton, UNC, UMich): Janet Conrad, Joe Formaggio, Sarah Heine, Reyco Henning, Yoni Kahn, Joe Minervini, Jonathan Ouellet, Kerstin Perez, Alexey Radovinsky, B.S., Jesse Thaler, Daniel Winklehner, Lindley Winslow I Funded by the NSF! ABRACADABRA-10Cosmic Axion cm Detection at MIT with an AmplifyingABRACADABRA-10cm B-field Ring Apparatus 12 cm Super conducting pickup cylinder 12 cm Bmax ≈ 1 T Counter-wound superconducting coils. Reyco Henning PATRAS 2017 — May 16,2017 ABRACADABRA !16 Ben Safdi Massachusetts Institute of Technology 2015 ABRA-10 cm Jonathan Ouellet (postdoc) Lindley Winslow (PI) ABRA-10 cm ABRA-10 cm Light bosonic dark matter future I MIT: ABRA-10 cm followed by ABRA-1 m (B 5 T) ∼ I Axions and light bosonic dark matter well motivated by strong-CP problem and high-scale physics (e.g., compactified string theory) I New ideas to search for ultra-light scalars, dark-photons, etc. (laboratory experiments + astrophysics) 17 19 I e.g., CASPEr experiment (fa 10 10 GeV) ∼ 17− 19 I Black Hole superradiance (fa 10 10 GeV) 15 ∼ − I Florida LC circuit (fa 10 GeV) 11 ∼ I ADMX-HF (f 10 GeV) a ∼ I CMB (isocurvature + ∆Neff) I DM-radio (dark photons) Questions? Axion backup 2 I Axion effective current: I R J eff ∼ eff Ieff I B R g 2 ρ B0 sin(m t) ∼ R ∼ aγγ DM a 16 −22 I f = 10 GeV, B0p 5 T, R 4 m: B 10 T (KSVZ) a ∼ ∼ ∼ Axion dark matter generates magnetic flux Superconducting pickup loop R r I Estimate B-field induced through pickup loop (r = a = h = R) a h B0 Axion dark matter generates magnetic flux Superconducting pickup loop R r I Estimate B-field induced through pickup loop (r = a = h = R) a 2 I Axion effective current: I R J eff ∼ eff Ieff I B R g 2 ρ B0 sin(m t) h ∼ R ∼ aγγ DM a 16 B0 −22 I f = 10 GeV, B0p 5 T, R 4 m: B 10 T (KSVZ) a ∼ ∼ ∼ I Scale to R 4 m 1=2 ≈ 20 I S 5 10− T=pHz B ≈ × I t = 1 year interrogation time for GUT scale axion 2 3 I Coherence time: τ 2π=(mav ) 10 s (v 10− ) 1∼=2 1=4 ∼ 22 ∼ I S=N = 1 for B = S (tτ)− 10− T B ∼ Broadband estimate M R Lp L Li I Example from MRI application: (Myers et. al. 2007) 1=2 17 I B-field sensitivity: S 6:4 10− T=pHz B ≈ × I R 3:3 cm ≈ I t = 1 year interrogation time for GUT scale axion 2 3 I Coherence time: τ 2π=(mav ) 10 s (v 10− ) 1∼=2 1=4 ∼ 22 ∼ I S=N = 1 for B = S (tτ)− 10− T B ∼ Broadband estimate M R Lp L Li I Example from MRI application: (Myers et. al. 2007) 1=2 17 I B-field sensitivity: S 6:4 10− T=pHz B ≈ × I R 3:3 cm ≈ I Scale to R 4 m 1=2 ≈ 20 I S 5 10− T=pHz B ≈ × 1=2 1=4 22 I S=N = 1 for B = S (tτ)− 10− T B ∼ Broadband estimate M R Lp L Li I Example from MRI application: (Myers et.