Laser Cooling of Ra ions for Atomic Parity Violation - PowerPoint Presentation

Slide1

Laser Cooling of Ra ions for Atomic Parity Violation

CERN-INTC-2017-069 CERN, June 27, 2017Lorenz Willmann

Slide2

CERN-INTC-2017-069

Slide3

The Weinberg AngleAtomic Parity Violation

Slide4

Kumar, Marciano,

Annu

. Rev. of

Nucl

. Part. Sci.

63,

237 (2013)

Davoudiasl, Lee, Marciano, Phys. Rev. D 89, 095006 (2014); Phys. Rev. D 92, 055005 (2015)

Atomic

parity violation

(APV)

sin

2

(θW) = (1 – (MW/MZ)2) + rad. corrections + New Physics

Standard Model

Slide5

F. Maas,

PSI2016

Cs

Ra

+

Slide6

Cs

Atomic Parity Violation

Stark induced

forbidden transition

(C.

Wieman

et al. 1985-1996)

Slide7

Single Ion APV

Experimental Method

Slide8

Weak Interaction in Atoms

Interference of EM and Weak interactionsE1PNC = Kr

Z

3

Q

w = Kr

Z3 (- N + Z (1-4sin

2 θW

))

Atomic Theory

Measurement

Heavy System

Slide9

Relativistic coupled-cluster (CC)

calculation of E1

APV

in Ra

+

E1

APV = 46.4(1.4) · 10-11 iea0

(−Qw/N) (3% accuracy)

Other results:

45.9 · 10-11 iea0

(−Qw/N) (R. Pal

et al., Phys. Rev. A 79

, 062505 (2009), Dzuba et al., Phys Rev. A 63, 062101 (2001).)Scaling of the APV

increase faster than Z3 (Bouchiat & Bouchiat, 1974)

K

r

relativistic enhancement factor

Atomic Number

Z

3

Ba

+

Sr

+

Ca

+

Ra

+

Z

3

K

r

Ra

+

effects

larger by:

20 (Ba

+

)

50 (Cs)

Enhancement

L.W. Wansbeek

et al.

,

Phys. Rev. A

78

, 050501 (2008)

Slide10

Experiment requires Trapping

Differential Light shift

Energy splittings

not to scale

N.

Fortson

,

Phys

. Rev.

Lett

. 70, 2383-2386 (1993)

Slide11

Trapping Ra ion

Previous Work

Slide12

Radium Isotopes

206

Pb beam

12

C target

TRI

μ

P separator

Thermal ionizer

206

Pb +

12

C

ARa + (218-A) nTo RFQ (Paul trap)Rate after TI

TRImP@KVI

Sources

or

fragmentation

Δ

N

<10

225

Ra

extraction

from

229

Th source (

ANL)

Long

lived

229

Th source in an oven (

TRI



P)

Other Isotopes

Online production at accelerator

facilities

e.g.

TRI



P

(

flux

>

10

5

/s

) (until 2013)

ISOLDE ( flux <

107/s)

Slide13

Trapped

Ra

+

Spectroscopy

7S

1/2

6D

3/2

6D

5/2

1079

n

m

468 nm

7P

1/2

7P

3/2

708

n

m

Radiofrequency Quadrupole (RFQ)

Level Scheme of Ra

+

Slide14

O. O

Versolatao et. al., Phys.

Lett

. A

375 (2011) 3130–3133

G. S.

Giri

et al. Phys. Rev. A 84, 020503(R) (2011)[10] B.K. Sahoo

et al. Phys. Rev. A, 76 (2007

) B.K. Sahoo

et al. Phys. Rev. A, 79, 052512 (2009

)

Hyperfine Structure

of 6d 2D3/2 in Ra+

̴̴ 3,5 σ

Probe of atomic wave functions at the origin

Probe of atomic theory & size and shape of the nucleus

Slide15

Isotope Shifts:

Atomic theory & size and shape of the nucleus

Hyperfine

Structure:

Atomic wave functions at the origin

State lifetime:

Probe of S-D E2 matrix element

agreement with

atomic structure calculations at

% level

Summary

Ra

+

M

easurements

Slide16

Complementary Radium experiments Atomic Properties

Slide17

Activity at CERN/ISOLDE

Slide18

muX@PSI

Radium Charge RadiumBeamtime to improve sensitivity of muonic

x-ray

measurements

this summer

Slide19

Barium IonBa

+ Atomic Parity Violation

Slide20

Hyperbolic

Single Ion

Trap

10µm

Slide21

21

V

RF

5 mm

138

Ba

+

494 nm

650 nm

2

S

1/2

2

D

3/2

2

D

5/2

2

P

1/2

2

P

3/2

Hyperbolic Paul trap

Slide22

650 nm laser frequency (MHz)

EMCCD

PMT

138

Ba

+

494 nm

650 nm

2

S

1/2

2

D

3/2

2

D

5/2

2

P

1/2

2

P

3/2

Ion trap

Lasers

Detection

Slide23

Importance of Line

Shape

Δ

1

,

Δ

2

laser

detunings

Ω

1

,

Ω2

Rabi frequencies(laser power)

Γ

=

Γ

1

+

Γ

2

relaxation rate

γ

=

Γ

/2

decoherence

rate

γ

c

laser linewidth

Optical Bloch equation

3 level example

Ba

+

|

2

S

1/2

⟩

Δ

1

Δ

2

γ

γ

γ

c

|

2

P

1/2

⟩

|

2

D

3/2

⟩

Γ

1

Γ

2

|1

⟩

|2

⟩

|3

⟩

|4

⟩

|5

⟩

|6

⟩

|7

⟩

|8

⟩

Ω

2

Ω

1

Slide24

Ba

+

2

P

3/2

2

P

1/2

2

D

3/2

2

S

1/2

494

nm

650

nm

2

D

5/2

494

nm

650

nm

Frequency 650 nm laser − 461 311 000

MHz

650 nm laser intensity varied

Frequency 650 nm laser − 461 311 000

MHz

494 nm laser detuning varied

Dijck

et al., Phys. Rev. A

91

, 060501(R) (2015)

Fitted with optical Bloch equation model

Extract transition frequencies with 100 kHz accuracy

Transition frequencies

Slide25

Ba

+

2

P

3/2

2

P

1/2

2

D

3/2

2

S

1/2

494

nm

650

nm

2

D

5/2

494

nm

650

nm

Frequency 650 nm laser − 461 311 000

MHz

650 nm laser intensity varied

Dijck

et al., Phys. Rev. A

91

, 060501(R) (2015)

Fitted with optical Bloch equation model

Extract transition frequencies with 100 kHz accuracy

B

-field

rotated

2

°

1

2

0

One-photon peak

frequency (MHz)

3

4

5

461 311 878.0

878.5

879.0

879.5

Expected

Power 650 nm laser (

Ω

2

/

Ω

2,sat

)

2

2

Light shift?

Correction in transition frequencies

for

Ω

2

dependent shift consistent with

2° rotation of

B

-field

Transition frequencies

Slide26

Summary

Atomic Parity Violation

Slide27

Accuracy

of

Single

Ion

Experiment

If

coherence time can be fully

exploited

Slide28

Ratio measurement

Insensitivity of Ratio of measurements of E1APV for isotopes to atomic structure.

Best case scenario:

For radium a wide range of isotopes is available

V. A. Dzuba

, V. V. 

Flambaum

, and I. B. 

Khriplovich

, Z. Phys. D,

1

, 243 (1985)

Slide29

Laser Cooling of Ra ions for

Atomic Parity Violation

 

D

eveloping

experimental setup

A

tomic

properties determination

Light shifts and Line shapes

Atomic Properties from online produced radium

Trapping and laser spectroscopy done at TRImP

Activity on Ra

+ colinear spectroscopy (ISOLDE)Muonic Radium experiments for charge radiusBa+Ra+Atomic Parity Violation:

ISOLDEIon trapping permits access to many transitionsLaser cooling for precisionAvailability of a large range of Ra isotopesLab with experience of precision lasers experiments at acceleratorsBuilding up of a collaboration

Frequency 650 nm laser − 461 311 000 MHz