2,055 research outputs found
Real time simulations and the electroweak phase transition
We review recent developments in real-time simulations of SU(2)-Higgs theory
near the electroweak transition and related topics.Comment: 6 pages, latex, 4 figures; to appear in the proceedings of LATTICE
'9
Cold Electroweak Baryogenesis
We present arguments that the CKM CP-violation in the standard model may be
sufficient for the generation of the baryon asymmetry, if the electroweak
transition in the early universe was of the cold, tachyonic, type after
electroweak-scale inflation. A model implementing this is described which
complies with the CMB constraints and which is falsifiable with the LHC.
Numerical simulations of the tachyonic transition with an effective CP-bias
indicate that the observed baryon asymmetry can be generated this way.Comment: 10 pages, 4 figures, presented at Strong and ElectroWeak Matter 200
Simulations of Cold Electroweak Baryogenesis: Dependence on Higgs mass and strength of CP-violation
Cold electroweak baryogenesis was proposed as a scenario to bypass generic
problems of electroweak baryogenesis within the Standard Model. In this
scenario, baryogenesis takes place during an electroweak symmetry breaking
transition, which is also responsible for preheating after inflation. In the
simplest modelling of the scenario, only two parameters remain undetermined:
The Higgs mass and the strength of CP violation. Using full real-time lattice
simulations, we compute the dependence of the asymmetry on these parameters.Comment: 14 pages, 13 figure
No strong coupling regime in the fermion-Higgs sector of the standard model
We present results for the renormalized quartic self-coupling \lm_R and the
renormalized Yukawa coupling in a fermion-Higgs model with two SU(2)
doublets, indicating that these couplings are not very strong.Comment: 4 pages, 4 postscript figures (appended), ITFA-92-32, HLRZ-92-92,
UCSD/PTH 92-43, Contribution to the Conference Lattice'9
Chern-Simons number asymmetry from CP violation at electroweak tachyonic preheating
We consider the creation of non-zero Chern-Simons number in a model of the
early Universe, where the Higgs field experiences a fast quench at the end of
inflation and subsequently rolls down its potential barrier. Neglecting the
expansion, we perform numerical lattice simulations in the Abelian Higgs model
in 1+1 dimensions with an added phenomenological C and P violating term during
this stage of so-called tachyonic preheating. The results suggest that even the
sign of the Chern-Simons and thus baryon number is dependent on the ratio of
the Higgs to W mass. We also discuss the appropriate choice of vacuum initial
conditions for classical simulations.Comment: 24 pages, 17 figures, added references, published versio
Chiral gauge theories on the lattice and restoration of gauge symmetry
We investigate a proposal for the construction of models with chiral fermions
on the lattice using staggered fermions. In this approach the gauge invariance
is broken by the coupling of the staggered fermions to the gauge fields. We aim
at a dynamical restoration of the gauge invariance in the full quantum model.
If the gauge symmetry breaking (SB) is not too severe, this procedure could
lead in the continuum limit to the desired gauge invariant chiral gauge theory.Comment: 3 pages, 2 postscript files appended (uuencoded), contribution to
Lattice'93, ITFA 93-32, UCSD/PTH 93-3
Sphaleron rate at high temperature in 1+1 dimensions
We resolve the controversy in the high temperature behavior of the sphaleron
rate in the abelian Higgs model in 1+1 dimensions. The behavior at
intermediate lattice spacings is found to change into behavior in the
continuum limit. The results are supported by analytic arguments that the
classical approximation is good for this model.Comment: LATTICE98(electroweak
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