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Georg G. Raffelt, Max-Planck<br />
Planck-Institut <strong>Axion</strong>s<br />
für f<br />
Physik, München<br />
PONT d’Avignon, 21-25 25 April 2008, Avignon, France<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Motivation, Limits and Searches
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
<strong>Axion</strong> Physics in a Nut Shell<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Particle-Physics Physics Motivation<br />
CP conservation in QCD by<br />
Peccei-Quinn mechanism<br />
→ <strong>Axion</strong>s a ~ π 0<br />
m π f π ≈ m a f a<br />
For f a ≫ f π axions are “invisible”<br />
and very light<br />
a<br />
γ<br />
γ<br />
Solar and Stellar <strong>Axion</strong>s<br />
<strong>Axion</strong>s thermally produced in stars,<br />
e.g. by Primakoff production<br />
γ<br />
a<br />
• Limits from avoiding excessive<br />
energy drain<br />
• Search for solar axions (CAST, Sumico)<br />
Cosmology<br />
Search for <strong>Axion</strong> Dark Matter<br />
In spite of small mass, axions<br />
are born non-relativistically<br />
(“non-thermal relics”)<br />
N<br />
Microwave resonator<br />
(1 GHz = 4 μeV)<br />
→ “Cold dark matter”<br />
candidate<br />
m a ~ 1-10001<br />
1000 μeV<br />
Cosmic<br />
String<br />
S<br />
a<br />
Primakoff<br />
conversion<br />
B ext<br />
γ
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
The CP Problem of Strong Interactions<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Characterizes degenerate<br />
QCD ground state (Θ(<br />
vacuum)<br />
Phase of Quark<br />
Mass Matrix<br />
Standard<br />
QCD Lagrangian<br />
contains<br />
a CP violating term<br />
L<br />
CP<br />
α<br />
= −<br />
s<br />
(<br />
Θ −<br />
arg det M<br />
) Tr G ~<br />
q μν<br />
G<br />
8<br />
π<br />
14 4<br />
2<br />
4 4<br />
3<br />
0<br />
≤Θ≤<br />
2<br />
π<br />
μν<br />
Induces a neutron<br />
electric dipole moment<br />
(EDM) much in excess<br />
of experimental limits<br />
d<br />
n<br />
≈<br />
Θ<br />
10<br />
−<br />
16<br />
e cm<br />
≈<br />
Θ<br />
10<br />
2<br />
μ<br />
n<br />
<<br />
3<br />
×<br />
10<br />
−<br />
26<br />
e<br />
cm<br />
Θ<br />
≲<br />
10 −10<br />
Why so small
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Dynamical Solution<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Peccei & Quinn 1977 - Wilczek 1978 - Weinberg 1978<br />
Θ<br />
Re-interpret as<br />
a dynamical variable<br />
(scalar field)<br />
L<br />
CP<br />
Θ →<br />
a(x)<br />
f a<br />
Pseudo-scalar<br />
scalar axion field<br />
Peccei-Quinn scale,<br />
<strong>Axion</strong> decay constant<br />
α<br />
s<br />
Tr(GG ~<br />
α<br />
= − Θ )<br />
a(x)<br />
L<br />
s<br />
Tr(GG ~<br />
CP = −<br />
)<br />
8<br />
π<br />
8<br />
π<br />
f<br />
a<br />
V(a)<br />
Θ =<br />
0<br />
a<br />
Potential (mass term)<br />
induced by L CP drives<br />
a(x) to CP-conserving<br />
minimum<br />
CP-symmetry<br />
dynamically restored<br />
a<br />
gluon<br />
gluon<br />
<strong>Axion</strong>s generically couple<br />
to gluons and mix with π 0<br />
⎛<br />
<strong>Axion</strong><br />
mass<br />
⎞<br />
⎛<br />
Pion<br />
mass<br />
⎞<br />
f<br />
⎜<br />
⎟<br />
~<br />
⎜<br />
⎟ ×<br />
π<br />
⎝<br />
& couplings<br />
⎠<br />
⎝<br />
& couplings<br />
⎠<br />
f a<br />
f<br />
π<br />
≈<br />
93<br />
MeV<br />
Pion decay constant
Peccei-Quinn Mechanism Proposed in 1977<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
The Pool Table Analogy<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
