74 research outputs found
Photoproduction of mesons associated with a leading neutron
The photoproduction of mesons associated with a leading
neutron has been observed with the ZEUS detector in collisions at HERA
using an integrated luminosity of 80 pb. The neutron carries a large
fraction, {}, of the incoming proton beam energy and is detected at
very small production angles, { mrad}, an indication of
peripheral scattering. The meson is centrally produced with
pseudorapidity {
GeV}, which is large compared to the average transverse momentum of the neutron
of 0.22 GeV. The ratio of neutron-tagged to inclusive production is
in the photon-proton
center-of-mass energy range { GeV}. The data suggest that the
presence of a hard scale enhances the fraction of events with a leading neutron
in the final state.Comment: 28 pages, 4 figures, 2 table
Measurement of the Isolated Photon Cross Section in p-pbar Collisions at sqrt{s}=1.96 TeV
The cross section for the inclusive production of isolated photons has been
measured in p anti-p collisions at sqrt{s}=1.96 TeV with the D0 detector at the
Fermilab Tevatron Collider. The photons span transverse momenta 23 to 300 GeV
and have pseudorapidity |eta|<0.9. The cross section is compared with the
results from two next-to-leading order perturbative QCD calculations. The
theoretical predictions agree with the measurement within uncertainties.Comment: 7 pages, 5 figures, submitted to Phys.Lett.
Exigências de energia de borregas mestiças alimentadas com níveis crescentes de concentrado na dieta
Recommended from our members
Linking soil microbial community structure to potential carbon mineralization: A continental scale assessment of reduced tillage
Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity
Measurement of the differential cross section for the production of an isolated photon with associated jet in ppbar collisions at sqrt(s)=1.96 TeV
The process ppbar -> photon + jet + X is studied using 1.0 fb^-1 of data
collected by the D0 detector at the Fermilab Tevatron ppbar collider at a
center-of-mass energy sqrt(s)=1.96 TeV. Photons are reconstructed in the
central rapidity region |y_gamma|<1.0 with transverse momenta in the range
30<Pt_gamma<400 GeV while jets are reconstructed in either the central
|y_jet|15 GeV.
The differential cross section d^3sigma/dPt_gamma dy_gamma dy_jet is measured
as a function of Pt_gamma in four regions, differing by the relative
orientations of the photon and the jet in rapidity. Ratios between the
differential cross sections in each region are also presented. Next-to-leading
order QCD predictions using different parameterizations of parton distribution
functions and theoretical scale choices are compared to the data. The
predictions do not simultaneously describe the measured normalization and
Pt_gamma dependence of the cross section in any of the four measured regions.Comment: 13 pages, 10 figure
Fecal excretion patterns and short term bias of internal and external markers in a digestion assay with cattle
Patterns of camelid sacrifice at the site of Pachacamac, Peruvian Central Coast, during the Late Intermediate Period (AD1000\u20131470): Perspectives from funerary archaeoentomology
Funerary archaeoentomology entails the study of insects from archaeological contexts, in order to examine funerary practices, thanatology and hygiene/sanitation in ancient populations. However, while insects from human mummies have been widely studied, there is a limited literature dealing with archaeoentomology of animal sacrifices. Andean camelid sacrifices are common in ritual contexts, as funerary or foundation offerings. The current paper addresses camelid remains recovered from the archaeological site of Pachacamac, during the 2016 excavation season. The insect fauna was assessed in order to determine the social context of the remains, and the manner in which the camelids were utilised. The carcasses yielded remains pertaining to Diptera and Coleoptera. The presence of Cochliomyia macellaria (Diptera, Calliphoridae), Sarcophaga sp. (Diptera, Sarcophagidae) and Synthesiomyia nudiseta (Diptera, Muscidae) suggest an initial colonisation in the open, while other species typical of later phases of the colonisation \u2013 including Hydrotaea aenescens (Diptera, Muscidae) and members of the family Phoridae \u2013 suggest that the carcasses were subsequently buried. Despite the evident importance of camelids to Andean populations, both historically and archaeologically, this is the first time that entomology has been used to examine animal sacrifice methods in this area, and comprises a watershed in the development of multidisciplinary approaches to sacrificial rites in ancient Peru
- …