4,070 research outputs found
Duality and other Exotic Gauge Dynamics in Softly Broken Supersymmetric QCD
We analyze the theory of softly broken supersymmetric . Exotic behavior
like spontaneously broken baryon number, massless composite fermions and
Seiberg's duality seems to persist also in the presence of (small) soft
supersymmetry breaking. We argue that certain, specially tailored, lattice
simulations may be able to detect the novel phenomena. Most of the exotic
behavior does not survive the decoupling limit of large SUSY breaking
parameters.Comment: 13 page
On Heterotic Orbifolds, M Theory and Type I' Brane Engineering
Horava--Witten M theory -- heterotic string duality poses special problems
for the twisted sectors of heterotic orbifolds. In [1] we explained how in M
theory the twisted states couple to gauge fields apparently living on M9 branes
at both ends of the eleventh dimension at the same time. The resolution
involves 7D gauge fields which live on fixed planes of the (T^4/Z_N) x
(S^1/Z_2) x R^{5,1} orbifold and lock onto the 10D gauge fields along the
intersection planes. The physics of such intersection planes does not follow
directly from the M theory but there are stringent kinematic constraints due to
duality and local consistency, which allowed us to deduce the local fields and
the boundary conditions at each intersection. In this paper we explain various
phenomena at the intersection planes in terms of duality between HW and type I'
superstring theories. The orbifold fixed planes are dual to stacks of D6
branes, the M9 planes are dual to O8 orientifold planes accompanied by D8
branes, and the intersections are dual to brane junctions. We engineer several
junction types which lead to distinct patterns of 7D/10D gauge field locking,
7D symmetry breaking and/or local 6D fields. Another aspect of brane
engineering is putting the junctions together; sometimes, the combined effect
is rather spectacular from the HW point of view and the quantum numbers of some
twisted states have to `bounce' off both ends of the eleventh dimension before
their heterotic identity becomes clear. Some models involve D6/O8 junctions
where the string coupling diverges towards the orientifold plane. We use the
heterotic-HW-I' duality to predict what should happen at such junctions.Comment: 118 pages, uses phyzzx, color printer advice
A Rare Case of Jejunal Arterio-Venous Fistula: Treatment with Superselective Catheter Embolization with a Tracker-18 Catheter and Microcoils
Arterio-venous fistulas may develop spontaneously, following trauma or infection, or be iatrogenic in nature. We present a rare case of a jejunal arterio- venous fistula in a 35-year-old man with a history of pancreatic head resection that had been performed two years previously because of chronic pancreatitis. The patient was admitted with acute upper abdominal pain, vomiting and an abdominal machinery-type bruit. The diagnosis of a jejunal arterio-venous fistula was established by MR imaging. Transfemoral angiography was performed to assess the possibility of catheter embolization. The angiographic study revealed a small aneurysm of the third jejunal artery, abnormal early filling of dilated jejunal veins and marked filling of the slightly dilated portal vein (13-14 mm). We considered the presence of segmental portal hypertension. The patient was treated with coil embolization in the same angiographic session. This case report demonstrates the importance of auscultation of the abdomen in the initial clinical examination. MR imaging and color Doppler ultrasound are excellent noninvasive tools in establishing the diagnosis. The role of interventional radiological techniques in the treatment of early portal hypertension secondary to jejunal arterio-venous fistula is discussed at a time when this condition is still asymptomatic. A review of the current literature is include
Maximum intensity projection of cranial computed tomography data for dental identification
Dental radiographs play the major role in the identification of victims in mass casualties besides DNA. Under circumstances such as those caused by the recent tsunami in Asia, it is nearly impossible to document the entire dentition using conventional x-rays as it would be too time consuming. Multislice computed tomography can be used to scan the dentition of a deceased within minutes, and the postprocessing software allows visualization of the data adapted to every possible antemortem x-ray for identification. We introduce the maximum intensity projection of cranial computed tomography data for the purpose of dental identification exemplarily in a case of a burned corpse. As transportable CT scanners already exist, these could be used to support the disaster victim identification teams in the fiel
(T) Duality and other Exotic Gauge Dynamics in Softly Broken Supersymmetric QCD
We analyze the theory of softly broken supersymmetric QCD. Exotic behavior like spontaneously broken baryon number, massless composite fermions and Seiberg’s duality seems to persist also in the presence of (small) soft supersymmetry breaking. We argue that certain, specially tailored, lattice simulations may be able to detect the novel phenomena. Most of the exotic behavior does not survive the decoupling limit of large SUSY breaking parameters. Based on a talk presented by J. S in SUSY 95
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