Transcript Neutrinos: Ghostparticles of the Universe

ISAPP 2011, International
Physics
NeutrinosSchool
from on
theAstroparticle
Sun
26th July–5th August 2011, Varenna, Italy
Neutrinos and the Stars II
Neutrinos from the Sun
Georg G. Raffelt
Max-Planck-Institut für Physik, München, Germany
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Neutrinos from the Sun
Helium
Reactionchains
Energy
26.7 MeV
Solar radiation: 98 % light
2 % neutrinos
At Earth 66 billion neutrinos/cm2 sec
Hans Bethe (1906-2005, Nobel prize 1967)
Thermonuclear reaction chains (1938)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Hydrogen Burning: Proton-Proton Chains
p + p → 2H + e+ + 𝜈𝑒
< 0.420 MeV
p + e− + p → 2H + 𝜈𝑒
1.442 MeV
100%
2
3
He + 3He
→ 4He + 2p
7
H + p → 3He + 𝛾
85%
PP-I
Be + e− → 7Li + 𝜈𝑒
0.862 MeV
PP-II
7
3
15%
hep
He + 4He → 7Be + 𝛾
90%
7
10%
3
He + p → 4He + e+ + 𝜈𝑒
< 18.8 MeV
0.02%
7
Be + e− → Li∗ + 𝜈𝑒
0.384 MeV
Li + p → 4He + 4He
Georg Raffelt, MPI Physics, Munich
0.24%
PP-III
7
Be + p → 8B + 𝛾
8
B
8
→ Be∗ +
e+ MeV
+ 𝜈𝑒
< 15
8
Be∗ → 4He + 4He
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Neutrino Spectrum
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Proposing the First Solar Neutrino Experiment
John Bahcall
1934 – 2005
Raymond Davis Jr.
1914 – 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
First Measurement of Solar Neutrinos
Inverse beta decay
of chlorine
600 tons of
Perchloroethylene
Homestake solar neutrino
observatory (1967–2002)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Results of Chlorine Experiment (Homestake)
ApJ 496:505, 1998
Average
Rate
Average (1970-1994) 2.56  0.16stat  0.16sys SNU
(SNU = Solar Neutrino Unit = 1 Absorption / sec / 1036 Atoms)
Theoretical Prediction 6-9 SNU
“Solar Neutrino Problem” since 1968
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Neutrino Flavor Oscillations
𝜈𝑒
cos 𝜃
=
𝜈𝜇
−sin 𝜃
Two-flavor mixing
sin 𝜃
cos 𝜃
𝜈1
𝜈2
Each mass eigenstate propagates as 𝑒 i𝑝𝑧
with 𝑝 = 𝐸 2 − 𝑚2 ≈ 𝐸 − 𝑚2 2𝐸
Phase difference
𝛿𝑚2
𝑧
2𝐸
implies flavor oscillations
Probability 𝜈𝑒 → 𝜈𝜇
Bruno Pontecorvo
(1913–1993)
Invented nu oscillations
sin2(2𝜃)
z
𝐸
Oscillation 4𝜋𝐸
= 2.5 m
2
Length
𝛿𝑚
MeV
Georg Raffelt, MPI Physics, Munich
eV 2
𝛿𝑚
ISAPP 2011, 3/8/11, Varenna, Italy
GALLEX/GNO and SAGE
Inverse Beta Decay
Gallium  Germanium
GALLEX/GNO (1991–2003)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Gallium Results as Shown at Neutrino 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Cherenkov Effect
Elastic scattering or
CC reaction
Light
Electron or Muon
(Charged Particle)
Light
Cherenkov
Ring
Georg Raffelt, MPI Physics, Munich
Water
ISAPP 2011, 3/8/11, Varenna, Italy
Super-Kamiokande Neutrino Detector (Since 1996)
42 m
39.3 m
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Super-Kamiokande: Sun in the Light of Neutrinos
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Sudbury Neutrino Observatory (SNO)
1000 tons of heavy water
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Sudbury Neutrino Observatory (SNO)
1000 tons of heavy water
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Sudbury Neutrino Observatory (SNO)
1000 tons of heavy water
Normal (light) water
H20
Heavy water
D20
Nucleus of hydrogen (proton)
Nucleus of heavy hydrogen
(deuterium)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Sudbury Neutrino Observatory (SNO)
Heavy
hydrogen
(deuterium)
Electron neutrinos
Georg Raffelt, MPI Physics, Munich
Heavy
hydrogen
(deuterium)
All neutrino flavors
ISAPP 2011, 3/8/11, Varenna, Italy
Missing Neutrinos from the Sun
Electron-Neutrino Detectors
Chlorine
Gallium
Water
nne+ e- ne++ee--
All Flavors
Heavy Water
ne+d p + p +e-
Heavy Water
n+dp+n+n
8B
