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 f a . 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 : 1 [ f a + φ ( x )] e ia ( x ) /f a . Φ( x ) = √ 2 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 f a . 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 : 1 [ f a + φ ( x )] e ia ( x ) /f a . Φ( x ) = √ 2 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 f a -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 ) = V 0 ( φ ) + V CW ( φ ) + V T ( φ, T ) , 4

Scalar Potential V ( φ, T ) = V 0 ( φ ) + V CW ( φ ) + V T ( φ, T ) , � 2 | Φ | 2 − 1 Tree-level: V 0 = − µ 2 | H | 2 + λ | H | 4 + κ | Φ | 2 | H | 2 + λ a � 2 f 2 . a = λ a � 2 + � κ 2 φ 2 − µ 2 � � 1 2 h 2 + 1 φ 2 − f 2 � 2 G 2 � 0 + G + G − a 4 � 2 � 1 2 h 2 + 1 2 G 2 + λ 0 + G + G − . 4

Scalar Potential V ( φ, T ) = V 0 ( φ ) + V CW ( φ ) + V T ( φ, T ) , � 2 | Φ | 2 − 1 Tree-level: V 0 = − µ 2 | H | 2 + λ | H | 4 + κ | Φ | 2 | H | 2 + λ a � 2 f 2 . a = λ a � 2 + � κ 2 φ 2 − µ 2 � � 1 2 h 2 + 1 φ 2 − f 2 � 2 G 2 � 0 + G + G − a 4 � 2 � 1 2 h 2 + 1 2 G 2 + λ 0 + G + G − . ( − 1) F n i m 4 � log m 2 � i ( φ ) i ( φ ) � One-loop: V CW ( φ ) = − C i . 64 π 2 Λ 2 i ( − 1) F n i T 4 � m 2 � i ( φ ) � Finite-temperature: V T ( φ, T ) = 2 π 2 J B/F , T 2 i 4

Scalar Potential V ( φ, T ) = V 0 ( φ ) + V CW ( φ ) + V T ( φ, T ) , � 2 | Φ | 2 − 1 Tree-level: V 0 = − µ 2 | H | 2 + λ | H | 4 + κ | Φ | 2 | H | 2 + λ a � 2 f 2 . a = λ a � 2 + � κ 2 φ 2 − µ 2 � � 1 2 h 2 + 1 φ 2 − f 2 � 2 G 2 � 0 + G + G − a 4 � 2 � 1 2 h 2 + 1 2 G 2 + λ 0 + G + G − . ( − 1) F n i m 4 � log m 2 � i ( φ ) i ( φ ) � One-loop: V CW ( φ ) = − C i . 64 π 2 Λ 2 i ( − 1) F n i T 4 � m 2 � i ( φ ) � Finite-temperature: V T ( φ, T ) = 2 π 2 J B/F , T 2 i Temperature-dependent mass terms: 1 T 2 , 9 g 2 2 + 3 g 2 1 + 12 y 2 � t + 24 λ + 4 κ � Π h ( T ) = Π G 0 , ± ( T ) = 48 1 3 ( κ + 2 λ a ) T 2 . Π φ ( T ) = [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 h 2 Ω GW = h 2 Ω φ + h 2 Ω SW + h 2 Ω MHD . [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 h 2 Ω GW = h 2 Ω φ + h 2 Ω SW + h 2 Ω MHD . [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: rad = g ∗ π 2 T 4 α = ρ vac Vacuum energy density: with ρ ∗ 30 . ∗ ρ ∗ rad 6

Gravitational Wave Production h 2 Ω GW = h 2 Ω φ + h 2 Ω SW + h 2 Ω MHD . [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: rad = g ∗ π 2 T 4 α = ρ vac Vacuum energy density: with ρ ∗ 30 . ∗ ρ ∗ rad � � d 2 S E ( T ) (Inverse) Bubble nucleation rate: � β/H ∗ = T . � dT 2 � T = T ∗ 6

Gravitational Wave Production h 2 Ω GW = h 2 Ω φ + h 2 Ω SW + h 2 Ω MHD . [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: rad = g ∗ π 2 T 4 α = ρ vac Vacuum energy density: with ρ ∗ 30 . ∗ ρ ∗ rad � � d 2 S E ( T ) (Inverse) Bubble nucleation rate: � β/H ∗ = T . � dT 2 � T = T ∗ 6

Gravitational Wave Production h 2 Ω GW = h 2 Ω φ + h 2 Ω SW + h 2 Ω MHD . [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: rad = g ∗ π 2 T 4 α = ρ vac Vacuum energy density: with ρ ∗ 30 . ∗ ρ ∗ rad � � d 2 S E ( T ) (Inverse) Bubble nucleation rate: � β/H ∗ = T . � dT 2 � T = T ∗ � β � β � β � − 2 � − 1 � − 1 h 2 Ω φ ∝ , h 2 Ω SW ∝ , h 2 Ω MHD ∝ . H ∗ H ∗ H ∗ 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 f a , complementary to other laboratory, cosmological and astrophysical probes, which depend on both f a and m a . 9

GW Complementarity beam dump 10 - 6 LSW SN LISA g a γγ [ GeV - 1 ] Sun 10 - 8 BBO helioscopes HB stars 10 - 10 aLIGO + γ - rays telescopes haloscopes x ion CMB BBN EBL 10 - 12 X - rays DFSZ KSVZ 10 - 8 10 - 5 10 4 10 7 0.01 10 m a [ eV ] 10

Higgs Trilinear Coupling 14 perturbative limit 12 ] % 0 3 [ C H L 10 - ILC [ 13 %] L H FCC - hh [ 5 %] κ 8 6 4 2 10 3.0 10 3.1 10 3.2 10 3.3 10 3.4 10 3.5 10 3.6 10 3.7 f a [ GeV ] + κ 3 v 3 m 2 λ 3 ≃ λ SM EW with λ SM h , = 2 v EW . 3 3 24 π 2 m 2 φ Current LHC limit: − 9 � λ 3 /λ SM � 15 . 3 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 10 3 GeV � f a � 10 8 GeV . Independent of the ALP mass. Complementary to various laboratory, cosmological and astrophysical constraints on 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 10 3 GeV � f a � 10 8 GeV . Independent of the ALP mass. Complementary to various laboratory, cosmological and astrophysical constraints on the ALP . THANK YOU. 12