Observable Gravitational Waves from Axion-Like Particles Bhupal Dev - - PowerPoint PPT Presentation

Observable Gravitational Waves from Axion-Like Particles

Bhupal Dev Washington University in St. Louis BD, F. Ferrer, Y. Zhang and Y. C. Zhang, arXiv:1905.00891 [hep-ph]. PHENO 2019 University of Pittsburgh May 6, 2019

Outline

Introduction to ALP Scalar Potential Gravitational Wave Spectrum Comparison with Other Constraints Conclusion

1

Axion-Like Particle (ALP)

Light SM-singlet pseudoscalar. Pseudo-Nambu-Goldstone boson in theories with global U(1) symmetry breaking. Originally introduced to solve the strong CP problem. [Peccei, Quinn (PRL ’77)] Could also play important role in addressing other open issues of the SM, such as hierarchy problem [Graham, Kaplan, Rajendran (PRL ’15)], inflation [Freese, Frieman, Olinto (PRL ’90)], dark matter [Preskill, Wise, Wilczek (PLB ’83); Abbott, Sikivie (PLB ’83); Dine, Fischler (PLB ’83)], dark energy [Kim, Nilles (JCAP ’09)], baryogenesis [De Simone, Kobayashi, Liberati (PRL ’17)]. Could provide a common framework to simultaneously address many of these

• issues. [Ballesteros, Redondo, Ringwald, Tamarit (PRL ’17); Ema, Hamaguchi, Moroi, Nakayama (JHEP ’17); Gupta,

Reiness, Spannowsky ’19]

2

A Simple ALP Model

ALP couplings to SM is suppressed by inverse powers of the U(1)-symmetry breaking scale fa. Can be identified as the VEV of a SM-singlet complex scalar field Φ. The ALP field is the massless mode of the angular part of Φ: Φ(x) = 1 √ 2 [fa + φ(x)] eia(x)/fa . Explicit low-energy U(1)-breaking effects can induce a small mass for a(x).

3

A Simple ALP Model

ALP couplings to SM is suppressed by inverse powers of the U(1)-symmetry breaking scale fa. Can be identified as the VEV of a SM-singlet complex scalar field Φ. The ALP field is the massless mode of the angular part of Φ: Φ(x) = 1 √ 2 [fa + φ(x)] eia(x)/fa . Explicit low-energy U(1)-breaking effects can induce a small mass for a(x). Key point: The spontaneous U(1)-symmetry breaking at the fa-scale could induce a strongly first-order phase transition, if Φ has a non-zero coupling to the SM Higgs doublet field. Gives rise to stochastic gravitational wave signals potentially observable in current and future GW detectors. [BD, Mazumdar (PRD ’16)]

3

Scalar Potential

V(φ, T) = V0(φ) + VCW(φ) + VT (φ, T) ,

4

Scalar Potential

V(φ, T) = V0(φ) + VCW(φ) + VT (φ, T) , Tree-level: V0 = −µ2|H|2 + λ|H|4 + κ|Φ|2|H|2 + λa

• |Φ|2 − 1

2f 2

a

2

. = λa 4

• φ2 − f 2

a

2 + κ

2 φ2 − µ2 1 2h2 + 1 2G2

0 + G+G−

• + λ

1

2h2 + 1 2G2

0 + G+G−

2

.

4

Scalar Potential

V(φ, T) = V0(φ) + VCW(φ) + VT (φ, T) , Tree-level: V0 = −µ2|H|2 + λ|H|4 + κ|Φ|2|H|2 + λa

• |Φ|2 − 1

2f 2

a

2

. = λa 4

• φ2 − f 2

a

2 + κ

2 φ2 − µ2 1 2h2 + 1 2G2

0 + G+G−

• + λ

1

2h2 + 1 2G2

0 + G+G−

2

. One-loop: VCW (φ) =

• i

(−1)F ni m4

i (φ)

64π2

• log m2

i (φ)

Λ2 − Ci

• .

Finite-temperature: VT (φ, T) =

• i

(−1)F ni T 4 2π2 JB/F

• m2

i (φ)

T 2

• ,

4

Scalar Potential

V(φ, T) = V0(φ) + VCW(φ) + VT (φ, T) , Tree-level: V0 = −µ2|H|2 + λ|H|4 + κ|Φ|2|H|2 + λa

• |Φ|2 − 1

2f 2

a

2

. = λa 4

• φ2 − f 2

a

2 + κ

2 φ2 − µ2 1 2h2 + 1 2G2

0 + G+G−

• + λ

1

2h2 + 1 2G2

0 + G+G−

2

. One-loop: VCW (φ) =

• i

(−1)F ni m4

i (φ)

64π2

• log m2

i (φ)

Λ2 − Ci

• .

Finite-temperature: VT (φ, T) =

• i

(−1)F ni T 4 2π2 JB/F

• m2

i (φ)

T 2

• ,

Temperature-dependent mass terms: Πh (T) = ΠG0,± (T) = 1 48

• 9g2

2 + 3g2 1 + 12y2 t + 24λ + 4κ

T 2 , Πφ (T) = 1 3 (κ + 2λa) T 2 .

[Dolan, Jackiw (PRD ’74); Arnold, Espinosa (PRD ’93); Curtin, Meade, Ramani (EPJC ’18)]

4

First-order Phase Transition

5

First-order Phase Transition

5

Gravitational Wave Production

h2ΩGW = h2Ωφ + h2ΩSW + h2ΩMHD .

