The BMV project : (Biréfringence Magnétique du Vide) Optical detection of axions? Carlo RIZZO LCAR-IRSAMC Université Paul Sabatier et CNRS Toulouse

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1 The project : (Biréfringence Magnétique du Vide) Optical detection of axions? Carlo RIZZO LCAR-IRSAMC Université Paul Sabatier et CNRS Toulouse 1

2 Outline Introduction Historical overview Recent results Future projects The project Conclusions 2

3 Propagation in a vacuum: c Propagation in a vacuum in the presence of a magnetic field O(α 2 ) O(α 3 ) 1,5 % du terme d O(α 2 ) V.I.Ritus,Sov. Phys. JETP 42, 774 (1975) 3

4 L = F + af + bg 2... ( F = ε E2 μ 1 2); Kochel, Euler, Heisenberg = B H.Euler et K.Kochel, Naturwiss. 23 (1935); W.Heisenberg et H.Euler, Z. Phys. 38 (1936) 714 b a G = 1 ε 0 μ 0 r r ( E B) in the presence of B 0 : n par n per Cotton-Mouton effect Δn = Δ n = ( ) 1 2 b 4a μ B npar nper 0 0 Δ -24 n = 4 x 10 B 2 0 with B 0 in Tesla Z.Bialynicka-Birula et I.Bialynicki-Birula, Phys. Rev. D 2 (1970) 2341 experimental challenge Ellipticity B 02 xl 4

5 low mass m, chargeless, spinless boson Φ Pseudoscalar particle (like axions of Peccei et Quinn) L ps = 1/M Φ G R. Peccei et H.R.Quinn, Phys. Rev. Lett. 38 (1977) 1440 Scalar particle L s = 1/M Φ F (Coupling constant g = 1/M) Φ dark matter? It depends. 5

6 Real particle Dicroism B 0 Eγ B 0 Eγ 0 «B 0 L»effects «Pseudoscalar» L.Maiani, R.Petronzio et E.Zavattini, Phys. Lett. B 175 (1986) 359 Photoregeneration B 0 B wall wall K. Van Bibber et al., Phys. Rev. Lett. 59 (1987) 759 6

7 Virtual particle 0 0 Δn > 0 Pseudoscalar Ellipticity Δn < 0 Scalar B 0 Eγ B 0 Eγ L.Maiani, R.Petronzio et E.Zavattini, Phys. Lett. B 175 (1986) 359 7

8 Outline Introduction Historical overview Recent results Future projects The project Conclusions 8

9 B 0 9

10 Brookhaven-Rochester-Fermilab-Trieste collaboration : A.C.Melissinos, E.Zavattini et al. Brookhaven National Laboratories Upton, NY, USA Multipass optical cavity 500 passages in the field B 0 L 16 Tm B 02 L 35 T 2 m R.Cameron, et al., Phys. Rev. D 47 (1993)

11 Ellipticity < 2.0x10-9 Measurements : Ellipticity Dicroism Photoregeneration Exclusion region R.Cameron, et al., Phys. Rev. D 47 (1993)

12 Outline Introduction Historical overview Recent results Future projects The project Conclusions 12

13 Since 1992, C.Rizzo Moriond 15/03/07 Polarizzazione del Vuoto con LASer (PVLAS) E.Zavattini et al. B 0 ²L = 25 T²m B 0 L = 5 Tm Cavity finesse = Modulation frequency = 0.6 Hz Sensitivity = / Hz Laboratori Nazionali di Legnaro, INFN, Italy D.Bakalov, et al., Quantum Semiclass. Opt. 10 (1998)

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17 E.Zavattini, et al., Phys. Rev. Lett. 96 (2006)

18 E.Zavattini, et al., Phys. Rev. Lett. 96 (2006)

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20 Zoom Scalar or Pseudoscalar? Dicroism > 0 Pseudoscalar!? Birefringence : Δn < 0 Scalar!? M. Karuza, PhD Thesis (2007) 20

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22 PVLAS X CAST Exclusion region CAST Cern Axion Solar Telescope K.Zioutas, et al., Phys. Rev. Lett. 94 (2005)

23 Scalar? CAST PVLAS X Non newtonian force! PRL in press 23

24 New theories? : AXION SCALAR The existence of a massive paraphoton which would couple with the standard photon and with the axionlike particle E.Masso et J.Redondo, J. of Cosmology and Astroparticle Physics, 9 (2005) 015 The photon-initiated real or virtual production of pairs of low mass millicharged particles H. Gies, J. Jaeckel and A. Ringwald, Phys. Rev. Lett., 97 (2006) The existence of an ultralight pseudo-scalar particle interacting with two photons and a scalar boson together with the existence of a low scale phase transition in the theory R. N. Mohapatra and Salah Nasri, Phys. Rev. Lett., 98 (2007) What next?? New experiments!! 24

25 Outline Introduction Historical overview Recent results Future projects The project Conclusions Very recent results 25

26 Since 1994 Q&A (Quantum electrodynamics test & search for Axion) Pr. Ni (University of Taiwan) Preliminary results on arxiv hep-ex/ Almost disproved PVLAS Confidence level of their limits? 1 σ 26

