5,322 research outputs found
Four Jets as a Probe of O(100 GeV) Physics beyond Standard Model at Hadron Colliders
O(100 GeV) physics beyond the standard model (BSM) could be overlooked
provided that it is hidden in the untouched Higgs sector or jets. The top quark
forward-backward asymmetry measurements and di-jet bump, which is observed in
the associated production with charged lepton plus missing energy (supposed
arising from W decay), may indicate the existence of a new color-octet
axial-vector Z_C with a mass about 145 GeV. Here Z_C only decays into two jets.
In this paper we investigated the possibility to discover Z_C pair via
analyzing the four jets as the final states, which are heavily polluted by huge
QCD background. Our simulation showed that, however, both Tevatron and LHC have
the excellent chance to discover Z_C through analyzing the four jets events in
the current accumulated data.Comment: 15 pages, 11figures and 2 table
Heavy surface state in a possible topological Kondo insulator: Magneto-thermoelectric transport on the (011)-plane of SmB
Motivated by the high sensitivity to Fermi surface topology and scattering
mechanisms in magneto-thermoelectric transport, we have measured the
thermopower and Nernst effect on the (011)-plane of the proposed topological
Kondo insulator SmB. These experiments, together with electrical
resistivity and Hall effect measurements, demonstrate that the (011)-plane also
harbors a metallic surface with the effective mass in the order of 10-10
. The surface and bulk conductances are well distinguished in these
measurements and are categorized into metallic and non-degenerate
semiconducting regimes, respectively. Electronic correlations play an important
role in enhancing scattering and also contribute to the heavy surface state.Comment: 4 figures, 1 tabl
Social media fandom for health promotion? Insights from East Los High, a transmedia edutainment initiative
As digital media technologies proliferate and social media spaces expand, how does one leverage popularity and cultivate fandom to promote health? Despite the easy entry, broad reach, and interactive features of social media such as Facebook and Twitter, health promoters are unsure how to meaningfully engage users and build lasting online communities. In this article, we examined the Facebook Insights and Twitter hashtag network over a nine-month period for Season 1 of the exemplary transmedia edutainment show East Los High. Premiered on Hulu, the popular entertainment streaming site, East Los High was purposefully designed to serve Latino youths in the United States, spurring conversations and promoting healthy relationships and safe sex practices across different digital platforms. We used Facebook analytics to gauge the audience reach, engagement, and dissemination; developed a 10-indicator index to identify the most successful among the 352 Facebook posts; analysed the position of East Los High in the Facebook co-commenting network; and assessed the top word pairs from those Facebook comments in accordance with the show’s social objectives. We also studied the underlying structure of the Twitter hashtag network representing the interactions between @EastLosHighShow and its 2,136 followers with tweets that included #ELH, #ELHaddict(s), and/or #EastLosHigh. While challenges exist in initiating and maintaining user engagement on these social media platforms, our findings revealed effective and actionable strategies for health promotion by cultivating fandom and building communities on social media.publishedVersio
Kinetics of coherent order-disorder transition in
Within a phase field approach which takes the strain-induced elasticity into
account, the kinetics of the coherent order-disorder transition is investigated
for the specific case of alloy. It is shown that a microstructure
with cubic precipitates appears as a transient state during the
decomposition of a homogeneous disordered solid solution into a microstructure
with tetragonal precipitates embedded into a disordered matrix. At
low enough temperature, favored by a weak internal stress, only
precipitates grow in the transient microstructure preceding nucleation of the
precipitates that occurs exclusively at the interface of the solid
solution with the precipitates. Analysis of microstructures at
nanoscopic scale shows a characteristic rod shape for the
precipitates due to the combination of their tetragonal symmetry and their
large internal stress.Comment: 2 postscript figures and 1 JPG pag
A new clustering method for detecting rare senses of abbreviations in clinical notes
