Electroweak baryogenesis and gravitational waves in a composite Higgs model with high dimensional fermion representations

Abstract

We study electroweak baryogenesis in the SO(6)/SO(5) composite Higgs model with the third generation quarks being embedded in the 20′ representation of SO(6). The scalar sector contains one Higgs doublet and one real singlet, and their potential is given by the Coleman-Weinberg potential evaluated from the form factors of the lightest vector and fermion resonances. We show that the resonance masses at $$ \mathcal{O}\left(1\sim 10\kern0.5em \mathrm{TeV}\right) $$ O 1 ∼ 10 TeV can generate a potential that triggers the strong first-order electroweak phase transition (SFOEWPT). The CP violating phase arising from the dimension-6 operator in the top sector is sufficient to yield the observed baryon asymmetry of the universe. The SFOEWPT parameter space is detectable at the future space-based detectors.

Strong first order electroweak phase transition in 2HDM confronting future Z & Higgs factories

“…Simple SM extensions include the addition of a SU(2) singlet [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], an extra doublet , an extra triplet [70][71][72][73], or extra higher dimensional operators [74][75][76][77][78][79]. Consideration of the hierarchy problem leads to further solutions such as embedding the Higgs boson in a Composite Higgs model [80][81][82] or a supersymmetric model [83][84][85][86][87][88][89][90][91][92][93][94][95][96][97][98] to obtain a SFOEWPT. For a SFOEWPT in other models see [99]…”

Lepton-mediated electroweak baryogenesis, gravitational waves and the 4τ final state at the collider

“…However this constraint can be relaxed if we consider new light BSM degrees of freedom. For example, the SM plus a real singlet scalar is able to generate the observed BAU and compatible with the EDM experiments [19,29], especially when there is a Z2 symmetry for the singlet [21]. 3 See ref.…”

“…Most literatures focus on EWBG mediated by quark transport, in particular by top transport since the large top Yukawa (y t ≈ 1) enhances the CPV source and hence the BAU [12][13][14] (for recent studies see [15][16][17][18][19][20][21]). 1 However, the top-mediated EWBG is not as efficient as expected, due to three reasons summarized in ref.…”

“…21) where i, j are generation indices, c ij are the (complex) Wilson coefficients, and Λ is the cutoff scale of EFT. For simplicity, we assume the Willson coefficients are flavor-diagonal, i.e.…”

Probing electroweak phase transition with multi-TeV muon colliders and gravitational waves

“…In the Standard Model (SM), lattice calculations have shown that the EWPT is a smooth crossover [3][4][5]. However, the EWPT could be first-order (FO) in many new physics models beyond the SM (BSM), such as the real singlet extended SM (xSM) [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], two-Higgsdoublet model [21][22][23][24][25][26][27][28][29][30][31][32][33][34], left-right symmetric model [35,36], 1 Georgi-Machacek model [38] and composite Higgs models [39][40][41][42][43][44][45][46], etc. A FOEWPT can drive the early Universe out of thermal equilibrium, providing the essential environment for the electroweak baryogenesis (EWBG) mechanism [47][48][49], which explains the observed ...…”