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CAST achievements and perspectivesK. Zioutas

University of Patras & CERN

Naxos, 8/5/2014

Abstract: CAST is a 3rd generation axion helioscope and its outcome since 2000 along with the ongoing activities will be presented. Recently, CAST became the first chameleon helioscope searching for such dark energy constituents. For the future, CAST has the potential to become an antenna for axion relics. The use of a home made highest sensitive force sensor from solid state physics might transform CAST to a powerfull chameleon helioscope, being sensitive also to the chameleon coupling to matter. If time allows, further implications in astroparticle physics will be mentioned.

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The CAST collaboration

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4 fundamental questions (+ gravity) after the HIGGS discovery:

• What is dark matter?

• What is dark energy?

• Matter - Antimatter asymmetry

• What is the origin of the ‘strong CP-problem’?

why nEDM → 0

Now: DM ≈ DE >> chance coincidence?

Physics motivation:

New physics!

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SPS accelerator

Geneva AirportLHC accelerator

CERN main site

CAST

g

BXvirtual

α

CAST

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Decommissioned prototype LHC dipole magnet: B=9 T, L=9.26 m

https://docs.google.com/open?id=0B5PI0ZVqwwvOQUVUejJidm1TUFk

SUN the convenient lab for new physics!?

Note: Allowed emission of exotica < 10% Lsolar !!

+ gravitational self-trapping of massive ~axions/WISPs (yield ~10-7)

accumulation over 4.5 Gyears …

… without visible ageing effects!

L.DiLella, K.Z., Astropart. Phys. (2003)

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GeV10

g110

aγ

keV4.2Ea

CERN Axion Solar Telescope: QCD Axions or other exotica

Detection => Inverse Primakoff effect: Axion / CH interacting coherently with a magnetic field (~B2) convert to a photon

Signal: excess of X-rays during sun tracking

Differential axion flux on Earth

Pierre Sikivie 1983

Production: Primakoff effect =>Thermal photons interacting with solar nuclei / B Axions & CHs

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CAST = a difficult experiment:

- 1.8K - superconducting ( quenches!)

- moving / alignment - Cryo Fluid Dynamics of buffer gas tracking - low background X-ray detectors

the only(!?) telescope at 1.8K

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Shielded Micromegas(bulk and microbulk technology)

Shielding upgrade

Unshielded Micromegas (classic technology)

Canfranc, undergroundlaboratory

Micromegas evolution

University of Zaragoza

T. Vafeiadis Rencontres de Moriond EW 2014

Transparent windows

=> nanotechnology

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Spare # from german space program

... not in the original proposal!

unique ID potential + signal and noise improvement

CAST fulfilled original proposal from 1999

CAST X-ray telescope

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BackgroundTracking Signal simulation

~ 8x10-5cts keV-1cm-2s-1

• Spot position well determined

• Full sensitivity of telescope exploited

• Counts in the spot compatible with background level

• Background rate 1-7keV:

X-ray Telescope / CCD

CAST Status & Perspectives, Theopisti Dafni (UNIZAR), Moriond2010

Solar axions! paraphotons, chameleons?

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CAST alignment with Sun, Moon, …

?

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This is CAST =>

CDM

Since Fritz Zwicky (1933) Q:

What is “dunkle Materie” made of? Beyond original CAST proposal >>

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CMB 400000 years ~400/cm3

CνB 1 sec ~50/cm3 ?

CaB 10-10 – 10-26 sec $ ~1012 cm3 (maxionc2≈meV) ?

Cosmic relics

$ Joerg Jaeckel

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Preliminary Analysis of data with SDD

PRELIMINARY

• First data from final configuration – Shielding and Cooling

• Background 6 hrs each night (field ON)• Solar tracking data ~ 100 mins each morning• Tracking (red) and background (blue) rates 400 – 1500 eV– Typically < 4∙10-5 Hz (per 76 eV bin)

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Solar Chameleon spectrum

First look at sub keV in CAST

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>> End 2013

The “first” solar chameleon helioscope βγ

βmatter

βmatter + βγ

A novel self-made force sensor

>> towards nominal sensitivity!

RadPres sensor

Dark Energy >> ~Chameleons => βmatter

KWISP

βγ

G. Cantatore M. Karuza

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Radiation pressure from solar Chameleons?

- A nano-membrane reflects solar chameleons radiation pressure & shift of membrane

- Membrane motion can be detected within a Fabry-Perot (FP) interferometer

shifted membrane

probe beamprofile

motionless membrane

Radiation pressure

FP cavitymirror

1917/12/2013

(1mm)x(1mm), 50nm thick Si3N4 membrane mounted on a 200 µm Si substrate

FP cavitymirror

A novel interdisciplinary concept in dark energy.

@ U. Trieste, U. Rijeka, … !work in progress!