CNO
8B
7Be
8B
8B
8B
pp
CNO
7Be
Homestake
Gallex/GNO
SAGE
Georg Raffelt, MPI Physics, Munich
(Super-)
Kamiokande
SNO
SNO
ISAPP 2011, 3/8/11, Varenna, Italy
Charged and Neutral-Current SNO Measurements
Ahmad et al. (SNO Collaboration), PRL 89:011301,2002
(nucl-ex/0204008)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Final SNO Measurement of Boron-8 Flux
SNO Collaboration, arXiv:0910.2984
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
KamLAND Long-Baseline Reactor-Neutrino Experiment
• Japanese Nuclear Reactors
80 GW (20% world capacity)
• Average distance 180 km
• Flux 6  105 cm-2 s-1
• Without oscillations
~ 2 captures per day
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Oscillation of Reactor Neutrinos at KamLAND (Japan)
Oscillation pattern for anti-electron neutrinos from
Japanese power reactors as a function of L/E
KamLAND Scintillator
detector (1000 t)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Best-fit “solar” oscillation parameters
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Neutrino Spectrum
7-Be line measured
by Borexino (2007)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Neutrino Spectroscopy with BOREXINO
• Neutrino electron scattering
• Liquid scintillator technology
(~ 300 tons)
• Low energy threshold
(~ 60 keV)
• Online since 16 May 2007
• Expected without flavor
oscillations
75 ± 4
counts/100 t/d
• Expected with oscillations
49 ± 4
counts/100 t/d
• BOREXINO result (May 2008)
49 ± 3stat ± 4sys cnts/100 t/d
arXiv:0805.3843 (25 May 2008)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Neutrinos in Borexino
Borexino Collaboration, arXiv:1104.1816
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Geo Neutrinos
Geo Neutrinos
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Geo Neutrinos: What is it all about?
We know surprisingly little about
the Earth’s interior
• Deepest drill hole ~ 12 km
• Samples of crust for chemical
analysis available (e.g. vulcanoes)
• Reconstructed density profile
from seismic measurements
• Heat flux from measured
temperature gradient 30-44 TW
(Expectation from canonical BSE
model ~ 19 TW from crust and
mantle, nothing from core)
• Neutrinos escape unscathed
• Carry information about chemical composition, radioactive energy
production or even a hypothetical reactor in the Earth’s core
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Geo Neutrinos
Expected Geoneutrino Flux
KamLAND Scintillator-Detector (1000 t)
Reactor Background
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Latest KamLAND Measurements of Geo Neutrinos
K. Inoue at Neutrino 2010
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Geo Neutrinos in Borexino
Geo neutrino signal
Borexino Collaboration, arXiv:1003.0284v
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Geo Neutrinos in Borexino
Expectation Reactors
99.73%
95%
68%
Expectation
BSE model of Earth
Borexino Collaboration, arXiv:1003.0284
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Models
Solar Models
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Equations of Stellar Structure
Assume spherical symmetry and static structure (neglect kinetic energy)
Excludes: Rotation, convection, magnetic fields, supernova-dynamics, …
Hydrostatic equilibrium
𝑑𝑃
𝐺𝑁 𝑀𝑟 𝜌
=−
𝑑𝑟
𝑟2
Energy conservation
𝑑𝐿𝑟
= 4𝜋𝑟 2 𝜖𝜌
𝑑𝑟
Energy transfer
4𝜋𝑟 2 𝑑 𝑎𝑇 4
𝐿𝑟 =
3𝜅𝜌 𝑑𝑟
Literature
• Clayton: Principles of stellar evolution and
nucleosynthesis (Univ. Chicago Press 1968)
• Kippenhahn & Weigert: Stellar structure
and evolution (Springer 1990)
Georg Raffelt, MPI Physics, Munich
𝑟
𝑃
𝐺𝑁
𝜌
𝑀𝑟
𝐿𝑟
𝜖
𝜅
𝜅𝛾
𝜅c
Radius from center
Pressure
Newton’s constant
Mass density
Integrated mass up to r
Luminosity (energy flux)
