646 research outputs found
Pseudomoduli Dark Matter and Quiver Gauge Theories
We investigate supersymmetric models for dark matter which is represented by
pseudomoduli in weakly coupled hidden sectors. We propose a scheme to add a
dark matter sector to quiver gauge theories with metastable supersymmetry
breaking. We discuss the embedding of such scheme in string theory and we
describe the dark matter sector in terms of D7 flavour branes. We explore the
phenomenology in various regions of the parameters.Comment: 24 pages, 12 figures, JHEP3.cl
Direct generation of photon triplets using cascaded photon-pair sources
Non-classical states of light, such as entangled photon pairs and number
states, are essential for fundamental tests of quantum mechanics and optical
quantum technologies. The most widespread technique for creating these quantum
resources is the spontaneous parametric down-conversion (SPDC) of laser light
into photon pairs. Conservation of energy and momentum in this process, known
as phase-matching, gives rise to strong correlations which are used to produce
two-photon entanglement in various degrees of freedom. It has been a
longstanding goal of the quantum optics community to realise a source that can
produce analogous correlations in photon triplets, but of the many approaches
considered, none have been technically feasible. In this paper we report the
observation of photon triplets generated by cascaded down-conversion. Here each
triplet originates from a single pump photon, and therefore quantum
correlations will extend over all three photons in a way not achievable with
independently created photon pairs. We expect our photon-triplet source to open
up new avenues of quantum optics and become an important tool in quantum
technologies. Our source will allow experimental interrogation of novel quantum
correlations, the post-selection free generation of tripartite entanglement
without post- selection and the generation of heralded entangled-photon pairs
suitable for linear optical quantum computing. Two of the triplet photons have
a wavelength matched for optimal transmission in optical fibres, ideally suited
for three-party quantum communication. Furthermore, our results open
interesting regimes of non-linear optics, as we observe spontaneous
down-conversion pumped by single photons, an interaction also highly relevant
to optical quantum computing.Comment: 7 pages, 3 figures, 1 table; accepted by Natur
Association between labour market trends and trends in young people's mental health in ten European countries 1983-2005
<p>Abstract</p> <p>Background</p> <p>Mental health problems have become more common among young people over the last twenty years, especially in certain countries. The reasons for this have remained unclear. The hypothesis tested in this study is that national trends in young people's mental health are associated with national trends in young people's labour market.</p> <p>Methods</p> <p>National secular changes in the proportion of young people with mental health problems and national secular labour market changes were studied from 1983 to 2005 in Austria, Belgium, Denmark, Finland, Hungary, Norway, Spain, Sweden, Switzerland and the United Kingdom.</p> <p>Results</p> <p>The correlation between the national secular changes in the proportion of young people not in the labour force and the national secular changes in proportion of young people with mental health symptoms was 0.77 for boys and 0.92 for girls.</p> <p>Conclusion</p> <p>Labour market trends may have contributed to the deteriorating trend in mental health among young people. A true relationship, should other studies confirm it, would be an important aspect to take into account when forming labour market policies or policies concerning the delivery of higher education.</p
General Neutralino NLSPs at the Early LHC
Gauge mediated supersymmetry breaking (GMSB) is a theoretically
well-motivated framework with rich and varied collider phenomenology. In this
paper, we study the Tevatron limits and LHC discovery potential for a wide
class of GMSB scenarios in which the next-to-lightest superpartner (NLSP) is a
promptly-decaying neutralino. These scenarios give rise to signatures involving
hard photons, 's, 's, jets and/or higgses, plus missing energy. In order
to characterize these signatures, we define a small number of minimal spectra,
in the context of General Gauge Mediation, which are parameterized by the mass
of the NLSP and the gluino. Using these minimal spectra, we determine the most
promising discovery channels for general neutralino NLSPs. We find that the
2010 dataset can already cover new ground with strong production for all NLSP
types. With the upcoming 2011-2012 dataset, we find that the LHC will also have
sensitivity to direct electroweak production of neutralino NLSPs.Comment: 26 page
Anomalous Dimensions of Non-Chiral Operators from AdS/CFT
Non-chiral operators with positive anomalous dimensions can have interesting
applications to supersymmetric model building. Motivated by this, we develop a
new method for obtaining the anomalous dimensions of non-chiral double-trace
operators in N=1 superconformal field theories (SCFTs) with weakly-coupled AdS
duals. Via the Hamiltonian formulation of AdS/CFT, we show how to directly
compute the anomalous dimension as a bound state energy in the gravity dual.
