Frascati 17/12/2015 Javier Redondo Universidad De Zaragoza (Spain) Max Planck Institute Für Physik Overview

Axions, Astrophysics and Dark matter

Frascati 17/12/2015 Javier Redondo Universidad de Zaragoza (Spain) Max Planck Institute für Physik Overview

- Strong CP problem

- Axions

- Axions and stars

- Axion Dark matter

- Dark matter experiments Parity and Time reversal in particle physics (electroweak interactions)

P-violation (Wu 56) T-violation (CPLEAR 90’s)

R(K¯ 0 K0) R(K0 K¯ 0) ! ! R(K¯ 0 K0)+R(K0 K¯ 0) 60% ! !

40% ... but not in the strong interactions many theories based on SU(3)c (QCD)

1 ↵ = G Gµ⌫ + iq¯µD q qmq¯ + s ✓G Gµ⌫ LQCD 4 µ⌫a a µ 8⇡ µ⌫a a q X e P,T conserving P,T violating

we tend to forget this

↵s µ⌫ ✓Gµ⌫aGa induces P and T (CP) violation ✓ 8⇡ / e ✓ ( ⇡, ⇡) inﬁnitely versions of QCD... all are P,T violating 2 Neutron EDM

15 Most important P, T violating observable dn ✓ (10 )e cm ⇠ ⇥ O ✓ (1) ⇠ O

EDM violates P,T The theta angle of the strong interactions - The value of ✓ controls P,T violation in QCD

✓ ⇡ ⇡ 0 n n n n¯ n¯ n¯

10 Measured today ✓ < 10 | | (strong CP problem) Roberto Peccei and Helen Quinn 77 QCD vacuum energy minimised at theta = 0 - ... if ✓ ( t, x ) is dynamical ﬁeld, relaxes to its minimum Energy generated by QCD!

✓ ⇡ ⇡ 0 n n¯

10 Measured today ✓ < 10 | | (strong CP problem) ain’t you forgetting something?

P. Higgs and a new particle is born ... - if ✓ ( t, x ) is dynamical ﬁeld Energy generated by QCD!

✓ ⇡ ⇡ 0 Field Excitations around the vacuum are particles

clears the strong CP problem it’s a higgslet! like my favorite soap

S. Weinberg F. Wiczek and a new particle is born ... the axion - if ✓ ( t, x ) is dynamical ﬁeld Energy generated by QCD!

✓ ⇡ ⇡ 0 Field Excitations around the vacuum are particles

clears the strong CP problem it’s a higgslet! like my favorite soap and a new scale sets the game, fa - kinetic term for ✓ requires a new scale Energy generated by QCD!

✓ = a/fa ⇡ ⇡ 0 ↵ 1 = s G Gµ⌫ ✓ + (@ ✓)(@µ✓)f 2 L✓ 8⇡ µ⌫a a 2 µ a e ↵s µ⌫ a 1 µ ✓ = Gµ⌫aGa + (@µa)(@ a) L 8⇡ fa 2 e Axion couplings at low energy - From ✓ -term, axion mixes with eta’ and the rest of mesons

↵s µ⌫ a 1 µ ✓ = Gµ⌫aGa + (@µa)(@ a) L 8⇡ fa 2 e a ⌘0

fa Axion couplings at low energy Mass 9 f⇡ 10 GeV ma m⇡ 6 meV ' fa ' fa hadrons, Photons 1 1 a a fa fa

Leptons (in some models)

1 a fa

The lighter the more weakly interacting Axion Landscape

f v fa vEW a EW ⇠ Invisible models PQWW models

Reactors Had. dec Simple model KSVZ

- Peccei-Quinn symmetry, color anomalous, spontaneously broken at fa = + iQDQ¯ (yQ¯ Q +h.c) 4 + µ2 2 L LSM L R | | | | i a(x) (x)=⇢(x)e fa a f ~ 1 2 ↵s a - At energies below f a (SSB) (@a) + GG L 2 2 8⇡ fa

