Georg G. Raffelt, Max-Planck-Institut für Physik, München Solar Axions Globular Cluster Supernova 1987A TeV Gamma Rays Gravity Waves Axions in the Skies Georg G. Raffelt, Max-Planck-Institut für Physik, München

High- and Low-Energy Frontiers in Particle Physics 10 27 eV Planck mass GUT scale Electroweak QCD Cosmological constant 10 24 10 21 10 18 10 15 10 12 10 9 10 6 10 3 1 10 −3 10 −6 Cosmic rays High-Energy Frontier CERN 22 mg Low-E Frontier “Intensity Frontier” (feeble interactions)

High- and Low-Energy Frontiers in Particle Physics 10 27 eV Planck mass GUT scale Electroweak QCD Cosmological constant 10 24 10 21 10 18 10 15 10 12 10 9 10 6 10 3 1 10 −3 10 −6 𝒎 𝑫 𝒎 𝑫 𝟐 𝑴 𝑴 Heavy right-handed neutrinos (see-saw mechanism) Axion dark matter (related to Peccei-Quinn symmetry) 𝒇 𝒂 𝒎 𝒂 ∼ 𝒎 𝝅 𝒇 𝝅 𝒇 𝒂 𝒎 𝝅 , 𝒇 𝝅

High- and Low-Energy Frontiers in Particle Physics 10 27 eV Planck mass GUT scale Electroweak QCD Cosmological constant 10 24 10 21 10 18 10 15 10 12 10 9 10 6 10 3 1 10 −3 10 −6 Black Hole Super-Radiance AxDM Experimental & Astro Limits Allowed fa SR Axion dark matter (related to Peccei-Quinn symmetry) 𝒇 𝒂 𝒎 𝒂 ∼ 𝒎 𝝅 𝒇 𝝅 𝒇 𝒂 𝒎 𝝅 , 𝒇 𝝅

Super-Radiance Masha Baryakhtar, Talk at Invisibles 2016, https://indico.cern.ch/event/464402/

Super-Radiance Masha Baryakhtar, Talk at Invisibles 2016, https://indico.cern.ch/event/464402/

Gravitational Wave Signals Arvanitaki, Baryakhtar, Dimopoulos, Dubovsky & Lasenby, arXiv:1604.03958 Masha Baryakhtar, Talk at Invisibles 2016, https://indico.cern.ch/event/464402/

High- and Low-Energy Frontiers in Particle Physics 10 27 eV Planck mass GUT scale Electroweak QCD Cosmological constant 10 24 10 21 10 18 10 15 10 12 10 9 10 6 10 3 1 10 −3 10 −6 Grav.Waves from BHs AxDM Experimental & Astro Limits Allowed fa SR Axion dark matter (related to Peccei-Quinn symmetry) 𝒇 𝒂 𝒎 𝒂 ∼ 𝒎 𝝅 𝒇 𝝅 𝒇 𝒂 𝒎 𝝅 , 𝒇 𝝅

Solar Axions and Axion-Like Particles Solar Models Solar Axions and Axion-Like Particles

Phenomenological Axion Properties Gluon coupling (generic), defines normalization of axion scale 𝑓 𝑎 ℒ 𝑎𝐺 = 𝛼 𝑠 8𝜋 𝑎 𝑓 𝑎 𝐺 𝐺 Mass (generic) depends on up/down quark masses 𝑚 𝑎 = 𝑚 𝑢 𝑚 𝑑 𝑚 𝑢 + 𝑚 𝑑 𝑚 𝜋 𝑓 𝜋 𝑓 𝑎 ≈ 6 𝜇eV 𝑓 𝑎 10 12 GeV Axion-photon coupling (model dependent) ℒ 𝑎𝛾 =− 𝑔 𝑎𝛾 4 𝐹 𝐹 𝑎= 𝑔 𝑎𝛾 𝐄⋅𝐁 𝑎= 𝛼 2𝜋 𝐸 𝑁 −1.92 𝑎 𝑓 𝑎 𝐄⋅𝐁 Generic from 𝑎-𝜋-𝜂 mixing γ 𝑎 Model-dependent, E/N = 0 (KSVZ), 8/3 (DFSZ), many others γ Axion-nucleon coupling (model-dependent numerical factors 𝐶 𝑁 ) ℒ 𝑎𝑁 = 𝐶 𝑁 Ψ 𝑁 𝛾 𝜇 𝛾 5 Ψ 𝑁 𝜕 𝜇 𝑎 2 𝑓 𝑎 Axion-electron coupling in non-hadronic models is analogous with 𝐶 𝑒 𝑓 • Axial-vector current • Spin-dependent int’n 𝑎 𝑓

