1,432 research outputs found
Dirac Gauginos in General Gauge Mediation
We extend the formulation by Meade, Seiberg and Shih of general gauge
mediation of supersymmetry breaking to include Dirac masses for the gauginos.
These appear through mixing of the visible sector gauginos with additional
states in adjoint representations. We illustrate the method by reproducing the
existing results in the literature for the gaugino and sfermion masses when
preserving R-symmetry. We then explain how the generation of same sign masses
for the two propagating degrees of freedom in the adjoint scalars can be
achieved. We end by commenting on the use of the formalism for describing U(1)
mixing.Comment: 22 pages, no figures. V2: minor corrections
Transonic and supersonic Euler computations of vortex-dominated flow fields about a generic fighter
Flow fields about a generic flighter model were computed using FL057, a 3-D, finite volume Euler code. Computed pressure coefficients, forces, and moments at several Mach numbers (0.6, 0.8, 1.2, 1.4, and 1.6) are compared with wind tunnel data over a wide range of angles of attack in order to determine the applicability of the code for the analysis of fighter configurations. Two configurations were studied, a wing-body and a wing-body-chine. FL057 predicted pressure distributions, forces, and moments well at low angles of attack, at which the flow was fully attached. The FL057 predictions were also accurate for some test conditions once the leading edge vortex became well established. At the subsonic speeds, FL057 predicted vortex breakdown earlier than that seen in the experimental results. Placing the chine on the forebody delayed the onset of bursting and improved the correlation between numerical and experimental data at the subsonic conditions
One-loop adjoint masses for branes at non-supersymmetric angles
This proceeding is based on arXiv:1105.0591 [hep-th] where we consider
breaking of supersymmetry in intersecting D-brane configurations by slight
deviation of the angles from their supersymmetric values. We compute the masses
generated by radiative corrections for the adjoint scalars on the brane
world-volumes. In the open string channel, the string two-point function
receives contributions only from the infrared limits of N~4 and N~2
supersymmetric configurations, via messengers and their Kaluza-Klein
excitations, and leads at leading order to tachyonic directions.Comment: 15 pages, 5 figures. Contribution to the proceedings of the Corfu
Summer Institute 2011 School and Workshops on Elementary Particle Physics and
Gravity, September 4-18 2011 Corfu, Greec
Dark Matter and Dark Forces from a supersymmetric hidden sector
We show that supersymmetric "Dark Force" models with gravity mediation are
viable. To this end, we analyse a simple string-inspired supersymmetric hidden
sector model that interacts with the visible sector via kinetic mixing of a
light Abelian gauge boson with the hypercharge. We include all induced
interactions with the visible sector such as neutralino mass mixing and the
Higgs portal term. We perform a detailed parameter space scan comparing the
produced dark matter relic abundance and direct detection cross sections to
current experiments.Comment: 40 pages, 11 figures comprising 21 plots. 4Mb total size. v2: figures
and references updated; typos removed; some extra explanations added. Matches
version published in PR
Promoting a structural view of biology for varied audiences: an overview of RCSB PDB resources and experiences
The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) serves a community of users with diverse backgrounds and interests. In addition to processing, archiving and distributing structural data, it also develops educational resources and materials to enable people to utilize PDB data and to further a structural view of biology
Chemical induction of spawning by serotonin in the ocean quahog Arctica islandica (Linne)
Serotonin injected into the anterior adductor muscle induced spawning in the ocean quahog Arcrica islandica (Linne) when using either individual or mass spawning techniques. This represents the fir st successful attempt to induce the release of gametes in this species which historically has been unresponsive to conventional spawning stimuli. The gametes released were competent and fertilization occurred without treating the encapsulated eggs with ammonium hydroxide or other chemicals. Larvae were reared through metamorphosis to early juvenile stage
A Three-dimensional Printed Low-cost Anterior Shoulder Dislocation Model for Ultrasound-guided Injection Training.
