9,407 research outputs found
High energy DVCS on a photon and related meson exclusive production
In this work we estimate the differential cross section for the high energy
deeply virtual Compton scattering on a photon target within the QCD
dipole-dipole scattering formalism. For the phenomenology, a saturation model
for the dipole-dipole cross section for two photon scattering is considered.
Its robustness is supported by good description of current accelerator data. In
addition, we consider the related exclusive vector meson production processes.
This analysis is focused on the light and meson production, which
produce larger cross sections. The phenomenological results are compared with
the theoretical calculation using the CD BFKL approach.Comment: 6 pages, 5 figures. Version to be published in Physical Review
Charm and bottom production in inclusive double Pomeron exchange in heavy ion collisions at the LHC
The inclusive double Pomeron exchange cross section for heavy quark pair
production is calculated for nucleus-nucleus collisions at the LHC. The present
estimate is based on hard diffractive factorization, corrected by absorptive
corrections and nuclear effects. The theoretical uncertainties for nuclear
collisions are investigated and a comparison to other approaches is presented.
The production channels producing a similar final state configuration are
discussed as well.Comment: 7 pages, 3 tables. Final version to be published in Physical Review
Diffractive photoproduction of heavy quarks in hadronic collisions
In this letter we study the diffractive photoproduction of heavy quarks in
hadronic (pp/pA/AA) interactions for Tevatron and LHC energies. The integrated
cross section and rapidity distribution for the process h_1 h_2 --> h_1 h_2
QQBAR (h_i = p,A and Q = c,b) are estimated using the Color Glass Condensate
(CGC) formalism. Our results indicate that this production channel has larger
cross sections than the competing reactions of double diffractive production
and coherent AA reactions initiated by two-photon collisions.Comment: 4 pages, 2 figures, 1 table. Version to be published in Physical
Review
Ultrahigh energy neutrinos and non-linear QCD dynamics
The ultrahigh energy neutrino-nucleon cross sections are computed taking into
account different phenomenological implementations of the non-linear QCD
dynamic s. Based on the color dipole framework, the results for the saturation
model supplemented by DGLAP evolution as well as for the BFKL formalism in the
geometric scaling regime are presented. They are contrasted with recent
calculations using NLO DGLAP and unified BFKL-DGLAP formalisms.Comment: 5 pages, 2 figures. Version to be published in Physical Review
Collection of relevant results obtained with the Skylab images by the Institute for Space Research, INPE
There are no author-identified significant results in this report
Imaging stress and magnetism at high pressures using a nanoscale quantum sensor
Pressure alters the physical, chemical and electronic properties of matter.
The development of the diamond anvil cell (DAC) enables tabletop experiments to
investigate a diverse landscape of high-pressure phenomena ranging from the
properties of planetary interiors to transitions between quantum mechanical
phases. In this work, we introduce and utilize a novel nanoscale sensing
platform, which integrates nitrogen-vacancy (NV) color centers directly into
the culet (tip) of diamond anvils. We demonstrate the versatility of this
platform by performing diffraction-limited imaging (~600 nm) of both stress
fields and magnetism, up to pressures ~30 GPa and for temperatures ranging from
25-340 K. For the former, we quantify all six (normal and shear) stress
components with accuracy GPa, offering unique new capabilities for
characterizing the strength and effective viscosity of solids and fluids under
pressure. For the latter, we demonstrate vector magnetic field imaging with
dipole accuracy emu, enabling us to measure the pressure-driven
phase transition in iron as well as the complex
pressure-temperature phase diagram of gadolinium. In addition to DC vector
magnetometry, we highlight a complementary NV-sensing modality using T1 noise
spectroscopy; crucially, this demonstrates our ability to characterize phase
transitions even in the absence of static magnetic signatures. By integrating
an atomic-scale sensor directly into DACs, our platform enables the in situ
imaging of elastic, electric and magnetic phenomena at high pressures.Comment: 18 + 50 pages, 4 + 19 figure
Influence of biological activity on 65Zn and 109Cd removal from tidal water by chronically-polluted mangrove sediments
The biological activity influence on the mangrove sediment capacity to remove 65Zn and 109Cd from tidal water was evaluated in a site chronically polluted. Benthic Activity Indexes (BAI), corresponding to relative estimates of biological impact on radiotracer accumulation, were higher for 109Cd (~ 38%) than for 65Zn (~ 10%) in the top centimetre of sediment. However, BAI exceeded 96% for deeper sediment layers. This apparent decrease in radiotracer diffusion into deep sediments through biological activity inhibition is stronger than reported for much less polluted mangrove nearby, suggesting that benthic organisms tolerant of chronic metal pollution may affect metal sorption mechanisms.info:eu-repo/semantics/publishedVersio
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