First discussion of Primakoff effect for WW axions ( 𝑚 𝑎 ≫𝑇) For “invisible axions” ( 𝑚 𝑎 ≪𝑇) screening effects crucial (G.R., PRD 33, 897:1986)

Solar Observables Modified by Axion Losses New opacity Old opacity Surface He abundance Depth Convective Zone Boron neutrinos Beryllium neutrinos Vinyoles, Serenelli, Villante, Basu, Redondo & Isern, arXiv:1501.01639

Solar Sound-Speed Variation New opacity New energy loss makes disagreement with seismic observations worse, especially in the central regions Vinyoles, Serenelli, Villante, Basu, Redondo & Isern, arXiv:1501.01639

Global Fit from Solar Observables Allow all input parameters to float, including chemical composition, and marginalize except for axion losses 𝑔 10 = 𝑔 𝑎𝛾 × 10 10 GeV Vinyoles, Serenelli, Villante, Basu, Redondo & Isern, arXiv:1501.01639

Experimental Tests of Invisible Axions Primakoff effect: Axion-photon transition in external static E or B field (Originally discussed for 𝜋 0 by Henri Primakoff 1951) Pierre Sikivie: Macroscopic B-field can provide a large coherent transition rate over a big volume (low-mass axions) Axion helioscope: Look at the Sun through a dipole magnet Axion haloscope: Look for dark-matter axions with A microwave resonant cavity

Search for Solar Axions Axion Helioscope (Sikivie 1983) Primakoff production Axion flux N a g a g Magnet S Axion-Photon-Oscillation Sun Tokyo Axion Helioscope (“Sumico”) (Results since 1998, up again 2008) CERN Axion Solar Telescope (CAST) (Data since 2003) Alternative technique: Bragg conversion in crystal Experimental limits on solar axion flux from dark-matter experiments (SOLAX, COSME, DAMA, CDMS ...)

LHC Magnet Mounted as a Telescope to Follow the Sun

CAST Results

Parameter Space for Axion-Like Particles (ALPs) Two parameters: - ALP mass 𝑚 𝑎 - ALP-𝛾 coupling 𝑔 𝑎𝛾 Weinberg Wilczek “standard axion” Model dependence (KSVZ, DFSZ, …) broadens the “axion line” Γ 𝑎→𝛾𝛾 = 𝑔 𝑎𝛾 2 𝑚 𝑎 3 64𝜋

Parameter Space for Axion-Like Particles (ALPs) Maximal mixing (“coherent”, small 𝑚 𝑎 ) End of solar spectrum Large 𝑚 𝑎 , 𝑎-𝛾-oscillations suppressed 𝑎-𝛾-oscillations enhanced with He filling ( 𝑚 𝛾 ∼ 𝑚 𝑎 ) CAST exclusion range

Next Generation Axion Helioscope (IAXO) Need new magnet w/ – Much bigger aperture: ~1 m2 per bore – Lighter (no iron yoke) – Bores at Troom • Irastorza et al.: Towards a new generation axion helioscope, arXiv:1103.5334 • Armengaud et al.: Conceptual Design of the International Axion Observatory (IAXO), arXiv:1401.3233

Parameter Space for Axion-Like Particles (ALPs) - Improvement by a factor of 30 - Leaping into uncharted territory Pushing generic ALP frontier QCD Axion meV frontier

Axion Dark Matter from Topological Defects Editor’s suggestion Diversity of scenarios for cosmic axion production depending on domain-wall index NDW and phase parameter δ of the bias term

Historical Neutrino Dark Matter Lessons Early 1980s - If neutrinos have mass, probably they are dark matter ( 𝒎 𝝂 ~𝟏𝟎 𝐞𝐕) (“Neutrinos are known to exist”, only SM candidate) - Detection of 𝒎 𝝂 𝒆 ∼𝟑𝟎 𝐞𝐕 at ITEP, Moscow (PRL 58:2019, 1987) - Dedicated oscillation experiments (NOMAD 1995–1998 and CHORUS 1994–1997) Status 2015 - 70% of gravitating “mass” is dark energy - Dark matter must be mostly “cold” (structure formation) - Neutrinos have sub-eV masses (oscillations, cosmo limits) - Sub-dominant dark matter component History does not always repeat itself, but … - If axions (or similar) exist, MUST be ALL of dark matter?