Local rate of energy
generation [erg g −1 s −1 ]
𝜖 = 𝜖nuc + 𝜖grav − 𝜖𝜈
Opacity
𝜅 −1 = 𝜅𝛾−1 + 𝜅c−1
Radiative opacity
𝜅𝛾 𝜌 = 𝜆𝛾 −1
Rosseland
Electron conduction
ISAPP 2011, 3/8/11, Varenna, Italy
Convection in Main-Sequence Stars
Sun
Kippenhahn & Weigert, Stellar Structure and Evolution
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Constructing a Solar Model: Fixed Inputs
Solve stellar structure equations with good microphysics, starting from a
zero-age main-sequence model (chemically homogeneous star) to present age
Fixed quantities
Solar mass
Solar age
M⊙ = 1.989  1033 g
0.1%
t⊙ = 4.57  109 yrs
0.5%
Kepler’s 3rd law
Meteorites
Quantities to match
Solar luminosity
L⊙ = 3.842  1033 erg s-1
0.4%
Solar constant
Solar radius
R⊙ = 6.9598  1010 cm
0.1%
Angular diameter
(Z/X)⊙ = 0.0229
Photosphere and
meteorites
Solar metals/hydrogen
ratio
Adapted from A. Serenelli’s lectures at Scottish Universities Summer School in Physics 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Constructing a Solar Model: Free Parameters
3 free parameters
• Convection theory has 1 free parameter:
Mixing length parameter aMLT
determines the temperature stratification where convection
is not adiabatic (upper layers of solar envelope)
• 2 of the 3 quantities determining the initial composition:
Xini, Yini, Zini (linked by Xini + Yini + Zini = 1).
Individual elements grouped in Zini have relative abundances
given by solar abundance measurements (e.g. GS98, AGSS09)
• Construct a 1 M⊙ initial model with Xini, Zini, Yini = 1 - Xini - Zini and aMLT
• Evolve it for the solar age t⊙
• Match (Z/X)⊙, L⊙ and R⊙ to better than one part in 105
Adapted from A. Serenelli’s lectures at Scottish Universities Summer School in Physics 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Standard Solar Model Output Information
Eight neutrino fluxes:
Production profiles and integrated values.
Only 8B flux directly measured (SNO)
Chemical profiles X(r), Y(r), Zi(r)
 electron and neutron density profiles
(needed for matter effects in neutrino studies)
Thermodynamic quantities as a function of radius:
T, P, density (r), sound speed (c)
Surface helium abundance Ysurf
(Z/X and 1 = X + Y + Z leave 1 degree of freedom)
Depth of the convective envelope, RCZ
Adapted from A. Serenelli’s lectures at Scottish Universities Summer School in Physics 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Standard Solar Model: Internal Structure
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Models
Helioseismology
and the
New Opacity Problem
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Helioseismology: Sun as a Pulsating Star
• Discovery of oscillations: Leighton et al. (1962)
• Sun oscillates in > 105 eigenmodes
• Frequencies of order mHz (5-min oscillations)
• Individual modes characterized by
radial n, angular l and longitudinal m numbers
Adapted from A. Serenelli’s lectures at Scottish Universities Summer School in Physics 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Helioseismology: p-Modes
• Solar oscillations are acoustic waves
(p-modes, pressure is the restoring force)
stochastically excited by convective motions
• Outer turning-point located close to temperature inversion layer
• Inner turning-point varies, strongly depends on l (centrifugal barrier)
Credit: Jørgen Christensen-Dalsgaard
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Examples for Solar Oscillations
+
+
=
http://astro.phys.au.dk/helio_outreach/english/
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Helioseismology: Observations
• Doppler observations of spectral
lines measure velocities of a few cm/s
• Differences in the frequencies
of order mHz
• Very long observations needed.
