897 research outputs found
New Supergravity Backgrounds Dual to N=1 SQCD-like Theories with N_f=2N_c
We present new supergravity backgrounds generated by N_c D5-branes, wrapping
the S^2 of the resolved conifold, in the presence of N_f = 2 N_c smeared flavor
D5-branes. The smearing allows us to take their backreaction on the geometry
into account. We discuss the consistency, stability, and supersymmetry of these
types of setups. We find near horizon geometries that we expect to be
supergravity duals of SQCD-like theories with N_f= 2N_c. From these backgrounds
we numerically extract rectangular Wilson loops and beta functions of the dual
field theory for the regime where our approximations are valid.Comment: 22+24 pages, 17 figures, Figure 12 replace
Drag force in a string model dual to large-N QCD
We compute the drag force exerted on a quark and a di-quark systems in a
background dual to large-N QCD at finite temperature. We find that appears a
drag force in the former setup with flow of energy proportional to the mass of
the quark while in the latter there is no dragging as in other studies. We also
review the screening length.Comment: 15 pages, typos removed, error corrected, refs adde
Baryon Binding Energy in Sakai-Sugimoto Model
The binding energy of baryon has been studied in the dual
string theory with a black hole interior. In this picture baryon is constructed
of a brane vertex wrapping on and fundamental strings
connected to it. Here, we calculate the baryon binding energy in Sakai-Sugimoto
model with a in which the supersymmetry is completely
broken. Also we check the dependence of the baryon binding energy. We
believe that this model represents an accurate description of baryons due to
the existence of Chern-Simones coupling with the gauge field on the brane. We
obtain an analytical expression for the baryon binding energy . In that case we
plot the baryon binding energy in terms of radial coordinate. Then by using the
binding energy diagram, we determine the stability range for baryon
configuration. And also the position and energy of the stable equilibrium point
is obtained by the corresponding diagram. Also we plot the baryon binding
energy in terms of temperature and estimate a critical temperature in which the
baryon would be dissociated.Comment: 14 pages, 1 fi
Nonextensivity and multifractality in low-dimensional dissipative systems
Power-law sensitivity to initial conditions at the edge of chaos provides a
natural relation between the scaling properties of the dynamics attractor and
its degree of nonextensivity as prescribed in the generalized statistics
recently introduced by one of us (C.T.) and characterized by the entropic index
. We show that general scaling arguments imply that , where and are the
extremes of the multifractal singularity spectrum of the attractor.
This relation is numerically checked to hold in standard one-dimensional
dissipative maps. The above result sheds light on a long-standing puzzle
concerning the relation between the entropic index and the underlying
microscopic dynamics.Comment: 12 pages, TeX, 4 ps figure
Safety and Health in Mining
In the history of the mining sector, in its beginnings it faced very high levels of risks both safety and health.
The data are limited to serious accidents, and these are mainly associated with falls from land, transport and machinery.
Analysis of these data suggests that the leading causes of death tend to be the same as those of serious injuries, while disasters have a different profile. Over the past decade, mining disasters have been associated with explosions due to flammable gases, a fire on a conveyor belt, a flood of mud and water, and rock outbursts.
Mandatory compliance with a company's safety, health and environmental regulations is a minimum and can be significantly improved by adding a long-term management planning and implementation process with a deeper cultural shift towards continuous improvement in safety and quality. Note that the purpose of integrating health and safety into other management systems is the need for health and safety management to be central, rather than an organizational objective
Supersymmetric defects in the Maldacena-Nunez background
We find supersymmmetric configurations of a D5-brane probe in the
Maldacena-Nunez background which are extended along one or two of the spatial
directions of the gauge theory. These embeddings are worldvolume solitons which
behave as codimension two or one defects in the gauge theory and preserve two
of the four supersymmetries of the background.Comment: 37 pages, 2 figures, LaTeX; v2: references adde
Drag force in SYM plasma with B field from AdS/CFT
We investigate drag force in a thermal plasma of N=4 super Yang-Mills theory
via both fundamental and Dirichlet strings under the influence of non-zero NSNS
-field background. In the description of AdS/CFT correspondence the endpoint
of these strings correspondes to an external monopole or quark moving with a
constant electromagnetic field. We demonstrate how the configuration of string
tail as well as the drag force obtains corrections in this background.Comment: 13 pages, 2 figures, more discussion and reference adde
Unveiling the intruder deformed 0 state in Si
The 0 state in Si has been populated at the {\sc Ganil/Lise3}
facility through the -decay of a newly discovered 1 isomer in
Al of 26(1) ms half-life. The simultaneous detection of pairs
allowed the determination of the excitation energy E(0)=2719(3) keV and
the half-life T=19.4(7) ns, from which an electric monopole strength of
(E0)=13.0(0.9) was deduced. The 2 state is
observed to decay both to the 0 ground state and to the newly observed
0 state (via a 607(2) keV transition) with a ratio
R(2)=1380(717). Gathering all
information, a weak mixing with the 0 and a large deformation parameter
of =0.29(4) are found for the 0 state, in good agreement with
shell model calculations using a new {\sc sdpf-u-mix} interaction allowing
\textit{np-nh} excitations across the N=20 shell gap.Comment: 5 pages, 3 figures, accepted for publication in Physical Review
Letter
The Holographic Dual of 2+1 Dimensional QFTs with N=1 SUSY and Massive Fundamental Flavours
The Maldacena Nastase solution is generalised to include massive fundamental
matter through the addition of a flavour profile. This gives a holographic dual
to N=1 SYM-CS with massive fundamental matter with a singularity free IR. We
study this solution in some detail confirming confinement and asymptotic
freedom. A recently proposed solution generating technique is then applied
which results in a new type-IIA supergravity solution. In a certain limit the
geometry of this solution is asymptotically AdS_4X Y, where Y is the metric at
the base of the Bryant-Salamon G_2 cone, which has topology S^3XS^3.Comment: 31 pages plus appendices, 6 figures. v3: Typos corrected, version to
appear in JHE
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