Поиск ЭДМ нейтрона кристалл-дифракционным методом

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

2. Neutron EDM P – spatial inversion С – particle – antiparticle inversion Т – time inversion Non zero EDM means the P and T violation CPTtheorem (Lüders (1954); Pauli(1955)) (Our world is СРТinvariant) Non zero nEDM means СРviolation

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

4. D +E 2(E·D) -E D Idea nEDM experiment Interaction time withЕ Sensitivity to nEDM Current accuracy to dn Neutron sizeRn ~ 10-13cm, dn/Rn ~ 3 10-13. Corresponding size from Earth is ~ 2μm

5. Еτ Å 107 (V·s)/cm Sensitivity to neutron EDM Crystal-diffraction method Electron bonding energy ~ a few eV E~ grad Ve ~(0.1-1)GV/cm UCNmethod τa~ 0.01 c (absorption) E ~ 10 kV/cm τ ~ 1000s (time of life) Еτ ~107(V·s)/cm NowЕτ≈106(V·s)/cm

6. - + k d L v  g V || k+g Electric field depends ona deviation from Bragg condition Neutron optic of NCS crystal Wave function Electric field Deviation from Bragg condition E(Neutron energy) • 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.

7. +E -E /2 Idea of the experiment For /2 reflection E|| vn and Hs~[E x vn]≈0

8. + 0.8·108V/cm Theory -0.8·108V/cm Electric field quartz (110) plane Lc=14 cm Bragg angle ≈ 860 Variation of the T on 1K E ≈ 108 V/cm

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

10. . Layout of the experiment 6 m

11. nEDM measurement E=(0.7±0.1) 108 V/cm P0=0.82 KBG= 0.85 Kr=0.7 dn=(2.46.5)10-24 e cm

12. Improvement the sensitivity for current geometry of experiment dn,e cm per day 1.6 10-23 Ks=57 2.8 10-25

13. Crystal quartz test Доклад Семенихина С.Ю. Now we have quartz crystal with summary size 100x100x500 mm3 withd/d~ 4 10-6

14. P HL≈0 HL≠0 3-Danalysis of neutron polarization Magnetic field || surface of the superconductor. Current accuracy of spin orientation is ~10-2rad for routine experiment ~10-3rad 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

15. . CRYOPAD-D under construction Size - 60cm Beam aperture –10x10 cm2 Nutator fields homogeneity – 10-3

16. Crystal Symmetry group hkl d, (Å) Eg,108V/cm a,ms Ega,(kVs/cm) -quartz(SiO2) 32(D63) 111 2.236 2.3 1 230 110 2.457 2.0 200 Bi12SiO20 I23 433 1.75 4.3 4 1720 444 1.46 4.65 1860 Bi12GeO20 I23 433 1.74 4.65 1 465 444 1.46 4.8 480 PbO P c a 21 002 2.94 10.4 1 1040 004 1.47 10 1000 BeO 6mm 011 2.06 5.4 7 3700 201 1.13 6.5 4500 Parameters of some NCS crystals !!! We should looking for new NCS crystal !!!

17. Storage variant Perfect crystal reflection T=T0T T=T0T T=T0 t=0 0<t<2ta 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) 3He cell Detector t=2ta Hi Hf

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

19. Sensitivity estimation

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

21. Summary of the systematic Residual magnetic field Value Timestability 3D analysis of polarization ~0.01 arc degree The crystals alignment ~0.010K The ΔT0 control Flat windows of CRYOPAD P odd rotation is dn~10-27 e cm