64,609 research outputs found
Studying trilinear gauge couplings at LEP2 using optimal observables
We study the sensitivity of the processes `e+ e- -> lepton (l) neutrino (v)
quark (u) antiquark (d)' at LEP2 energies on the non-standard trilinear gauge
couplings (TGC), using the optimal observables method. All relevant leading
logarithmic corrections to the tree-order cross section, as well as
experimental resolution effects have been studied. Taking into account
correlations among the different TGC parameters we show that the limits on the
TGC can reach the level of 0.15~(1sd) at 161 GeV with 100 pb, a
challenge for the first LEP2 phase. At higher energies this can be improved
drastically, reaching the level of 0.02~(1sd).Comment: 14 pages, latex, minor typos correcte
Holographic Techni-dilaton
Techni-dilaton, a pseudo-Nambu-Goldstone boson of scale symmetry, was
predicted long ago in the Scale-invariant/Walking/Conformal Technicolor
(SWC-TC) as a remnant of the (approximate) scale symmetry associated with the
conformal fixed point, based on the conformal gauge dynamics of ladder
Schwinger-Dyson (SD) equation with non-running coupling. We study the
techni-dilaton as a flavor-singlet bound state of techni-fermions by including
the techni-gluon condensate (tGC) effect into the previous (bottom-up)
holographic approach to the SWC-TC, a deformation of the holographic QCD with
by large anomalous dimension . With
including a bulk scalar field corresponding to the gluon condensate, we first
improve the Operator Product Expansion of the current correlators so as to
reproduce gluonic term both in QCD and SWC-TC. We find in QCD about
(negative) contribution of gluon condensate to the meson mass. We
also calculate the oblique electroweak -parameter in the presence of the
effect of the tGC and find that for the fixed value of the tGC effects
dramatically reduce the flavor-singlet scalar (techni-dilaton) mass (in the unit of ), while the vector and axial-vector masses
and are rather insensitive to the tGC, where is the
decay constant of the techni-pion. If we use the range of values of tGC implied
by the ladder SD analysis of the non-perturbative scale anomaly in the large
QCD near the conformal window, the phenomenological constraint predicts the techni-dilaton mass GeV which is within
reach of LHC discovery.Comment: 28 pages, 11 eps files, typos corrected, references added, Fig.1
corrected, some discussions added, to be published in PR
River discharges of carbon to the world's oceans: determining local inputs of alkalinity and of dissolved and particulate organic carbon
An empirical modelling that allows a prediction the amount of atmospheric CO2 consumed by continental erosion is combined with a river-routing file in order to determine the spatial distribution of river carbon inputs to the world's oceans. The total fluvial carbon input is calculated to be 710 teragrams of carbon per year (TgC/yr). 205 TgC/yr are discharged as dissolved organic carbon, 185 TgC/yr as particulate organic carbon, and 320 TgC/yr as bicarbonate ions. Of the latter figure, 230 TgC/yr stem from the atmosphere, while the remainder 90 TgC/yr originate from carbonate mineral dissolution. The Atlantic Ocean receives the greatest amount of river carbon, followed by the Pacific Ocean, the Indian Ocean, and the Arctic Ocean. The spatial distribution of the predicted river carbon inputs may be included in further modelling studies in order to better understand the lateral transports of carbon in the present-day global carbon cycle
Promoting renewable electricity generation in imperfect markets: price vs. quantity control
The search for economically effcient policy instruments designed to promote the diffusion of renewable energy technologies in liberalized markets has led to the introduction of quota-based tradable `green' certifcate (TGC) schemes for renewable power. However, there is a debate about the pros and cons of TGC, a quantity control policy, compared to guaranteed feed-in tariffs (FIT), a price control policy. In this paper we contrast these two alternatives in terms of cost effectiveness and social welfare, taking into account that electricity markets are not perfectly competitive.Renewable electricity, Feed-in tariffs, Tradable green certifcates, Quota, Energy policy, Duopoly
Promoting renewable electricity generation in imperfect markets: price vs. quantity policies
The search for economically efficient policy instruments designed to promote the diffusion of renewable energy technologies in liberalized markets has led to the introduction of quota-based tradable ‘green’ certificate (TGC) schemes for renewable electricity. However, there is a debate about the pros and cons of TGC, a quantity control policy, compared to guaranteed feed-in tariffs, a price control policy. In this paper we contrast these two alternatives in terms of social welfare, taking into account that electricity markets are not perfectly competitive, and show that the price control policy dominates the quantity control policy in terms of social welfare.Tradable green certificates, Renewable portfolio standard, Quota target, Feed-in tariff, Cournot duopoly
Renormalization of the EWCL and its Application to LEP2
We perform a systematic one-loop renormalization on the electroweak chiral
Lagrangian (EWCL) up to operators and construct the renormalization
group equations (RGE) for the anomalous couplings. We examine the impact of the
triple gauge coupling (TGC) measurement from LEP2 to the uncertainty of the
parameter at the , and find that the uncertainty in the
TGC measurements can shift at least .Comment: 4 pages, 1 eps figure, uses ws-ijmpa.cls. Paralell talk given at
"International Conference on QCD and hadronic Physics", Beijing, China, 16-20
June, 200
Tigecycline is efficacious in the treatment of complicated intra-abdominal infections
Background
Empiric treatment of complicated intra-abdominal infections (cIAI) represents a clinical challenge because of the diverse bacteriology and the emergence of bacterial resistance. The efficacy and safety of tigecycline (TGC), a first-in-class, expanded broad-spectrum glycylcycline antibiotic, were compared with imipenem/cilastatin (IMI/CIS) in patients with cIAI.
