meV frontier of axion physicsJavier Redondo

(Zaragoza U & MPP)

Invisibles WorkshopIFT, Madrid, 23rd June 2015

The theta angle of the strong interactions

✓0 ⇡�⇡

- The value of controls matter-antimatter differences in QCD

n

n

n

n

✓

n

n

Measured today |✓| < 10�10 (strong CP problem)

Axions

0 ⇡�⇡

time

n

nCoherent oscillations

=Dark Matter Axions

Energy

~ One parameter theory

axion mass✓(t, x) = a(t, x)/fa

ma = 6meV109 GeV

fa

Measured today |✓| < 10�10 (strong CP problem)

- is it a dynamical field? ✓(t,x)generated by QCD!

✓(t) = ✓0 cos(mat)

- Axion DM scenarios

oktuned (anthropic?) tuned

Excluded (too much DM) ok sub

Excluded (too much DM) ? tuned

Phase transition (N=1)strings+unstable DW’s

Phase transition (N>1)strings+long-lived DWs

Inflation smooth⌦aDMh2 ' ✓2I

✓80µeV

ma

◆1.19

Axion dark matter

Initial conditions set by :

- Axion DM scenarios

oktuned (anthropic?) tuned

Excluded (too much DM) ok sub

Excluded (too much DM) ? tuned

Phase transition (N=1)strings+unstable DW’s

Phase transition (N>1)strings+long-lived DWs

Inflation smooth⌦aDMh2 ' ✓2I

✓80µeV

ma

◆1.19

Axion dark matter

Initial conditions set by :

- Axion DM scenarios

oktuned (anthropic?) tuned

Excluded (too much DM) ok sub

Excluded (too much DM) ? tuned

Phase transition (N=1)strings+unstable DW’s

Phase transition (N>1)strings+long-lived DWs

Inflation smooth⌦aDMh2 ' ✓2I

✓80µeV

ma

◆1.19

Excluded

Axion dark matter

Initial conditions set by :

Dark Matterhuge parameter space!

Astro meets cosmo

Axions in stars

Tip of the Red Giant branch (M5)Increase He core until 3alpha ignition (T~8.6 KeV)

Axion emission cools down core, delays ignition

HeH-burning

Mcore ", TH ",L "Brighter Helium flash!

Strong constraint, small hint!

COLOR

Brig

thne

ss

Globular ClusterM5

White dwarf luminosity function

dNWD

Vol dL =

k

dL/dt

White dwarf luminosity function

dNWD

Vol dL =

k

dL/dt+ dLa/dtwith axion-electron bremsstrahlung

increase couplingStrong constraint, small hint!

Cassiopeia A: neutron star cooling

- Cooling measured by Chandra, ~4% in ten years!

- Evidence of emission in n Cooper pair formation 3P2

- Factor of ~2 extra cooling required, axions?

⌫⌫

⌫⌫

3P2

nn

3P2

nn

a

Hints, constraints and models ... any preference?

Tip of the Red Giant branch (M5)

White dwarf luminosity function

Cassiopeia A: neutron star cooling

SN1987A

gae = Caeme

fa= (2± 1.5)⇥ 10�13

gae = Caeme

fa= (1.4± 1.4)⇥ 10�13

gan = Canmn

fa= (3.8± 3)⇥ 10�10

gap = Capmp

fa< 0.8⇥ 10�10

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

mu

md

fa/109GeV

�2

fa/109GeV

cos

2�

DFSZ1 DFSZ2

cos

2�

fa/109GeV

Preliminary Preliminary

Preliminary

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

mu

md

fa/109GeV

�2

fa/109GeV

cos

2�

DFSZ1 DFSZ2

cos

2�

fa/109GeV

cos

2�

fa/109GeV

DFSZ (no RG, no WD, 2 pref.)

0.0 0.2 0.4 0.6 0.8 1.0

-0.6

-0.4

-0.2

0.0

0.2

0.4

cos

2 �

Cap

Can

Cae

DFSZ1

DFSZ2 DFSZ

KSVZ

KSVZ

DFSZ

Hints, constraints and models ... any preference?

Preliminary

Preliminary Preliminary

Preliminary

IAXO: The international axion observatory

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

Helioscopes

focus detect

Conversion probability

P (a $ �) =

✓2ga�BT!

m2a

◆2

sin2✓m2

aL

4!

