606 research outputs found
On Entangled Multi-particle Systems in Bohmian Theory
Arguments are presented to show that in the case of entangled systems there
are certain difficulties in implementing the usual Bohmian interpretation of
the wave function in a straightforward manner. Specific examples are given.Comment: 7 page
Clusters of Galaxies: New Results from the CLEF Hydrodynamics Simulation
Preliminary results are presented from the CLEF hydrodynamics simulation, a
large (N=2(428)^3 particles within a 200 Mpc/h comoving box) simulation of the
LCDM cosmology that includes both radiative cooling and a simple model for
galactic feedback. Specifically, we focus on the X-ray properties of the
simulated clusters at z=0 and demonstrate a reasonable level of agreement
between simulated and observed cluster scaling relations.Comment: 7 pages, 4 figures, accepted for publication in Advances in Space
Research (proceedings of the COSPAR 2004 Assembly, Paris
The detection of Gravitational Waves
This chapter is concerned with the question: how do gravitational waves (GWs)
interact with their detectors? It is intended to be a theory review of the
fundamental concepts involved in interferometric and acoustic (Weber bar) GW
antennas. In particular, the type of signal the GW deposits in the detector in
each case will be assessed, as well as its intensity and deconvolution. Brief
reference will also be made to detector sensitivity characterisation, including
very summary data on current state of the art GW detectors.Comment: 33 pages, 12 figures, LaTeX2e, Springer style files --included. For
Proceedings of the ERE-2001 Conference (Madrid, September 2001
Determination of the Deep Inelastic Contribution to the Generalised Gerasimov-Drell-Hearn Integral for the Proton and Neutron
The virtual photon absorption cross section differences [sigma_1/2-sigma_3/2]
for the proton and neutron have been determined from measurements of polarised
cross section asymmetries in deep inelastic scattering of 27.5 GeV
longitudinally polarised positrons from polarised 1H and 3He internal gas
targets. The data were collected in the region above the nucleon resonances in
the kinematic range nu < 23.5 GeV and 0.8 GeV**2 < Q**2 < 12 GeV**2. For the
proton the contribution to the generalised Gerasimov-Drell-Hearn integral was
found to be substantial and must be included for an accurate determination of
the full integral. Furthermore the data are consistent with a QCD
next-to-leading order fit based on previous deep inelastic scattering data.
Therefore higher twist effects do not appear significant.Comment: 6 pages, 3 figures, 1 table, revte
Observation of a Coherence Length Effect in Exclusive Rho^0 Electroproduction
Exclusive incoherent electroproduction of the rho^0(770) meson from 1H, 2H,
3He, and 14N targets has been studied by the HERMES experiment at squared
four-momentum transfer Q**2>0.4 GeV**2 and positron energy loss nu from 9 to 20
GeV. The ratio of the 14N to 1H cross sections per nucleon, known as the
nuclear transparency, was found to decrease with increasing coherence length of
quark-antiquark fluctuations of the virtual photon. The data provide clear
evidence of the interaction of the quark- antiquark fluctuations with the
nuclear medium.Comment: RevTeX, 5 pages, 3 figure
Quantifying regulating ecosystem services with increased tree densities on European Farmland
Agroforestry systems have been compared to agricultural and forestry alternatives, providing a land-use solution for additional environmental benefits while maintaining similar levels of productivity. However, there is scarce research assessing such patterns across a pan-European scale using a common methodology. This study aims to improve our understanding of the role of trees in three different regulating ecosystem services—(1) soil erosion, (2) nitrate leaching and (3) carbon sequestration—in traditional and innovative agroforestry systems in Europe through a consistent modeling approach. The systems’ assessment spans environmentally from the Mediterranean environmental region in Portugal to the Continental environmental region in Switzerland and Germany to the Atlantic environmental region in the United Kingdom. Modeled tree densities were compared in the different land-use alternatives, ranging from zero (agriculture with only crops or pasture) to forestry (only trees). The methodology included the use of a biophysical model (Yield-SAFE) where the quantification of the environmental benefits was integrated. Results show a consistent improvement of regulating ecosystem services can be expected when introducing trees in the farming landscapes in different environmental regions in Europe. For all the systems, the forestry alternatives presented the best results in terms of a decrease in soil erosion of 51% (±29), a decrease of nearly all the nitrate leaching (98% ± 1) and an increase in the carbon sequestration of up to 238 Mg C ha−1 (±140). However, these alternatives are limited in the variety of food, energy and/or materials provided. On the other hand, from an arable or pure-pasture alternative starting point, an increase in agroforestry tree density could also be associated with a decrease in soil erosion of up to 25% (±17), a decrease in nitrates leached of up to 52% (±34) and an increase in the carbon sequestered of 163 Mg C ha−1 (±128) while at the same time ensuring the same levels of biomass growth and an increase in product diversification.We acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the scholarship (SFRH/BD/52691/2014) and the European Community's Seventh Framework Programme under Grant Agreement No. 613520 (Project AGFORWARD). This research was funded by the Forest Research Centre, a research unit funded by Funda??o para a Ci?ncia e a Tecnologia I.P. (FCT), Portugal (UIDB/00239/2020)
Keeping a parameter-sparse concept in agroforestry modeling while integrating new processes and dynamics: new developments in yield-safe
info:eu-repo/semantics/publishedVersio
Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector
The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements
Genome-Wide Joint Meta-Analysis of SNP and SNP-by-Smoking Interaction Identifies Novel Loci for Pulmonary Function
A search for resonances decaying into a Higgs boson and a new particle X in the XH → qqbb final state with the ATLAS detector
A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb−1 of proton–proton collision data at collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the resonance
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