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

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

Shells and Shapes in the N=28 isotones

International audienceNew experimental results on 43S and 44S reveal that these nuclei are located in a transitional region of shape coexistence between the spherical 48Ca and the oblate 42Si. The origin of the deformation is discussed in terms of the evolution of the single particle energy levels leading to the compression of the energy difference of the orbitals in the sd and pf shells for protons and neutrons, respectively. Therefore, due to quadrupole excitations across the Z = 14 and N = 28 gaps, the intruder configuration in the neutron rich S isotopes became the ground state

Baryon Binding Energy in Sakai-Sugimoto Model

The binding energy of baryon has been studied in the dual $AdS_5\times S^5$ string theory with a black hole interior. In this picture baryon is constructed of a $D_5$ brane vertex wrapping on $S^5$ and $N_c$ fundamental strings connected to it. Here, we calculate the baryon binding energy in Sakai-Sugimoto model with a $D_4/D_8/\bar{D_8}$ in which the supersymmetry is completely broken. Also we check the $T$ 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

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 $B$-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

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

Leishmaniose en Equateur : 6. Note épidémiologique et entomologique sur le foyer de leishmaniose de Zumba

La région de Zumba se trouve au sud de la province méridionale amazonienne d'Equateur de Zamora-Chinchipe, considérée comme la seconde zone d'endémie leishmanienne de ce pays. Une enquête clinico-épidémiologique a été effectuée sur 83 patients en détection passive. De plus, tous les biotopes du foyer de Zumba, dont les habitations, ont été échantillonés, de février à septembre 92, pour la récolte des phlébotomes au piège lumineux et sur appât humain (2.547 phlébotomes récoltés). La faune anthrophile est pauvre et trois espèces seulement ont été observées. #Lutzomyia serrana est une espèce abondante piquant même de jour. #Lu. maranonensis est une nouvelle espèce proche de #Lu. nevesi. Lu. castanea, autre nouvelle espèce, est rare. La localisation de nombreuses lésions à la face suggère, au moins en partie, une transmission domiciliaire, pour laquelle #Lu. serrana serait un candidat-vecteur possible étant donné son omniprésence et son anthropophile. (Résumé d'auteur

The Non-SUSY Baryonic Branch: Soft Supersymmetry Breaking of N=1 Gauge Theories

We study a non-supersymmetric deformation of the field theory dual to the baryonic branch of Klebanov-Strassler. Using a combination of analytical (series expansions) and numerical methods we construct non-supersymmetric backgrounds that smoothly interpolate between the desired UV and IR behaviors. We calculate various observables of the field theory and propose a picture of soft breaking by gaugino masses that is consistent with the various calculations on the string side.Comment: 32 pages plus many appendixes. One figur