◆

ma ! 0, P !✓ga�BTL

2

◆2

ma ! large, P !✓2ga�BT!

m2a

◆2

Axions from the Sun

Hadronic axions (KSVZ)

Non hadronic (DFSZ, e-coupling!)

Ceme

faie�5e a

C�↵

2⇡fa

Fµ⌫eFµ⌫

4a

ga�

gae

gae = 10�13

ga� = 10�12

typical of non-hadronic meV mass axions

CAST Helioscope

CAST (LHC dipole 9.3 m, 9T) hadronic axions

non-hadronic axions- 1~2 h tracking/day (sunset,dawn)- 3 Detectors (2 bores)

CCD, Micromegas- X-ray optics- He gas for large masses

P (a $ �) =

✓2ga�BT!

m2a �m2

�

◆2

sin2 (m2

a �m2�)L

4!

!

PhaseI

PhaseII

PhaseI

Next generation (proposed) IAXO

Boost parameters to the maximum

-NGAG paper JCAP 1106:013,2011-Conceptual design report IAXO 2014 JINST 9 T05002-LOI submitted to CERN, TDR in preparation

-Possibility of Direct Axion DM experiments (cavities)

Large toroidal 8-coil magnet L = ~20 m 8 bores: 600 mm diameter each8 x-ray optics + 8 detection systemsRotating platform with services

IAXO magnet (under development)

IAXO magnet concept presented in:IEEE Trans. Appl. Supercond. 23 (ASC 2012)Adv. Cryo. Eng. (CEC/ICMC 2013)IEEE Trans. Appl. Supercond. (MT 23)

Transverse B-field (peak 5T, average 2.5T)

IAXO optics

Focal length

- IAXO optics conceptual designAC Jakobsen et al, Proc. SPIE 8861 (2013)- NuSTAR optics groups LLNL, Columbia U., DTU Denmark all in IAXO

IAXO detectors

- Small Micromegas-TPC chambers:ShieldingRadiopure componentsOffline discrimination

Goal background level for IAXO:10-7 – 10-8 c keV-1 cm-2 s-1

Already demonstrated:~8×10-7 c keV-1 cm-2 s-1 (in CAST 2014 result)10-7 c keV-1 cm-2 s-1 (underground at LSC)

Active program of development. Clear roadmap for improvement

- Other detectors, Gridpix/InGrid, MMC,CCDs

10-3 10-2 10-1 110-13

10-12

10-11

10-10109 108 107

10-13

10-12

10-11

10-10

Physics reach (preliminary)

Conservative

Not soKSVZDFSZ1DFSZ2

ma[eV]

fa[GeV]

10-3 10-2 10-1 110-13

10-12

10-11

10-10109 108 107

10-13

10-12

10-11

10-10

fa[GeV]

KSVZDFSZ1DFSZ2

Conservative

Not so

ma[eV]

qg a

�[10�

10GeV

�1]⇥

g ae

g a�[10�

10GeV

�1]

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

IAXO IAXOSN

1987

A

P1 P2

Possibility to unveal the hints!

IAXO timeline

~ 3.5 y construction

~18 month TDR ~ 2.5 y integration/commisioning

IAXO costs

Physics case +

Betelgeuse is the next galactic SN- up to 5 1014 a’s (E~80 MeV) in 10 sec- Early warning (Si nu’s)- check visibility- 50-100 MeV detectors- needs a boost ~30

10-3 10-2 10-1 110-13

10-12

10-11

10-10109 108 107

10-13

10-12

10-11

10-10

g a�[10�

10GeV

�1]

ma[eV]

fa[GeV]

10-3 10-2 10-1 110-13

10-12

10-11

10-10109 108 107

10-13

10-12

10-11

10-10

KSVZ

DFSZ

DM detectors inside IAXO volume- huge magnetic volume- low masses than ADMX is straightforward- high masses, combine cavities- dish antennas (miniclusters) see Redondo, talk at Patras 2014

ma[eV]

Conclusions

meV frontier

- Astro hints (RGs,WD,NS)

- Experiment: IAXO

- Axion DM (hard to test otherwise)