Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userInfrared Effects and Bubble Propagation at the Electroweak Phase Transition
66
0
0.0
(
0
)
Authors
R.G. Leigh
Ask ChatGPT about the research
No Arabic abstract
We discuss aspects of poor infrared behaviour of the perturbation expansion for the effective potential of the Higgs mode near the electroweak phase transition, and enlarge on the discovery that higher order effects weaken the transition. In addition, we outline our recent attempts at understanding the dynamics involved in the propagation of bubbles formed in the first order transition.
rate research
Read More
The bubble wall velocity is essential for the phase transition dynamics in the early universe and its cosmological implications, such as the energy budget of phase transition gravitational wave and electroweak baryogenesis. One key factor to determine the wall velocity is the collision term that quantifies the interactions between the massive particles in the plasma and the bubble wall. We improve the calculations of the collision term beyond the leading-log approximation, and further obtain more precise bubble wall velocity for a representative effective model.
We study the correlation between the value of the triple Higgs coupling and the nature of the electroweak phase transition. We use an effective potential approach, including higher order, non-renormalizable terms coming from integrating out new physics. We show that if only the dimension six operators are considered, large positive deviations of the triple Higgs coupling from its Standard Model (SM) value are predicted in the regions of parameter space consistent with a strong first order electroweak phase transition (SFOEPT). We also show that at higher orders sizable and negative deviations of the triple Higgs coupling may be obtained, and the sign of the corrections tends to be correlated with the order of the phase transition. We also consider a singlet extension of the SM, which allows us to establish the connection with the effective field theory (EFT) approach and analyze the limits of its validity. Furthermore, we study how to probe the triple Higgs coupling from the double Higgs production at the LHC. We show that selective cuts in the invariant mass of the two Higgs bosons should be used, to maximize the sensitivity for values of the triple Higgs coupling significantly different from the Standard Model one.
A cosmological first order electroweak phase transition could explain the origin of the cosmic matter-antimatter asymmetry. While it does not occur in the Standard Model, it becomes possible in the presence of a second Higgs doublet. In this context, we obtain the properties of the new scalars $H_0$, $A_0$ and $H^{pm}$ leading to such a phase transition, showing that its key LHC signature would be the decay $A_0 rightarrow H_0 Z$, and we analyze the promising LHC search prospects for this decay in the $ell ell bbar{b}$ and $ell ell W^{+} W^{-}$ final states. Finally, we comment on the impact of the $A_0 rightarrow H_0 Z$ decay on current LHC searches for $A_0$ decaying into SM particles.
We report on an investigation of various problems related to the theory of the electroweak phase transition. This includes a determination of the nature of the phase transition, a discussion of the possible role of higher order radiative corrections and the theory of the formation and evolution of the bubbles of the new phase. We find in particular that no dangerous linear terms appear in the effective potential. However, the strength of the first order phase transition is 2/3 times less than what follows from the one-loop approximation. This rules out baryogenesis in the minimal version of the electroweak theory.
Light new physics weakly coupled to the Higgs can induce a strong first-order electroweak phase transition (EWPT). Here, we argue that scenarios in which the EWPT is driven first-order by a light scalar with mass between $sim 10$ GeV - $m_h/2$ and small mixing with the Higgs will be conclusively probed by the high-luminosity LHC and future Higgs factories. Our arguments are based on analytic and numerical studies of the finite-temperature effective potential and provide a well-motivated target for exotic Higgs decay searches at the LHC and future lepton colliders.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
