How to detect dark matter? Part 2 MARIANNA MARIANNA MARIANNA - - PowerPoint PPT Presentation

MARIANNA MARIANNA MARIANNA MARIANNA SAFRONOV A SAFRONOV A SAFRONOV A SAFRONOV A

Summer school Search for new physics with low-energy precision tests June 2019, Ameland Netherlands

How to detect dark matter? Part 2

10 10 10 10-

• 22

22 22 22 eV 10

eV 10 eV 10 eV 10-

• 12

12 12 12 eV

eV eV eV µ µ µ µeV eV eV eV eV GeV eV GeV eV GeV eV GeV

How to detect ultralight dark matter?

Ultralight dark matter has to be bosonic – Fermi velocity for DM with mass >10 eV is higher than our Galaxy escape velocity. Bosonic dark matter (DM) with mass mφ < 1eV Dark matter density in our Galaxy > where is the de Broglie wavelength of the particle. Then, the dark matter exhibits coherence and behaves like a classical field.

3 dB

λ −

dB

λ

Such DM classical field can:  Cause precession of nuclear and electron spins  Drive currents in electromagnetic systems  Induce equivalence principle-violating accelerations of matter  Modulate the values of the fundamental constants of nature, inducing changes in atomic transition frequencies and local gravitational field.

Effects of ultralight DM on standard model particles

Signal is line at frequency = DM mass and width 10-6

2 6

v 10 c

−

  ≈    

Interactions of bosonic ultralight dark matter

• M. S. Safronova, D. Budker, D. DeMille, Derek F. Jackson-Kimball,
• A. Derevianko, and Charles W. Clark, Rev. Mod. Phys. 90, 025008 (2018).

DM: SM: are

Current experimental efforts in searches for bosonic ultralight dark matter

Spin

0 S 0 PS 1 V 1 AV HAYSTAC

• M. S. Safronova, D. Budker, D. DeMille, Derek F. Jackson-Kimball,
• A. Derevianko, and Charles W. Clark, Rev. Mod. Phys. 90, 025008 (2018).

The Axion

θ

(think)

T T CP

Slide from: Karl van Bibber, GPMFC workshop

S = 0 pseudoscalar

γ∗

Sea of virtual photons

≡

∴

γ

a Primakoff Effect

B

Classical EM field

Magnet

The Primakoff Effect P. Sikivie, Phys. Rev. Lett. 51 (1983) 1415 the

Slide from: Karl van Bibber, GPMFC workshop

The microwave cavity axion search -Your car radio on steroids

×

FFT Local Oscillator Preamplifier Magnet Cavity

a γ γ∗

Power Frequency f = mac2 / h

∆f / f ~ 10–6

For e.g., ma = 10 µeV : ρa ~ 1014 cm–3 λDeB ~ 100 m Slide from: Karl van Bibber, GPMFC workshop

How to go higher & lower in frequency (mass) Size & geometry of the cavity determines the frequency of the microwave cavity experiment

Natural scale is cavities of diameter 50 – 5 cm ~ 0.5 GHz – 5 GHz, or 2 – 20 µeV mass

To go lower in frequency, a lumped-parameter LC circuit allows one to decouple the dimension of the cavity from the frequency

LC, DM Radio

To go higher in frequency, an open (Fabry-Perot) resonator is much more natural than cavities

ORPHEUS, MADMAX

Slide from: Karl van Bibber, GPMFC workshop

Slide from Peter Graham

Slide from Peter Graham

DARK MATTER SEARCHES WITH ATOMIC CLOCKS

How do fundamental constants vary?

Slow drifts Transient variations

Topological dark matter

Oscillations Stochastic

Dilaton dark matter or axion-like particles Dark energy?

• A. Derevianko, Conf. Ser. 723 (2016) 012043

Ultralight dark matter

• A. Arvanitaki et al., PRD 91, 015015 (2015)

Dark matter coupling to the Standard Model photons gluons electrons quarks Dark matter Measure: couplings di vs. DM mass

Ultralight dark matter searches with clocks

Comparing frequencies of hyperfine to optical clocks Comparing frequencies of optical to optical clocks

2 K q E =

2 2

1 E E α α   = + −     q

Enhancement factor

Dark matter

Measuring ratios of optical clock frequencies for dark matter detection

Need:

• Best short-term stability σ

σ σ σ1 at ∆τ ∆τ ∆τ ∆τ

• Long total measurement time to improve sensitivity

But: only until you reach the DM coherence time

• Lowest systematic uncertainty
• Largest possible enhancement factor combination (K2-K1)

Ultralight dark matter

Dark matter parameters

One oscillation per 11 days One oscillation per second

DM virial velocities ~ 300 km/s

Clock measurement protocols for the dark matter detection

Make N such measurements, preferably regularly spaced Single clock ratio measurement: averaging over time τ1

• A. Arvanitaki et al., PRD 91, 015015 (2015)

∆τ τint Detection signal:

A peak with monochromatic frequency in the discrete Fourier transform of this time series.

