1. Поиск ЭДМ нейтрона кристалл-дифракционным методом Воронин Владимир ПИЯФ, Гатчина Секция ЯФ ОФН РАН, ИТЭФ 2011 21 March 20161

2. Neutron EDM Non zero EDM means the P and T violation P P – spatial inversion С С – particle – antiparticle inversion Т Т – time inversion CPT theorem (Lüders (1954); Pauli(1955)) (Our world is СРТ invariant) Non zero nEDM means СР violation 21 March 20162

3. History of nEDM experiment Standard model d n ~(10 -31 -10 -33 ) e cm New physics to explain the baryon asymmetry (experiment - n b /n  ~10 -11 SM - n b /n  ~10 -21 ) d n ~(10 -25 -10 -30 ) e cm Neutron scattering in-flight magnetic resonance UCN magnetic resonance 21 March 20163

4. Idea nEDM experiment 2(E·D) -E +EDD Interaction time with Е Sensitivity to nEDM Neutron size R n ~ 10 -13 cm, d n /R n ~ 3  10 -13. Corresponding size from Earth is ~ 2 μm Current accuracy to d n 21 March 20164

5. Sensitivity to neutron EDM E~ grad V e ~(0.1-1)GV/cm UCN method Crystal-diffraction method E ~ 10 kV/cm τ ~ 1000s (time of life) Е τ ~ 10 7 (V·s)/cm Е τ Now Е τ ≈ 10 6 (V·s)/cm τ a ~ 0.01 c (absorption) 10 7 (V·s)/cm ЕτЕτЕτЕτ Electron bonding energy ~ a few eV Å 21 March 20165

6. + - Neutron optic of NCS crystal M. Forte, J. Phys. G: Nucl. Phys. (1983) 745-754. V. G. Baryshevskii and S. V. Cherepitsa, Phys. Stat. Sol. B128 (1985) 379-387. V. V. Fedorov, Proc. of XXVI Winter LNPI School, vol. 1, Leningrad (1991) 65. Wave function g d L V || v  k k+g Electric field Deviation from Bragg condition Electric field depends on a deviation from Bragg condition E E (Neutron energy) 21 March 20166

7.  /2 Idea of the experiment For  /2 reflection E || v n and H s ~[E x v n ]≈0+E-E 21 March 20167

8. Electric field quartz (110) plane L c =14 cm Bragg angle ≈ 86 0 -0.8 · 10 8 V/cm Theory + 0.8·10 8 V/cm Variation of the  T on  1K E ≈  10 8 V/cm 21 March 20168

9. Test experiment PNPI V.V. Fedorov, E.G. Lapin, I.A. Kusnetsov, S.Yu. Semenikhin, V.V. VoroninILL M. Jentschel, E. Lelievre-Berna, V. Nesvizhevsky, A. Petoukhov, T. Soldner, F.Tasset 21 March 20169

10. Layout of the experiment. 6 m 21 March 201610

11. nEDM measurement d n =(2.4  6.5)10 -24 e cm P 0 =0.82 K BG = 0.85 K r =0.7 E= (0.7±0.1) 10 8 V/cm 21 March 201611

12. Improvement the sensitivity for current geometry of experiment Test setup Full scale setup K imp Crystal size, cm14x2x250x10x10 3.6 Beam size, cm  27 S=5.7 6x12 S=72 3.6 Beam collimation, sr (4/700 )2 = 3.2 · 10 -5 (12/450) 2 =7.1 · 10 -4 4.7 Reducing the background 0.851 1.17 Absorption in quartz 0.840.54 0.8 K s =57 1.6 10 -23 d n, e cm per day 2.8 10 -25 21 March 201612

13. Crystal quartz test Now we have quartz crystal with summary size 100x100x500 mm 3 with  d/d~ 4 10 -6 21 March 201613 Доклад Семенихина С.Ю.

14. 21 March 2016 3-D analysis of neutron polarization Magnetic field || surface of the superconductor. H L ≈0H L ≠0 P Current accuracy of spin orientation is ~10 -2 rad ~10 -2 rad for routine experiment ~10 -3 rad ~10 -3 rad can be reached for special cases F. Tasset, P.J. Brown, E. Lelie`vre-Berna, T. Roberts, S. Pujol, J. Allibon, E. Bourgeat-Lami, Physica B, 267-268 (1999) 69-74 14

15. 21 March 201615 CRYOPAD-D under construction 60cm Size - 60cm 10x10 cm 2 Beam aperture –10x10 cm 2 10 -3 Nutator fields homogeneity – 10 -3.

16. CrystalSymmetry group hkld, (Å)E g, 10 8 V/cm  a, ms E g  a, (kV  s/cm)  -quartz (SiO 2 ) 32(D 6 3 )1112.236 2.31230 1102.4572.0 200 Bi 12 SiO 20 I234331.75 4.341720 4441.464.65 1860 Bi 12 GeO 20 I234331.744.651465 4441.464.8 480 PbOP c a 210022.9410.411040 0041.47101000 BeO6mm0112.065.473700 2011.136.5 4500 Parameters of some NCS crystals !!! We should looking for new NCS crystal !!! 21 March 201616

17. Storage variant t=0 0<t<2t a t=2t a 3 He cell Detector HfHf HiHi Perfect crystal reflection T=T 0 T=T 0  T Up to 1000 reflections (  s ~1 s) M.R. Jaekel, C.J. Carlile, E.Jericha, D.E. Schwab and H. Rauch, SPIE Vol. 3767 EUV, X-Ray, and Neutron Opticas and Sources, 353 (2000) 21 March 201617

18. Some numerical estimation Bragg width – Responsible time – Crystal acceleration – (fast piezoelectric element?) 21 March 201618

19. Sensitivity estimation E g, 10 8 V/cm , ms Count rateKgKg  d, e  cm per day  -quartz (110) in-flight 2.00.6 (L=50cm) 10 4 n/s (ILL PF1) (2-3)10 -25 Bi 12 SiO 20 (444) storage 4.658 (L=15 cm) 10 3 n/s (ESS - SP) 10 (2-3)10 -26 21 March 201619

20. Conclusion  d ~(2-3)·10 -26 e·cm per 100 day of measurement Full-scale setup with quartz crystal could have a sensitivity  d ~(2-3)·10 -26 e·cm per 100 day of measurement Storage modification of crystal-diffraction nEDM experiment could reach a sensitivity  d ~(2-3)·10 -27 e·cm  d ~(2-3)·10 -27 e·cm for the short pulse ESS and BSO crystal 21 March 201620

21. 21 March 201621 Summary of the systematic Residual magnetic field Value Time stability 3D analysis of polarization The crystals alignment The ΔT 0 control ~0.01 0 K ~0.01 arc degree Flat windows of CRYOPAD P odd rotation is d n ~10 -27 e cm