Andreas Ringwald

ALPS Collaboration Meeting Mainz, D 6-8 March 2017

Axion in Reach of ALPS II?.

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 2

Plan

>  The axion window in photon coupling vs. mass parameter space is much wider than previously thought:

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 3

Axionic solution of strong CP problem

>  A singlet complex scalar field featuring a global symmetry is added to SM

>  Symmetry is broken by vev

§  Excitation of modulus:

§  Excitation of angle: NGB

U(1)PQ

[Raffelt]

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 4

Axionic solution of strong CP problem

>  A singlet complex scalar field featuring a global symmetry is added to SM

>  Symmetry is broken by vev

§  Excitation of modulus:

§  Excitation of angle: NGB

>  Quarks (SM or extra) carry PQ charges such that is anomalously broken due to a gluonic triangle anomaly

U(1)PQ

U(1)PQ

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 5

Axionic solution of strong CP problem

>  A singlet complex scalar field featuring a global symmetry is added to SM

>  Symmetry is broken by vev

§  Excitation of modulus:

§  Excitation of angle: NGB

>  Quarks (SM or extra) carry PQ charges such that is anomalously broken due to a gluonic triangle anomaly

>  No strong CP problem, since axion field acts as x-dependent theta parameter

QCD dynamics:

U(1)PQ

[Peccei,Quinn 77; Weinberg 78; Wilczek 78]

U(1)PQ

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 6

How wide is the axion window?

>  Coupling to photons most important for experimental searches

>  How wide is the axion window, i.e. what is realistic range of ?

>  Consider KSVZ-type axion models: Anomaly induced by heavy fermions in the representation under

>  Fifteen cases survive phenomenologi-cal requirements §  sufficiently short lived to avoid issues with

long-lived strongly interacting relics,

§  no Landau poles induced below Planck scale

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 7

How wide is the axion window?

>  Axion window in pho-ton coupling much wi-der than commonly assumed

>  ALPS II discovery reach nearly touches extended axion win-dow

10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 1 1010-16

10-15

10-14

10-13

10-12

10-11

10-10

10-9

10-8

ma @eVD

»g agg»@Ge

V-

1 DE/N

=170/3

E/N

=44/3

NQ=1

E/N

=5/3

NQ > 1

HDM

CAST

IAXO

ALPS-II

Haloscopes

HB

[Di Luzio, Mescia, Nardi 16]

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 8

How wide is the axion window?

>  Axion window in pho-ton coupling much wi-der than commonly assumed

>  ALPS II discovery reach nearly touches extended axion win-dow

>  Even wider window in clockwork axion mo-dels involving additio-nal pseudo NGBs

E,Ec D,Dc

⇡0 ⇡1 ⇡M ⇡N⇡N�1

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 9

How wide is the axion window?

>  Axion window in pho-ton coupling much wi-der than commonly assumed

>  ALPS II discovery reach nearly touches extended axion win-dow

>  Even wider window in clockwork axion mo-dels involving additio-nal pseudo NGBs

>  Particle spectrum: one massless NGB and pseudo NGBs with mass

>  Couplings of axion:

§  Photon coupling exponentially enhanced compared to gluon coupling

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 10

How wide is the axion window?

>  Axion window in pho-ton coupling much wi-der than commonly assumed

>  ALPS II discovery reach nearly touches extended axion win-dow

>  Even wider window in clockwork axion mo-dels involving additio-nal pseudo NGBs

>  Particle spectrum: one massless NGB and pseudo NGBs with mass

>  Couplings of axion:

§  Photon coupling exponentially enhanced compared to gluon coupling

§  Boosted decay constant: ⇤ ⇤N = qN⇤

[Giudice, McCullough 16]

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 11

How wide is the axion window?

>  Axion window in pho-ton coupling much wi-der than commonly assumed

>  ALPS II discovery reach nearly touches extended axion win-dow

>  Even wider window in clockwork axion mo-dels involving additio-nal pseudo NGBs §  For large axion in

reach of ALPS II

10-5 10-4 10-3 10-2 10-1 1/2 1θ/π

★★

10-14 10-12 10-10 10-8 10-6 10-4 10-2 100

10-20

10-18

10-16

10-14

10-12

10-10

10-8

10-6108101010121014101610181020

ma (eV)

gaγγ(GeV-1)

fa (GeV)

KSVZ

N-M=2

N-M=2

N-M=26

IAXOADMX

ABRA-ResABRA-BroadCASPEr-EDMCASPEr-wind

[Farina et al. 16]

Andreas Ringwald | Axion in Reach of ALPS II?, ALPS Collaboration Meeting, Mainz, D, 6-8 March 2017 | Page 12

How wide is the axion window?

>  Axion window in pho-ton coupling much wi-der than commonly assumed

>  ALPS II discovery reach nearly touches extended axion win-dow

>  Even wider window in clockwork axion mo-dels involving additio-nal pseudo NGBs §  For large axion in

reach of ALPS II

§  Additional ALPs may be searched for at LHC

102 10310-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

m (GeV)

σ(pp

→A→γγ

)⨯s/Cgg

ATLAS@8TeVATLAS@13TeVCMS@13TeV

N=15

N=30

f = 50, 100, 250, 500, 1000 GeV

[Farina et al. 16]