Gamma-ALP Conversion in Astrophysical B-Fields Credit: SLAC National Accelerator Laboratory/Chris Smith http://svs.gsfc.nasa.gov/vis/a010000/a012300/a012317/

Axion-Photon-Conversion from SN 1987A in transverse galactic B-field SN 1987A SMM Primakoff production in SN core No excess g rays in coincidence with SN 1987A Galactic B-field models Payez, Evoli, Fischer, Giannotti, Mirizzi & Ringwald, arXiv:1410.3747

Astrophysical ALP-Photon Conversion Galactic and cluster fields (mG range) or intergalactic (nG) can cause significant conversion over kpc–Mpc scales: Low-mass ALPs Manuel Meyer, arXiv:1611.07784

Hillas Plot ALP-g conversion 𝒈 𝒂𝜸 𝟏𝟎 𝟏𝟐 𝐆𝐞𝐕 𝑩𝑳∼𝟏 A. M. Hillas Ann. Rev. Astron. Astrophys. 22, 425 (1984) Size and B field strength of possible sites for particle acceleration. Objects below the line cannot accelerate protons to 1020 eV ALP-g conversion 𝒈 𝒂𝜸 𝟏𝟎 𝟏𝟐 𝐆𝐞𝐕 𝑩𝑳∼𝟏

Galactic Globular Cluster M55

Color-Magnitude Diagram for Globular Clusters H He C O Asymptotic Giant H He Red Giant H He Horizontal Branch H Main-Sequence Particle emission reduces helium burning lifetime, i.e. number of HB stars C O White Dwarfs Hot, blue cold, red Color-magnitude diagram synthesized from several low-metallicity globular clusters and compared with theoretical isochrones (W.Harris, 2000)

New ALP Limits from Globular Clusters Helium abundance and energy loss rate from modern number counts HB/RGB in 39 globular clusters Planck Ayala, Dominguez, Giannotti, Mirizzi & Straniero, arXiv:1406.6053

Parameter Space for Axion-Like Particles (ALPs)

Axion-Electron Interaction • Axions can interact with electrons, notably in GUT models, e.g. DFSZ model • Strong constraints from stars Electrons 𝐶 𝑒 2 𝑓 𝑎 Ψ 𝑒 𝛾 𝜇 𝛾 5 Ψ 𝑒 𝜕 𝜇 𝑎 Compton Pair Annihilation Electromagnetic Bremsstrahlung

Color-Magnitude Diagram of Globular Cluster M5 Brightest red giant measures nonstandard energy loss CMD (a) before and (b) after cleaning CMD of brightest 2.5 mag of RGB Viaux, Catelan, Stetson, Raffelt, Redondo, Valcarce & Weiss, arXiv:1308.4627

Limits on Axion-Electron Coupling from GC M5 I-band brightness of tip of red-giant brach [magnitudes] Detailed account of theoretical and observational uncertainties • Uncertainty dominated by distance • Can be improved in future (GAIA mission) Axion-electron Yukawa 𝑔 𝑎𝑒 × 10 13 Limit on axion-electron Yukawa Mass limit in DFSZ model 𝑔 𝑎𝑒 < 2.6× 10 −13 (68% CL) 4.3× 10 −13 (95% CL) 𝑚 𝑎 cos 2 𝛽 < 9.3 meV (68% CL) 15.4 meV (95% CL) Viaux, Catelan, Stetson, Raffelt, Redondo, Valcarce & Weiss, arXiv:1311.1669

Axion Bounds from WD Luminosity Function Limits on axion-electron coupling and mass limit in DFSZ model: 𝑔 𝑎𝑒 ≲3× 10 −13 𝑚 𝑎 cos 2 𝛽 ≲10 meV Miller Bertolami, Melendez, Althaus & Isern, arXiv:1406.7712, 1410.1677

Period Change of Variable White Dwarfs Period change Π of pulsating white darfs depends on cooling speed White dwarf G117−B15A White dwarf PG 1351+489 Favored by Π Limited by Π Córsico et al., arXiv:1205.6180 Battich et al., arXiv:1605.07668

Summary of White Dwarf Bounds Tip of RGB Luminosity Function Period Change Variable White Dwarfs Córsico et al., arXiv:1605.06458

