Search for the nEDM at the Paul Scherrer Institute Outlines 2 - - PowerPoint PPT Presentation

Search for the nEDM at the Paul Scherrer Institute

• S. Roccia, on behalf of the nEDM collaboration at PSI

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Outlines

ILL 1979-2009 PSI 2020-???? PSI 2009-2017 OILL n2EDM OILL RAL/Sussex/ILL collab. dn<3.10-26 e.cm (2006) EDM, ALP, mirror neutrons Co-magnetometer era Co-magnetometer + magnetometer era

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Standardmodel calculations

ORNL, Harvard MIT, BNL LNPI Sussex, RAL, ILL

Neutron EDM Upper Limit [ecm]

Year of Publication Supersymmetry predictions

SM predictions (strong sector) 10 orders of magnitude SM predictions (weak sector) Strong CP problem

QCD < 10-10

Phase in the CKM matrix

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The nEDM landscape

Beyond SM + cosmology

A nonzero particle EDM violates T, P and, assuming CPT conservation, also CP.

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> > > > T h e n E D M B0

E B m

d

E B m

d

Neutrons reflected for all incidence angles: UCNs

The nEDM search

See poster by N. HILD

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The Ramsey’s method of separated oscillating fields

29.7 29.8 29.9 30.0 30.1 10000 12000 14000 16000 18000 20000 22000 24000 x x

x = working points

Resonant freq.

x x

Spin-Up Neutron Counts Applied Frequency (Hz)

The nEDM search

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The nEDM search

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The nEDM search First limitation ….. Magnetic field fluctuations

Mercury co-magnetometer (1998) Cesium magnetometer array (2009)

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The nEDM search

• Excellent stability

(dynamic SFC & 4 layer magnetic shield)

• Stability (AD) @400s: ~<400fT

Afach et al., J. Appl. Phys. 116, 084510 (2014)

Stabilisation of the ambient field ~ 100 nT Stabilisation of the inner field ~ 100 pT

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The nEDM search 1.6pT 1 p T 3.5 days

The Hg co-magnetometer

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The nEDM search

Monitoring of the vertical gradient Homogenisation of the magnetic field

A nEDM apparatus

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g UCNs Mercury In the precession chamber PSI 2012 B0 up B0 down G

A non perfect Co-magnetometer

• Gravitational shift

Some results

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• S. Afach et al., PLB 739, 128 (2014)

The nEDM apparatus

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Geometrical phase shift Motional (transverse) field Magnetic transverse field Frequency shift correlated with electric field False EDM for Mercury (fast regime of GPE)

Pendlebury et al, PRA 70 032102 (2004)

Hg comagnetometer

• S. Afach et al, EPJD 69, 225 (2015)

See Poster by L. FERRARIS-BOUCHEZ At 1st order in gradients

A nEDM apparatus

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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) At 1st order in gradients Indirect systematic effect due to local dipoles In the case of an inhomogeneous B-field

Pignol et al, PRA 85 042105 (2012)

B down B up EDM

Some results

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Gravitational enhanced depolarization and associated frequency shift

• P. G. Harris et al., Phys. Rev. D 89, 016011, (2014)

Gravitational depolarization of ultracold neutrons: Comparison with data, Phys Rev D 92,5 (2015)

Some results

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gz Spin-echo spectroscopy See poster by

• G. ZSIGMOND

Physical review letters 115 (16), 162502 (2015)

Some results

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Physical Review D 92 (9), 092003 (2015)

nEDM@ILL 2006 nEDM@PSI 2016 n2EDM@PSI 2020 Chamber 1 1 2 Diameter (cm) 47 47 100 Neutron/cycle 14 000 15 000 400 000 E(kV/cm) 8.3 11 (15) 15 T(s) 130 180 180 α 0.45 (0.6) 0.75 (0.80) 0.8 Sens/day(e.cm) 30*10-26 11*10-26 1.4*10-26 Sens (500 days) 1.3*10-26 5.0*10-27 6.4*10-28 Statistical sensitivity

nEDM sensitivity

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World record for sensitivity Pushing the limit of the technique at room temperature

2016 : 1.5 % of available pulses missed

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2016 + 2015: data taking

2015: 112 days 2016: 139 days

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On-going analysis (preliminary)

• Blinded data
• 2 analysis teams (East/West)

2016 + 2015: data taking

Demonstrated sensitivity after analysis (2015-2016) PRELIMINARY & BLINDED *

* but systematic effects

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EDM by product

• C. Abel et al. (RAL-Sussex-ILL collab. + PSI

collab + King’s College London)

Physical Review X 7, 041034 (2017)

PSI data: high sensitivity Still blinded ILL data: long data taking Another result to come (2017 data taking) : see poster by P. MOHANMURTHY

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n2EDM

ILL 1979-2009 PSI 2020-???? PSI 2009-2017 OILL n2EDM OILL RAL/Sussex/ILL collab. dn<3.10-26 e.cm (2006) EDM, ALP, mirror neutrons Co-magnetometer era Co-magnetometer + magnetometer era

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n2EDM

ILL 1979-2009 PSI 2020-???? PSI 2009-2017 OILL n2EDM OILL RAL/Sussex/ILL collab. dn<3.10-26 e.cm (2006) EDM, ALP, mirror neutrons Co-magnetometer era Co-magnetometer + magnetometer era D

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b l e c h a m b e r e r a P N P I & I L L

nEDM@ILL 2006 nEDM@PSI 2016 n2EDM@PSI 2020 Chamber 1 1 2 Diameter (cm) 47 47 80 Neutron/cycle 14 000 15 000 121 000 E(kV/cm) 8.3 11 (15) 15 T(s) 130 180 180 α 0.45 (0.6) 0.75 (0.80) 0.8 Sens/day(e.cm) 30*10-26 11*10-26 2.6*10-26 Sens (500 days) 1.3*10-26 5.0*10-27 1.2*10-27

nEDM sensitivity: looking backward and going forward

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See poster by D. VICENTE PAIS See poster by

• G. ZSIGMOND

1.5*10-27

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Hg co-magnetometer nEDM sensitivity: 50-70 fT (35 fT) n2EDM requirements: 26 fT

R&D towards n2EDM

Demonstrated sensitivity: 8 fT Used for nEDM data taking in 2017 But also new current source Using a potassium magnetometer → see poster by P. Koss

June 2018 installation of the shielded room

2017&2018: Hard work in the UCN hall

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See n2EDM poster by B. LAUSS See poster by P. Flaux

Merci !

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Thanks Merci

Summary

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• n2EDM R&D efforts merged into one concept design
• Highly based on demonstrated techniques
• Shielded room expected in 2018
• nEDM operated with high efficiency and world-record sensitivity
• Systematic effect studies reanalysis of 2006 data
• More data in 2017 for by products