Anterior shoulder dislocations are the most common, large joint dislocations that present to the emergency department (ED). Numerous studies support the use of intraarticular local anesthetic injections for the safe, effective, and time-saving reduction of these dislocations. Simulation training is an alternative and effective method for training compared to bedside learning. There are no commercially available ultrasound-compatible shoulder dislocation models. We utilized a three-dimensional (3D) printer to print a model that allows the visualization of the ultrasound anatomy (sonoanatomy) of an anterior shoulder dislocation. We utilized an open-source file of a shoulder, available from embodi3D® (Bellevue, WA, US). After approximating the relative orientation of the humerus to the glenoid fossa in an anterior dislocation, the humerus and scapula model was printed with an Ultimaker-2 Extended+ 3D® (Ultimaker, Cambridge, MA, US) printer using polylactic acid filaments. A 3D model of the external shoulder anatomy of a live human model was then created using Structure Sensor®(Occipital, San Francisco, CA, US), a 3D scanner. We aligned the printed dislocation model of the humerus and scapula within the resultant external shoulder mold. A pourable ballistics gel solution was used to create the final shoulder phantom. The use of simulation in medicine is widespread and growing, given the restrictions on work hours and a renewed focus on patient safety. The adage of see one, do one, teach one is being replaced by deliberate practice. Simulation allows such training to occur in a safe teaching environment. The ballistic gel and polylactic acid structure effectively reproduced the sonoanatomy of an anterior shoulder dislocation. The 3D printed model was effective for practicing an in-plane ultrasound-guided intraarticular joint injection. 3D printing is effective in producing a low-cost, ultrasound-capable model simulating an anterior shoulder dislocation. Future research will determine whether provider confidence and the use of intraarticular anesthesia for the management of shoulder dislocations will improve after utilizing this model
Angular Dependence of the Dipole-Dipole Interaction in a Nearly One-Dimensional Sample of Rydberg Atoms
Atoms in an ultracold highly excited sample are strongly coupled through the dipole-dipole interaction. In an effort to understand and manipulate the complicated interactions in this system we are investigating their dependence on the relative orientation of the dipoles. By focusing a 480 nm beam from a tunable dye laser into a magneto-optical trap, we produce a nearly one-dimensional sample of Rydberg atoms. The trap lies at the center of four conducting rods with which we can vary the magnitude and direction of the electric field at the trap, thus controlling the orientation of the dipoles with respect to the sample axis. We have measured the strength of the interaction for a variety of relative orientations
Angular Dependence of the Dipole-Dipole Interaction in a Nearly One-Dimensional Sample of Rydberg Atoms
Atoms in an ultracold highly excited sample are strongly coupled through the dipole-dipole interaction. In an effort to understand and manipulate the complicated interactions in this system we are investigating their dependence on the relative orientation of the dipoles. By focusing a 480 nm beam from a tunable dye laser into a magneto-optical trap, we produce a nearly one-dimensional sample of Rydberg atoms. The trap lies at the center of four conducting rods with which we can vary the magnitude and direction of the electric field at the trap, thus controlling the orientation of the dipoles with respect to the sample axis. We have measured the strength of the interaction for a variety of relative orientations
Angular Dependence of the Dipole-Dipole Interaction in a Nearly One-Dimensional Sample of Rydberg Atoms
Atoms in an ultracold highly excited sample are strongly coupled through the dipole-dipole interaction. In an effort to understand and manipulate the complicated interactions in this system we are investigating their dependence on the relative orientation of the dipoles. By focusing a 480 nm beam from a tunable dye laser into a magneto-optical trap, we produce a nearly one-dimensional sample of Rydberg atoms. The trap lies at the center of four conducting rods with which we can vary the magnitude and direction of the electric field at the trap, thus controlling the orientation of the dipoles with respect to the sample axis.We have measured the strength of the interaction for a variety of relative orientations
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