27 2.3 T x 0.6 m permanent rotating magnet Finesse Sensitivity = / Hz 27

28 Outline Introduction Historical overview Recent results Future projects The project Conclusions 28

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30 HERA magnets 30

31 CERN OSQAR project LHC magnets 31

32 C.Rizzo Moriond 15/03/07 Data early 2007? 32

33 Outline Introduction Historical overview Recent results Future projects The project Conclusions 33

34 The Biréfringence Magnétique du Vide project Laboratoire Collisions Agrégats Réactivité, Toulouse, France : B.Pinto da Souza (Ph-D), M.Fouché, C.Robilliard, J.Vigué, C.Rizzo. Laboratoire National Champs Magnétiques Pulsés, Toulouse, France : S.Batut (Ph-D), G.Rikken, R.Battesti. and 10 Engineers et Technicians In collaboration with LMA-VIRGO, Lyon, France : LULI, Ecole Polytechnique, France. 34

35 LNCMP : European record of magnetic field Power supply 24 kv, 14 MJ 65 ka 77.3 T Campus of the Toulouse III University 35

36 The project : at the LNCMP Funded since 2001 Motivated by the QED Regeneration of photons at the LULI Funded in 2006 Motivated by PVLAS results i.e. axionlike particle search 36

37 Experimental scheme : based on Iacopini and Zavattini s paper (1979) Cavity mirrors (P ~ ppm) B 0 Fiber Polarizer Analyzer Fiber λ=1064 nm laser Pulsed magnetic field Photodiode S.Askenazy, et al., CP564, Quantum Electrodynamics and Physics of the Vacuum, edited by G.Cantatore (2001) AIP 37

38 Xcoil 25 cm LN cooling 38

39 X coil Winding Test at liquid nitrogen temperature 39

40 LN cryostat 12 mm The coil in its cryostat 40

41 T A B = 14.3 T; B²L = 28 T²m; BL = 2.6 Tm Duty cycle : 5 pulses per hours 100 pulses at 11.5 T 100 pulses at 12.5 T ms

42 Fabry-Perot cavity Ellipticity x 2F/π. Mirrors birefringence Pound-Drever-Hall locking Finesse F > Mirrors made at the LMA-VIRGO of Lyon Clean room 42

43 Mirrors for the Fabry-Perot : 4 ready in Toulouse P D P A T F = T + π P D + P A

44 Particle counting in our experimental room 0 ISO 3 ISO ISO 5 20 ISO 4 90 ISO 5 90 ISO 5 44

45 Magnet #1 Magnet #2 Laser Mirror #1 Mirror #2 Extra vacuum chamber Polarizer 2 m Set-up Analyzer 45

46 50 cm 2 m 90 46

47 Optical set-up completed july 2006 Optical fiber injection 47

48 Noise measurements with field up to 7 T 48

49 Polarisation noise Thanks to a polarisation stabilisation of the laser light after the fiber, 10-7 Hz -1/2 Corresponding sensitivity 10-9 Hz -1/2!! PVLAS : qq 10-7 Hz -1/2 Q&A : qq 10-6 Hz-1/2 Expected for : 10-8 Hz -1/2 49

50 expected : BL = (2x)2.3 Tm; B²L = (2x)21 T²m finesse Sensitivity = 10-8 /Hz 1/2, 30 pulses, 1 day M Dicroism Test of PVLAS results in 2007 Ellipticity PVLAS Brookhaven, 1993 Exclusion region m 50

51 Photon regeneration at LULI (Laboratoire pour l Utilisation des Lasers Intenses) Campus of the École Polytechnique Outside Paris 51

52 Thanks to the pulsed coils of 24 kv; 3x(1,2) 3 m 3 Transportable power supply (here at the ESRF, Grenoble) 52

53 Experimental scheme 10 T over 0.4 m 1.5 kj μm photons 5 ns Fiber Single photon counter, 0.4 detection efficiency, Noise : counts/ns 53

54 Lens 20 m focus Vacuum pipe and cryostats to be mounted at LULI in the two following weeks 54

55 Laser room at LULI here! 55

56 Pulsed coils Xcoil 10 T * 0,45 m B.L = 4,5 T.m for 5 ms Tested up to 5,15 T.m (Bmax = 14,15 T / 58 T 2.m) Single photon counter detection efficiency = 0.4 Low noise Injected by fiber Under final test 56

57 Beam time : one week in May, July and September 07 More than 1 photon for laser pulse following PVLAS! J; w=1.2 ev; B*L=4 Tm; 20 tirs; eta=0,10 PVLAS Limits after 20 laser pulses (5 days) M en GeV PVLAS Exclusion region m en ev 57

58 Conclusions : A new discovery? the answer in 2007! If not QED vacuum birefringence measurement coming soon soon after upgrade to 4 magnets of 25 T. 58

59 LCAR The project (Biréfringence Magnétique du Vide) Carlo RIZZO LCAR-IRSAMC Université Paul Sabatier et CNRS Toulouse CNRS PostDoc position open starting 9/07!!!!! 59