P.Sikivie<br />
Sikivie, , Physics Today, Dec. 1996, pg. 22<br />
Gravity<br />
Pool table<br />
Symmetric<br />
relative<br />
to gravity
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
The Pool Table Analogy<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
P.Sikivie<br />
Sikivie, , Physics Today, Dec. 1996, pg. 22<br />
Gravity<br />
Pool table<br />
Symmetric<br />
relative<br />
to gravity<br />
Floor<br />
inclined<br />
Symmetry<br />
broken
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
The Pool Table Analogy<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
P.Sikivie<br />
Sikivie, , Physics Today, Dec. 1996, pg. 22<br />
Gravity<br />
Pool table<br />
Axis<br />
Symmetric<br />
relative<br />
to gravity<br />
Floor<br />
inclined<br />
Symmetry<br />
broken<br />
f a<br />
Symmetry<br />
dynamically<br />
restored<br />
(Peccei & Quinn 1977)
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
The Pool Table Analogy<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
P.Sikivie<br />
Sikivie, , Physics Today, Dec. 1996, pg. 22<br />
Gravity<br />
Pool table<br />
Axis<br />
Symmetric<br />
relative<br />
to gravity<br />
Floor<br />
inclined<br />
Symmetry<br />
broken<br />
New degree<br />
of freedom<br />
<strong>Axion</strong><br />
Θ _<br />
(Weinberg 1978, Wilczek 1978)<br />
f a<br />
Symmetry<br />
dynamically<br />
restored<br />
(Peccei & Quinn 1977)
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
30 Years of <strong>Axion</strong>s<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
The Cleansing <strong>Axion</strong><br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Frank Wilczek<br />
“I named them after a laundry<br />
detergent, since they clean up<br />
a problem with an axial current.”<br />
(Nobel lecture 2004, written version)
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Windows of Opportunity<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
<strong>Axion</strong>s<br />
Solve strong CP problem<br />
by Peccei-Quinn<br />
dynamical symmetry restoration<br />
Alternatives<br />
• Massless up-quark<br />
• Spontaneous CP violation<br />
• Θ =<br />
0<br />
set at some high energy scale<br />
(no radiative corrections)<br />
• Supersymmetric particles<br />
• Superheavy particles<br />
• Cosmic cold dark matter candidate<br />
• Sterile Neutrinos<br />
• Direct detection possible<br />
• Many others …<br />
(but usually not experimentally<br />
accessible)<br />
Search for new physics at E ≫ TeV<br />
in low-energy experiments<br />
(<strong>Axion</strong>s Nambu-Goldstone boson of<br />
spontaneously broken symmetry)<br />
• Neutrino masses (see-saw)<br />
saw)<br />
• Proton decay<br />
• Neutron electric dipole moment<br />
• Deviation from Newton’s Law<br />
(e.g. large extra dimensions)
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
<strong>Axion</strong>s as a Research Topic<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
160<br />
140<br />
120<br />
100<br />
80<br />
60<br />
40<br />
20<br />
0<br />
1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007<br />
Papers in SPIRES that cite one of the two original Peccei and Quinn papers or<br />
Weinberg’s or Wilczek’s paper or with “axion” or “axino” in their title<br />
(total of 3186 papers up to 2007)
<strong>Axion</strong>s as Pseudo Nambu-Goldstone Bosons<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
• The realization of the Peccei-Quinn mechanism involves a new chiral<br />
U(1) symmetry, spontaneously broken at a scale f a<br />
