3,892 research outputs found
Energy barrier in the two-Higgs model
The electroweak model is extended by a second Higgs doublet and a numerical
investigation of static, finite energy classical solutions is performed. The
results indicate that for a large domain of the parameters of the Higgs
potential, the energy barrier between topologically distinct vacua of the
Lagrangian is constituted by a bisphaleron.Comment: 19 pages, including 4 eps figures, LaTex format, new results include
On Axially Symmetric Solutions in the Electroweak Theory
We present the general ansatz, the energy density and the Chern-Simons charge
for static axially symmetric configurations in the bosonic sector of the
electroweak theory. Containing the sphaleron, the multisphalerons and the
sphaleron-antisphaleron pair at finite mixing angle, the ansatz further allows
the construction of the sphaleron and multisphaleron barriers and of the
bisphalerons at finite mixing angle. We conjecture that further solutions
exist.Comment: 17 pages, latex, THU-94/0
Sphalerons with CP-Violating Higgs Potentials
We investigate the effect on the sphaleron in the two Higgs doublet
electroweak theory of including CP violation in the Higgs potential. To have
better control over the relation between the sphaleron energy and the physical
quantities in the theory, we show how to parametrize the Higgs potential in
terms of physical masses and mixing angles, one of which causes CP violation.
By altering this CP violating angle (and keeping the other physical quantities
fixed) the sphaleron energy increases by up to 10%. We also calculate the
static minimum energy path between adjacent vacua as a function of Chern-Simons
number, using the method of gradient flow. The only effect CP violation has on
the barrier is the change in height. As a by-product of our work on
parametrization of the potential, we demonstrate that CP violation in the Higgs
sector favours nearly degenerate light Higgs masses.Comment: 13pp LaTeX2e, 2 eps figs, uses graphicx, a
Yang--Mills sphalerons in all even spacetime dimensions , : =3,4
The classical solutions to higher dimensional Yang--Mills (YM) systems, which
are integral parts of higher dimensional Einstein--YM (EYM) systems, are
studied. These are the gravity decoupling limits of the fully gravitating EYM
solutions. In odd spacetime dimensions, depending on the choice of gauge group,
these are either topologically stable or unstable. Both cases are analysed, the
latter numerically only. In even spacetime dimensions they are always unstable,
describing saddle points of the energy, and can be described as {\it
sphalerons}. This instability is analysed by constructing the noncontractible
loops and calculating the Chern--Simons (CS) charges, and also perturbatively
by numerically constructing the negative modes. This study is restricted to the
simplest YM system in spacetime dimensions , which is amply
illustrative of the generic case.Comment: 16 pages, 3 figures ; comments added, to appear in J. Phys.
- …