This simplifies previous approaches based on the four-point function and the
OPE. We apply our method to a class of effective AdS5 supergravity models, and
we find that the binding energy can have either sign. If such models can be UV
completed, they will provide the first calculable examples of SCFTs with
positive anomalous dimensions.Comment: 38 pages, 2 figures, refs adde
Self-supervised Outdoor Scene Relighting
Outdoor scene relighting is a challenging problem that requires good
understanding of the scene geometry, illumination and albedo. Current
techniques are completely supervised, requiring high quality synthetic
renderings to train a solution. Such renderings are synthesized using priors
learned from limited data. In contrast, we propose a self-supervised approach
for relighting. Our approach is trained only on corpora of images collected
from the internet without any user-supervision. This virtually endless source
of training data allows training a general relighting solution. Our approach
first decomposes an image into its albedo, geometry and illumination. A novel
relighting is then produced by modifying the illumination parameters. Our
solution capture shadow using a dedicated shadow prediction map, and does not
rely on accurate geometry estimation. We evaluate our technique subjectively
and objectively using a new dataset with ground-truth relighting. Results show
the ability of our technique to produce photo-realistic and physically
plausible results, that generalizes to unseen scenes.Comment: Published in ECCV '20,
http://gvv.mpi-inf.mpg.de/projects/SelfRelight
The effect of initial local anesthetic dose with continuous interscalene analgesia on postoperative pain and diaphragmatic function in patients undergoing arthroscopic shoulder surgery: a double-blind, randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Interscalene block (ISB) is commonly performed using 20-40 mL of local anesthetic. Spread to adjacent structures and consequent adverse effects including paralysis of the ipsilateral hemidiaphragm are frequent. Pain ratings, analgesic requirements, adverse events, satisfaction, function and diaphragmatic excursion were compared following interscalene block (ISB) with reduced initial bolus volumes.</p> <p>Methods</p> <p>Subjects undergoing arthroscopic rotator cuff repair were randomized to receive 5, 10, or 20 mL ropivacaine 0.75% for ISB in a double-blind fashion (N = 36). Continuous infusion with ropivacaine 0.2% was maintained for 48 h. Pain and diaphragmatic excursion were assessed before block and in the recovery unit.</p> <p>Results</p> <p>Pain ratings in the recovery room were generally less than 4 (0-10 NRS) for all treatment groups, but a statistically significant difference was noted between the 5 and 20 mL groups (NRS: 2.67 vs. 0.62 respectively; p = 0.04). Pain ratings and supplemental analgesic use were similar among the groups at 24 h, 48 h and 12 weeks. There were no differences in the quality of block for surgical anesthesia. Dyspnea was significantly greater in the 20 mL group (p = 0.041). Subjects with dyspnea had significant diaphragmatic impairment more frequently (Relative risk: 2.5; 95%CI: 1.3-4.8; p = 0.042). Increased contralateral diaphragmatic motion was measured in 29 of the 36 subjects. Physical shoulder function at 12 weeks improved over baseline in all groups (baseline mean SST: 6.3, SEM: 0.6; 95%CI: 5.1-7.5; 12 week mean SST: 8.2, SEM: 0.46; 95%CI: 7.3-9.2; p = 0.0035).</p> <p>Conclusions</p> <p>ISB provided reliable surgical analgesia with 5 mL, 10 mL or 20 mL ropivacaine (0.75%). The 20 mL volume was associated with increased complaints of dyspnea. The 5 mL volume was associated with statistically higher pain scores in the immediate postoperative period. Lower volumes resulted in a reduced incidence of dyspnea compared to 20 mL, however diaphragmatic impairment was not eliminated. Compensatory increases in contralateral diaphragmatic movement may explain tolerance for ipsilateral paresis.</p> <p>Trial Registration</p> <p>clinicaltrials.gov. identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00672100">NCT00672100</a></p
Case report of right hamate hook fracture in a patient with previous fracture history of left hamate hook: is it hamate bipartite?
BACKGROUND: Hamate hook fracture is a common fracture in golfers and others who play sports that involve rackets or sticks such as tennis or hockey. This patient had a previous hamate fracture in the opposing wrist along with potential features of hamate bipartite. CASE PRESENTATION: A 19 year old male presented with a complaint of right wrist pain on the ulnar side of the wrist with no apparent mechanism of injury. The pain came on gradually one week before being seen in the office and he reported no prior care for the complaint. His history includes traumatic left hamate hook fracture with surgical excision. CONCLUSION: The patient was found to have marked tenderness over the hamate and with a prior fracture to the other wrist, computed tomography of the wrist was ordered revealing a fracture to the hamate hook in the right wrist. He was referred for surgical evaluation and the hook of the hamate was excised. Post-surgically, the patient was able to return to normal activity within eight weeks. This case is indicative of fracture rather than hamate bipartite. This fracture should be considered in a case of ulnar sided wrist pain where marked tenderness is noted over the hamate, especially after participation in club or racket sports
The Status of GMSB After 1/fb at the LHC
We thoroughly investigate the current status of supersymmetry in light of the
latest searches at the LHC, using General Gauge Mediation (GGM) as a
well-motivated signature generator that leads to many different simplified
models. We consider all possible promptly-decaying NLSPs in GGM, and by
carefully reinterpreting the existing LHC searches, we derive limits on both
colored and electroweak SUSY production. Overall, the coverage of GGM parameter
space is quite good, but much discovery potential still remains even at 7 TeV.
We identify several regions of parameter space where the current searches are
the weakest, typically in models with electroweak production, third generation
sfermions or squeezed spectra, and we suggest how ATLAS and CMS might modify
their search strategies given the understanding of GMSB at 1/fb. In particular,
we propose the use of leptonic to suppress backgrounds.
Because we express our results in terms of simplified models, they have broader
applicability beyond the GGM framework, and give a global view of the current
LHC reach. Our results on 3rd generation squark NLSPs in particular can be
viewed as setting direct limits on naturalness.Comment: 44 pages, refs added, typos fixed, improved MC statistics in fig 1
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