• <strong>Axion</strong>s are the corresponding Nambu-Goldstone mode<br />
E ≈ f a<br />
V(a)<br />
• U PQ (1) spontaneously broken<br />
• Higgs field settles in<br />
“Mexican hat”<br />
a<br />
E ≈ Λ QCD ≪ f a<br />
V(a)<br />
• U PQ (1) explicitly broken<br />
by instanton effects<br />
• Mexican hat tilts<br />
• <strong>Axion</strong>s acquire a mass<br />
_<br />
Θ=0<br />
a
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
From Standard to Invisible <strong>Axion</strong>s<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Standard Model<br />
All Higgs degrees of<br />
freedom are used up<br />
Standard <strong>Axion</strong><br />
Weinberg 1978, Wilczek 1978<br />
• Peccei-Quinn scale f a =<br />
electroweak scale f ew<br />
• Two Higgs fields,<br />
separately giving mass<br />
to up-type quarks and<br />
down-type quarks<br />
Invisible <strong>Axion</strong><br />
Kim 1979, Shifman,<br />
Vainshtein, Zakharov 1980,<br />
Dine, Fischler, Srednicki 1981<br />
Zhitnitsky 1980<br />
• Additional Higgs with<br />
f a ≫ f ew<br />
• <strong>Axion</strong>s very light and<br />
and very weakly<br />
interacting<br />
No room for axions<br />
<strong>Axion</strong>s quickly ruled out<br />
experimentally and<br />
astrophysically<br />
• New scale required<br />
• <strong>Axion</strong>s can be<br />
cold dark matter<br />
• Can be detected
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
<strong>Axion</strong> Properties<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Gluon coupling<br />
(Generic property)<br />
Mass<br />
Photon coupling<br />
Pion coupling<br />
Nucleon coupling<br />
(axial vector)<br />
Electron coupling<br />
(optional)<br />
L<br />
m<br />
L<br />
g<br />
L<br />
L<br />
L<br />
aG<br />
a<br />
a<br />
a<br />
α<br />
= s<br />
GG ~<br />
a<br />
a<br />
8<br />
π<br />
f<br />
=<br />
f<br />
a<br />
a<br />
0.6 eV<br />
/10<br />
7<br />
GeV<br />
C<br />
= N<br />
Ψ<br />
N<br />
γμ<br />
γ<br />
2f<br />
m<br />
f<br />
≈<br />
π<br />
f<br />
Ψ<br />
∂<br />
aN 5 N<br />
μ<br />
a<br />
C<br />
= e<br />
Ψ<br />
e<br />
γ<br />
μ<br />
γ<br />
2f<br />
Ψ<br />
∂<br />
a<br />
a<br />
ae 5 e<br />
μ<br />
a<br />
π<br />
g<br />
a<br />
γ<br />
FF ~ r r<br />
γ = − a<br />
=<br />
g<br />
a<br />
γ<br />
E<br />
⋅<br />
Baa<br />
4<br />
α<br />
⎛<br />
E<br />
⎞<br />
γ =<br />
⎜<br />
−<br />
1.<br />
92<br />
⎟ 2<br />
π<br />
f<br />
⎝<br />
N<br />
⎠ a<br />
π<br />
a<br />
C<br />
=<br />
a<br />
π<br />
(<br />
π<br />
0<br />
π<br />
+<br />
∂<br />
−<br />
...)<br />
μ<br />
μπ<br />
+ ∂<br />
a<br />
f<br />
f<br />
a<br />
π<br />
a<br />
a<br />
a<br />
a<br />
π<br />
π<br />
G<br />
G<br />
γ<br />
γ<br />
π<br />
a<br />
N<br />
N<br />
e<br />
e
Supernova 1987A Energy-Loss Argument<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Neutrino<br />
sphere<br />
SN 1987A neutrino signal<br />
Neutrino<br />
diffusion<br />
Volume emission<br />
of novel particles<br />
Emission of very weakly interacting<br />
particles would “steal” energy from the<br />
neutrino burst and shorten it.<br />
(Early neutrino burst powered by accretion,<br />
not sensitive to volume energy loss.)<br />
Late-time time signal most sensitive observable
<strong>Axion</strong>s as Pseudo Nambu-Goldstone Bosons<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
• The realization of the Peccei-Quinn mechanism involves a new chiral<br />
U(1) symmetry, spontaneously broken at a scale f a<br />
• <strong>Axion</strong>s are the corresponding Nambu-Goldstone mode<br />
E ≈ f a<br />