0 e - At energies below ⇤ QCD , a ⌘ 0 ⇡ ⌘ ... mixing ~GeV

9 m⇡f⇡ 10 GeV axion mass ma 6meV ' fa ⇠ fa

¯ µ a ↵ µ⌫ a couplings a,I = cN,aN 5N + ca Fµ⌫ F + ... L fa 2⇡ fa XN nucleons ... photons ... e mesons ... ENERGY DFSZ

- Two Higgs, one new scalar fa 2 2 2 2 Dq¯ H q + Uq¯ H˜ u + ... v + H†H L 2 L d R L u R 4 | | d u axion ✓ ✓ + cos2 ✓ +sin2 ✓ ⇠ d u a f ~ 1 2 ↵s a µ @µa - Below f a (@a) + GG Ng + Cf f¯ 5f L 2 2 8⇡ fa fa Xf e 0 - At energies below ⇤ QCD , a ⌘ 0 ⇡ ⌘ ... mixing ~GeV

9 m⇡f⇡ 10 GeV axion mass ma 6meV ' fa ⇠ fa

¯ µ a ↵ µ⌫ a couplings a,I = cN,aN 5N + ca Fµ⌫ F + ... L fa 2⇡ fa XN nucleons ... photons ... e mesons ... ENERGY Axion Couplings and some models

2 photon proton neutron electron

µ⌫ ↵s µ⌫ ↵Ca a Fµ⌫ F a a a ✓Gµ⌫ G +m.d. + Capmp [ip¯5p]+Canmn [in¯5n]+Caeme [ie¯5e]+... 8⇡ ! 2⇡ fa 4 fa fa fa e e p n e a a a p n e

md mu E 2 4md + mu Cap [Cau ]u +[Cad ]d Ca ' mu + md mu + md ' N 3 md + mu md mu Can [Cau ]d +[Cad ]u ' mu + md mu + md

C =0 KSVZ a(u,d,e) Ca 1.92 (-0.5,-0.38) (0.1,-0.04) ~ 0 ' 1 C = sin2 au 3 8 DFSZ1 1 Ca 1.92 C = cos2 ...... a(d,e) 3 ' 3

1 2 Ca(u,e) = sin 2 3 DFSZ2 1 Ca 1.92 ...... C = cos2 ' 3 ad 3 Axion Couplings and some models

2 photon proton neutron electron

µ⌫ ↵s µ⌫ ↵Ca a Fµ⌫ F a a a ✓Gµ⌫ G +m.d. + Capmp [ip¯5p]+Canmn [in¯5n]+Caeme [ie¯5e]+... 8⇡ ! 2⇡ fa 4 fa fa fa e e p n e a a a p n e

md mu 0.4 E 2 4md + mu Cap [Cau ]u +[Cad ]d C ' mu + md DFSZ2mu + md DFSZ a ' N 3 m + m d u md 0.2 mu Can [Cau ]d +[Cad DFSZ1 ]u ' mu + md mu + md Cap 0.0 KSVZ Can C =0 -0.2 KSVZ a(u,d,e) Ca 1.92 (-0.5,-0.38) (0.1,-0.04) ~ 0 ' Cae 1 -0.4 C = sin2 KSVZ au 3 8 DFSZ1 1 Ca 1.92 DFSZ C = cos2 ...-0.6 ...... a(d,e) 3 ' 3 1 2 0.0 0.2 0.4 0.6 0.8 1.0 Ca(u,e) = sin 2 3 DFSZ2 1 Ca 1.92 ...... 2 ... C = cos2 ' 3 cos ad 3 Bounds and hints from astrophysics

- Axions emitted from stellar cores accelerate stellar evolution - Too much cooling is strongly excluded (obs. vs. simulations) - Some systems improve with additional axion cooling!

Tip of the Red Giant branch (M5)

White dwarf luminosity function HB stars in globular clusters

Neutron Star CAS A Tip of the Red Giant branch (M5)

Increase He core until 3alpha ignition (T~8.6 KeV) Globular ClusterM5 s s

H-burning ne

He th ig Br

COLOR Axion emission cools down core, delays ignition

,T , Mcore " H " L " Brighter Helium ﬂash! Strong constraint, small hint! White dwarf luminosity function

C,O

⌫, ⌫¯

- White dwarfs are death stars (sustain no fusion) - ﬁnal phase of intermediate mass stars which cannot fuse C and O (Sun...) - Cool by 1) neutrino emission and 2) by photon surface emission White dwarf luminosity function dN k WD = Vol d d /dt L L White dwarf luminosity function dN k WD = with axion-electron Vol d d /dt + d /dt bremsstrahlung L L La

increase coupling Strong constraint, small hint! Core collapse SN

Iron Core collapse when electron degeneracy pressure The gravitational energy cannot support its grav. pull of the core is mainly to be radiated away in neutrinos core 1.4 E =3 1053 erg M ⇠ M ⇥ ...

