相关论文: Electroweak Baryogenesis
Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links…
We propose a mechanism for baryogenesis in which the baryon asymmetry is generated as an equilibrium response of weak sphalerons in a region where electroweak sphaleron transitions remain unsuppressed, $h/T\lesssim 1$. A nonzero equilibrium…
We know that the generally accepted theories of gravity and quantum mechanics are fundamentally incompatible. Thus, when we try to combine these theories, we must beware of physical pitfalls. Modern theories of quantum gravity are trying to…
Many models of baryogenesis rely on anomalous particle physics processes to give baryon number violation. By numerically evolving the electroweak equations on a lattice, we show that baryogenesis in these models creates helical cosmic…
There is a paradox in the standard model of cosmology. How can matter in the early universe have been in thermal equilibrium, indicating maximum entropy, but the initial state also have been low entropy (the "past hypothesis"), so as to…
Electroweak baryogenesis is severely challenged in its traditional settings: the Minimal Supersymmetric Standard Model, and in more general two Higgs doublet models. Fine tuning of parameters is required, or large couplings leading to a…
The dramatic confrontation between new observations and theories of the early and recent universe makes cosmology one of the most rapidly advancing fields in the physical sciences. The universe is a unique laboratory in which to probe…
The current Universe is composed by a mixture of relativistic species, baryonic matter, dark matter and dark energy which evolve in a non-trivial way at perturbative level. An advanced description of the cosmological dynamics should include…
A possible connection between the abundances of baryonic and dark matter (DM) has been explored so far mostly in the context of the so-called asymmetric DM. Recently, a very different mechanism, dubbed "WIMPy baryogenesis", has been…
Over the last decades, observations with increasing quality have revolutionized our understanding of the general properties of the Universe. Questions posed for millenia by mankind about the origin, evolution and structure of the cosmos…
After some introductory remarks about the prospects of first order phase transitions in the early universe, we discuss in some detail the electroweak phase transition. In the standard model case a clear picture is arising including…
The simplest explanation for early time acceleration (inflation) and the late time acceleration indicated by recent data is that they have a common origin. We investigate another generic cosmological implication of this possiblity, that the…
Standard electroweak baryogenesis in the context of a first order phase transition is effective in generating the baryon asymmetry of the universe if the broken phase bubbles expand at subsonic speed, so that CP asymmetric currents can…
We study the electroweak baryogenesis in the framework of the effective field theory. Our study shows that by introducing a light singlet scalar particle and a dimension-5 operator, it can provide the strong first order phase transition and…
One signature of an expanding universe is the time-variation of the cosmological abundances of its different components. For example, a radiation-dominated universe inevitably gives way to a matter-dominated universe, and critical moments…
Some cosmological consequences of including the adequate conserved quantities in the density matrix of the electroweak theory are investigated. Several arguments against including the charges associated to the spontaneously broken symmetry…
1. Why we do Believe in the Standard Model 2. Why we do not Believe in the Standard Model 2.1 Conceptual Problems 2.2 Hints from Experiment 2.2.1 Unification of Couplings 2.2.2 Dark Matter 2.2.3 Neutrino Masses 2.2.4 Baryogenesis 3. Status…
In one scenario of baryogenesis, the matter-antimatter asymmetry was generated in the early universe during a cold electroweak transition. We model this transition by changing the sign of the effective mass-squared parameter of the Higgs…
We discuss the constraints on the Higgs sector coming from the requirement of the generation of the matter-antimatter asymmetry at the electroweak phase transition. These relate to both a strongly first order first transition, necessary for…
We study the viability of electroweak baryogenesis in a two Higgs doublet model scenario augmented by vector-like, electroweakly interacting fermions. Considering a limited, but illustrative region of the model parameter space, we obtain…