BiSON network (low-l modes)
has data for  5000 days
• Relative accuracy in frequencies is 10-5
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Full-Disk Dopplergram of the Sun
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Helioseismology: Comparison with Solar Models
• Oscillation frequencies depend on r, P, g, c
• Inversion problem:
From measured frequencies and from a reference solar model
determine solar structure
• Output of inversion procedure: dc2(r), dr(r), RCZ, YSURF
Relative sound-speed
difference between
helioseismological model
and standard solar model
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
New Solar Opacities (Asplund, et al. 2005, 2009)
• Large change in solar composition:
Mostly reduction in C, N, O, Ne
• Results presented in many papers by the “Asplund group”
• Summarized in Asplund, Grevesse, Sauval & Scott (2009)
Authors
(Z/X)⊙
Main changes (dex)
Grevesse 1984
0.0277
Anders & Grevesse 1989
0.0267
Grevesse & Noels 1993
0.0245
Grevesse & Sauval 1998
0.0229
DC = -0.04, DN = -0.07, DO = -0.1
Asplund, Grevesse & Sauval
2005
0.0165
DC = -0.13, DN = -0.14, DO = -0.17
DNe = -0.24, DSi = -0.05
Asplund, Grevesse, Sauval &
Scott (arXiv:0909.0948, 2009)
0.0178
DC = -0.1, DN = +0.06
Adapted from A. Serenelli’s lectures at Scottish Universities Summer School in Physics 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Origin of Changes
Spectral lines
from solar
photosphere
and corona
• Improved modeling
3D model atmospheres
MHD equations solved
NLTE effects accounted for in most cases
• Improved data
Better selection of spectral lines
Previous sets had blended lines
(e.g. oxygen line blended with nickel line)
• Volatile elements
do not aggregate easily into solid bodies
e.g. C, N, O, Ne, Ar only in solar spectrum
Meteorites
Georg Raffelt, MPI Physics, Munich
• Refractory elements
e.g. Mg, Si, S, Fe, Ni
both in solar spectrum and meteorites
meteoritic measurements more robust
ISAPP 2011, 3/8/11, Varenna, Italy
Consequences of New Element Abundances
• Much improved modeling
What is good
• Different lines of same element give
same abundance (e.g. CO and CH lines)
• Sun has now similar composition
to solar neighborhood
• Agreement between helioseismology
and SSM very much degraded
New problems
• Was previous agreement a coincidence?
Adapted from A. Serenelli’s lectures at Scottish Universities Summer School in Physics 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Standard Solar Model 2005: Old and New Opacity
Sound Speed
Density
Old: BS05 (GS98)
New: BS05 (ASG05)
Helioseismology
RCZ
0.713
0.728
0.713 ± 0.001
YSURF
0.243
0.229
0.2485 ± 0.0035
<dc>
0.001
0.005
—
<dr>
0.012
0.044
—
Adapted from A. Serenelli’s lectures at Scottish Universities Summer School in Physics 2006
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Old and New Neutrino Fluxes
Old: (GS98)
New: (AGSS09)
Best Measurements
Flux
cm-2 s-1
Error
%
Flux
cm-2 s-1
Error
%
Flux
cm-2 s-1
Error
%
pp
5.98  1010
0.6
6.03  1010
0.6
6.05  1010
0.6
pep
1.44  108
1.1
1.47  108
1.2
1.46  108
1.2
hep
8.04  103
30
8.31  103
30
18  103
45
7Be
5.00  109
7
4.56  109
7
4.82  109
4.5
8B
5.58  106
14
4.59  106
14
5.0  106
3
13N
2.96  108
14
2.17  108
14
< 6.7  108
15O
2.23  108
15
1.56  108
15
< 3.2  108
17F
5.52  106
17
3.40  106
16
< 59  106
• Directly measured 7-Be (Borexino) and 8-B (SNO) fluxes are halfway between
• CN fluxes depend linearly on abundances, measurements needed
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Hydrogen Burning: CNO Cycle
4
He
17
8O
(𝑝, 𝛼)
𝑒+
𝜈𝑒
15
(𝑝, 𝛾)
7N
(𝑝, 𝛼)
16
8O (𝑝, 𝛾)
17
9F
𝑒+
𝜈𝑒
13
6C (𝑝, 𝛾)
14
7N (𝑝, 𝛾)
15
8O
𝑒+
𝜈𝑒
12
6C
(𝑝, 𝛾) 13N
6
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Neutrino Spectrum Including CNO Reactions
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Models
Search for
Solar Axions
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Axion Physics in a Nut Shell
Particle-Physics Motivation
CP conservation in QCD by
Peccei-Quinn mechanism
p0
 Axions a ~
mpfp  mafa
g
Axions thermally produced in stars,
e.g. by Primakoff production
g
a
a
For fa ≫ fp axions are “invisible”
and very light
Cosmology
In spite of small mass, axions are born
non-relativistically
(non-thermal relics)
Cold dark matter
candidate
ma ~ 10 meV or even smaller
Georg Raffelt, MPI Physics, Munich
Solar and Stellar Axions
g
• Limits from avoiding excessive
energy drain
• Solar axion searches (CAST, Sumico)
Search for Axion Dark Matter
N
Microwave resonator
(1 GHz = 4 meV)
g
a
Primakoff
conversion
S
Bext
ADMX (Seattle)
New CARRACK (Kyoto)
ISAPP 2011, 3/8/11, Varenna, Italy
Experimental Tests of Invisible Axions
Primakoff effect:
Pierre Sikivie:
Axion-photon transition in external
static E or B field
(Originally discussed for 𝜋 0
by Henri Primakoff 1951)
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
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Search for Solar Axions
Axion Helioscope
(Sikivie 1983)
Primakoff
production
a
g
Sun
Axion flux
a
N
g
Magnet
S
Axion-Photon-Oscillation
 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 ...)
