933 research outputs found
Gluon-gluon contributions to the production of continuum diphoton pairs at hadron colliders
We compute the contributions to continuum photon pair production at hadron
colliders from processes initiated by gluon-gluon and gluon-quark scattering
into two photons through a four-leg virtual quark loop. Complete two-loop cross
sections in perturbative quantum chromodynamics are combined with contributions
from soft parton radiation resummed to all orders in the strong coupling
strength. The structure of the resummed cross section is examined in detail,
including a new type of unintegrated parton distribution function affecting
azimuthal angle distributions of photons in the pair's rest frame. As a result
of this analysis, we predict diphoton transverse momentum distributions in
gluon-gluon scattering in wide ranges of kinematic parameters at the Fermilab
Tevatron collider and the CERN Large Hadron Collider.Comment: 28 pages, 11 figures; published versio
Methane activation and exchange by titanium-carbon multiple bonds
We demonstrate that a titanium-carbon multiple bond, specifically an alkylidyne ligand in the transient complex, (PNP)Ti≡C^(t)Bu (A) (PNP^− = N[2-P(CHMe_2)_(2)-4-methylphenyl]_2), can cleanly activate methane at room temperature with moderately elevated pressures to form (PNP)Ti=CHtBu(CH_3). Isotopic labeling and theoretical studies suggest that the alkylidene and methyl hydrogens exchange, either via tautomerization invoking a
methylidene complex, (PNP)Ti=CH_(2)(CH_(2)^(t)Bu), or by forming the methane adduct (PNP)Ti≡C^(t)Bu(CH_4). The thermal, fluxional and chemical behavior of (PNP)Ti=CH^(t)Bu(CH_3) is also presented in this study
Triangle percolation in mean field random graphs -- with PDE
We apply a PDE-based method to deduce the critical time and the size of the
giant component of the ``triangle percolation'' on the Erd\H{o}s-R\'enyi random
graph process investigated by Palla, Der\'enyi and VicsekComment: Summary of the changes made: We have changed a remark about k-clique
percolation in the first paragraph. Two new paragraphs are inserted after
equation (4.4) with two applications of the equation. We have changed the
names of some variables in our formula
Mapping Natura 2000 Habitat Conservation Status in a Pannonic Salt Steppe with Airborne Laser Scanning
Sensory evaluation and electronic tongue for sensing grafted and non-grafted watermelon taste attributes
The objective of our study was to analyse the results of two measuring methods (sensory evaluation and electronic tongue) and to find differences in taste between grafted and non-grafted watermelon fruit. The trained sensory panel evaluated in two years three differently treated watermelon fruit. The studied fruit samples were produced on the same growing-areas in both years but with different growing technologies. The experiment used the non-grafted/self-rooted watermelon as control sample, while the other two treatments were grafting on two rootstock types: a Lagenaria and an interspecific squash hybrid rootstock. The electronic tongue measurement showed that it is the environment/growing technology that mainly determines the characteristics of the fruit quality, not grafting. The two measurement methods can complement each other in a detailed and practical way, as technology and growing area strongly influence the quality of watermelon fruit. The research also showed that it is possible to have similar watermelon fruit quality, independently from the used rootstock type
Many-body position operator in lattice fermionic systems with periodic boundary conditions
A total position operator in the position representation is derived for
lattice fermionic systems with periodic boundary conditions. The operator is
shown to be Hermitian, the generator of translations in momentum space, and its
time derivative is shown to correspond to the total current operator in a
periodic system. The operator is such that its moments can be calculated up to
any order. To demonstrate its utility finite size scaling is applied to the
Brinkman-Rice transition as well as metallic and insulating Gutzwiller
wavefunctions.Comment: to appear in Journal of Physics A: Mathematical and General
(reference will be added later
Biomass potential assessment for locating biorefinery plant in Hungary
To find a suitable site for a 150,000 metric ton dry material per year (t dm/yr) input capacity biorefinery plant in Hungary is a challenging task. Not only biomass potentials have to be assessed, competing uses, sustainability aspects, public opinion and future threats to feedstock availability should be also taken into account. As a result of our calculations, currently there is enough feedstock available for the targeted input capacity to operate in an ecologically sustainable way. However, several factors may threaten the future of feedstock availability. In the long run enhanced price competition is anticipated for biomass among biorefinery, livestock keeping, timber industry and biomass based renewable energy production. The majority of stakeholders accept in general biorefinery as a promising solution for substituting fossil based plastics, still local interests give priority to a balanced agricultural production including higher shares of husbandry
Effects of copper-adsorption on the line-profile of first basal reflection of montmorillonite
SU(7) Unification of SU(3)_C*SU(4)_W* U(1)_{B-L}
We propose the SUSY SU(7) unification of the SU(3)_C* SU(4)_W* U(1)_{B-L}
model. Such unification scenario has rich symmetry breaking chains in a
five-dimensional orbifold. We study in detail the SUSY SU(7) symmetry breaking
into SU(3)_C* SU(4)_W* U(1)_{B-L} by boundary conditions in a Randall-Sundrum
background and its AdS/CFT interpretation. We find that successful gauge
coupling unification can be achieved in our scenario. Gauge unification favors
low left-right and unification scales with tree-level \sin^2\theta_W=0.15. We
use the AdS/CFT dual of the conformal supersymmetry breaking scenario to break
the remaining N=1 supersymmetry. We employ AdS/CFT to reproduce the NSVZ
formula and obtain the structure of the Seiberg duality in the strong coupling
region for 3/2N_c<N_F<3N_C. We show that supersymmetry is indeed broken in the
conformal supersymmetry breaking scenario with a vanishing singlet vacuum
expectation value.Comment: 25 pages, 1 figure
Multiboost: a multi-purpose boosting package
http://jmlr.csail.mit.edu/papers/v13/benbouzid12a.htmlThe MultiBoost package provides a fast C++ implementation of multi-class/multi-label/multi-task boosting algorithms. It is based on AdaBoost.MH but it also implements popular cascade classifiers and FilterBoost. The package contains common multi-class base learners (stumps, trees, products, Haar filters). Further base learners and strong learners following the boosting paradigm can be easily implemented in a flexible framework
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