LCH ≥ 10-

10Lʘ

New perspective: CAST as a tracking haloscope for relics

•Helioscope (axion/chameleon/paraphoton)

•Haloscope(*) for (streaming) axions/ALPS/paraphotons m ≳ 10-4 eV/c2 ( λ ≲ 1 cm ) Single photon detection! ⇒ recover existing detectors!? ⇒ search in progress

CAST plusses: large B, moveable, T~1.8K- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ⇒ m ≲ 10-4 eV/c2 ? ⇒ cavity? … ADMX

?The “Dish Antenna” concept (arXiv:1212.2970, arXiv:1307.7181

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D. Hoffmann (TU-Darmstadt), A. Lindner (DESY), K.Z.

Needed:

• wide band detectors + expertise => from astrophysics

- Photoconductor detectors => ~25 - 250 μm [MPE] Sensitivity: 10-19W/Hz1/2 => 10-21 W /#/10h <= 100x? 100 dishes?

=> 10-23 W => subcritical for aDM (≈10-25W)

- Kinetic Induction Detectors (KIDs) [MPI-Bonn] ~105 # ADCs binning with Fourier analysis READOUT!? => a quasi Q=105 & no scan ~75 - 300GHz >>aDM - work in progress

• more DM => directional, streams, caustics, … => (Planetary) gravitational Lensing => ~104x flux?

~.01c (Sun) & ~.001c (Jupiter)21

New perspective: CAST as a tracking haloscope for relics

… CAST: past + pioneering future!?

The “Dish Antenna” concept / DESY

Streaming DM (axions/ALPS/paraphotons/..)

+

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If so …

Feasibility study: MPE (Garching) … μm sensors MPI (Bonn) … mm sensors Grav. Lensing => ~104 higher flux? ~.01c (Sun) & ~.001c (Jupiter) 𝚯𝐝𝐞𝐟𝐥𝐞𝐜𝐭𝐢𝐨𝐧

𝐌(𝐑 )𝑹𝒗𝟐

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in all experimental DM

=> important challenge: ~10-4 - ~102eV

Y. Semertzidis

TES : >10-4eV << = one solution G. Cantatore

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CAST:

• has a “good” name since 1999 -

• to replace? => ~100M€ >> 2019

• A reference axion experiment >> next #

http://journals.aps.org/prd/pdf/10.1103/PhysRevD.87.125030

2013

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astrophysical (solar) signatures!CAST inspiring for ……overlooked?!

=> Solar mysteries suggest (out)streaming DM#)

- Simulation

- GAIA in orbit (Febr2014 - ) >> galactic streams? => streaming DM!!

#) The 11-years solar cycle as the manifestation of the dark Universe, K.Z., M. Tsagri, Y.K. Semertzidis, T. Papaevangelou, D.H.H. Hoffmann, V. Anastassopoulos, Mod. Phys. Lett. A (2014) in press (arXiv:1309.4021)

GAIA calibration

CAST + DM search

2013

2014 @ CERN

2015 @ Zaragoza

2016 @ Patra

s

5227

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http://axion-wimp2014.desy.de/ 28

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Conclusion =>

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Conclusion => … we insist

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Conclusion => … we insist

CAST has a future!!

Solar ChameleonsP. Brax, K. Zioutas, Phys. Rev. D82 (2010) 043007 arXiv:1004.1846 [astro-ph.SR]Detection prospects for solar and terrestrial chameleonsP. Brax, A. Lindner, K. Zioutas, Phys. Rev. D85 (2012) 043014 arXiv:1110.2583 [hep-ph]Detection of radiation pressure from solar chameleonsO.K. Baker, A. Lindner, Y.K. Semertzidis, A. Upadhye, K. Zioutas arXiv:1201.6508 [astro-ph.IM] A chameleon helioscope, K. Baker, A. Lindner, A. Upadhye, K. Zioutas arXiv:1201.0079 [astro-ph.SR]Gravitational lensing by the Sun of non-relativistic penetrating particlesD.H.H. Hoffmann, J. Jacoby, K. Zioutas, Astropart. Phys. 20 (2003) 73 DOI: 10.1016/S0927-6505(03)00138-5Flux Enhancement of Slow-moving Particles by Sun or Jupiter: Can they be Detected on Earth?B.R. Patla, R.J. Nemiroff, D.H.H. Hoffmann, K. Zioutas, ApJ. 780 (2014) 158 http://arxiv.org/abs/1305.2454 The 11-years solar cycle as the manifestation of the dark UniverseK. Zioutas, M. Tsagri, Y.K. Semertzidis, T. Papaevangelou, D.H.H. Hoffmann, V. Anastassopouloshttp://arxiv.org/abs/1309.4021 >> special issue of Mod. Phys. Lett. A (2014) "Indirect Dark Matter Searches“Searching for WISPy Cold Dark Matter with a Dish Antenna,D. Horns, J. Jaeckel, A. Lindner, A. Lobanov, J. Redondo, A. Ringwald, JCAP 1304 (2013) 016, DOI: 10.1088/1475-7516/2013/04/016CAST opens a new window into dark energy and dark matter after 11 years of operation and continuous renewal.D. Hoffmann, K. Zioutas, PH – NEWSLETTER (Dec. 2013) http://ph-news.web.cern.ch/content/cast-opens-new-window-dark-energy-and-dark-matter-after-11-years-operation-and-continuous

