3,181 research outputs found
A supersymmetric resolution of the anomaly in charmless nonleptonic -decays
We examine the large branching ratio for the process
from the standpoint of R parity violating supersymmetry. We have given all
possible violating contributions to amplitudes. We
find that only two pairs of -type violating couplings
can solve this problem after satisfying all other experimental bounds. We also
analyze those modes where these couplings can appear, {\em e.g.}, , , etc., and predict their branching ratios. Further, one of these two
pairs of couplings is found to lower the branching ratio of , thereby allowing larger . This allows us to fit
and , which could not
be done in the SM framework.Comment: 12 pages, 5 figure
Quantum entanglement: The unitary 8-vertex braid matrix with imaginary rapidity
We study quantum entanglements induced on product states by the action of
8-vertex braid matrices, rendered unitary with purely imaginary spectral
parameters (rapidity). The unitarity is displayed via the "canonical
factorization" of the coefficients of the projectors spanning the basis. This
adds one more new facet to the famous and fascinating features of the 8-vertex
model. The double periodicity and the analytic properties of the elliptic
functions involved lead to a rich structure of the 3-tangle quantifying the
entanglement. We thus explore the complex relationship between topological and
quantum entanglement.Comment: 4 pages in REVTeX format, 2 figure
A statistical model with a standard Gamma distribution
We study a statistical model consisting of basic units which interact
with each other by exchanging a physical entity, according to a given
microscopic random law, depending on a parameter . We focus on the
equilibrium or stationary distribution of the entity exchanged and verify
through numerical fitting of the simulation data that the final form of the
equilibrium distribution is that of a standard Gamma distribution. The model
can be interpreted as a simple closed economy in which economic agents trade
money and a saving criterion is fixed by the saving propensity .
Alternatively, from the nature of the equilibrium distribution, we show that
the model can also be interpreted as a perfect gas at an effective temperature
, where particles exchange energy in a space with an effective
dimension .Comment: 5 pages, including 4 figures. Uses REVTeX styl
A Curious Truncation of N=4 Yang-Mills
The coupling constant dependence of correlation functions of BPS operators in
N=4 Yang-Mills can be expressed in terms of integrated correlation functions.
We approximate these integrated correlators by using a truncated OPE expansion.
This leads to differential equations for the coupling dependence. When applied
to a particular sixteen point correlator, the coupling dependence we find
agrees with the corresponding amplitude computed via the AdS/CFT
correspondence. We conjecture that this truncation becomes exact in the large N
and large 't Hooft coupling limit.Comment: 10 pages, LaTeX; additional comments, added reference
Two-loop neutrino masses with large R-parity violating interactions in supersymmetry
We attempt to reconcile large trilinear R-parity violating interactions in a
supersymmetric (SUSY) theory with the observed pattern of neutrino masses and
mixing. We show that, with a restricted number of such interaction terms with
the -type couplings in the range (0.1-1.0), it is possible to forbid
one-loop contributions to the neutrino mass matrix. This is illustrated with
the help of a `working example' where an econnomic choice of SUSY parameters is
made, with three non-vanishing and `large' R-parity violating terms in the
superpotential. The two-loop contributions in such a case can not only generate
the masses in the requisite order but can also lead us to specific allowed
regions of the parameter space.Comment: Revised version, 25 pages, 16 figure
Constraining Scalar Leptoquarks from the K and B Sectors
Upper bounds at the weak scale are obtained for all
type product couplings of the scalar leptoquark
model which may affect K-K(bar), B_d-B_d(bar), and B_s-B_s(bar)$ mixing, as
well as leptonic and semileptonic K and B decays. Constraints are obtained for
both real and imaginary parts of the couplings. We also discuss the role of
leptoquarks in explaining the anomalously large CP-violating phase in
B_s-B_s(bar) mixing.Comment: 16 pages, 5 figures, more constraints analyzed, added a number of
reference
Interpolating Action for Strings and Membranes - a Study of Symmetries in the Constrained Hamiltonian Approach
A master action for bosonic strings and membranes, interpolating between the
Nambu--Goto and Polyakov formalisms, is discussed. The role of the gauge
symmetries vis-\`{a}-vis reparametrization symmetries of the various actions is
analyzed by a constrained Hamiltonian approach. This analysis reveals the
difference between strings and higher branes, which is essentially tied to a
degree of freedom count. The cosmological term for membranes follows naturally
in this scheme. The conncetion of our aproach with the Arnowitt--Deser--Misner
representation in general relativity is illuminated.Comment: LaTex, 23 pages; discussion on ADM representation included and new
references adde
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