Cosmological Inflation, Electroweak Phase Transition And Dark Matter Within Scalar Models

So far,the Standard Model of particle physics(SM)has been a brilliant success in describing strong,weak and electromagnetic interactions in nature.However,due to the imperfection of SM,it is still unable to deal with many problems in particle physics and cosmology,such as the problem of cosmic horizon and flatness,the asymmetry of baryon number in the universe,and the existence of dark matter(DM).It has been discovered that adding an inflationary period before the big bang could explain the cosmic horizon problem,the problem of flatness and the large-scale structure observed in the cosmic microwave background(CMB)in the standard cosmological big bang theoretical model.In order to produce baryon number asymmetry in the evolution of the universe,three constraints proposed by Sakharov should be satisfied:1)the broken of baryon number B;2)the broken of C and CP symmetry;3)deviation from the thermal equilibrium state.In the electroweak baryon generation mechanism,the third constraint can be achieved by the Strong first order electro weak phase transition(SFOEWPT).The introduction of new physics beyond the particle physics SM can achieve the cosmological inflation explanation without the vacuum stability,theoretical perturbation and unitary problems.Meanwhile,in order to realize SFOEWPT,extension of SM is also required.The reason is that although SFOEWPT can be realized under the SM framework,the Higgs mass is required to be no more than 80GeV,which is inconsistent with the experimental results of the large hadron collider(LHC)in Europe.In this paper,the standard model of particle physics based on real scalar and complex scalar extension is used to study cosmological inflation,SFOEWPT and Dark Matter(DM)simultaneously,so as to deepen the understanding of these problems.This paper first discusses the standard model of particle physics based on real scalar field expansion.Based on the standard model,we introduce several real scalar particles which satisfy the global O N)symmetry.Until the inflation energy scale,the range of input parameters allowed by the stability,perturbation and unitary will narrow as the N increase.The results show that if the real scalar particle that meets the symmetry can t be the dark matter candidate,its mass in the feasible parameter region of inflation will be limited to TeV energy scale by CEPC,ILC and FCC-ee experiments.SFOEWPT will be invalidated due to the limitation of the number of scalar introduced by the precise weak observations.When the O N symmetry spontaneously breaks into O(N-1)symmetry,the rest N-1 becomes goldstone particles,which can act as pseudoneutrinos or gain mass through non-perturb gravitational effects,leading to dark radiation.In this case,one-or two-step SFOEWPT can occur in some parameter regions where inflation is feasible and stability,perturbation,and unitary problems do not occur.The number of goldstone particles is also limited by observable inflation,under the constraints of Higgs’s precise measurement and electroweak’s precise observation.The relationship between the number of goldstone particles and SFOEWPT depends on the type of phase transition.Future high-energy physics experimental platforms such as CEPC,ILC and fcc-ee will impose restrictions on the mixing Angle between the introduced Higgs and the standard model Higgs,and it is possible to test both slow roll inflation and SFOEWPT at the same time.The possibility of realizing cosmological inflation,SFOEWPT and dark matter simultaneously by using SM with complex scalar monomorphic expansion is discussed.A real mass term μb2 is introduced into the potential energy of the complex scalar model.When the U(1)global symmetry is broken,S→eiαS,the real part of the model will be coupled with SM Higgs,and the pseudoscalar will be taken as the dark matter candidate.Based on the four independent parameters of the model,three coupling constants λs、λh and.Under the complex scalar model,the coupling constant parameter space of the inflation energy scale which meets the limit of the slow rolling inflation condition and the cosmological observation quantity(scalar spectrum index,tensor ratio and scalar fluctuation amplitude)is calculated.The coupling constant space of two-step model in SFOEWPT is studied by using finite temperature effective potential method.We find that the feasible parameter space of SFOEWPT falls into the feasible parameter space of cosmological inflation.This paper also discusses the density of dark matter relics and finds that the current density of dark matter relics is also in their overlapping parameter space.The cancellation of dark matter-nuclear scattering amplitude in the Higgs window enables the pseudoscalar to explain dark matter in any mass region,thus avoiding the parameter limitation of the strongest direct dark matter detection experiment XENON1T.The results show that SM model based on complex scalar expansion can explain cosmological inflation,SFOEWPT and dark matter candidate simultaneously.