10 1 ⌫g,= 10 GeV ⌫¯

Fe n,p Neutrino burst

-Neutrinos TRAPPED -Emitted from neutrino-sphere T~MeV - ~10 sec to cool it down n,p

- Axions (more weakly interacting) - Emitted from the bulk T~tens MeV - can cool much faster! N + N N + N + a Reduction of nu burst ! a p, n

p, n ⇡

ﬁrst approx. (pi pole too hard...)

10 1 g = 10 GeV

Cool the PNS axions are axion production eﬁciently reabsorbed not signiﬁcant reduce the inside the SN neutrino burst! N + N N + N + a Reduction of nu burst ! a

p, n

axion emission is suppressed due to high density effects ! 10 1 g = 10 GeV SN1987A

- Cooling ~ 10 s - Exotics, Eloss/mass and time 19 ✏ . 10 erg/gs - Axion emission . . . T 4 ✏ g2 1.6 1037erg/gs a ⇠ ap ⇥ 30MeV ✓ ◆ - Constraint . . . 9 g 8 10 ap . ⇥ 10 1 g = 10 GeV

- Axions saturating the bound take ~50% Ecore

Diffuse Supernova Axion Background Cassiopeia A: neutron star cooling ⌫¯ - Cooling measured by Chandra, ~4% in ten years! ⌫ n 3 3 - Evidence of ⌫⌫¯ emission in n Cooper pair formation P2 P2 n a n - Factor of ~2 extra cooling required, axions? 3 n P2 Hints, constraints and models ... any preference?

me 13 Tip of the Red Giant branch (M5) gae = Cae =(2 1.5) 10 fa ± ⇥ me 13 White dwarf luminosity function gae = Cae =(1.4 1.4) 10 fa ± ⇥ mn 10 Cassiopeia A: neutron star cooling gan = Can =(3.8 3) 10 fa ± ⇥ mp 10 SN1987A gap = Cap < 0.8 10 fa ⇥

KSVZ (no RG, no WD, no pref.) DFSZ1 DFSZ2

2 Preliminary m 2 u 2

m cos d cos

Preliminary Preliminary

9 9 9 fa/10 GeV fa/10 GeV fa/10 GeV Hints, constraints and models ... any preference? KSVZ (no RG, no WD, no pref.) 0.4 DFSZ DFSZ2 0.2 2 DFSZ1 KSVZ Cap 0.0 Can mu -0.2 Cae md -0.4 KSVZ DFSZ -0.6

Preliminary 0.0 0.2 0.4 0.6 0.8 1.0 cos2 9 fa/10 GeV DFSZ (no RG, no WD, 2 pref.) DFSZ1 DFSZ2

Preliminary 2 2 2 cos cos cos

Preliminary Preliminary

9 9 9 fa/10 GeV fa/10 GeV fa/10 GeV Axion Landscape

Reactors Had. dec Axion Landscape

Excluded Astro-hints?

Reactors Had. dec Detecting Solar Axions : Helioscopes Axions from the Sun

Hadronic axions (KSVZ)

C ↵ F F µ⌫ µ⌫ a 2⇡fa 4 e ga

Non hadronic (DFSZ, e-coupling!)