Neutrinos from Thermal Processes Photo (Compton) Plasmon decay Pair annihilation Bremsstrahlung These processes were first discussed in 1961-63 after V-A theory

Neutrino-Photon-Coupling in a Plasma Neutrino effective in-medium coupling 𝐿 eff =− 2 𝐺 F Ψ 𝛾 𝛼 1 2 1− 𝛾 5 Ψ Λ 𝛼𝛽 𝐴 𝛽 Λ V 𝜇𝜈 𝐾 = 𝐶 V 𝑒 Π V 𝜇𝜈 (𝐾) Λ 𝜇ν For vector current it is analogous to photon polarization tensor Emission almost purely electron flavor sin 2 Θ W =0.2312 𝐶 V 2 = + 1 2 +2 sin 2 Θ W 2 =0. 9262 for 𝜈 𝑒 𝐶 V 2 = − 1 2 +2 sin 2 Θ W 2 =0. 0014 for 𝜈 𝜇 and 𝜈 𝜏

Sanduleak -69 202 Supernova 1987A 23 February 1987 Sanduleak -69 202

Supernova 1987A Energy-Loss Argument SN 1987A neutrino signal Neutrino sphere Volume emission of new particles Neutrino diffusion Emission of very weakly interacting particles would “steal” energy from the neutrino burst and shorten it. (Early neutrino burst powered by accretion, not sensitive to volume energy loss.) Late-time signal most sensitive observable

Three Phases of Neutrino Emission Explosion triggered Cooling on neutrino diffusion time scale Shock breakout De-leptonization of outer core layers Shock stalls ~ 150 km Neutrinos powered by infalling matter Spherically symmetric Garching model (25 M⊙) with Boltzmann neutrino transport

Cooling Time Scale Exponential cooling model: T = T0 e-t/4, constant radius, L = L0 e-t/ Fit parameters are T0, , radius, 3 offset times for KII, IMB & BST detectors Loredo and Lamb, Bayesian analysis astro-ph/0107260

Long-Term Cooling of EC SN (Garching 2009) Neutrino opacities with strong NN correlations and nucleon recoil in neutrino-nucleon scattering. Exponential cooling with 𝜏=2.6 s Barely allowed by SN 1987A Neutrino opacities without these effects Much longer cooling times L. Hüdepohl et al. (Garching Group), arXiv:0912.0260

Axion Emission from a Nuclear Medium Axion-nucleon interaction: ℒ int = 𝐶 𝑁 2 𝑓 𝑎 Ψ 𝑁 𝛾 𝜇 𝛾 5 Ψ 𝑁 𝜕 𝜇 𝑎= 𝐶 𝑁 2 𝑓 𝑎 𝐽 𝜇 𝐴 𝜕 𝑎 𝜇 a N N Energy-loss rate (erg c m −3 s −1 ) 𝑄=∫𝑑 Γ 𝑎 ∫𝑑 Γ Nucleons ℳ 2 𝜔 (axion energy 𝜔) = 𝐶 𝑁 2 𝑓 𝑎 2 𝑛 𝐵 4 𝜋 2 0 ∞ 𝑑𝜔 𝜔 4 𝑆(−𝜔) Dynamical structure function, in nonrelativistic limit correlator of nucleon spin density operator 𝑆 𝜔,𝑘 = 4 3 𝑛 𝐵 −∞ +∞ 𝑑𝑡 𝑒 𝑖𝜔𝑡 〈𝝈 𝑡,𝑘 ⋅𝝈 0,𝑘 〉 + ... V N N Nucleon-Nucleon Bremsstrahlung Early calculations using one-pion exchange potential without many body effects or multiple-scattering effects over-estimated emission rate, see e.g. • Janka, Keil, Raffelt & Seckel, PRL 76:2621,1996. • Hanhart, Phillips & Reddy, PLB 499:9, 2001. • Bacca, Hally, Liebendörfer, Perego, Pethick & Schwenk, ApJ 758: 34 (2012). • Bartl, Pethick & Schwenk, PRL 113:081101 (2014).

Axion-Nucleon Couplings Axion-nucleon coupling (model-dependent numerical factors 𝐶 𝑁 ) ℒ 𝑎𝑁 = 𝐶 𝑁 Ψ 𝑁 𝛾 𝜇 𝛾 5 Ψ 𝑁 𝜕 𝜇 𝑎 2 𝑓 𝑎 Axion-electron coupling in non-hadronic models is analogous with 𝐶 𝑒 𝑓 • Axial-vector current • Spin-dependent int’n 𝑎 𝑓 Values from Grilli di Cortona et al. arXiv:1511.02867 Coupling to neutron could be very small!