[Kosowsky, Turner, Watkins (PRL ’92); Kamionkowski, Kosowsky, Turner (PRD ’94); Caprini, Durrer, Servant (PRD ’08); Huber, Konstandin (JCAP ’08); Hindmarsh, Huber, Rummukainen, Weir (PRL ’14); Ellis, Lewicki, No ’18]

6

Gravitational Wave Production

h2ΩGW = h2Ωφ + h2ΩSW + h2ΩMHD .

[Kosowsky, Turner, Watkins (PRL ’92); Kamionkowski, Kosowsky, Turner (PRD ’94); Caprini, Durrer, Servant (PRD ’08); Huber, Konstandin (JCAP ’08); Hindmarsh, Huber, Rummukainen, Weir (PRL ’14); Ellis, Lewicki, No ’18]

Depends on two important parameters: Vacuum energy density: α = ρvac ρ∗

rad

with ρ∗

rad = g∗π2 T 4 ∗

30 .

6

Gravitational Wave Production

h2ΩGW = h2Ωφ + h2ΩSW + h2ΩMHD .

[Kosowsky, Turner, Watkins (PRL ’92); Kamionkowski, Kosowsky, Turner (PRD ’94); Caprini, Durrer, Servant (PRD ’08); Huber, Konstandin (JCAP ’08); Hindmarsh, Huber, Rummukainen, Weir (PRL ’14); Ellis, Lewicki, No ’18]

Depends on two important parameters: Vacuum energy density: α = ρvac ρ∗

rad

with ρ∗

rad = g∗π2 T 4 ∗

30 . (Inverse) Bubble nucleation rate: β/H∗ = T

• d2SE (T)

dT 2

• T =T∗

.

6

Gravitational Wave Production

h2ΩGW = h2Ωφ + h2ΩSW + h2ΩMHD .

[Kosowsky, Turner, Watkins (PRL ’92); Kamionkowski, Kosowsky, Turner (PRD ’94); Caprini, Durrer, Servant (PRD ’08); Huber, Konstandin (JCAP ’08); Hindmarsh, Huber, Rummukainen, Weir (PRL ’14); Ellis, Lewicki, No ’18]

Depends on two important parameters: Vacuum energy density: α = ρvac ρ∗

rad

with ρ∗

rad = g∗π2 T 4 ∗

30 . (Inverse) Bubble nucleation rate: β/H∗ = T

• d2SE (T)

dT 2

• T =T∗

.

6

Gravitational Wave Production

h2ΩGW = h2Ωφ + h2ΩSW + h2ΩMHD .

[Kosowsky, Turner, Watkins (PRL ’92); Kamionkowski, Kosowsky, Turner (PRD ’94); Caprini, Durrer, Servant (PRD ’08); Huber, Konstandin (JCAP ’08); Hindmarsh, Huber, Rummukainen, Weir (PRL ’14); Ellis, Lewicki, No ’18]

Depends on two important parameters: Vacuum energy density: α = ρvac ρ∗

rad

with ρ∗

rad = g∗π2 T 4 ∗

30 . (Inverse) Bubble nucleation rate: β/H∗ = T

• d2SE (T)

dT 2

• T =T∗

. h2Ωφ ∝

β

H∗

−2

, h2ΩSW ∝

β

H∗

−1

, h2ΩMHD ∝

β

H∗

−1

.

6

Gravitational Wave Spectrum

7

Gravitational Wave Spectrum

7

Gravitational Wave Spectrum

7

GW Sensitivity

8

GW Sensitivity

8

GW Sensitivity

8

GW Sensitivity

8

GW Sensitivity

Independent of the ALP mass. Provides a new probe of fa, complementary to other laboratory, cosmological and astrophysical probes, which depend on both fa and ma.

9

GW Complementarity

10-8 10-5 0.01 10 104 107 10-12 10-10 10-8 10-6

ma [eV] gaγγ [GeV-1]

LSW helioscopes Sun HB stars γ-rays haloscopes DFSZ KSVZ telescopes xion X-rays EBL CMB BBN SN beam dump LISA BBO aLIGO+

10

Higgs Trilinear Coupling

103.0 103.1 103.2 103.3 103.4 103.5 103.6 103.7 2 4 6 8 10 12 14

fa [GeV] κ

perturbative limit H L

• L

H C [ 3 % ] ILC [13%] FCC-hh [5%]

λ3 ≃ λSM

3

+ κ3v3

EW

24π2m2

φ

, with λSM

3

= m2

h

2vEW . Current LHC limit: −9 λ3/λSM

3

15.

11

Conclusion

Considered generic ALP scenarios with the VEV of a complex scalar field Φ breaking the global U(1) symmetry. Gives rise to strong first-order phase transition and stochastic gravitational waves for a sizable coupling to the SM Higgs. Current and future GW experiments can probe a broad range of ALP parameter space with 103 GeV fa 108 GeV. Independent of the ALP mass. Complementary to various laboratory, cosmological and astrophysical constraints

• n the ALP

.

12

Conclusion

Considered generic ALP scenarios with the VEV of a complex scalar field Φ breaking the global U(1) symmetry. Gives rise to strong first-order phase transition and stochastic gravitational waves for a sizable coupling to the SM Higgs. Current and future GW experiments can probe a broad range of ALP parameter space with 103 GeV fa 108 GeV. Independent of the ALP mass. Complementary to various laboratory, cosmological and astrophysical constraints

• n the ALP

. THANK YOU.

12