17,668,052 research outputs found
N-[4-(4-Nitrophenoxy)phenyl]-propionamide
The title compound, C15H14N2O4, is an important intermediate for the synthesis of thermotropic liquid crystals. The dihedral angle between the two aromatic rings is 84.29 (4)°. An N-H...O hydrogen bond connects the molecules into chains running along the b axis. In addition, the crystal packing is stabilized by weak C-H...O hydrogen bonds. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.002 Å; R factor = 0.036; wR factor = 0.096; data-to-parameter ratio = 14.3
N=4 Extended MSSM
We investigate a perturbative N=4 sector coupled to the MSSM and show that it
allows for a stable vacuum correctly breaking the electroweak symmetry. The
particle spectrum of the MSSM is enrichened by several new particles stemming
out from the new N=4 sector of the theory, and a new lepton doublet required to
cancel global and gauge anomalies of the theory. Even if the conformal
invariance of the N=4 sector is explicitly broken, a nontrivial UV behavior of
the coupling constants is possible: by studying the renormalization group
equations at two loops we find that the Yukawa couplings of the heavy fermionic
states flow to a common fixed point at a scale of a few TeVs. The parameter
space of the new theory is reduced imposing naturalness of the couplings and
soft supersymmetry breaking masses, perturbativity of the model at the EW scale
as well as phenomenological constraints. Our preliminary results on the
spectrum of the theory suggest that the LHC can rule out a significant portion
of the parameter space of this model.Comment: 22 pages, 2 figure
Gauged N=4 supergravities
We present the gauged N=4 (half-maximal) supergravities in four and five
spacetime dimensions coupled to an arbitrary number of vector multiplets. The
gaugings are parameterized by a set of appropriately constrained constant
tensors, which transform covariantly under the global symmetry groups SL(2) x
SO(6,n) and SO(1,1) x SO(5,n), respectively. In terms of these tensors the
universal Lagrangian and the Killing Spinor equations are given. The known
gaugings, in particular those originating from flux compactifications, are
incorporated in the formulation, but also new classes of gaugings are found.
Finally, we present the embedding chain of the five dimensional into the four
dimensional into the three dimensional gaugings, thereby showing how the
deformation parameters organize under the respectively larger duality groups.Comment: 36 pages, v2: references added, comments added, v3: published
version, references added, typos corrected, v4: sign mistakes in footnote 4
and equation (2.13) correcte
The N=2(4) string is self-dual N=4 Yang-Mills
N=2 string amplitudes, when required to have the Lorentz covariance of the
equivalent N=4 string, describe a self-dual form of N=4 super Yang-Mills in 2+2
dimensions. Spin-independent couplings and the ghost nature of SO(2,2)
spacetime make it a topological-like theory with vanishing loop corrections.Comment: 7 pg., ITP-SB-92-24 (uuencoded dvi file; otherwise same as original
Electrically gauged N=4 supergravities in D=4 with N=2 vacua
We study N=2 vacua in spontaneously broken N=4 electrically gauged
supergravities in four space-time dimensions. We argue that the classification
of all such solutions amounts to solving a system of purely algebraic
equations. We then explicitly construct a special class of consistent N=2
solutions and study their properties. In particular we find that the spectrum
assembles in N=2 massless or BPS supermultiplets. We show that (modulo U(1)
factors) arbitrary unbroken gauge groups can be realized provided that the
number of N=4 vector multiplets is large enough. Below the scale of partial
supersymmetry breaking we calculate the relevant terms of the low-energy
effective action and argue that the special Kahler manifold for vector
multiplets is completely determined, up to its dimension, and lies in the
unique series of special Kahler product manifolds.Comment: 48 pages; v2: one reference adde
N=4 Topological Strings
We show how to make a topological string theory starting from an
superconformal theory. The critical dimension for this theory is
(). It is shown that superstrings (in both the RNS and GS formulations)
and critical strings are special cases of this topological theory.
Applications for this new topological theory include: 1) Proving the vanishing
to all orders of all scattering amplitudes for the self-dual string with
flat background, with the exception of the three-point function and the
closed-string partition function; 2) Showing that the topological partition
function of the string on the background may be interpreted as
computing the superpotential in harmonic superspace generated upon
compactification of type II superstrings from 10 to 6 dimensions; and 3)
Providing a new prescription for calculating superstring amplitudes which
appears to be free of total-derivative ambiguities.Comment: 71 pages tex (some minor corrections and additional references
Large N=4 Holography
The class of 2d minimal model CFTs with higher spin AdS3 duals is extended to
theories with large N=4 superconformal symmetry. We construct a higher spin
theory based on the global D(2,1|alpha) superalgebra, and propose a large N
family of cosets as a dual CFT description. We also indicate how a non-abelian
version of this Vasiliev higher spin theory might give an alternative
description of IIB string theory on an AdS3 x S3 x S3 x S1 background.Comment: 41 pages, LaTe
Oxidizing SuperYang-Mills from (N=4,d=4) to (N=1,d=10)
We introduce superspace generalizations of the transverse derivatives to
rewrite the four-dimensional N=4 Yang-Mills theory into the fully
ten-dimensional N=1 Yang-Mills in light-cone form. The explicit SuperPoincare
algebra is constructed and invariance of the ten-dimensional action is proved.Comment: 15 page
Symmetries of N=4 supersymmetric CP(n) mechanics
We explicitly constructed the generators of group which commute
with the supercharges of N=4 supersymmetric mechanics in the
background U(n) gauge fields. The corresponding Hamiltonian can be represented
as a direct sum of two Casimir operators: one Casimir operator on
group contains our bosonic and fermionic coordinates and momenta, while the
second one, on the SU(1,n) group, is constructed from isospin degrees of
freedom only.Comment: 10 pages, PACS numbers: 11.30.Pb, 03.65.-w; minor changes in
Introduction, references adde
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