AbstractAbbreviations are widely used in clinical documents and they are often ambiguous. Building a list of possible senses (also called sense inventory) for each ambiguous abbreviation is the first step to automatically identify correct meanings of abbreviations in given contexts. Clustering based methods have been used to detect senses of abbreviations from a clinical corpus [1]. However, rare senses remain challenging and existing algorithms are not good enough to detect them. In this study, we developed a new two-phase clustering algorithm called Tight Clustering for Rare Senses (TCRS) and applied it to sense generation of abbreviations in clinical text. Using manually annotated sense inventories from a set of 13 ambiguous clinical abbreviations, we evaluated and compared TCRS with the existing Expectation Maximization (EM) clustering algorithm for sense generation, at two different levels of annotation cost (10 vs. 20 instances for each abbreviation). Our results showed that the TCRS-based method could detect 85% senses on average; while the EM-based method found only 75% senses, when similar annotation effort (about 20 instances) was used. Further analysis demonstrated that the improvement by the TCRS method was mainly from additionally detected rare senses, thus indicating its usefulness for building more complete sense inventories of clinical abbreviations
Hyperon polarization in e^-p --> e^-HK with polarized electron beams
We apply the picture proposed in a recent Letter for transverse hyperon
polarization in unpolarized hadron-hadron collisions to the exclusive process
e^-p --> e^-HK such as e^-p-->e^-\Lambda K^+, e^-p --> e^-\Sigma^+ K^0, or
e^-p--> e^-\Sigma^0 K^+, or the similar process e^-p\to e^-n\pi^+ with
longitudinally polarized electron beams. We present the predictions for the
longitudinal polarizations of the hyperons or neutron in these reactions, which
can be used as further tests of the picture.Comment: 15 pages, 2 figures. submitted to Phys. Rev.
Probing gluon helicity distribution and quark transversity through hyperon polarization in singly polarized pp collisions
We study the polarization of hyperon in different processes in singly
polarized collisions, in particular its relation to the polarized parton
distributions. We show that by measuring hyperon polarization in particularly
chosen processes, one can extract useful information on these parton
distributions. We show in particular that, by measuring the
polarization in high direct photon production process, one can extract
information on the gluon helicity distribution; and by measuring the transverse
polarization of hyeprons with high in singly polarized reactions, one can
obtain useful information on the transversity distribution. We present the
numerical results obtained for those hyperon polarizations using different
models for parton distribution function and those for the spin transfer in
fragmentation processes.Comment: 25 pages, 8 figures, to appear in Phys. Rev.
What Causes High Resistivity in CdTe
CdTe can be made semi-insulating by shallow donor doping. This is routinely
done to obtain high resistivity in CdTe-based radiation detectors. However, it
is widely believed that the high resistivity in CdTe is due to the Fermi level
pinning by native deep donors. The model based on shallow donor compensation of
native acceptors was dismissed based on the assumption that it is practically
impossible to control the shallow donor doping level so precisely that the free
carrier density can be brought below the desired value suitable for radiation
detection applications. In this paper, we present our calculations on carrier
statistics and energetics of shallow donors and native defects in CdTe. Our
results show that the shallow donor can be used to reliably obtain high
resistivity in CdTe. Since radiation detection applications require both high
resistivity and good carrier transport, one should generally use shallow donors
and shallow acceptors for carrier compensation and avoid deep centers that are
effective carrier traps
Extraction of Prostatic Lumina and Automated Recognition for Prostatic Calculus Image Using PCA-SVM
Identification of prostatic calculi is an important basis for determining the tissue origin. Computation-assistant diagnosis of prostatic calculi may have promising potential but is currently still less studied. We studied the extraction of prostatic lumina and automated recognition for calculus images. Extraction of lumina from prostate histology images was based on local entropy and Otsu threshold recognition using PCA-SVM and based on the texture features of prostatic calculus. The SVM classifier showed an average time 0.1432 second, an average training accuracy of 100%, an average test accuracy of 93.12%, a sensitivity of 87.74%, and a specificity of 94.82%. We concluded that the algorithm, based on texture features and PCA-SVM, can recognize the concentric structure and visualized features easily. Therefore, this method is effective for the automated recognition of prostatic calculi
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