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]