1,805 research outputs found
The Measurement of Tri-Linear Gauge Boson Couplings at Colliders
We describe a detailed study of the process and the measurement of tri-linear gauge boson couplings (TGV's) at
LEP200 and at a 500~GeV and 1~TeV NLC. We included all tree level Feynman
diagrams contributing to the four-fermion final states including gauge boson
widths and non-resonance contributions. We employed a maximum likelihood
analysis of a five dimensional differential cross section of angular
distributions. This approach appears to offer an optimal strategy for
measurement of TGV's. LEP200 will improve existing measurements of TGV's but
not enough to see loop contributions of new physics. Measurements at the NLC
will be roughly 2 orders of magnitude more precise which would probe the
effects of new physics at the loop level.Comment: Latex file uses aipbook.sty with revtex and psfig.sty. 2 figures
(uuencoded) will be added with figures command. Full postcript version with
embedded figures is available at
ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocipc9504.ps To appear in
the Proceedings of the International Symposium on Vector Boson
Self-Interactions, UCLA, Feb. 1-3, 199
The Functional Significance of Social Cognition in Schizophrenia: A Review
Deficits in a wide array of functional outcome areas (eg, social functioning, social skills, independent living skills, etc) are marked in schizophrenia. Consequently, much recent research has attempted to identify factors that may contribute to functional outcome; social cognition is one such domain. The purpose of this article is to review research examining the relationship between social cognition and functional outcome. Comprehensive searches of PsycINFO and MEDLINE/PUBMED were conducted to identify relevant published manuscripts to include in the current review. It is concluded that the relationship between social cognition and functional outcome depends on the specific domains of each construct examined; however, it can generally be concluded that there are clear and consistent relationships between aspects of functional outcome and social cognition. These findings are discussed in light of treatment implications for schizophrenia
Supersymmetric QCD flavor changing top quark decay
We present a detailed and complete calculation of the gluino and scalar
quarks contribution to the flavour-changing top quark decay into a charm quark
and a photon, gluon, or a Z boson within the minimal supersymmetric standard
model including flavour changing gluino-quarks-scalar quarks couplings in the
right-handed sector. We compare the results with the ones presented in an
earlier paper where we considered flavour changing couplings only in the
left-handed sector. We show that these new couplings have important
consequences leading to a large enhancement when the mixing of the scalar
partners of the left- and right-handed top quark is included. Furthermore CP
violation in the flavour changing top quark decay will occur when a SUSY phase
is taken into account.Comment: 14 pages, latex, 3 figure
Single top production at the LHC as a probe of R parity violation
We investigate the potential of the LHC to probe the R parity violating
couplings involving the third generation by considering single top production.
This study is based on particle level event generation for both signal and
background, interfaced to a simplified simulation of the ATLAS detector.Comment: 11 pages, 5 figures, 5 tables (LaTeX, style revtex), few references
adde
Soil weathering rates in 21 catchments of the Canadian Shield
Soil mineral weathering represents an essential source of nutrient base cation (Ca, Mg and K) for forest growth in addition to provide a buffering power against precipitation acidity for soils and surface waters. Weathering rates of base cations were obtained for 21 catchments located within the temperate and the boreal forest of the Canadian Shield with the geochemical model PROFILE. Weathering rates ranged from 0.58 to 4.46 kmol<sub>c</sub> ha<sup>−1</sup> yr<sup>−1</sup> and their spatial variation within the studied area was mostly in agreement with spatial variations in soil mineralogy. Weathering rates of Ca and Mg were significantly correlated (<i>r</i> = 0.80 and 0.64) with their respective lake concentrations. Weathering rates of K and Na did not correlate with lake concentrations of K and Na. The modeled weathering rates for each catchment were also compared with estimations of net catchment exportations. The result show that modeled weathering rates of Ca were not significantly different than the net catchment exportations while modeled weathering rates of Mg were higher by 51%. Larger differences were observed for K and Na weathering rates that were significantly different than net catchment exportations being 6.9 and 2.2 times higher than net exportations, respectively. The results for K were expected given its high reactivity with biotic compartments and suggest that most of the K produced by weathering reactions was retained within soil catchments and/or above ground biomass. This explanation does not apply to Na, however, which is a conservative element in forest ecosystems because of the insignificant needs of Na for soil microorganisms and above ground vegetations. It raises concern about the liability of the PROFILE model to provide reliable values of Na weathering rates. Overall, we concluded that the PROFILE model is powerful enough to reproduce spatial geographical gradients in weathering rates for relatively large areas as well as adequately predict absolute weathering rates values for the sum of base cations, Ca and Mg
Charge-Transfer Excitations in the Model Superconductor HgBaCuO
We report a Cu -edge resonant inelastic x-ray scattering (RIXS) study of
charge-transfer excitations in the 2-8 eV range in the structurally simple
compound HgBaCuO at optimal doping ( K).
The spectra exhibit a significant dependence on the incident photon energy
which we carefully utilize to resolve a multiplet of weakly-dispersive ( eV) electron-hole excitations, including a mode at 2 eV. The observation
of this 2 eV excitation suggests the existence of a charge-transfer pseudogap
deep in the superconducting phase. Quite generally, our data demonstrate the
importance of exploring the incident photon energy dependence of the RIXS cross
section.Comment: 5 pages, 3 figure
Joint and individual analysis of breast cancer histologic images and genomic covariates
A key challenge in modern data analysis is understanding connections between
complex and differing modalities of data. For example, two of the main
approaches to the study of breast cancer are histopathology (analyzing visual
characteristics of tumors) and genetics. While histopathology is the gold
standard for diagnostics and there have been many recent breakthroughs in
genetics, there is little overlap between these two fields. We aim to bridge
this gap by developing methods based on Angle-based Joint and Individual
Variation Explained (AJIVE) to directly explore similarities and differences
between these two modalities. Our approach exploits Convolutional Neural
Networks (CNNs) as a powerful, automatic method for image feature extraction to
address some of the challenges presented by statistical analysis of
histopathology image data. CNNs raise issues of interpretability that we
address by developing novel methods to explore visual modes of variation
captured by statistical algorithms (e.g. PCA or AJIVE) applied to CNN features.
Our results provide many interpretable connections and contrasts between
histopathology and genetics
- …