Any Light Particle Search II

Transcription

1 Any Light Particle Search II 79. Physics Research Committee Christoph Weinsheimer Johannes Gutenberg-University Mainz Spring 2015

2 Hidden Sector PRC Report ALPS II Physics Case 2 / 16

3 Weakly Interacting Sub-eV Particles Axions / Axion-Like-Particles (ALPs) Axion introduced to solve strong-cp problem (1978) L α s 8π θ G µν a a,µν G γ Axions / ALPs arise generically in various BSM theories g aγγ a Candidates for dark matter γ Common feature: Effective photon coupling PRC Report ALPS II Physics Case 3 / 16

4 Weakly Interacting Sub-eV Particles Hints to Axions / ALPs Anomalous TeV-Transparency [ ] Globular Clusters [ ], White-Dwarf-Cooling [ ] γ a γ PRC Report ALPS II Physics Case 4 / 16

5 Weakly Interacting Sub-eV Particles Hidden Photons Gauge boson of hidden local U(1) symmetry Kinetic Mixing with SM-γ γ γ Quantum fluctuations during inflation allowing HP production Lower bound: [ ] ρ γ ρ DM ( m ) γ 1/2 ( ) HI ev GeV Log 10 χ τ 2 >1 Coulomb CMB CMB Distortions Haloscope Searches N ν eff ALPS CAST Sun- L LVS HP CDM L- mode HP CDM Sun- T +HB +RG Log 10 m γ' [ev] ALPS II sensitivity: χ m γ ev Cosmology of thermal HP DM X- rays PRC Report ALPS II Physics Case 5 / 16

6 Light-Shining-Through-Wall γ γ wall Bx xb Conversion Probability for Axions / ALPs Pa γ = PRC Report ALPS II B 10 T 2 L 10 m Any Light Particle Search II 2 2 gaγγ GeV 1 6 / 16

7 ALPS II Sensitivity Development Stage Production-Cavity: Power Buildup: βpc = 5000 sensitivity ( Regeneration-Cavity: 1 β PC β RC Power Buildup: βrc = ) 1 4 Sensitivity Gain (ALPS-I II): PRC Report ALPS II Any Light Particle Search II 7 / 16

8 ALPS II Sensitivity Final Stage Magnetic Length: ( ) HERA dipoles sensitivity BL = 468 T m ( ) ( 1 1 BL β PC β RC ) 1 4 Sensitivity Gain (ALPS-I II): 21 PRC Report ALPS II Any Light Particle Search II 8 / 16

9 ALPS II Collaboration... too busy to take an up-to-date picture PRC Report ALPS II Any Light Particle Search II 9 / 16

10 ALPS II: Optics Conceptual design Stabilize cavities Pound-Drever-Hall Differential-Wavefront- Sensing Keep regeneration cavity on resonance with green light overlap of cavity modes ALPs signal: reconverted red photons PRC Report ALPS II Any Light Particle Search II 10 / 16

11 ALPS II: Optics PRC Report ALPS II Any Light Particle Search II 11 / 16

12 ALPS II: Optics PRC Report ALPS II Any Light Particle Search II 11 / 16

13 ALPS II: Optics PRC Report ALPS II Any Light Particle Search II 11 / 16

14 ALPS II: Optics PRC Report ALPS II Any Light Particle Search II 11 / 16

15 ALPS II: Detector Transition Edge Sensor (TES) 25 µm 25 µm Tungsten-Film Microcalorimeter operating at 80 mk Signal O(70 na) read via SQUID Intrinsic bkg. rate 10 4 Hz Energy resolution below 10% PRC Report ALPS II Any Light Particle Search II 12 / 16

16 ALPS II: Detector Performance Setting-up operation done! Performance paper published [ ] Optimized detection efficiency measurement ongoing Water circuit Heavy contamination lead to Long-Shutdown-1 Improved (closed cycle) cooling circuit PRC Report ALPS II Any Light Particle Search II 13 / 16

17 ALPS II: Magnets Status & Procedure First straightened test magnet operated successfully Even with I > Idesign Second magnet on test bench Successfully operated after 25 y in storage PRC Report ALPS II Any Light Particle Search II 14 / 16

18 Summary New aspect on physics case Hidden Photons from inflation Lot of progress in all scopes ALPS IIa preparatory phase (hopefully) finished this year setup / performance checks Physics Run (HP) in early 2016 Continue setting up ALPS IIc PRC Report ALPS II Summary 15 / 16

19 DESY Physics Seminar Searching for Dark-Matter Axions. Leslie Rosenberg (Seattle) Tuesday, 12 May 2015, 16:45 h, Auditorium The axion is a hypothetical elementary particle whose existence would explain the baffling absence of CP violation in the strong interactions. Axions also happen to be a compelling dark-matter candidate. Even if dark-matter axions were to comprise the overwhelming majority of mass in the universe, they would be extraordinarily difficult to detect. However, several experiments, either under construction or taking data, would be sensitive to even the more pessimistically coupled axions. This talk describes the current state of these searches. Coffee, tea and cookies will be served at 16:30h. After the seminar there is a chance for private discussions with the speaker over wine and pretzels. Accelerators Photon Science Particle Physics Deutsches Elektronen-Synchrotron A Research Centre of the Helmholtz Association

20 BACKUP

21 Conversion Probability for Axions/ALPs γ wall γ Bx xb P a γ = 1 4 g 2 aγγ (BL) 2 ω k a ( ) ql sin2 2 ( ) 2 ql 2 k 2 a = ω 2 m 2 a q = nω ω 2 ma 2 PRC Report ALPS II Backup 18 / 16

22 Conversion Probability for Hidden Photons γ wall γ P γ γ = 4χ 2 m4 γ M 4 γ sin 2 ( M 2 γ L 4ω ) 2 M 2 γ = (m2 γ + 2ω2 (n 1)) PRC Report ALPS II Backup 19 / 16

23 Sensitivity S(g aγγ ) 1 ( ) 1 DC 8 BL t ( 1 DE β PC β RC N prod ) 1 4 PRC Report ALPS II Backup 20 / 16

24 ALPS-I ( ) Specifications: Magnet: 1 HERA dipole ( T) Laser: nm CW Detektor: PIXIS 70 C Production Cavity Fabry-Pérot Resonator 1.2 kw circulating power PRC Report ALPS II Backup 21 / 16

25 HERA-X Heisenberg Euler BiRefringence ALPs experiment γ B x x B γ Measure Ellipticity: Ψ B 2 L Magnetic Length: B 2 L 2480 T 2 m (PVLAS: 10 T 2 m) Pathfinder-Experiment starting soon New NPRO laser funded by SFB PRC Report ALPS II Backup 22 / 16