1,348 research outputs found
Sim(2) and SUSY
The proposal of hep-ph/0601236, that the laws of physics in flat spacetime
need be invariant only under a SIM(2) subgroup of the Lorentz group, is
extended to include supersymmetry. SUSY gauge theories which
include SIM(2) couplings for the fermions in chiral multiplets are formulated.
These theories contain two conserved supercharges rather than the usual four.Comment: 10 pages, revtex4. Note added and sign correcte
Diffusion Enhances Spontaneous Electroweak Baryogenesis
We include the effects of diffusion in the electroweak spontaneous
baryogenesis scenario and show that it can greatly enhance the resultant baryon
density, by as much as a factor of over previous
estimates. Furthermore, the baryon density produced is rather insensitive to
parameters characterizing the first order weak phase transition, such as the
width and propagation velocity of the phase boundary.Comment: 15 pages, uses harvmac and epsf macro
Towards a Nonequilibrium Quantum Field Theory Approach to Electroweak Baryogenesis
We propose a general method to compute -violating observables from
extensions of the standard model in the context of electroweak baryogenesis. It
is alternative to the one recently developed by Huet and Nelson and relies on a
nonequilibrium quantum field theory approach. The method is valid for all
shapes and sizes of the bubble wall expanding in the thermal bath during a
first-order electroweak phase transition. The quantum physics of -violation
and its suppression coming from the incoherent nature of thermal processes are
also made explicit.Comment: 19 pages, 1 figure available upon e-mail reques
3D N = 1 SYM Chern-Simons theory on the Lattice
We present a method to implement 3-dimensional N = 1 SUSY Yang-Mills theory
(a theory with two real supercharges containing gauge fields and an adjoint
Majorana fermion) on the lattice, including a way to implement the Chern-Simons
term present in this theory. At nonzero Chern-Simons number our implementation
suffers from a sign problem which will make the numerical effort grow
exponentially with volume. We also show that the theory with vanishing
Chern-Simons number is anomalous; its partition function identically vanishes.Comment: v2, minor changes: expanded discussion in section III c, typos
corrected, 17 pages, 9 figure
Relations among Supersymmetric Lattice Gauge Theories via Orbifolding
We show how to derive Catterall's supersymmetric lattice gauge theories
directly from the general principle of orbifolding followed by a variant of the
usual deconstruction. These theories are forced to be complexified due to a
clash between charge assignments under U(1)-symmetries and lattice assignments
in terms of scalar, vector and tensor components for the fermions. Other
prescriptions for how to discretize the theory follow automatically by
orbifolding and deconstruction. We find that Catterall's complexified model for
the two-dimensional N=(2,2) theory has two independent preserved
supersymmetries. We comment on consistent truncations to lattice theories
without this complexification and with the correct continuum limit. The
construction of lattice theories this way is general, and can be used to derive
new supersymmetric lattice theories through the orbifolding procedure. As an
example, we apply the prescription to topologically twisted four-dimensional
N=2 supersymmetric Yang-Mills theory. We show that a consistent truncation is
closely related to the lattice formulation previously given by Sugino.Comment: 20 pages, LaTeX2e, no figur
Debye Screening and Baryogenesis during the Electroweak Phase Transition
We examine a recent claim that Debye screening will affect the charge
transport mechanism of anomalous electroweak baryogenesis. We show that the
effects of gauge charge screening do not affect the baryon number produced
during a first order electroweak phase transition. (Requires harvmac.tex)Comment: 12 pages, UCSD-PTH-92-19, BU-HEP-92-2
Lattice formulation of super Yang-Mills theory
We construct a lattice action for super Yang-Mills theory in
four dimensions which is local, gauge invariant, free of spectrum doubling and
possesses a single exact supersymmetry. Our construction starts from the
observation that the fermions of the continuum theory can be mapped into the
component fields of a single real anticommuting Kahler-Dirac field. The
original supersymmetry algebra then implies the existence of a nilpotent scalar
supercharge and a corresponding set of bosonic superpartners. Using this
field content we write down a -exact action and show that, with an
appropriate change of variables, it reduces to a well-known twist of super Yang-Mills theory due to Marcus. Using the discretization
prescription developed in an earlier paper on the theory in two
dimensions we are able to translate this geometrical action to the lattice.Comment: 15 pages. 1 reference correcte
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