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First results from the CERN Axion Solar Telescope (CAST) - CAST Collaboration (Zioutas, K. et al.) Phys. Rev. Lett. 94 (2005) 121301 hep-ex/0411033An Improved limit on the axion-photon coupling from the CAST experiment - CAST Collaboration (Andriamonje, S. et al.) JCAP 0704 (2007) 010 hep-ex/0702006Search for 14.4-keV solar axions emitted in the M1-transition of Fe-57 nuclei with CAST - CAST Collaboration (Andriamonje, S. et al.) JCAP 0912 (2009) 002 arXiv:0906.4488 [hep-ex] SLAC-PUB-14825Search for solar axion emission from 7Li and D(p,γ) 3He nuclear decays with the CAST γ -ray calorimeter - CAST Collaboration (Andriamonje, S. et al.) JCAP 1003 (2010) 032 arXiv:0904.2103 [hep-ex] FERMILAB-PUB-09-854Probing eV-scale axions with CAST - CAST Collaboration (Arik, E. et al.) JCAP 0902 (2009) 008 arXiv:0810.4482 [hep-ex]CAST search for sub-eV mass solar axions with 3He buffer gas - CAST Collaboration (Aune, S. et al.) Phys. Rev. Lett. 107 (2011) 261302 arXiv:1106.3919 [hep-ex]CAST solar axion search with 3He buffer gas: Closing the hot dark matter gap - CAST Collaboration (M. Arik, et al.) Phys. Rev. Lett. 112 (2014) 091302 arXiv:1307.1985 [hep-ex]

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P R E L I M I N

A R Y

Chameleons : exclusion plot

InGrid Detector• Detector for Q4 was developed starting

from Micromegas detectors.

• InGrid based on Timepix

• Drift distance 3 cm

• Gas mixture Ar:iC4H10 97.7:2.3

• Entrance window 2 µm aluminized Mylar foil.

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Radiation pressure from solar Chameleons

• A thin micromembrane having a suitable density absorbs momentum from a flux of chameleons coming from the sun and reflecting off it: the resulting radiation pressure causes a collettive motion (shift) of the membrane (arXiv:1206.0614)

• Membrane motion can be detected with high sensitivity by exploiting the multiplication factor afforded by the finesse (resonator Q in practice) of a Fabry-Perot (FP) interferometer

• During operation the FP is kept at resonance with a probe laser beam by means of a feedback loop: the control signal of this loop contains the information on membrane motion and hence on chameleon properties

Optical cavity … with a movable end mirror (membrane).6nN=1W

Pcirc

Mass m & Frequency ωΜ

10-50 nm, ~50ngram

(r1,t1)

~7mm

(r2,t2)

~2-3 mm

LCH ≥ 10-

10Lʘ

>> first test soon!36

21/7/2012

Maximum sensor area: 1 mm2 & Typical thickness: 100 - 200 nmMaterial: amorphous Si3Ni4 or single-crystal SiResonance frequency: 1 kHz - 1 MHz

Force sensitivity at RT: 10-15 N/Hz1/2(on resonance) & 10-13 N/Hz1/2(at dc)Force sensitivity at resonance frequency, at 300 mK:

10-17 N/Hz1/2(on resonance) & 10-14 N/Hz1/2 (at dc)Note:

10-11N/m2 ► 10-13 mbar ► 0.1 μW/cm2, OR

10 μW/cm2 ► 10-9N/m2 = 10-15N/mm2 + (104 s)1/2 =100x improved sensitivity:

► 10-17N/mm2/3hours(DC) ► 100nW/cm2 ►10-5Lmax-solar-CH

Potential improvements: x10 (#sensors) + x100 (focusing mirror(s)) + x100 (resonance)

► 10-22N/mm2 / 3hours (DC @ RT)

► 1 pW/cm2 ► 10-10Lmax-solar-CHs @ RT

http://xxx.lanl.gov/ftp/arxiv/papers/1201/1201.6508.pdf

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CAST Detectors - active and planned

• Micromegas (active) and new generation MM (commissioning) - few keV range

• Low-threshold detectors

• SDD (active) - > 400 eV range

• InGrid (commissioning) - 280 eV and above

• BaRBE (commissioning) - eV range

• Detectors for expanding sensitivity

• KWISP Radiation Pressure force sensor (prototype)

• dish antenna tracking haloscope (feas. study phase)

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