Methods
In this prospective, double-blind, phase 3, multinational trial, patients were randomly assigned to intravenous (IV) TGC (100 mg initial dose, then 50 mg every 12 h) or IV IMI/CIS (500/500 mg every 6 h) for 5–14 days. Clinical response was assessed at the test-of-cure (TOC) visit (14–35 days after therapy) for microbiologically evaluable (ME) and microbiologically modified intent-to-treat (m-mITT) populations (co-primary efficacy endpoint populations in which cure/failure response rates were determined).
Results
Of 817 mITT patients (i.e., received ≥ 1 dose of study drug), 641 (78%) comprised the m-mITT cohort (322 TGC, 319 IMI/CIS) and 523 (64%) were ME (266 TGC, 256 IMI/CIS). Patients were predominantly white (88%) and male (59%) with a mean age of 49 years. The primary diagnoses for the mITT group were complicated appendicitis (41%), cholecystitis (22%), and intra-abdominal abscess (11%). For the ME population, clinical cure rates at TOC were 91.3% (242/265) for TGC versus 89.9% (232/258) for IMI/CIS (95% CI −4.0, 6.8; P < 0.001). Corresponding clinical cure rates within the m-mITT population were 86.6% (279/322) for TGC versus 84.6% (270/319) for IMI/CIS (95% CI −3.7, 7.5; P < 0.001 for noninferiority TGC versus IMI/CIS). The most commonly reported adverse events for TGC and IMI/CIS were nausea (17.6% TGC versus 13.3% IMI/CIS; P = 0.100) and vomiting (12.6% TGC versus 9.2% IMI/CIS; P = 0.144).
Conclusions
TGC is efficacious in the treatment of patients with cIAIs and TGC met per the protocol-specified statistical criteria for noninferiority to the comparator, IMI/CIS
The First Result of Global Commissioning of the ATLAS Endcap Muon Trigger System in ATLAS Cavern
We report on the ATLAS commissioning run from the view point of the Thin Gap Chamber (TGC), which is the ATLAS end cap muon trigger detector. All the TGC sectors with on-detector electronics are going to be installed to the ATLAS cavern by the end of September 2007. To integrate all sub-detectors before the physics run starting from early 2008, the global commissioning run together with other sub-detectors has been performed from June 2007. We have evaluated the performance of the complete trigger chain of the TGC electronics and provide the trigger signal using cosmic-ray to the sub-systems in the global run environment
Fire-induced Carbon Emissions and Regrowth Uptake in Western U.S. Forests: Documenting Variation Across Forest Types, Fire Severity, and Climate Regions
The forest area in the western United States that burns annually is increasing with warmer temperatures, more frequent droughts, and higher fuel densities. Studies that examine fire effects for regional carbon balances have tended to either focus on individual fires as examples or adopt generalizations without considering how forest type, fire severity, and regional climate influence carbon legacies. This study provides a more detailed characterization of fire effects and quantifies the full carbon impacts in relation to direct emissions, slow release of fire-killed biomass, and net carbon uptake from forest regrowth. We find important variations in fire-induced mortality and combustion across carbon pools (leaf, live wood, dead wood, litter, and duff) and across low- to high-severity classes. This corresponds to fire-induced direct emissions from 1984 to 2008 averaging 4 TgC/yr and biomass killed averaging 10.5 TgC/yr, with average burn area of 2723 sq km/yr across the western United States. These direct emission and biomass killed rates were 1.4 and 3.7 times higher, respectively, for high-severity fires than those for low-severity fires. The results show that forest regrowth varies greatly by forest type and with severity and that these factors impose a sustained carbon uptake legacy. The western U.S. fires between 1984 and 2008 imposed a net source of 12.3 TgC/yr in 2008, accounting for both direct fire emissions (9.5 TgC/yr) and heterotrophic decomposition of fire-killed biomass (6.1 TgC yr1) as well as contemporary regrowth sinks (3.3 TgC/yr). A sizeable trend exists toward increasing emissions as a larger area burns annually
Stellar systems following the R^1/m luminosity law, IV : the total energy and the central concentration of galaxies
We expand our previous analytical and numerical studies of the family of Sérsic models, which are routinely used to describe early-type galaxies and the bulges of spiral galaxies. In particular, we focus on the total energy budget, an important dynamical property that has not been discussed in detail in previous works. We use two different methods to calculate the total energy for the Sérsic model family that result in two independent expressions that can be used along the entire sequence of Sérsic models. We use these expressions to investigate whether the Spitzer concentration index is a reliable measure for the intrinsic 3D concentration of galaxies, and we conclude that it is not a very useful measure for the central concentration. The popular Third Galaxy Concentration index, on the other hand, is shown to be a reliable measure for the intrinsic 3D concentration, even though it is based on the surface brightness distribution and not on the intrinsic 3D density
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