1,643 research outputs found
Pomerons and Jet Events at HERA
We study two and three jet events with a large rapidity gap at HERA. Unlike
in the Ingelman-Schlein approach we do not adscribe a structure to the Pomeron.
Instead, the coupling of the Pomeron to quarks or gluons is taken pointlike,
which makes the model easy to test: the only degrees of freedom are the
coupling constants of the Pomeron to the quarks or the gluons and a cutoff
procedure to keep the Pomeron-gluon coupling well behaved.Comment: Latex fil
Search for solar electron anti-neutrinos due to spin-flavor precession in the Sun with Super-Kamiokande-IV
ArtĂculo escrito por un elevado nĂșmero de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboraciĂłn, si le hubiere, y los autores pertenecientes a la UAMDue to a very low production rate of electron anti-neutrinos ( -v e) via nuclear fusion in the Sun, a flux of solar -v e is unexpected. An appearance of -v e in solar neutrino flux opens a new window for the new physics beyond the standard model. In particular, a spin-flavor precession process is expected to convert an electron neutrino into an electron anti-neutrino (ve â Ìve) when neutrino has a finite magnetic moment. In this work, we have searched for solar v e in the Super-Kamiokande experiment, using neutron tagging to identify their inverse beta decay signature. We identified 78 v e candidates for neutrino energies of 9.3 to 17.3 MeV in 2970.1 live days with a fiducial volume of 22.5 kiloton water (183.0 ktonâ
year exposure). The energy spectrum has been consistent with background predictions and we thus derived a 90% confidence level upper limit of 4.7Ă10â4 on the ve -> -v e conversion probability in the Sun. We used this result to evaluate the sensitivity of future experiments, notably the Super-Kamiokande Gadolinium (SK-Gd) upgrad
Measurement of hadronic event shapes in high-pT multijet final states at âs = 13 TeV with the ATLAS detecto
ArtĂculo escrito por un elevado nĂșmero de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboraciĂłn, si le hubiere, y los autores pertenecientes a la UA
Measurements of top-quark pair single- and double-differential cross-sections in the all-hadronic channel in pp collisions at âs = 13 TeV using the ATLAS detector
ArtĂculo escrito por un elevado nĂșmero de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboraciĂłn, si le hubiere, y los autores pertenecientes a la UA
Population differences in allele frequencies at the OLR1 locus may suggest geographic disparities in cardiovascular risk events.
Abstract
Background: Several studies have demonstrated a link between cardiovascular disease (CVD) susceptibility
and the genetic background of populations.
Endothelial activation and dysfunction induced by oxidized low-density lipoprotein (ox-LDL) is one of
the key steps in the initiation of atherosclerosis. The oxidized low density lipoprotein (lectin-like)
receptor 1 (OLR1) gene is the main receptor of ox-LDL. We have previously characterized two
polymorphisms (rs3736235 and rs11053646) associated with the risk for coronary artery disease
(CAD) and acute myocardial infarction (AMI).
Aim: Given their clinical significance, it is of interest to know the distribution of these variants in
populations from different continents.
Subjects and methods: A total of 1229 individuals from 17 different African, Asian and European
populations was genotyped for the two considered markers.
Results: The high frequencies of ancestral alleles in South-Saharan populations is concordant with the
African origin of our species. The results highlight that African populations are closer to Asians, and
clearly separated from the Europeans.
Conclusion: The results confirm significant genetic structuring among populations and suggest a
possible basis for varying susceptibility to CVD among groups correlated with the geographical
location of populations linked with the migrations out of Africa, or with different lifestyle
GARBAN: genomic analysis and rapid biological annotation of cDNA microarray and proteomic data
Genomic Analysis and Rapid Biological ANnotation (GARBAN) is a new tool that provides an integrated framework to analyze simultaneously and compare multiple data sets derived from microarray or proteomic experiments. It carries out automated classifications of genes or proteins according to the criteria of the Gene Ontology Consortium at a level of depth defined by the user. Additionally, it performs clustering analysis of all sets based on functional categories or on differential expression levels. GARBAN also provides graphical representations of the biological pathways in which all the genes/proteins participate. AVAILABILITY: http://garban.tecnun.es
The ZEUS Forward Plug Calorimeter with Lead-Scintillator Plates and WLS Fiber Readout
A Forward Plug Calorimeter (FPC) for the ZEUS detector at HERA has been built
as a shashlik lead-scintillator calorimeter with wave length shifter fiber
readout. Before installation it was tested and calibrated using the X5 test
beam facility of the SPS accelerator at CERN. Electron, muon and pion beams in
the momentum range of 10 to 100 GeV/c were used. Results of these measurements
are presented as well as a calibration monitoring system based on a Co
source.Comment: 38 pages (Latex); 26 figures (ps
Food at the heart of the Empire. Dietary reconstruction for Imperial Rome inhabitants
This paper aims to provide a broad diet reconstruction for people buried in archaeologically defined contexts in Rome (first to third centuries CE), in order to combine archaeological and biological evidence focusing on dietary preferences in Imperial Rome. A sample of 214 human bones recovered from 6 funerary contexts was selected for carbon and nitrogen stable isotope analysis. The baseline for the terrestrial protein component of the diet was set using 17 coeval faunal remains recovered from excavations at Rome supplemented by previously published data for the same geographic and chronological frames. ÎŽ13C ranges from â 19.9 to â 14.8â°, whereas ÎŽ15N values are between 7.2 and 10.0â°. The values are consistent with an overall diet mainly based on terrestrial resources. All the human samples rely on a higher trophic level than the primary consumer faunal samples. Certainly, C3 plants played a pivotal role in the dietary habits. However, C4 plants also seem to have been consumed, albeit they were not as widespread and were not always used for human consumption. The environment played a critical role also for Romans of lower social classes. The topographical location determined the preferential consumption of food that people could obtain from their neighborhood
Position resolution and particle identification with the ATLAS EM calorimeter
In the years between 2000 and 2002 several pre-series and series modules of
the ATLAS EM barrel and end-cap calorimeter were exposed to electron, photon
and pion beams. The performance of the calorimeter with respect to its finely
segmented first sampling has been studied. The polar angle resolution has been
found to be in the range 50-60 mrad/sqrt(E (GeV)). The neutral pion rejection
has been measured to be about 3.5 for 90% photon selection efficiency at pT=50
GeV/c. Electron-pion separation studies have indicated that a pion fake rate of
(0.07-0.5)% can be achieved while maintaining 90% electron identification
efficiency for energies up to 40 GeV.Comment: 32 pages, 22 figures, to be published in NIM
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