V(a)<br />
• U PQ (1) spontaneously broken<br />
• Higgs field settles in<br />
“Mexican hat”<br />
a<br />
E ≈ Λ QCD ≪ f a<br />
V(a)<br />
• U PQ (1) explicitly broken<br />
by instanton effects<br />
• Mexican hat tilts<br />
• <strong>Axion</strong>s acquire a mass<br />
_<br />
Θ=0<br />
a
Series of Papers on <strong>Axion</strong> Cosmology in PLB 120 (1983)<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Page 127
Series of Papers on <strong>Axion</strong> Cosmology in PLB 120 (1983)<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Page 133
Series of Papers on <strong>Axion</strong> Cosmology in PLB 120 (1983)<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Page 137
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Killing Two Birds with One Stone<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Peccei-Quinn mechanism<br />
• Solves strong CP problem<br />
• May provide dark matter<br />
in the form of axions
Production of Cold <strong>Axion</strong> Population in the Early Universe<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Approximate axion<br />
cold dark matter density<br />
Ω<br />
a<br />
≈<br />
7/6<br />
⎛<br />
f<br />
12 a ⎞ ⎛1μeV<br />
⎞<br />
0.5<br />
⎜ ⎟ ≈ 4 ⎜ ⎟<br />
⎝<br />
10<br />
GeV<br />
⎠<br />
⎝<br />
m<br />
a<br />
⎠<br />
7/6<br />
Inflation after PQ symmetry breaking<br />
Reheating restores PQ symmetry<br />
Homogeneous mode oscillates after<br />
T ≲ Λ QCD<br />
Dependence on initial misalignment<br />
angle<br />
Ω<br />
∝<br />
Θ<br />
a<br />
Θi<br />
• Cosmic strings of broken U PQ (1)<br />
form by Kibble mechanism<br />
• Radiate long-wavelength axions<br />
• Ω a independent of initial conditions<br />
• Isocurvature fluctuations from large<br />
quantum fluctuations of massless<br />
axion field created during inflation<br />
• Strong CMBR bounds on isocurvature<br />
fluctuations<br />
• Scale of inflation required to be<br />
very small Λ I ≲ 10 13 GeV<br />
[Beltrán, García-Bellido & Lesgourgues<br />
hep-ph/0606107]<br />
ph/0606107]<br />
Inhomogeneities of axion field large,<br />
self-couplings lead to formation of<br />
mini-clusters<br />
Typical properties<br />
• Mass ~ 10 −12<br />
M sun<br />
• Radius ~ 10 10 cm<br />
• Mass fraction up to several 10%
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
<strong>Axion</strong>s from Cosmic Strings<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Strings form by Kibble mechanism<br />
after break-down of U PQ (1)<br />
Small loops form by self-intersection<br />
Paul Shellard
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
<strong>Axion</strong> Mini Clusters<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
The inhomogeneities of the axion field are large, leading to bound objects,<br />
“axion mini clusters”. . [Hogan & Rees, PLB 205 (1988) 228.]<br />
Self-coupling of axion field crucial for dynamics.<br />
Typical mini cluster properties:<br />
Mass ~ 10 −12<br />
M sun<br />
Radius ~ 10 10 cm<br />
Mass fraction up to several 10%<br />
Potentially detectable with<br />
gravitational femtolensing<br />
Distribution of axion energy density.<br />
2-dim slice of comoving length 0.25 pc<br />
[Kolb & Tkachev, ApJ 460 (1996) L25]
Inflation, <strong>Axion</strong>s, and the Anthropic Principle<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Late inflation scenario of axion cosmology<br />
• Initial misalignment angle constant in our patch of the universe<br />
• Dark matter density determined by the initial random number Θ i<br />
• Is different in different patches of the universe<br />
