603 research outputs found
Enhancement of prompt photons in ultrarelativistic proton-proton collisions from nonlinear gluon evolution at small-
In this paper we estimate the influence of nonlinear gluon evolution in the
production of prompt photons at the LHC pp collider. We assume the validity of
collinear factorization and consider the EHKQS parton distributions, which are
solutions of the GLR-MQ evolution equations and describe quite well the DESY
HERA data, as input in our calculations. We find that both single and
double photon production are enhanced for low- photons and central
rapidities, while this effect is absent for the high- photons. The
implications of this effect for the Quark-Gluon Plasma searches and for the QCD
background to Higgs are also discussed.Comment: 4 pages, 4 figures. Version to be published in Physical Review
Nuclear Medium Effects in Production at HERA-B
In this paper we estimate the influence of the shadowing effect and initial
state parton energy loss in the quarkonium production at HERA-B. We analyze the
behavior of the effective exponent and present a
comparison with the preliminary HERA-B data for production. Moreover,
we estimate the magnitude of these effects in the production at RHIC.Comment: 9 pages, 4 figure
Prompt J/psi production at the LHC
Models with essential non-perturbative QCD dynamics for the production of
charmonium are extrapolated to give predictions of prompt J/psi production at
the LHC. Differences of up to an order of magnitude occurs, although the
different models all describe the Tevatron data on high-pT charmonium. An
important point is here the treatment of higher order perturbative QCD effects.
We also discuss the large rate of prompt J/psi from these models as a
background to CP violation studies.Comment: 8 pages, 8 eps figure
Diffractive Higgs boson production at the Tevatron and LHC
Improved possibilities to find the Higgs boson in diffractive events, having
less hadronic activity, depend on whether the cross section is large enough.
Based on the soft color interaction models that successfully describe
diffractive hard scattering at HERA and the Tevatron, we find that only a few
diffractive Higgs events may be produced at the Tevatron, but we predict a
substantial rate at the LHC.Comment: 4 pages, 4 figures, uses Revtex
Viscosity, Boson Peak and Elastic Moduli in the Na2O-SiO2 System
The temperature and chemical dependence of the melt viscosity are ubiquitous in the model development of the volcanic dynamics, as well as in the glass production and design. We focussed on the yet-explored relationship between the bulk and shear moduli ratio and boson peak with the melt fragility of their parental glasses. Here, we explored the extension of the observed trend by testing the conventional binary system Na2O-SiO2, thus providing new evidence supporting the link between the flow of melts and supercooled liquids and the vibrational dynamics of their parental glasses. This was accomplished by integrating new low-frequency Raman measurements and integrating data from the literature on Brillouin light scattering and viscometry. This approach allows us to feed the MYEGA equation with reliable input parameters to quantitatively predict the viscosity of the Na2O-SiO2 system from the liquid up to the glass transition
Controle químico da ferrugem (Hemileia vastatrix Berk & BR.) do cafeeiro (Coffea arabica, L.) e seus efeitos na produção, nas condições do estado de Rondônia.
Durante cinco anos consecutivos foi desenvolvido no município de Cacoal, RO, um experimento visando avaliar o comportamento da ferrugem do cafeeiro e determinar um programa adequado de aplicação de produto químico, para o seu controle. A doença desenvolveu-se rapidamente, durante os meses de dezembro e janeiro e se manteve em níveis elevados ate a colheita, depois declinou progressivamente, ate o mês de agosto, permanecendo em baixo índice ate outubro. O retardamento do inicio das aplicações de fungicida permitiu a livre evolução da ferrugem nesse período, o que proporcionou efeito negativo, principalmente no programa de pulverizações janeiro-abril. O mesmo comportamento da ferrugem foi observado, adiantando-se o termino das aplicações, pois a incidência da doença a níveis elevados ocorreu após fevereiro, causando danos a produção do ano seguinte. Os programas de maior eficiência no controle da ferrugem e aumento da produção, foram os que estabeleceram pulverizações nos períodos de outubro a abril e novembro a abril
Integrating virtual reality and gis tools for geological mapping, data collection and analysis: An example from the metaxa mine, santorini (Greece)
In the present work we highlight the effectiveness of integrating different techniques and tools for better surveying, mapping and collecting data in volcanic areas. We use an Immersive Virtual Reality (IVR) approach for data collection, integrated with Geographic Information System (GIS) analysis in a well-known volcanological site in Santorini (Metaxa mine), a site where volcanic processes influenced the island’s industrial development, especially with regard to pumice mining. Specifically, we have focused on: (i) three-dimensional (3D) high-resolution IVR scenario building, based on Structure from Motion photogrammetry (SfM) modeling; (ii) subsequent geological survey, mapping and data collection using IVR; (iii) data analysis, e.g., calculation of extracted volumes, as well as production of new maps in a GIS environment using input data directly from the IVR survey; and finally, (iv) presentation of new outcomes that highlight the importance of the Metaxa Mine as a key geological and volcanological geosite
Fabrication and Results of the First MgB2 Round Coil Superferric Magnet at LASA
The LASA Laboratory (INFN, Milan) is working in the High Luminosity LHC program to develop, in collaboration with CERN, six different types of High Order corrector magnets. In this framework, in parallel with a conventional design of superferric magnets with LTS conductor, the LASA is focusing on the research of new superconducting materials which may have applications in particle accelerator magnets. To this purpose, LASA is developing a new type of superferric magnet suitable to arbitrary multipole order, called Round Coil Superferric Magnets (RCSM). The iron yoke shaped with an arbitrary number of poles is able to create the desired harmonic component using only one single round coil with a large bending radius suitable for very strain-sensitive superconductors. The electromagnetic design of a sextupole configuration of the magnet and the production of the first superconducting MgB2 round coil prototype have been already presented. In this paper, we expose the optimization of the iron yoke and polar expansions assembly of the first magnet semi-module prototype. The results of the whole powering test are described in detail and the analysis of the magnetic performances are compared with those of classical superferric correctors
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