Heidelberg Axions University! - Motivated by the Strong Interactions, Perfect for Cosmology
** J. Jaeckel
† S. Abel , G. Alonso**, J. Berges**, B. Doebrichz, L. Gastaldo**, M. Goodsellxx, H. Gies0, F. Kahlhoefer*, S. Knirck**, † V. Khoze , A. Lobanovy, J. Redondox, A. Ringwald*, U. Schmidt**, K. Schmidt-Hoberg* and The FUNK Collaboration
** † ITP Heidelberg, zCERN, IPPP Durham, *DESY, YMPIfR Bonn, xU. Zaragoza, xxParis LPTHE, 0ITP Jena We need...
Physics beyond the Standard Model
Inventory of the Universe Heidelberg University!
Dark Energy 68%
Neutrinos 0.1-0.5%
Ordinary matter 5% Dark Matter 27% Where does it hide?
New physics Exploring is (at least) 2 dimensional Heidelberg University!
ν,Fixed target Exploring is (at least) 2 dimensional Heidelberg University!
“dark” ν,Fixed target = weakly coupled What are Axion? And why do we need them? A „visible“ Hint for new Physics
The strong CP Problem A dirty little secret... Heidelberg University!
• The θ-term violates time reversal (T=CP)!
- - T
+ + A dirty little secret... Heidelberg University!
• The θ-term violates time reversal (T=CP)!
T A dirty little secret... Heidelberg University!
• The θ-term violates time reversal (T=CP)!
T=CP A dirty little secret... Heidelberg University!
• The θ-term violates time reversal (T=CP)! • Connected to strong interactions!
Electric dipole moment of the neutron!
https://en.wikipedia.org/wiki/ Neutron_electric_dipole_moment Measure neutron electric dipole moment Heidelberg University! • θ would cause neutron EDM Experiment
Measure transition frequency. No neutron electric dipole moment... Heidelberg University!
RAL-Sussex-ILL EDM collaboration What do we expect? Heidelberg University! • Two mass scales in the game: “Argument” EDM Blackboard Implications Heidelberg University! • Detailed calculation gives
Extremely unnatural! Strong CP Problem The axion solution to the strong CP problem In pictures… The axion solution to the strong CP problem Heidelberg University! • Make µ dynamical è it can change its value
Classical potential The axion solution to the strong CP problem Heidelberg University! • Make µ dynamical è it can change its value
Classical potential
With QCD quantum corrections The axion solution to the strong CP problem Heidelberg University! • Make µ dynamical è it can change its value
initially Classical potential
With QCD quantum corrections The axion solution to the strong CP problem Heidelberg University! • Make µ dynamical è it can change its value
after some time Classical potential
With QCD quantum corrections
è QCD likes to be CP conserving (if we allow it) The axion solution to the strong CP problem Heidelberg University! • Make µ dynamical è it can change its value
Classical potential
With QCD quantum corrections
è Can still move è new particle = axion Axions Heidelberg University! • Classical flatness from symmetry • Quantum corrections are small
• New light particle: The Axion (it’s a Weakly Interacting Sub-eV Particle)
Dark matter candidate
Good motivation for axion/WISP experiments In Equations… A Dynamical θ Heidelberg University! • Idea: – Make θ a dynamical degree of freedom a – Let a have no tree level potential – Let a have only derivative couplings • Then: A Dynamical θ Heidelberg University! • Idea: – Make θ a dynamical degree of freedom a. – Let a have no tree level potential – Let a have only derivative couplings • Then:
µ=a will evolve to a=θ=0 CP is conserved What is a? Heidelberg University! • Properties: – Let a be a dynamical degree of freedom. – Let a have no tree level potential – Let a have only derivative couplings
– a2[0,2π] since
a is Goldstone boson of a U(1) symmetry Axion! Peccei-Quinn Symmetry Heidelberg University! • Toy model:
• U(1):
• If µ2<0 we have SSB
Phase is Goldstone Use it as Axion The Coupling to and Heidelberg University! • A diagram
• And a dimensional argument: The Coupling to Heidelberg University! • Adler-Bell-Jackiw anomaly
• Chiral rotations not a good symmetry: it is anomalous The Coupling to Heidelberg University! • Adler-Bell-Jackiw anomaly
• Chiral rotations not a good symmetry: it is anomalous The mass of the Axion Heidelberg University!
• U(1)PQ is not exact. It‘s anomalous!
Goldstone Pseudogoldstone • Dimensional considerations – SSB scale
– Quark masses
– QCD scale
PseudoGoldstone mass “Argument” Topological Suszeptibility on blackboardl Axion-like Particles Heidelberg University! mass/energy
0 CDF LHC
Y inv. LEP + - -3 e e inv.+
Beam LSW dump
] -6 1 - 0 SN1987a ¼ GeV [ CAST
aBB -9 +
g SUMICO HB stars 10 SN1987a Cosmology
Log -12 Weaker interactionWeaker
-15 Axion band -18
-15 -12 -9 -6 -3 0 3 6 9 12 15
Log10 ma[eV] How to find the Axion… Exploring fundamental high energy physics… Heidelberg University! • The direct approach: MORE POWER
LHC, Tevatron + ILC,CLIC
• Detects most things within energy range • E.g. may find SUSY particles, WIMPs etc. But… Heidelberg University! • May miss very weakly interacting matter (Axions, WIMPs, WISPs…) • Current maximal energy few TeV But… Heidelberg University! • May miss very weakly interacting matter (Axions, WIMPs, WISPs…) • Current maximal energy few TeV
• Man it’s DANGEROUS… But… Heidelberg University! • May miss very weakly interacting matter (Axions, WIMPs, WISPs…) • Current maximal energy few TeV
• Or much much more horrifying:
No signal above background!
