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O ptical S earch for Q ED vacuum magnetic birefringence, A xion & photon R egeneration

O ptical S earch for Q ED vacuum magnetic birefringence, A xion & photon R egeneration. Laser-based Particle/ Astroparticle Physics Experiment s at CERN To Test QED & probe the Low Energy Frontier…. 2010 Status Report , from P. Pugnat on the behalf of the OSQAR Collaboration

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O ptical S earch for Q ED vacuum magnetic birefringence, A xion & photon R egeneration

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  1. Optical Search for QED vacuum magnetic birefringence, Axion & photon Regeneration Laser-based Particle/Astroparticle Physics Experiments at CERN To Test QED & probe the Low Energy Frontier… 2010 Status Report , from P. Pugnat on the behalf of the OSQAR Collaboration 99th Meeting of the SPSC (CERN), 16 November 2010

  2. ►26 Members from 11 Institutes (CERN, Cz, Fr & Po) CERN, Geneva, Switzerland G.Deferne, P. Pugnat (now at LNCMI-CNRS), M. Schott, A. Siemko • Charles University, Faculty of Mathematics & Physics, Prague, Czech Republic M. Finger Jr., M. Finger, M. Slunecka • Czech Technical University, Faculty of Mechanical Engineering, Prague, Czech RepublicJ. Hošek,M. Kràl,K. Macuchova, M. Virius, J. Zicha ISI, ASCR, Brno, Czech Republic A. Srnka IMEP/LAHC - INPG, 38016 Grenoble Cédex-1, FranceL. Duvillaret, G. Vitrant, J.M. Duchamp IN, CNRS – UJF & INPG, BP 166, 38042 Grenoble Cédex-9, France B. Barbara, R. Ballou • LASIM , UCB Lyon1 & CNRS, 69622 Villeurbannes, France • M. Durand (now at NIST, Gaithersburg), J. Morville LSP, UJF & CNRS, 38402 Saint-Martin d'Hères, FranceR. Jost,S. Kassi,D. Romanini TUL, Czech Republic M. Šulc Warsaw University, Physics Department, Poland A. Hryczuk,K. A. Meissner The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  3. Outline • Introduction • Scientific Motivations • Reminder of the OSQAR Experiments • VMB Measurement • Photon Regeneration (PR) Experiment • Progress achieved in 2010 & Expected for 2011/12 • Short & Long Time Perspectives • Summary, Perspectives & Requirements for 2011 The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  4. Scientific Motivations ►Complementary to the LHC Physicsat the TeVscaleto search WIMPs (Weakly Interacting Massive Particles) Physicsat the Sub-eV scale to searchWISPs (Weakly Interacting Sub-eV Particles) Many extensions of the Standard Model, like those based on supergravity or superstrings, predict not only WIMPS but also WISPs… The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  5. Scientific Motivations in a Nutshell • To measure for the 1st time the Vacuum Magnetic Birefringence predicted by the QED (Heisenberg & Euler, Weisskopf, 1936) i.e. the vacuum magnetic “anomaly” of the refraction index “ n-1” ~ 10-22 in 9.5 T • To explore the Physics at the Low Energy Frontier (sub-eV) • Axion & Axion Like Particles i.e. solution to the strong CP problem (Weinberg, Wilczek, 1978) & Non-SUSY Dark Matter candidates (Abbott & Sikivie; Preskill, Wise & Wilczek, 1983) • Paraphotons(Georgi, Glashow & Ginsparg, 1983),Milli-charged Fermions • Chameleons (Khoury& Weltman, 2003) • The unknown … • A New Way of doing Particle Physics based on Laser beam(s) • Spin-offs in the domain of the metrology of electric & magnetic fields x x Delbrück scattering The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  6. Principles of the Experiments x ~ 53 m a g g 9.5 T x Use of 2 LHC cryo-dipoles (double apertures) for Phase-1 & 2 ► In one aperture of dipole-1, measurement of the Vacuum Magnetic Birefringence & Dichroïsm ► In the 2nd aperture of dipole-1 & one aperture of dipole-2, Photon Regeneration Experiment LN2 cooled CCD The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  7. Axions Change of the linear polarisation of a laser beam after propagation in the vacuum with B transverse : Elliptical “Pseudo”-rotation Background for the ellipticity coming from the QED VMB  Physics is guaranteed Very small effects ~10-14rad/ T2 km3  optical cavity to increase the path in B VMB & Linear Dichroism measurements to test QED & Search Axion/ALP: Principle &Proposed Optical Scheme P. Pugnat, L. Duvillaret, M. Finger, M. Kral, A. Siemko, J. Zicha Czechoslovak Journal of Physics, Vol.55 (2005), A389; Optical scheme with inputs from D. Romanini. Phase 1 VMB ~10-14rad/ T2 km Field Modulation at 1-10 mHz & dedicated filtering techniques L. Maiani, R. Petronzio, and E. Zavattini, Phys. Lett. 175B (1986) 359 The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  8. VMB measurement– The keyproblem to solve : How to getrid of the birefringence & dichroism of the opticalcavity ? • A new approachwasproposed by a team from OSQAR & presented in 2009 (SPSC-SR-053-2009; http://indico.cern.ch/conferenceDisplay.py?confId=73796) The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  9. VMB & Linear Dichroism measurements - (R)evolution of the optical scheme Use residual mirrors birefringence as an optical bias for homodyne detection qout B y x qin fout fin VMB ~10-13rad Maintain the high finesse of the cavity during the synchronous rotation of the mirrors around their optical axis An update for the OSQAR-VMB is in preparation The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  10. “An invisible light shining through a wall” K. van Bibber et al. PRL 59 (1987) 759 Photon Regenerationruns in 2010 Borrowed from Aaron S. Chou, SLAC HEP seminar, Jan. 14, 2008 The Boss