Clock measurement protocols for the dark matter detection

Make N such measurements, preferably regularly spaced Single clock ratio measurement: averaging over time τ1

• A. Arvanitaki et al., PRD 91, 015015 (2015)

∆τ τint Detection signal:

A peak with monochromatic frequency in the discrete Fourier transform of this time series.

No more than one dark matter oscillation during this time or use extra pulse sequence Al least one dark matter oscillation during this time

Dy: K. Van Tilburg, N. Leefer, L. Bougas, and D. Budker, Phys.

• Rev. Lett. 115, 011802 (2015).

Rb/Cs: A. Hees, J. Guéna, M. Abgrall, S.Bize,and P. Wolf,

• Phys. Rev. Lett. 117, 061301 (2016)

Experimental results

From PRL 120, 141101 (2018)

From PRL 120, 141101 (2018)

?

Projected clock limits

• A. Arvanitaki et al., PRD 91, 015015 (2015)

Sr optical clock vs. silicon cavity project limits

Dark matter clumps: point-like monopoles,

• ne-dimensional strings or two-dimensional

sheets (domain walls). If they are large (size of the Earth) and frequent enough they may be detected by measuring changes in the synchronicity of a global network of atomic clocks, such as the Global Positioning System.

Transient variations

GPM.DM collaboration: Roberts at el., Nature Communications 8, 1195 (2017)

Global sensor network. The participating Sr and Yb optical lattice atomic clocks reside at NIST, Boulder, CO, USA, at LNE-SYRTE, Paris, France, at KL FAMO, Torun, Poland, and at NICT, Tokyo, Japan

Wcisło et al., Sci. Adv. 4: eaau4869 (2018)

Constraints on the coupling of dark matter to electromagnetism. The energy scale Λ which inversely parametrizes the strength of the DM-SM coupling as a function of the wall width d.

Wcisło et al., Sci. Adv. 4 (2018)

• 1. Improve uncertainties of current clocks – [????] more orders.
• 2. Improve stabilities of the clock ratio measurements

(particularly with trapped ion clocks). Clock sensitivity to all types of the searches for the variation

• f fundamental constants, including dark matter searches

require as large enhancement factors K to maximize the signal.

• 3. Build new clocks based on different systems
• a. Highly-charged ions
• b. Nuclear clock
• c. New Yb two-transition clock scheme
• d. Molecular clocks

How to improve laboratory searches for the variation of fundamental constants & dark matter?

The Future Advances in Atomic Clocks

Orders of magnitude improvements with current clocks

Large ion crystals Ion chains 3D optical lattice clocks Measurements beyond the quantum limit Entangled clocks

Image credits: NIST, Innsbruck group, MIT Vuletic group, Ye JILA group

The Future: New Atomic Clocks

Nuclear clock Clocks with ultracold highly charged ions First demonstration of quantum logic spectroscopy at PTB, Germany

Science 347, 1233 (2015)

Nuclear clock

Science 347, 1233 (2015)

229mTh 229Th

Nuclear transition 160(10) nm Lifetime ~ 5000s

Only 7.8eV energy of a nuclear transition (laser-accessible) ! Existence of this isomer 229mTh state was confirmed: Wense et al., Nature 533, 4751 (2016) Laser spectroscopic characterization of the nuclear clock isomer 229mTh (measured isomer nuclear radius and quadrupole moment): Thielking et al., Nature 556, 321(2018) Nuclear charge radii of 229Th from isotope and isomer shifts: Safronova et al., Phys. Rev.

• Lett. 121, 213001 (2018).

Then, possible 4-5 orders of magnitude enhancement to the variation of α and but orders of magnitude uncertainty in the enhancement factors.

Th nuclear clock

Large (MeV) Coulomb energy difference compensated by MeV difference in the nuclear binding energy?

q QCD

m Λ

Provides access to couplings of Standard Model particles to dark matter via other terms besides the de (E&M).

It is crucial to establish actual enhancement!

229mTh 229Th

Nuclear transition 160(10) nm Lifetime ~ 5000s

• M. G. Kozlov, M. S. Safronova, J. R. Crespo López-Urrutia, P. O. Schmidt,
• Rev. Mod. Phys. 90, 45005 (2018).

Great potential for AMO dark matter searches. Many new developments coming in the next 10 years!

A recent explosion of new proposals for dark matter searches at all masses!

NEW IDEAS?