Hearing the echoes of electroweak baryogenesis with gravitational wave detectors

Abstract

We report on the first joint analysis of observational signatures from the electroweak baryogenesis in both gravitational wave (GW) detectors and particle colliders. With an effective extension of the Higgs sector in terms of the dimension-6 operators, we derive a strong first-order phase transition in associated with a sizable CP violation to realize a successful electroweak baryogenesis. We calculate the GW spectrum resulting from the bubble nucleation, plasma transportation, and magnetohydrodynamic turbulence of this process that occurred after the big bang, and find that it yields GW signals testable in Evolved Laser Interferometer Space Antenna, Deci-hertz Interferometer Gravitational wave Observatory and Big Bang Observer. We further identify collider signals from the same mechanism that are observable at the planning Circular Electron Positron Collider. Our analysis bridges astrophysics/cosmology with particle physics by providing significant motivation for searches for GW event peaking at the $(10^{-4}, 1)$ Hz range, which are associated with signals at colliders, and highlights the possibility of an interdisciplinary observational window into baryogenesis. The technique applied in analyzing early universe phase transitions may enlighten the study of phase transitions in applied science.

Figures (2)

• Figure 1: The GW spectra $h^2\Omega_{GW}$ and the associated collider signals $\delta_{\sigma_{hZ}}$ for different cutoff scales $\Lambda$ (590 GeV, 600 GeV, 650 GeV, 700 GeV and 750 GeV) with $\kappa=1$. The colored regions correspond to the expected sensitivities of GW interferometers aLIGO, eLISA, BBO, DECIGO, and U-DECIGO. The red line depicts the GW spectrum for $\Lambda = 590~{\rm GeV}$, which is related to a collider signal of $\delta_{\sigma_{hZ}} \simeq 2.2\%$ at the CEPC. The magenta, blue, purple and black lines are the cases for 600 GeV, 650 GeV, 700 GeV and 750 GeV, respectively.
• Figure 2: The observational abilities of different experiments. For CEPC, the sensitive region is $\Lambda/\sqrt{\kappa} < 1357.65~{\rm GeV}$; for LHC, it corresponds to $\Lambda/\sqrt{\kappa} < 280~{\rm GeV}$; the theoretical condition for the SFOPT requires $480~ {\rm GeV} < \Lambda/\sqrt{\kappa} < 840~{\rm GeV}$; and the detectable region of GW interferometers reads $590 ~{\rm GeV} < \Lambda/\sqrt{\kappa} < 740 ~{\rm GeV}$.