A new QCD Dark Matter Axion search using a dielectric resonant - PowerPoint PPT Presentation

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits A new QCD Dark Matter Axion search using a dielectric resonant cavity A. Caldwell, C. Gooch, A. Hambarzumjan, B. Majorovits, A. Millar, G. Raffelt, J. Redondo, O. Reimann, F. Simon, F. Steffen MPI für Physik, München, Germany J. Redondo University of Zaragoza, Spain • Motivation: QCD Dark Matter Axions • The experimental idea • First simulations & measurements, expected sensitivity • Proposed magnet and prototype setup at MPI • Further plans Dec. 1 st 2015, München 1

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits Motivation: solution to strong CP problem Neutron EDM very small  Strong force (nearly?) invariant under CP while weak force CP violating Peccei Quinn mechanism: Add dynamical, spontaneously broken field  New pseudoscalar particle: Axion (oscillation around minimum) 2

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits Motivation: QCD axions as cold dark matter QCD Axions could also explain dark matter! Scenario I: Prediction for symmetry breaking before inflation Being experimentally covered Scenario II: Prediction for symmetry breaking after inflation: decay of strings and domain walls Experimentally not covered Axion mass [eV] 3

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits Experimental idea Axion field mixes with photon field in a static B-field At surfaces (reflecting or change in refractive index): emission of photons in both directions D. Horns, J. Jaeckel, A. Lindner, A. Lobanov, J. Redondo and A. Ringwald JCAP 1304 (2013) 016 [arXiv:1212.2970] . (P/A) single surface ~ 2 ∙ 10 – 27 W/m 2 ∙ (B ║ /5T) 2 ∙ (c γ /2) 2 Many surfaces → resonator→ “photon boost” J. Jaeckel and J. Redondo, Phys. Rev. D 88 (2013) 115002 [arXiv:1308.1103] Boost factor: power generated in resonator/power generated on single metallic ( ε r =∞ ) surface (P/A) resonant cavity ~ 2 ∙ 10 – 27 W/m 2 ∙ (B ║ /5T) 2 ∙ (c γ /2) 2 ∙ (Boost factor) Boost depends on: frequency, ε of materials, number of surfaces, displacement between surfaces, etc. 4

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits Experimental idea Detection system Metallic disc ( ε r =∞ ) High  20cm – 200cm  precision ~10T dipole Magnet motor drive Reflector Resonator with 80 high ε plates, spacing ~mm to cm range for boost in the frequency band 10 to 100 GHz 5

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First simulations: the boost factor 20 plates with ε r = 24 (LaAlO 3 ) Boost Factor Frequency [GHz] Bandwidth per setting: ~250MHz Precision of placement of high ε plates needed: ~few μ m 6

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First simulations: the boost factor 4500 Area (β · bandwidth) as 4000 function of number of 3500 dielectrics 3000 β 2500 2000 1500 1000 500 0 0 20 40 60 80 100 Number of dielectrics Number of dielectrics • Maximum boost factor scales ~quadratically with number of discs • Area of boost peak scales ~linearly with number of discs Simulations suggest: disc placement (80 discs) with precision of few μ m is enough to achieve β ~10 5 with a bandwidth of tens of MHz Boost factor can be probed by reflectance and transmittance measurements 7

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First measurements: transmission Amplifier and 0,5 Transmitter filter AlO 3 plates 0,4 Transmission 0,3 Waveguide Cut-off Region 0,2 0,1 0,0 10,0G 15,0G 20,0G 25,0G Frequency (GHz) • 5 AlO 3 discs with diameter 100mm positioned within uncertaintiy ~ 1mm • Disc positions determines transmission, reflection and boost factor ( β ) curves • Prediction (red) fits measurement (black) well.  Verification of boost by transmission measurement! 8

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First measurements: sensitivity -9 x 10 0.625 0.62 0.615 0.61 0.605 0.6 0.595 1350 1360 1370 1380 1390 6 x 10 • Inject fake axion signal with 3 . 10 -21 W power • Mesurement for one week (integrate signal): Receiver at Room Temp.  Independent „blind“ analysis  found > 6 σ signal succesfully  At LHe: noise level factor 100 better  Sensitivity at the level of 10 -23 W expected 9

