44 research outputs found
Spontaneous Left-Right Symmetry Breaking in Supersymmetric Models with only Higgs Doublets
We studied the question of parity breaking in a supersymmetric left-right
model, in which the left-right symmetry is broken with Higgs doublets (carrying
). Unlike the left-right symmetric models with triplet Higgs scalars
(carrying ), in this model it is possible to break parity
spontaneously by adding a parity odd singlet. We then discussed how neutrino
mass of type III seesaw can be invoked in this model by adding extra fermion
singlets. We considered simple forms of the mass matrices that are consistent
with the unification scheme and demonstrate how they can reproduce the required
neutrino mixing matrix. In this model, the baryon asymmetry of the universe is
generated via leptogenesis. The required mass scales in the model is then found
to be consistent with the gauge coupling unification.Comment: 19 pages, 1 eps figur
Naturalness of parity breaking in a supersymmetric SO(10) model
We consider a supersymmetric SO(10) model which remains renormalisable upto
Planck scale. The cosmology of such a model passes through a Left-Right
symmetric phase. Potential problems associated with domain walls can be evaded
if parity breaking is induced by soft terms when supersymmetry breaks in the
hidden sector. The smallness of this breaking permits a brief period of
domination by the domain walls ensuring dilution of gravitinos and other
unwanted relics. The requirement that domain walls disappear constrains some of
the soft parameters of the Higgs potential.Comment: 4 pages, To appear in Proceedings of SUSY06, the 14th International
Conference on Supersymmetry and the Unification of Fundamental Interactions,
UC Irvine, California, 12-17 June 200
Cosmology in a supersymmetric model with gauged
We consider salient cosmological features of a supersymmetric model which is
Left-Right symmetric and therefore possessing gauged symmetry. The
requirement of breaking parity and also obtaining charge preserving vacua
introduces some unique features to this model (MSLRM), resulting in a
preference for non-thermal Leptogenesis. Assuming that the model preserves TeV
scale supersymmetry, we show that the vacuum structure generically possesses
domain walls, which can serve two important purposes. They can signal a
secondary inflation required to remove unwanted relics such as gravitino and
moduli and also generate lepton asymmetry by a mechanism similar to electroweak
baryogenesis. The requirement of disappearance of domain walls imposes
constraints on the soft parameters of the theory, testable at the TeV scale. We
also propose an alternative model with spontaneous parity violation
(MSLR\rlap/P). Incorporating the same cosmological considerations in this case
entails constraints on a different set of soft parameters.Comment: 18 pages. Minor changes in text, but conclusion remains same.
Published in Phys. Rev.
Gauge mediated supersymmetry breaking and the cosmology of Left-Right symmetric model
Left-Right symmetry including supersymmetry presents an important class of
gauge models which may possess natural solutions to many issues of
phenomenology. Cosmology of such models indicates a phase transition
accompanied by domain walls. Such walls must be unstable in order to not
conflict with standard cosmology, and can further be shown to assist with open
issues of cosmology such as dilution of unwanted relic densities and
leptogenesis. In this paper we construct a model of gauge mediated
supersymmetry breaking in which parity breaking is also signalled along with
supersymmetry breaking and so as to be consistent with cosmological
requirements. It is shown that addressing all the stated cosmological issues
requires an extent of fine tuning, while in the absence of fine tuning,
leptogenesis accompanying successful completion of the phase transition is
still viable
Ultrathin thermoresponsive self-folding 3D graphene
Graphene and other two-dimensional materials have unique physical and chemical properties of broad relevance. It has been suggested that the transformation of these atomically planar materials to three-dimensional (3D) geometries by bending, wrinkling, or folding could significantly alter their properties and lead to novel structures and devices with compact form factors, but strategies to enable this shape change remain limited. We report a benign thermally responsive method to fold and unfold monolayer graphene into predesigned, ordered 3D structures. The methodology involves the surface functionalization of monolayer graphene using ultrathin noncovalently bonded mussel-inspired polydopamine and thermoresponsive poly(N-isopropylacrylamide) brushes. The functionalized graphene is micropatterned and self-folds into ordered 3D structures with reversible deformation under a full control by temperature. The structures are characterized using spectroscopy and microscopy, and self-folding is rationalized using a multiscale molecular dynamics model. Our work demonstrates the potential to design and fabricate ordered 3D graphene structures with predictable shape and dynamics. We highlight applicability by encapsulating live cells and creating nonlinear resistor and creased transistor devices.United States. Office of Naval Research. Multidisciplinary University Research Initiative (FA9550-16-1-0031)United States. Office of Naval Research. Multidisciplinary University Research Initiative ( FA9550-15-1-0514)National Science Foundation (U.S.) (CMMI-1635443)United States. Office of Naval Research (N00014-16-1-2333
Spontaneous CP violation in quark scattering from QCD Z(3) interfaces
In this paper, we explore the possibility of spontaneous CP violation in the
scattering of quarks and anti-quarks from QCD Z(3) domain walls. The CP
violation here arises from the nontrivial profile of the background gauge field
between different Z(3) vacua. We calculate the spatial variation of
across the Z(3) interface from the profile of the Polyakov loop
for the Z(3) interface and calculate the reflection of quarks and
antiquarks using the Dirac equation. This spontaneous CP violation has
interesting consequences for the relativistic heavy-ion collision experiments,
such as baryon enhancement at high . It also acts as a source of
additional J/ suppression. We also discuss its implications for the early
universe.Comment: 13 pages, Latex, 7 figures, Two different effective potentials
studied with similar temperatures showing consistent results. Final published
versio