• Dark matter fraction not calculable from first principles<br />
• Random number chosen by process of spontaneous symmetry breaking<br />
Natural case for applying anthropic reasoning for the observed darkd<br />
matter density relative to baryons<br />
• Linde, “Inflation and <strong>Axion</strong> Cosmology,” PLB 201:437, 1988<br />
• Tegmark, Aguirre, Rees & Wilczek,<br />
“Dimensionless constants, cosmology and other dark matters,”<br />
PRD 73, 023505 (2006) [arXiv:astro-ph/0511774]
<strong>Axion</strong> Hot Dark Matter from Thermalization after Λ QCD<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Cosmic thermal degrees of<br />
freedom<br />
Freeze-out temperature<br />
L<br />
a<br />
π<br />
C<br />
=<br />
a<br />
f<br />
f<br />
a<br />
π<br />
π<br />
(<br />
π<br />
π π<br />
0<br />
π<br />
+<br />
∂<br />
μ<br />
π<br />
−<br />
−<br />
2<br />
π<br />
+ π<br />
+<br />
0<br />
π<br />
π<br />
−<br />
−<br />
∂<br />
∂<br />
μ<br />
μ<br />
π<br />
π<br />
0<br />
+<br />
)<br />
∂<br />
μ<br />
a<br />
10 4 10 5 10 6 10 7<br />
f a (GeV)<br />
Cosmic thermal degrees of<br />
freedom at axion freeze-out<br />
π<br />
a<br />
C a<br />
1<br />
−<br />
z<br />
π<br />
=<br />
≈<br />
0.094094<br />
3(1<br />
+<br />
z)<br />
Chang & Choi, PLB 316 (1993) 51<br />
10 4 10 5 10 6 10 7<br />
f a (GeV)
Lee-Weinberg Curve for Neutrinos and <strong>Axion</strong>s<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
<strong>Axion</strong>s<br />
log(Ω a )<br />
Ω M<br />
Non-Thermal<br />
Relics<br />
CDM<br />
Thermal Relics<br />
HDM<br />
10 μeV<br />
10 eV<br />
log(m a )<br />
Neutrinos<br />
& WIMPs<br />
log(Ω ν )<br />
Ω M<br />
HDM<br />
Thermal Relics<br />
CDM<br />
10 eV<br />
10 GeV<br />
log(m ν )
<strong>Axion</strong> Hot Dark Matter Limits from Precision Data<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Credible regions for neutrino plus axion hot<br />
dark matter (WMAP-5, LSS, BAO, SNIa)<br />
Hannestad, Mirizzi, Raffelt & Wong<br />
[arXiv:0803.1585]<br />
Marginalizing over unknown neutrino hot dark matter component<br />
m a<br />
m a<br />
< 1.0 eV (95% CL)<br />
WMAP-5, LSS, BAO, SNIa<br />
< 0.4 eV (95% CL) WMAP-3, small-scale scale CMB,<br />
HST, BBN, LSS, Ly-α<br />
Hannestad, Mirizzi, Raffelt<br />
& Wong [arXiv:0803.1585[<br />
arXiv:0803.1585]<br />
Melchiorri, Mena & Slosar<br />
[arXiv:0705.2695]
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
<strong>Axion</strong> Bounds<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
10 3 10 6 10 9 10 12 [GeV] f a<br />
m a<br />
keV<br />
eV<br />
meV<br />
μeV<br />
Experiments<br />
Tele<br />
scope<br />
CAST<br />
Direct<br />
search<br />
ADMX<br />
Too much hot dark matter<br />
Too much<br />
cold dark matter<br />
Globular clusters<br />
(a-γ-coupling)<br />
Too many<br />
events<br />
Too much<br />
energy loss<br />
SN 1987A (a-N-coupling)
Experimental Tests of the Invisible <strong>Axion</strong><br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Primakoff effect:<br />
<strong>Axion</strong>s-photon transitions in external<br />
static E or B field<br />
(Originally discussed for π 0<br />
by Henri Primakoff 1951)<br />
Pierre Sikivie:<br />
Macroscopic B-field B<br />
can provide a<br />
large coherent transition rate over<br />
a big volume (low-mass axions)<br />
• <strong>Axion</strong> helioscope:<br />
Look at the Sun through a dipole<br />
magnet<br />
• <strong>Axion</strong> haloscope:<br />
Look for dark-matter axions with<br />
A microwave resonant cavity