13 gae = 10 Ceme 12 1 ie¯5ea ga = 10 GeV fa typical of meV mass axions gae Helioscopes

The Sun is a copious emitter of axions! convert into X-rays focus detect

Conversion probability 2g B ! 2 m2L P (a )= a T sin2 a 1 $ m2 4! ga a ⇠ fa ✓ ◆ 2✓ ◆ 20 B L P (a ) 10 $ ⇠ 3T20 m ✓ ◆ CAST Helioscope hadronic axions CAST (LHC dipole 9.3 m, 9T)

PhaseII

PhaseI

- 1~2 h tracking/day (sunset,dawn) non-hadronic axions - 3 Detectors (2 bores) CCD, Micromegas - X-ray optics

PhaseI Next generation (proposed) IAXO

Boost parameters to the maximum Large toroidal 8-coil magnet L = ~20 m 8 bores: 600 mm diameter each 8 x-ray optics + 8 detection systems -NGAG paper JCAP 1106:013,2011 Rotating platform with services -Conceptual design report IAXO 2014 JINST 9 T05002 -LOI submitted to CERN, TDR in preparation

-Possibility of Direct Axion DM experiments (cavities) Physics reach (preliminary)

Hadronic axions (KSVZ) Non hadronic (DFSZ, e-coupling!)

fa[GeV] fa[GeV] 9 8 7 10 10 10 9 8 7 -10 -10 10 10 10 10 10 10-10 10-10 IAXO IAXO ] ae 1 Conservative g Conservative ⇥

- - ] 10 11 10 11 1 10-11 10-11 GeV GeV 10 10 Not so P2 KSVZ P1 KSVZ [10 [10

-12 DFSZ1 -12 -12 -12 a 10 10 a DFSZ1

10 10 g g DFSZ2 q DFSZ2 Not so SN1987A

-13 -13 -13 -13 10 10 10 10 10-3 10-2 10-1 1 10-3 10-2 10-1 1 ma[eV] ma[eV] Possibility to unveal the hints! Axion Landscape

Reactors Had. dec Dark Matters Axions and dark matter - ... if ✓ ( t, x ) is dynamical ﬁeld, relaxes to its minimum Energy generated by QCD!

time

✓(t)=✓0 cos(mat) ⇡ ⇡ 0 Oscillation frequency Coherent oscillations ! = ma = Energy density (harm. oscillator) 1 1 Dark Matter Axions ⇢ = m2f 2✓2 = (75MeV)4✓2 aDM 2 a a 0 2 0 Theta evolution, Averaged SCENARIO I ⇡

✓

⇡ Strings Theta evolution, inﬂated SCENARIO I ⇡

our Universe ✓

One misalignment angle singled out ⇡ Theta evolution, inﬂated SCENARIO I ⇡

our Universe ✓

One misalignment angle singled out ⇡ Axion dark matter

- Axion DM scenarios tuned (anthropic?) ok tuned

Excluded (too much DM) ok sub

Excluded (too much DM) ? tuned

Initial conditions set by : Inﬂation smooth Phase transition (N=1) Phase transition (N>1) 1.19 2 2 80 µeV ⌦aDMh ✓I ' ma strings+unstable DW’s strings+long-lived DWs ✓ ◆ Axion dark matter

- Axion DM scenarios tuned (anthropic?) ok tuned Excluded Excluded (too much DM) ok sub

Excluded (too much DM) ? tuned

Initial conditions set by : Inﬂation smooth Phase transition (N=1) Phase transition (N>1) 1.19 2 2 80 µeV ⌦aDMh ✓I ' ma strings+unstable DW’s strings+long-lived DWs ✓ ◆ Detecting Axions

GeV ⇢ =0.3 aDM cm3

19 ✓ =3.6 10 0 ⇥ Cavities Mirrors LC-circuit

Spin precession Atomic transitions Optical CASPER: Cosmic Axion Spin Precession exPERiment Graham 2012

B~ ext

Spin precesion ! = µ B~ | ext| CASPER : Spin precession Mainz, Berkeley

B~ ext

E~ ⇤ Static EDM, effects cancel in a period

B~ ext - EDM + Large E-ﬁelds in PbTiO3 - Scan over frequencies, with Bext - Mainz (D. Budker’s group) & Berkeley - Phase I starts in 2016, Phase II physics results - Mass range limited by B-ﬁeld strength E~ ⇤ Oscillating EDM, effects add up, transverse magnetisation grows m = ! = µ B~ if a | ext| CASPER : Spin precession Mainz, Berkeley QUAX : electron Spin precession INFN, Legnaro

- Electron coupling in the non-relativistic limit, Electron spin - axion “wind”

