Electric dipole moment experiments

Transcription

1 Photo by Reidar Hahn, Fermilab with Sandbox Studio, Chicago Electric dipole moment experiments S. Roccia

2 Outlines Setting the stage The EDM landscape EDM of radioactive nuclei 2

3 Setting the stage 3 A nonzero particle EDM violates T, P and, assuming CPT conservation, also CP.

4 Setting the stage Despite the phenomenal success of SM, it is not the theory of everything SM only an effective theory valid up to some scale Most pressing problems of SM: neutrino masses (can be accommodated) matter-antimatter asymmetry dark matter strong CP problem hierarchy problem gravity, dark energy which of these are related to d = 0? 4

5 Setting the stage Despite the phenomenal success of SM, it is not the theory of everything SM only an effective theory valid up to some scale Most pressing problems of SM: neutrino masses (can be accommodated) matter-antimatter asymmetry dark matter strong CP problem hierarchy problem gravity, dark energy which of these are related to d = 0? need CP violation CP violation within the SM: weak CP violation δckm strong CP violation θqcd < - CP violation outside SM 5

6 The EDM landscape 6 C. R. Physique (2012) Probing a theory

7 The EDM landscape SUSY, EDMs and the LHC SUSY CP problem 7

8 The EDM landscape 8 C. R. Physique (2012) Single source hypothesis

9 The EDM landscape 9 EDMs from a model-independent perspective With single-source restriction Reduced Limit on the Permanent Electric Dipole Moment of 199Hg B. Graner, Y. Chen, E. G. Lindahl, and B. R. Heckel Arxiv Without single-source restriction Electric Dipole Moments: A Global Analysis By Timothy Chupp and Michael Ramsey-Musolf

10 The EDM landscape C. R. Physique (2012) A global analysis?

11 The EDM landscape 11 Electric Dipole Moments: A Global Analysis By Timothy Chupp and Michael Ramsey-Musolf EDMs from a model-independent perspective that does not impose the single-source restriction e EDM T&P-odd Pseudoscalar electron-nucleon interaction T&P-odd Tensor electron-nucleon interaction short distance contribution to the neutron EDM T-odd & P-odd Isoscalar pion-nucleon coupling T-odd & P-odd Isovector pion-nucleon coupling 95 % confidence level bounds on the six parameters characterizing the EDMs of the neutron, neutral atoms, and molecules

12 The EDM landscape 12 Electric Dipole Moments: A Global Analysis By Timothy Chupp and Michael Ramsey-Musolf EDMs from a model-independent perspective that does not impose the single-source restriction Paramagnetic atoms Paramagnetic atoms Diamagnetic atoms Neutron Neutron and Diamagnetic atoms Diamagnetic atoms 95 % confidence level bounds on the six parameters characterizing the EDMs of the neutron, neutral atoms, and molecules Limited by nuclear theory uncertainty (from 199Hg)

13 The EDM landscape 13 Electric Dipole Moments: A Global Analysis By Timothy Chupp and Michael Ramsey-Musolf EDMs from a model-independent perspective that does not impose the single-source restriction Francium (-28 e.cm) Francium Neutron, Xenon, Radium Neutron, Xenon, Radium 95 % confidence level bounds on the six parameters characterizing the EDMs of the neutron, neutral atoms, and molecules Limited by nuclear theory uncertainty (from 199Hg)

14 EDM of atoms and molecules P, T violating electron-nucleon interaction 14 Electron EDM Electron Proton Nuclei Nucleon EDM Neutron P, T violating nucleon- nucleon interaction

15 EDM of atoms and molecules 15 E Schiff Theorem +Q Neutral atomic system of point particles in Electric field readjusts itself to give zero E field at all charges -Q BUT relativistic effects and finite size of nucleus can break the symmetry S. Blundell, J. Griffith, J. Sapirstein, Phys. Rev. D (86) (2012). +Q -Q

16 EDM of atoms and molecules 16 Deformed nuclei Enhanced signal Intrinsic Schiff moment T-P odd interaction coupling of the 2 states of opposite parity V. Spevak et al., Phys. Rev. C, 56, 3, (1997)

17 EDM of atoms and molecules 17 Radium E= 65 KV/cm N=500 Ʈ=20 s

18 EDM of atoms and molecules 18 Protactinium -100 V. Flambaum, Phys. Rev. A, 77, 2, (2008) BUT: large uncertainty on those numbers! V. Spevak et al., Phys. Rev. C, 56, 3, (1997)

19 EDM of atoms and molecules 19 Protactinium Study of the octupolar deformation in 229Pa The Orsay Universal Plunger System (OUPS) for AGATA campaign at GANIL Ratio of Doppler shifted gamma lifetimes of excited states strength of the transition deformation

20 Summary 20 EDM landscape EDMs are P, T, CP violating probes Complementary to accelerator-based results EDM of radioactive nuclei High sensitivity Limited by nuclear structure knowledge Lot of on-going programs to be supported by associated nuclear structure studies Thanks Merci