Search for Galactic <strong>Axion</strong>s (Cold Dark Matter)<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
DM axions<br />
m a = 1-10001<br />
1000 μeV<br />
Velocities in galaxy<br />
v a ≈ 10 −3 c<br />
Energies therefore<br />
E a ≈ (1 ± 10 −6 ) m a<br />
Microwave Energies<br />
(1 GHz ≈ 4 μeV)<br />
<strong>Axion</strong> Haloscope (Sikivie 1983)<br />
B ext ≈ 8 Tesla<br />
Microwave<br />
Resonator<br />
Q ≈ 10 5<br />
Power<br />
Frequency<br />
m a<br />
<strong>Axion</strong> Signal<br />
Thermal noise of<br />
cavity & detector<br />
Primakoff Conversion<br />
a<br />
γ<br />
B ext<br />
Cavity<br />
overcomes<br />
momentum<br />
mismatch<br />
Power of galactic axion signal<br />
2<br />
×<br />
−21<br />
V ⎛ B ⎞ Q<br />
4 10<br />
W<br />
3<br />
⎜ ⎟<br />
⎝ 8.5T ⎠ 5<br />
0.22m 10<br />
⎛<br />
m<br />
⎞⎛<br />
× ⎜ a ⎟<br />
⎜<br />
⎝<br />
2<br />
π<br />
GHz<br />
⎠<br />
⎝<br />
5<br />
×<br />
10<br />
ρ<br />
a<br />
−<br />
25<br />
g/cm<br />
3<br />
⎞<br />
⎟<br />
⎠
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
<strong>Axion</strong> Dark Matter Searches<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Limits/sensitivities, assuming axions are the galactic dark matter<br />
3<br />
2<br />
1<br />
1. Rochester-Brookhaven<br />
Brookhaven-<br />
Fermilab<br />
PRD 40 (1989) 3153<br />
5<br />
4<br />
2. University of Florida<br />
PRD 42 (1990) 1297<br />
3. US <strong>Axion</strong> Search<br />
(Livermore)<br />
ApJL 571 (2002) L27<br />
4. CARRACK I (Kyoto)<br />
preliminary<br />
hep-ph/0101200<br />
ph/0101200<br />
5. ADMX (Livermore)<br />
foreseen<br />
e.g. Rev. Mod. Phys.<br />
75 (2003) 777
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
ADMX (G.Carosi, Fermilab, May 2007)<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
ADMX (G.Carosi, Fermilab, May 2007)<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
ADMX (G.Carosi, Fermilab, May 2007)<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
ADMX (G.Carosi, Fermilab, May 2007)<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
ADMX (G.Carosi, Fermilab, May 2007)<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Renewed ADMX<br />
data taking has begun<br />
on 28 March 2008<br />
(Same day as CAST He-3 3 began)
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
ADMX (G.Carosi, Fermilab, May 2007)<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Fine Structure in <strong>Axion</strong> Spectrum<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
• <strong>Axion</strong> distribution on a 3-dim 3<br />
sheet in 6-dim 6<br />
phase space<br />
• Is “folded up” by galaxy formation<br />
• Velocity distribution shows narrow peaks that can be resolved<br />
• More detectable information than local dark matter density<br />
P.Sikivie<br />
& collaborators
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Search for Solar <strong>Axion</strong>s<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
γ<br />
Primakoff<br />
production<br />
Sun<br />
a<br />
<strong>Axion</strong> flux<br />
<strong>Axion</strong> Helioscope (Sikivie 1983)<br />
a<br />
<strong>Axion</strong>-Photon<br />
Photon-Oscillation<br />
Magnet<br />
N<br />
S<br />
γ<br />
Tokyo <strong>Axion</strong> Helioscope (“Sumico”)<br />
(Results since 1998, up again 2008)<br />
CERN <strong>Axion</strong> Solar Telescope (CAST)<br />
(Data since 2003)<br />
Alternative technique:<br />
Bragg conversion in crystal<br />
Experimental limits on solar axion flux<br />
from dark-matter experiments<br />
(SOLAX, COSME, DAMA, ...)