= C [¯eµ e]@ ✓ C ( ✓) µ C m ~v ✓ µ Lae ae 5 µ ! ae r · e B ⇠ ae ah i · e B

Effective Magnetic ﬁeld

~ - Use Electron Spin Resonance (similar to NMR but with electrons) ! = µBBext = ma - Bohr magneton much larger, smaller B-ﬁelds required for large axion mass - Short coherence times, radiation damping (R+D) ~ - HF detection ? Use non-linearity and search for LF oscillations ! µB Bext ma ⇠ | | Future sensitivity

Astro-hints? Excluded

osc. EDM QUAX? Detecting axion DM

- Axion DM, ✓ = ✓ 0 cos( m a t ) , in a B-ﬁeld is a source in Maxwell’s eq.

D = ⇢ In a magnetised medium r · f @D ↵ @✓ c ↵✓0B H = Jf c B E(t)= cos(m t) r⇥ @t 2⇡ @t 2⇡✏ a B =0 @B r · + E =0 @t r⇥ Radiation from a magnetised mirror

In a magnetised medium c ↵✓ B E(t)= 0 cos(m t) 2⇡✏ a

Boundary conditions! E =0 || Radiation from a magnetised mirror

c ↵✓ B E(t)= 0 cos(m t) 2⇡✏ a

Boundary conditions! Emitted EM-wave E =0 || c ↵✓0B E = || cos(m (t nx)) 2⇡✏ a B = nsˆ E tan(m (t nx)) ⇥ a Radiation from a magnetised mirror : Power

2 1 2 1 2 P 27 W c B 1 u = ✏ E + B 2 10 || 2 | | µ| | Area ⇠ ⇥ m2 2 5T ✏ ✓ ◆ ✓ ◆

Emitted EM-wave

c ↵✓0B E = || cos(m (t nx)) 2⇡✏ a B = nsˆ E tan(m (t nx)) ⇥ a Cavity experiments

- Haloscope (Sikivie 83) “Amplify resonantly the EM ﬁeld in a cavity”

Signal if tuned ma = !res P P Q ! ⇥ - Slow scan over frequencies - Dominated by thermal+preamp noise

Waves interfere constructively and resonate Cavity experiments ADMX CARRACK (discontinued) CULTASK - CAPP -Korea RADES ADMX-HF ADMX-Fermilab CAST-CAPP Cavity experiments

⌫[GHz] 10-1 1 10 102 103 103 IAXO

102 102 RBF ADMX

10 10 c ADMX-HF

ADMX2 1 Scenario II I 1 CARRACK? ADMX 10-1 10-1 10-7 10-6 10-5 10-4 10-3

ma[eV] LC- circuit Sikivie 2012 - Detect low-frequency B-ﬁeld with a tunable LC - First moves in Florida U.

B v E | a| ⇠h i| a|

Earth-DM relative velocity Axion DM : A developing picture

5th forces? QUAX?

Dielectic mirror

LC CAPP

ADMX osc. EDM ADMX-HF Large freq ... Area vs volume

P E 2A ⇠ | a|

P Q E 2(Vm )  comparable if Q 104 Am2 ⇠ | a| a G ⇠ ⇠ a Mixed scheme?

If we could add the power emitted by many mirrors... Radiation from a dielectric interface ...

c ↵✓0B c ↵✓0B E(t)= cos(mat) E(t)= cos(m t) 2⇡✏ 2⇡ a

Boundary conditions!

E 1 = E 2 || || Radiation from a dielectric interface ...

c ↵✓0B c ↵✓0B E(t)= cos(mat) E(t)= cos(m t) 2⇡✏ 2⇡ a

Boundary conditions! Emitted EM-wave

E 1 = E 2 Emitted EM-wave || || Many dielectrics : MADMAX at MPP Munich

Emitted EM-waves from each interface

... + internal reﬂections ...

- Emission has large spatial coherence; adjusting plate separation -> coherence

2 P 27 W c B 1 2 10 || (!) boost factor Area ⇠ ⇥ m2 2 5T ✏ ⇥ ✓ ◆ - Work in progress at Max Planck Institute fur Physik (Conceptual design)