21 The EDM landscape 2 Electric Dipole Moments: A Global Analysis By Timothy Chupp and Michael Ramsey-Musolf EDMs from a model-independent perspective that does not impose the single-source restriction 95 % confidence level bounds on the six parameters characterizing the EDMs of the neutron, neutral atoms, and molecules (i) The EDMs of paramagnetic systems are prima the d e and C S. 2 (0,1) (ii) Diamagnetic atom EDMs carry the strongest s and the g π, whereas the neutron EDM depend (0) most strongly on d n and g π providing four eff parameters that are constrained by results from f experimental systems. (iii) Inclusion of both d e and C S in the global fit y bound on each parameter that is an order of magnitude less stringent than would be obtained source assumption. (1) (iv) Uncertainties in the nuclear theory preclude e significant limit on g π from d A ( 199 Hg), where (0) the situation regarding g π is under better theore Including the TlF and 129 Xe in the global fit (0)

22 The nedm search Adrian SIGNER I will discuss why we theorists always knew that you wouldn't find a non-vanishing nedm. Just in case you will measure one, it will also be discussed, why we theorists always knew that you would eventually find a non-vanishing nedm. 22

23 The nedm search Neutrons reflected for all incidence angles: UCNs 23 Interactions Kinetic energy Energy 1T Energy 1m Fermi potential β decay 0 nev 0 nev 0 nev 0 nev 886 s Can be stored! g λn>>2 Å : Neutrons see the Fermi potential

24 The nedm search 24 In vacuum? In He? R. Golub and J. M. Pendlebury, Phys. Lett. 62A (1977) 337.

25 A nedm apparatus T h e n E D M B > E 25 B d > m > > E d m First limitation.. Magnetic field fluctuations

26 A nedm apparatus Mercury co-magnetometer (1998) First limitation.. Magnetic field fluctuations 26

27 A nedm apparatus A completely new experiment or an old one? 27

28 A nedm apparatus Geometrical phase shift Motional (transverse) field 28 Hg comagnetometer Magnetic transverse field Frequency shift correlated with electric field False EDM for Mercury (fast regime of GPE) Pendlebury et al, PRA (2004) S. Afach et al, EPJD 69, 225 (2015) Measurement of a false electric dipole moment signal from 199Hg atoms exposed to an inhomogeneous magnetic field

29 A nedm apparatus 29 A non perfect Co-magnetometer Gravitational shift G In the precession chamber UCNs g Mercury PSI 2012 B0 up 2 f γ B Δ h BT R= UCN = γ n ( ) Hg f Hg z B 0 2 B 0 2 Δh=2.7 mm S. Afach et al., PLB 739, 128 (2014) B0 down

30 A nedm apparatus 30 The analysis strategy (RAL/Sussex/ILL like) and associated systematic errors Geometrical phase shift: frequency shift for particles in traps (large for the Hg atoms) EDM B down B up

31 Some results 31

32 Some results 32 S. Afach et al., PLB 739, 128 (2014)

33 Some results 33 S. Afach et al., PLB 745, 58 (2015)

34 Towards the neutron EDM 34 Gravitational enhanced depolarization and associated frequency shift P. G. Harris et al., Phys. Rev. D 89, , (2014) Also slower UCNs depolarize faster and contribute less to the measured frequency

35 Towards the neutron EDM 35 gz PRL 115, (2015)

36 RAL-Sussex-ILL limit revised 36 The strategy is validated J. M. Pendlebury et al. Phys. Rev. D 92, Published 4 November 2015

37 Towards the neutron EDM 37 RAL/Sx/ILL* 2015 best avg best avg best avg Tfree Tduty α E-field Neutrons ( -26ecm) PSI 2013 ( -25ecm) Cumulated sensitivity 1.7 * -26 e.cm 2015: 124 days of nedm data Sensitivity Stat Syst Tot RAL-Sussex-ILL (2015) PSI (2015)

38 Towards n2edm 38 Anticipated sensitivity e.cm / day e.cm / 4 years Two UCN precession chambers with opposite electric field directions Improved magnetometry Hg laser read out of Hg-FID to avoid light shift Cs vectorial 3He free from geometrical phase shift

39 The nedm search T h e n E D M 39 B0 B > E B d > m > > E d m

40 The nedm search 40 f1 fn S p in -U p N e u tro n C o u n ts The Ramsey s method of separated oscillating fields x x x x Resonant freq x = working points 30.1 Applied Frequency (Hz)

41 A nedm apparatus 41 Magnetic stability Afach et al., J. Appl. Phys. 116, 0845 (2014) Active compensation Improved degaussing procedure Temperature stabilization New current source

42 A nedm apparatus 42 Magnetic stability Active compensation Improved degaussing procedure Temperature stabilization New current source

43 Neutron EDM Upper Limit [ecm] The nedm landscape ORNL, Harvard MIT, BNL LNPI Sussex, RAL, ILL Supersymmetry predictions Standardmodel calculations Year of Publication