Axion Bounds and Searches 103 106 109 1012 [GeV] fa eV keV meV ma neV 1015 Microwave Searches CASPEr Experiments Tele scope CAST Hadronic axions Too much hot dark matter String DW Too much cold dark matter (re-alignment with Qi = 1) Too much CDM (misalignment) Helium-burning stars (a-g-coupling, hadronic axions) SN 1987A Too many events Too much energy loss Globular clusters (He ignition), WD cooling (a-e coupling)

Diffuse Supernova Axion Background (DSAB) Neutrinos from all core-collapse SNe comparable to photons from all stars Diffuse Supernova Neutrino Background (DSNB) similar energy density as extra-galactic background light (EBL), approx 10% of CMB energy density DSNB probably next astro neutrinos to be measured Axions with 𝑚𝑎 ~ 10 meV near SN 1987A energy-loss limit Provide DSAB with compable energy density as DSNB and EBL No obvious detection channel Raffelt, Redondo & Viaux work in progress (2011)

Cooling of Neutron Star in Cas A Chandra x-ray image of non-pulsar compact remnant 𝐶 𝑛 𝑚 𝑎 ∼2.4 meV Measured surface temperature over 10 years reveals unusually fast cooling rate • Neutron Cooper pair breaking and formation (PBF) as neutrino emission process? • Evidence for extra cooling (by axions)? Leinson, arXiv:1405.6873

CP-Violating Forces 𝑔 𝑠 𝑁 𝑔 𝑠 𝑁 𝑔 𝑠 𝑁 𝑔 𝑝 𝑒 𝑔 𝑝 𝑒 𝑔 𝑝 𝑒 𝑎 𝑎 𝑎 bulk bulk bulk spin spin spin 𝑎 𝑎 𝑎 Tests of Newton’s law & equivalence principle: Scalar axion coupling 𝑔 𝑠 𝑁 2 Torsion balance using polarized electron spins Axion couplings 𝑔 𝑠 𝑁 𝑔 𝑝 𝑒 T-violating force Spin-spin forces hard to measure Axion couplings 𝑔 𝑠 𝑒 2

Long-Range Force Experiments Long-range force limits from tests of Newton’s law and equivalence principle (Mostly from Eöt-Wash Group, Seattle) Limits from long-range 𝑔 𝑠 𝑁 limits times astrophysical 𝑔 𝑝 𝑁 limits, compared with direct 𝑔 𝑠 𝑁 𝑔 𝑝 𝑁 constraints Raffelt, arXiv:1205.1776 Raffelt, arXiv:1205.1776 Experimental Exp+astro bulk bulk bulk spin 𝑎 𝑎

ARIADNE: Axion Resonant InterAction DetectioN Experiment NMR Experiment meV ARIADNE: Axion Resonant InterAction DetectioN Experiment A.Geraci, A.Arvanitaki, A.Kapitulnik, Chen-Yu Liu, J.Long, Y.Semertzidis, M.Snow

Axion Dark Matter Density Partly excluded by cosmic HDM bounds & Euclid sensitivity [arXiv:1502.03325] Hot DM Cold DM Javier Redondo 2014 Realignment Cosmic Strings & Domain Walls

Thermal Axion Density and EUCLID Sensitivity Hot dark matter sensitivity of future surveys (EUCLID) is around minimal 𝑚 𝜈 Can probe axions down to 𝑚 𝑎 ∼0.15 eV Archidiacono, Basse, Hamann, Hannestad, Raffelt & Wong, arXiv:1502.03325

Axion Bounds and Searches 103 106 109 1012 [GeV] fa eV keV meV ma neV 1015 Microwave Searches CASPEr Experiments Tele scope CAST Hadronic axions Too much hot dark matter Future EUCLID ARIADNE String DW Too much CDM (misalignment) Too much cold dark matter (re-alignment with Qi = 1) IAXO Helium-burning stars (a-g-coupling, hadronic axions) SN 1987A Too many events Too much energy loss Globular clusters (He ignition), WD cooling (a-e coupling)

Pie Chart of Dark Universe Dark Energy ~70% (Cosmological Constant) Neutrinos 0.1-0.4% Ordinary Matter ~5% (of this only about 10% luminous) Dark Matter ~25%