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Tokyo <strong>Axion</strong> Helioscope (“Sumico”)<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
~ 3 m<br />
S.Moriyama, M.Minowa<br />
Minowa, , T.Namba<br />
Namba, , Y.Inoue, Y.Takasu<br />
& A.Yamamoto, PLB 434 (1998) 147
Results and Plans of Tokyo <strong>Axion</strong> Helioscope (“Sumico”)<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
S. Inoue at TAUP 07
Extending to higher mass values with gas filling<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
<strong>Axion</strong>-photon transition probability<br />
⎛ g<br />
γB<br />
2<br />
a ⎞<br />
⎛<br />
⎞<br />
= ⎜ ⎟<br />
2 qL<br />
Pa<br />
→γ<br />
sin<br />
⎜<br />
⎟ ⎝<br />
q<br />
⎠<br />
⎝<br />
2<br />
⎠ <strong>Axion</strong>-photon momentum transfer<br />
m<br />
2<br />
m<br />
2<br />
a − γ<br />
q<br />
=<br />
2E<br />
Transition suppressed for qL ≳ 1<br />
Gas filling: Give photons a refractive<br />
mass to restore full transition strength<br />
(~ MSW effect)<br />
2<br />
4<br />
πα<br />
m<br />
γ =<br />
n<br />
e<br />
(n m<br />
e electron density)<br />
e<br />
Z<br />
m<br />
γ<br />
=<br />
28.9 eV<br />
ρ<br />
Gas<br />
A<br />
He 4 vapour pressure at 1.8 K<br />
ρ<br />
≈<br />
0 .2<br />
×<br />
10<br />
−<br />
3 g<br />
cm<br />
−<br />
3<br />
m γ<br />
=<br />
0.26<br />
eV
LHC Magnet Mounted as a Telescope to Follow the Sun<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
CAST at CERN<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
CAST Focussing X-Ray X<br />
Telescope<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
• From 43 mm ∅ (LHC magnet aperture) to ~3 mm ∅<br />
• Signal/background improvement > 100<br />
• Signal and background simultaneously measured<br />
One spare mirror system from the failed Abrixas x-rayx<br />
satellite
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Sun Spot on CCD with X-Ray X<br />
Telescope<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Limits from CAST-I I and CAST-II<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
CAST-I I results: PRL 94:121301 (2005) and JCAP 0704 (2007) 010<br />
CAST-II results (He-4 4 filling): preliminary
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Limits on <strong>Axion</strong>-Photon<br />
Photon-Coupling<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
<strong>Axion</strong>-photon photon-coupling g aγ [GeV<br />
-1 ]<br />
10 -4<br />
10 -6<br />
10 -8<br />
10 -10<br />
10 -12<br />
10 -14<br />
10 -16<br />
Laser<br />
PVLAS expected<br />
Tokyo Helioscope<br />
CAST Sensitivity<br />
DM<br />
Search<br />
Future<br />
DFSZ model<br />
KSVZ model<br />
PVLAS<br />
Signature<br />
Helio<br />
seis<br />
mology<br />
+Gas<br />
Telescope<br />
<strong>Axion</strong> Line<br />
HB<br />
Stars<br />
10 -7<br />
10 -6<br />
10 -5<br />
10 -4<br />
10 -3<br />
10 -2<br />
10 -1<br />
1 10 100<br />
<strong>Axion</strong> mass m a [eV]
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Alps<br />
<strong>Axion</strong>-like particles (ALPs)<br />
(Pseudo)-scalar scalar particles with a two-photon vertex
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Particles with Two-Photon Coupling<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Particles with two-photon vertex:<br />
• Neutral pions (π(<br />
0 ), Gravitons<br />
• <strong>Axion</strong>s (a) and similar hypothetical particles<br />
L<br />
a<br />