44 Neutron EDM Upper Limit [ecm] The nedm landscape ORNL, Harvard MIT, BNL LNPI Sussex, RAL, ILL Supersymmetry predictions Standardmodel calculations Year of Publication

45 The nedm landscape 45 Neutron EDM Upper Limit [ecm] SM predictions (strong sector) Strong CP problem ORNL, Harvard MIT, BNL LNPI Sussex, RAL, ILL QCD < - orders of magnitude Supersymmetry predictions -28 SM predictions (weak sector) Standardmodel calculations Phase in the CKM matrix -31 Year of Publication 2020

46 A nedm apparatus 46 Magnetic stability Vertical gradient ~ 2 pt/cm daily variation

47 The EDM landscape Adrian SIGNER I will discuss why we theorists always knew that you wouldn't find a non-vanishing nedm. Just in case you will measure one, it will also be discussed, why we theorists always knew that you would eventually find a non-vanishing nedm. 47

48 The nedm search SV-shutter heavy water moderator thermal neutrons 3.6m3 D2O pulsed 1.3 MW p-beam 600 MeV, 2.4 ma, 1% duty cycle tank cryo-pump UCN guides towards experimental areas 8.6m(S) / 6.9m(W) 7m DLC coated UCN storage vessel height 2.5 m, ~ 2 m3 48 cold UCN-converter ~30 dm3 solid D2 at 5 K spallation target (Pb/Zr) (~ 8 neutrons/proton)

49 The EDM landscape 49 C. R. Physique (2012)

50 A nedm apparatus 50 A non perfect Co-magnetometer Gravitational shift G In the precession chamber UCNs g Mercury PSI 2012 B0 up =2,7 mm B0 down

51 A nedm apparatus 51 A non perfect Co-magnetometer Gravitational shift Adiabatic vs Non-adiabatic field sampling UCNs: Adiabatic regime 199 Hg: Non-adiabatic regime Field map using fluxgate

52 A nedm apparatus 52 A non perfect Co-magnetometer Gravitational shift Adiabatic vs Non-adiabatic field sampling Geometrical phase shift Motional (transverse) field Frequency shift correlated with electric field False EDM for Mercury (fast regime of GPE) Pendlebury et al, PRA (2004) Magnetic transverse field

53 A nedm apparatus 53 The analysis strategy (RAL/Sussex/ILL like) and associated systematic errors Geometrical phase shift: frequency shift for particles in traps (large for the Hg atoms) EDM B down B up And any shift of the neutron and/or Hg precession frequency linear with the E-field Direct systematic effect

54 A nedm apparatus 54 The analysis strategy (RAL/Sussex/ILL like) and associated systematic errors Geometrical phase shift: frequency shift for particles in traps (large for the Hg atoms) EDM B down B up In the case of an inhomogeneous B-field At 1st order in gradients Pignol et al, PRA (2012) Indirect systematic effect due to local dipoles

55 A nedm apparatus 55 The analysis strategy (RAL/Sussex/ILL like) and associated systematic errors Geometrical phase shift: frequency shift for particles in traps (large for the Hg atoms) Residual systematic effect if different for B up and down EDM Indirect systematic effect B down R B up

56 Some results 56

57 Some results 57

58 Some results 58

59 Some results 59 Transverse component? Gravitational?

60 Some results 60 Gravitational enhanced depolarization and associated frequency shift P. G. Harris et al., Phys. Rev. D 89, , (2014) Transverse component? Gravitational?

61 Some results 61 gz Impact for the nedm limit Impact for the neutron lifetime

62 Some results 62 Final result to appear in Phys. Rev. D

63 Some results /06/13 avg good E-field (kv/cm).3 11 Neutrons Tfree Tduty Α /22/13 06//14 12/27/14 07/15/15 01/31/16 PSI 15 best 0 PSI 14 avg Integrated sensitivity (-26 e.cm) Integrated sensitivity (-26 e.cm) PSI Blinded data /15/15 08/04/15 08/24/15 09/13/15 /03/15 /23/ Only

64 Some results 64 New limit in 2016? 1 05/06/13 avg good E-field (kv/cm).3 11 Neutrons Tfree Tduty Α /22/13 06//14 12/27/14 07/15/15 01/31/16 PSI 15 best 0 PSI 14 avg Integrated sensitivity (-26 e.cm) Integrated sensitivity (-26 e.cm) PSI Blinded data /15/15 08/04/15 08/24/15 09/13/15 /03/15 /23/ Only

65 Summary 65 Magnetic field Cs and Hg magnetometers are complementary Coherent picture for the magnetic field Improved control on systematics effects By-product: measurement of Hg and neutron gyromagnetic ratios nedm We are taking data with a high sensitivity We expect with 300 data-days until 2016 : statistical sensitivity of σ -26 e cm n2edm in R&D phase towards e.cm Thanks Merci

66 Towards n2edm ℏ σ(d n ) = 2αET N Anticipated sensitivity e.cm / day 66 work on improving (α,e,t,n) parameters e.cm / 4 years

67 The collaboration 2007 A growing team getting oversea