32,722 research outputs found
Spontaneous symmetry breaking in the -symmetric scalar sector
We present a detailed study of the vacua of the -symmetric
three-Higgs-doublet potential, specifying the region of parameters where these
minimisation solutions occur. We work with a CP conserving scalar potential and
analyse the possible real and complex vacua with emphasis on the cases in which
the CP symmetry can be spontaneously broken. Results are presented both in the
reducible-representation framework of Derman, and in the
irreducible-representation framework. Mappings between these are given. Some of
these implementations can in principle accommodate dark matter and for that
purpose it is important to identify the residual symmetries of the potential
after spontaneous symmetry breakdown. We are also concerned with constraints
from vacuum stability.Comment: 37 pages. v2: Minor changes in the references, matches published
version. v3: Table 6 corrected: two additional cases conserve CP. Related
discussion adapted. Version consistent with JHEP Erratu
Spontaneous symmetry breaking in three-Higgs-doublet -symmetric models
The talk summarises work done by the authors consisting of a detailed study
of the possible vacua in models with three Higgs doublets with symmetry
and without explicit CP violation. Different vacua require special regions of
the parameter space which were analysed in our work. We establish the
possibility of spontaneous CP violation in this framework and we also show
which complex vacua conserve CP. In our work we discussed constraints from
vacuum stability. The results presented here are relevant for model building.Comment: 11 pages, no figures. Prepared for the proceedings of DISCRETE2016:
the Fifth Symposium on Prospects in the Physics of Discrete Symmetries, 28
November-3 December 2016, University of Warsaw, Poland, to appear in the
Journal of Physics: Conference Series (JPCS
Random-energy model in random fields
The random-energy model is studied in the presence of random fields.
The problem is solved exactly both in the microcanonical ensemble, without
recourse to the replica method, and in the canonical ensemble using the replica
formalism. The phase diagrams for bimodal and Gaussian random fields are
investigated in detail. In contrast to the Gaussian case, the bimodal random
field may lead to a tricritical point and a first-order transition. An
interesting feature of the phase diagram is the possibility of a first-order
transition from paramagnetic to mixed phase.Comment: 18 pages, 5 figures (included
Gauge Field Emergence from Kalb-Ramond Localization
A new mechanism, valid for any smooth version of the Randall-Sundrum model,
of getting localized massless vector field on the brane is described here. This
is obtained by dimensional reduction of a five dimension massive two form, or
Kalb-Ramond field, giving a Kalb-Ramond and an emergent vector field in four
dimensions. A geometrical coupling with the Ricci scalar is proposed and the
coupling constant is fixed such that the components of the fields are
localized. The solution is obtained by decomposing the fields in transversal
and longitudinal parts and showing that this give decoupled equations of motion
for the transverse vector and KR fields in four dimensions. We also prove some
identities satisfied by the transverse components of the fields. With this is
possible to fix the coupling constant in a way that a localized zero mode for
both components on the brane is obtained. Then, all the above results are
generalized to the massive form field. It is also shown that in general an
effective and forms can not be localized on the brane and we have
to sort one of them to localize. Therefore, we can not have a vector and a
scalar field localized by dimensional reduction of the five dimensional vector
field. In fact we find the expression which determines what forms
will give rise to both fields localized. For , as expected, this is valid
only for the KR field.Comment: Improved version. Some factors corrected and definitions added. The
main results continue vali
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