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Axion-Photon-Transitions as Particle Oscillations
Raffelt & Stodolsky, PRD 37 (1988) 1237
Photon refractive and birefringence effects
(Faraday rotation, Cotton-Mouton-effect)
Stationary
Klein-Gordon
equation
for coupled
a-g-system
𝜔2 + 𝛻 2 + 2𝜔2
𝑛⊥ − 1
𝑛𝐹
𝑛𝐹
𝑛∥
0
𝑔𝑎𝛾 𝐵
2𝜔
0
𝑔𝑎𝛾 𝐵
2𝜔
𝑚𝑎2
− 2
2𝜔
𝐴⊥
𝐴∥ = 0
𝑎
Axion-photon transitions
• Axions roughly like another photon polarization state
• In a homogeneous or slowly varying B-field, a photon beam
develops a coherent axion component
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Tokyo Axion Helioscope (“Sumico”)
~3m
Moriyama, Minowa, Namba, Inoue, Takasu & Yamamoto
PLB 434 (1998) 147
Inoue, Akimoto, Ohta, Mizumoto, Yamamoto & Minowa
PLB 668 (2008) 93
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
LHC Magnet Mounted as a Telescope to Follow the Sun
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
CAST at CERN
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Extending to higher mass values with gas filling
Axion-photon transition probability
2
𝑔𝑎𝛾 𝐵
𝑞𝐿
2
𝑃𝑎→𝛾 =
sin
𝑞
2
Axion-photon momentum transfer
𝑚𝑎2 − 𝑚𝛾2
𝑞=
2𝐸
Transition is suppressed for 𝑞𝐿 ≳ 1
Gas filling: Give photons a refractive mass
to restore full transition strength
4𝜋𝛼
2
𝑚𝛾 =
𝑛
𝑚𝑒 𝑒
1 2
𝑍
𝑚𝛾 = 28.9 eV
𝜌gas
𝐴
He-4 vapour pressure at 1.8 K is
𝜌 ≈ 0.2 × 10−3 g cm−3
𝑚𝛾 = 0.26 eV
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Helioscope Limits
Solar neutrino limit
First experimental
crossing of the KSVZ line
CAST-I results: PRL 94:121301 (2005) and JCAP 0704 (2007) 010
CAST-II results (He-4 filling): JCAP 0902 (2009) 008
CAST-II results (He-3 filling): arXiv:1106.3919
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Solar Neutrino Limit on Solar Energy Losses
Self-consistent models of the present-day Sun provide a simple power-law connection
between a new energy loss La (e.g. axions) and the all-flavor solar neutrino flux from
the B8 reaction as measured by SNO
𝑎
0
ΦB8
= ΦB8
𝐿⊙ + 𝐿𝑎
𝐿⊙
4.6
Solar model prediction and SNO
measurements imply roughly
𝐿𝑎 ≲ 0.10 𝐿⊙
Gondolo & Raffelt, arXiv:0807.2926
Schlattl, Weiss & Raffelt, hep-ph/9807476
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Next Generation Axion Helioscope
• CAST has one of the best existing
magnets that one could “recycle”
for axion physics (LHC test magnet)
• Only way forward is building a new magnet,
especially conceived for this purpose
• Work ongoing, but best option
up to now is a toroidal configuration:
– Much bigger aperture than CAST:
~1 m2 per bore
– Lighter than a dipole (no iron yoke)
– Bores at room temperature
I. Irastorza et al., “Towards a new generation axion helioscope”, arXiv:1103.5334
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy
Helioscope Prospects
SN 1987A
Limits
Georg Raffelt, MPI Physics, Munich
ISAPP 2011, 3/8/11, Varenna, Italy