  11. F F E E 53 m D D E1 B1 C C B B A A Photon Regeneration ► 1st operation in 2010 with 2 aligned LHC dipoles The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  12. Safety Issues – Operation of a Class IV laser Additionalconstraintscomingfrom the open access of the SM18 hall to visitors Safety audit of March 8th - Strict Procedure for operation (EDMS doc1063882 v.3) - Improvements of the beamshielding - Modification of the water circuit for the laser cooling The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  13. Overview of the experimentalruns in 2010 The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  14. Exemple of raw & filtered data Preliminary Preliminary Statisticalanalysis • to built exclusion limits Filtering of raw data to supresscosmicsignalsfromeach frame before accumulation The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  15. PreliminaryResults for 2010 Runs • Detailedanalysisisundergoing • CCD background stability makes difficult the combined analysis between all data sets • 1stanalysis (conservative) of best data sets • 12.7h/6.5W for pseudoscalar • 7.37h/6.7W for scalar Preliminary ►The expectedsensitivity in 2009 (SPSC-M-770) has been reached The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  16. Sensitivity of the Photon RegenerationExperiment K. van Bibber et al. PRL 59 (1987) 759 P. Sikivie, PRL 51 (1983) 11415 The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  17. Expected exclusion limits for 2011/12 • Assumptions - 24 h of time integration - Optical power x 50 - New CCD allowing a background reduction by 50 ► Target = toimprove the ALPslimit by x5 Expectation The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  18. How to increase the optical power ?► By extending the laser cavity • A laser cavity extended up to 5 m inside the magnet aperture was already built ►With an intra-cavity CW power larger than few 100 W • Need to be repeated with the new laser & a mirror with a larger radius to extend the cavity up to 20 m… The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  19. PVLAS, PRL 96 (2006) CAST-2003, PRL 94 (2005) ALPs 2010 Expectation for 2011/12 OSQAR-PR Experiments-Expected results - Short & “Long” Term Perspectives Axion Search From C. Hagmann, K. van Bibber, L.J. Rosenberg,Physics Lett. B, vol.592, 2004 • Photon regeneration Experiment • Preliminary Phaseto test PVLAS results; 1 dipole with/without gas (done) * * • Phase-1 : 2 dipoles, CW laser beam, extra & intra cavity to improve BFRT/GammeV results (2009-2010) and ALPs (2011-2012) • Phase-2 : 2 dipoles, CW laser beam & High Finesse FP cavity (2013-2014) • Phase-3 : more than 2 dipoles to be competitive with CAST(long term) • “n-1 Experiment” i.e.VMB & Linear Dichroism - Phase-1&2 :Measurements of QED prediction in O(a2) & O(a3) respectively within 1 dipole (2013 & 2014 at the earliest…) *P. Pugnat, et al. Czech Journal of Physics, Vol.55 (2005), A389; Czech Journal of Physics, Vol.56 (2006), C193; * * 1st results in Phys. Rev. D 78, 092003 (2008) The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  20. For the longer term: Toward the “axionic” laser Phys. Rev. Lett. 98, 172002 (2007) With 4 + 4 LHC Dipoles, i.e. Experiment of ~150 m long,… The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  21. Summary, Perspectives & Requirements • The potentialdiscovery of the OSQAR-PR wassignificantlyimproved in 2010 with the simultaneous use of 2 LHC dipoles • The sensitivity obtained for pseudoscalar & scalar search has reached the foreseen target and is only surpassed today by the new results of the ALPs experiment • OSQAR-PR limitations due to the : - Less than expected availability of the LHe cooling capacity at SM18 - Reduced optical power of the laser - Poor performances of the CCD detector • Perspectives for 2011 & 2012 - To break the OSQAR-PR limitations ►Increase the time integration ►Extend the laser cavity up to 20 m ► New CCD - This, to improve the exclusion limitsfor pseudoscalar & scalar search by about one order of magnitude - To develop a first prototype of a rotating Fabryperot cavity for the VMB measurement • Requests for 2011 - 2 LHC dipolesat cold condition for at least 1 period of 2 weeks and 4 periods of 1 week each The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

  22. Acknowledgements The OSQAR collaboration would like to thank - Gilles Tessier from ESPCI-Paris (EcoleSupérieure de Physique & de ChimieIndustrielles de la ville de Paris) to have provided the new 14 W Ar+ laser, • The CERN teams of the SM18-test hall (MSC-TF, CRG-OD, RF-KS) for their valuable technical contributions, inputs and advices, as well as • The management of CERN-TE department for continuous support. The OSQAR Experiments @ CERN For Low Energy Laser-based Particle/Astroparticle Physics

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