The Power of Low Energy Experiments
Complementary approaches Light shining through walls Heidelberg University!
X X Light shining through walls Heidelberg University!
X X
• Test
• Enormous precision! • Study extremely weak couplings! Photons coming through the wall! Heidelberg University! • It could be Axion(-like particle)s!
• Coupling to two photons:
a a Light Shining Through Walls Heidelberg University! • A lot of activity – ALPS – BMV – GammeV – LIPPS – OSQAR Small coupling, small mass Heidelberg University! mass/energy Weaker interactionWeaker Axion band Helioscopes Heidelberg University! CAST@CERN SUMICO@Tokyo
SHIPS@Hamburg
Sun Detector
Ion Sensitivity Heidelberg University!
Axion band Going to the future: IAXO Heidelberg University! The International Axion Observatory An interesting area… Heidelberg University!
IAXOTeV °
Intermediate string scale models
Definite Test of Test of QCD axion TeV transparency + white dwarf anomaly WISPS=Weakly interacting sub-eV particles Heidelberg University! • Axions a a
• Massive hidden photons (without B-field) =analog ν-oscillations
• Hidden photon + MCP MCP minicharged particle (MCP) Axions and ALPs from String Theory String theory Heidelberg University! • Attempt to unify SM with gravity • New concept: strings instead of point particles String theory: Moduli and Axions Heidelberg University! • String theory needs Extra Dimensions
Must compactify
• Shape and size deformations correspond to fields: Moduli and Axions Connected to the fundamental scale, here string scale
Axion/ALP candidates Axion (like particles): Where are we? Heidelberg University! Axions and Moduli Heidelberg University! • Gauge field terms
+ Supersymmetry/supergravity
Scalar ALP/moduli coupling pseudoscalar ALP coupling Axions and Moduli Heidelberg University! • Gauge couplings always field dependent (no free coupling constants)
• Axions + Moduli always present in String theory
Masses and Couplings Heidelberg University! • “Axion scale” related to fundamental scale
• If QCD axion: ma fixed
• However, if not QCD axion
(nearly) arbitrary Axion (like particles): Where are we? Heidelberg University! Axion (like particles): Where are we? Heidelberg University! Axion (like particles): Where are we? Heidelberg University!
Intermediate strings Funny Higgs arguments Dark Matter(s) Can Dark Matter be Axiony/WISPy? (Weakly Interacting Sub-eV Particley ) Slim Properties of Dark Matter Heidelberg University!
• Dark matter is dark, i.e. it doesn‘t radiate! (and also doesn‘t absorb)
è very, very weak interactions with light and with ordinary matter
è Exactly the property of Axions/WISPs Exploring is (at least) 2 dimensional Heidelberg University!
“dark” ν,Fixed target = weakly coupled A common prejudice Heidelberg University! • Dark Matter has to be heavy:
• Prejudice based on thermal production! and/or fermionic DM!
Both assumptions give v>vescape minimal velocity è(thermal/Fermi) galaxy, i.e. structure, formation inhibited! v • Has to be non-thermally (cold!!!) produced See misalignment mechanism • Bosonic! Axion(-like particles) Hidden Photons Dark matter has to be heavy… Heidelberg University! Dark matter has to be heavy Dark matter has to be heavy… Heidelberg University! Dark matter has to be heavy Heidelberg University! SuperCold Dark Matter The axion has no clue where to start Heidelberg University! H>>m Field is stuck because of Hubble “breaking” The axion has no clue where to start Heidelberg University! H< Can start moving… The axion solution to the strong CP problem Heidelberg University! è Oscillations contain energy è behave like non-relativistic particles (T=0) Axion Dark Matter Heidelberg University! • è overdamped oscillator • è damped oscillator è Dark Matter Why Cold? Inflation! Heidelberg University! Field value space Axion(-like particle) Dark Matter Heidelberg University! ~107 GeV ~1012 GeV Detecting Axiony/WISPy DM Use a plentiful source of axions Heidelberg University! • Photon Regeneration Photon (amplified in resonator) axion (dark matter) Signal: Total energy of axion Heidelberg University! RF Receiver Virial velocity in galaxy halo! An extremely sensitive probe!!! Heidelberg University! A discovery possible any minute! Heidelberg University! Electricity from Dark Matter ;-). Heidelberg University! • Photon Regeneration Photon (amplified in resonator) axion (dark matter) Really sustainable Energy Heidelberg University! • Galaxy contains (6-30)x1011 solar masses of DM è (3-15)x1043 TWh @100000 TWh per year (total world today) è 1038 years J DM power ½*v~300 MeV/cm3*300km/s~10 W/m2 compared to 2W/m2 for wind Encircling the axion… Heidelberg University! Broadband Search Strategy Dark Matter Antenna Heidelberg University! Antenna converts axion->photon Radiation concentrated in center Detector B Probes here; very sensitive!! The FUNK Experiment Heidelberg University! Recycle Auger mirror Detector First Results Heidelberg University! -6 Coulomb's Law Solar physics 3 15