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First measurements: sensitivity Expected 4 σ detection sensitivity with and without boost for 80 discs, 1m 2 surface, 10T B-field, τ =200h, 50MHz boost andwidth, Δ ν a =10 -6 ; Cryogenic preamp @ 8 K Coupling constant g A γγ [GeV -1 ] 10 -10 10 -12 10 5 boost 10 -14 In case of 4 σ evidence: re- scan frequency range to achieve > 6 σ sensitivity 10 -16 0.1 10 -5 10 -3 10 Axion mass [eV]

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits Idea for ~10T magnet The Canted-Cosine-Theta of the Superconducting Magnet Group of the Lawrence Berkeley National Laboratory T wo superimposed coils, oppositely skewed, achieve a pure cosine-theta field and eliminate axial field. Inner coil structure Mandrels integrate windings and structure, assemble poles and are part of the reaction and impregnation tooling. 11

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First prototype setup at MPI Removable Wave copper guides Mirror mirror Horn Dielectric discs antenna Mirror Precision motors Slides for Cryo-tank discs Prototype setup partly funded Germanium as seed project by: Array 12 Water / Myon-Veto ( Č)‏

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First prototype setup at MPI • Test correlation btw. transmission and boost factor • Test needed disc prescision Prototype setup partly funded • Evaluate uncertainties as seed project by: • R&D on tiling 13

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First prototype setup at MPI • Test correlation btw. transmission and boost factor • Test needed disc prescision Prototype setup partly funded • Evaluate uncertainties as seed project by: • R&D on tiling 14

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits First prototype setup at MPI • Test correlation btw. transmission and boost factor • Test needed disc prescision Prototype setup partly funded • Evaluate uncertainties as seed project by: • R&D on tiling 15

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits Further plans 2016: • Finish first test measurements at room temperature at MPI • Test noise of preamplifier at LHe temperature • Find additional collaborators for specific parts of project • Start design of 10T magnet • Develope technique to cover frequencies above 30 GHz • R&D on production of large diameter high- ε discs 2017-2018: • Demonstrate low noise performance, operation with many discs, scalability to 1m diameter, work in ~10 T environment • Build prototype with preamp in LHe in cryostat and resonator in magnetic field 2019: • Start building full scale experiment 16

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits C O N C L U S I O N S • Axions in the mass range tens to hundres of μ eV could solve strong CP problem AND Dark Matter • Open dielectric resonator with 80 discs might boost axion to photon conversion rate by 5 orders of magnitude • First measurements with low noise preamp promising: With 80 big enough discs in 10 T B-field: sensitivity enough to probe models • 10 T dipole magnet with 1 m inner hole „very doable“ • Proof of principle setup being produced 17

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits Preparations: detectable power -15 1.2x10 Bandwidth:10kHz Attenuated signal (70dB in LN) -15 1.0x10 100kHz detected with 8 σ significance -16 Detector Power (W) 8.0x10 -16 6.0x10  Proved that detection system -16 4.0x10 can be operated at the physical -16 2.0x10 limit 0.0 -16 -2.0x10 -19 1.0x10 3G 3G 3G 3G 3G 3G 3G 3G 3G 3G 3G Detector Frequency (Hz) Signal and Noise Power (W) -20 8.0x10 Signal (Noise) Level (8  ) Extrapolation of sensitivty for cryo -20 6.0x10 detector at 8K: With LN temperature 10 -20 W/Hz 1/2 (NEP) -20 4.0x10 Measured Noise Level Expected Noise Level background T Sys =150K,  =600s -20 2.0x10 0.0 0.0 5.0k 10.0k 15.0k 20.0k 25.0k 18 Filter Bandwidth (Hz)

München, Nov. 30-Dec. 1 st 2015 Prospects in Low Mass Dark Matter B. Majorovits Proposed seed project Significant improvement of existing setup necessary: High precision motors to test ~ μ m precision of relative plate positioning Different high ε plates with diameter Cryogenic low 200mm to test transmission behavior noise amplifier for for different ε : reference  cross check simulations, ε measurements dependence, tiling of plates, precision of geometries 19