γ<br />
r<br />
= g<br />
γr E<br />
⋅<br />
Baa<br />
a<br />
Two-photon<br />
decay<br />
Γ<br />
a<br />
γ<br />
=<br />
g<br />
2<br />
a<br />
γ<br />
m<br />
64<br />
π<br />
3<br />
a<br />
Photon<br />
Coalescence<br />
Primakoff<br />
Effect<br />
Conversion of photons into<br />
pions, gravitons or axions,<br />
or the reverse<br />
Magnetically<br />
induced vacuum<br />
birefringence<br />
In addition to QED<br />
Cotton-Mouton<br />
Mouton-effect<br />
PVLAS experiment recently measured an<br />
effect ~ 10 4 larger than QED expectation<br />
(Signal now disproved)
Dimming of Supernovae without Cosmic Acceleration<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
<strong>Axion</strong>-photon<br />
photon-oscillations oscillations in intergalactic B-field domains dim photon flux<br />
Effect grows linearly with distance<br />
Saturates at equipartition between photons and axions (unlike grey g<br />
dust)<br />
Mixing matrix<br />
Domain size ~ 1 Mpc<br />
Field strength ~ 1 nG<br />
a-γ-coupling ~ 10 −10<br />
GeV −1<br />
<strong>Axion</strong> mass < 10 −16<br />
eV<br />
2<br />
1<br />
2<br />
1<br />
⎛<br />
pl<br />
ga<br />
B ⎞<br />
−<br />
γ ⎛<br />
10.8ne<br />
0.15ga<br />
B ⎞<br />
⎜<br />
ω ω<br />
⎟<br />
⎜<br />
ω<br />
γ<br />
−1<br />
=<br />
⎟ Mpc<br />
2<br />
ω<br />
⎜<br />
2<br />
⎟<br />
2<br />
4 2<br />
1<br />
ga<br />
B<br />
m<br />
⎜<br />
a 0.15g<br />
a B 7.8 10<br />
−<br />
m<br />
− ⎟<br />
γ<br />
⎝ γ × aω<br />
⎝<br />
ω<br />
⎠<br />
⎠<br />
Photon energy ~ 1 eV<br />
Electron density<br />
~ 10 −7 cm −3<br />
(average baryon density)<br />
Chromaticity depends<br />
sensitively on assumed<br />
values and distribution<br />
of n e and B<br />
Csáki, Kaloper & Terning (hep-ph/0111311, ph/0111311, hep-ph/0112212, ph/0112212, astro-ph/0409596). Erlich & Grojean<br />
(hep-ph/0111335). ph/0111335). Deffayet, et al. (hep-ph/0112118). ph/0112118). Christensson & Fairbairn (astro-ph/0207525).<br />
Mörtsell et al. (astro-ph/0202153).<br />
Mörtsell & Goobar (astro-ph/0303081). Bassett (astro-ph/<br />
0311495). Ostman & Mörtsell<br />
(astro-ph/0410501). Mirizzi, Raffelt & Serpico (astro-ph/0506078).
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Cantatore 12<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
The PVLAS Dichroism Signal<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
PVLAS, PRL 96:110406 (2006), hep-ex/0507107<br />
ex/0507107
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Latest PVLAS Results<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Zavattini et al., PRD 77:032006, 2008 [arXiv:0706.3419]
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
Photon Regeneration Experiments<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
Single pass<br />
“Shining light through a wall”<br />
Resonant<br />
cavities on<br />
generation &<br />
regeneration<br />
side<br />
hep-ph/0701198<br />
ph/0701198
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
No Light Shining Through a Wall<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
BMV Experiment, using a pulsed<br />
laser and pulsed magnetic field<br />
(Toulouse)<br />
Robilliard et al., arXiv:0707.1296<br />
GammeV Experiment<br />
with a variable baseline<br />
(Fermilab)<br />
Chou et al., arXiv:0710.3783
Technological Applications of PVLAS Particles<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
arXiv:0704.0490v1 [hep-ph]<br />
ph]