TMDlib and TMDplotter: library and plotting tools for transverse-momentum-dependent parton distributions

Transverse-momentum-dependent distributions (TMDs) are central in high-energy physics from both theoretical and phenomenological points of view. In this manual we introduce the library, TMDlib, of fits and parameterisations for transverse-momentum-dependent parton distribution functions (TMD PDFs) and fragmentation functions (TMD FFs) together with an online plotting tool, TMDplotter. We provide a description of the program components and of the different physical frameworks the user can access via the available parameterisations.Comment: version 2, referring to TMDlib 1.0.2 - comments and references adde

Collinear factorization in wide-angle hadron pair production in e+e-annihilation

We compute the inclusive unpolarized dihadron production cross section in the far from back-to-back region of e+e-annihilation in leading order pQCD using existing fragmentation function fits and standard collinear factorization, focusing on the large transverse momentum region where transverse momentum is comparable to the hard scale (the center-of-mass energy). We compare with standard transverse-momentum-dependent (TMD) fragmentation function-based predictions intended for the small transverse momentum region with the aim of testing the expectation that the two types of calculation roughly coincide at intermediate transverse momentum. We find significant tension, within the intermediate transverse momentum region, between calculations done with existing nonperturbative TMD fragmentation functions and collinear factorization calculations if the center-of-mass energy is not extremely large. We argue that e+e-measurements are ideal for resolving this tension and exploring the large-to-small transverse momentum transition, given the typically larger hard scales (~10 GeV) of the process as compared with similar scenarios that arise in semi-inclusive deep inelastic scattering and fixed-target Drell-Yan measurements

BRAND CONVERSATION IN FACEBOOK: LA PERCEZIONE DEGLI UTENTI

L'obiettivo della ricerca è di comprendere la percezione degli utenti Facebook sulla presenza e funzione dei "Brand Profiles" in tale social network. La ricerca ha utilizzato strumenti online (seguendo le linee guida del Digital Method Initiative), con tecnica di intervista strutturata su 423 utenti Fb, basata su questionario CAWI. La ricerca offre spunti sia in relazione al comportamento online su Fb degli utenti, sia sulla loro propensione alla condivisione di contenuti di pagine e profili pubblici. Ne emergono prescrizioni utili alle imprese su linguaggi, codifiche, e profili relazionali adatti al nuovo contesto social online in cui i Brand desiderano "pro-muoversi”

Matching factorization theorems with an inverse-error weighting

We propose a new fast method to match factorization theorems applicable in different kinematical regions, such as the transverse-momentum-dependent and the collinear factorization theorems in Quantum Chromodynamics. At variance with well-known approaches relying on their simple addition and subsequent subtraction of double-counted contributions, ours simply builds on their weighting using the theory uncertainties deduced from the factorization theorems themselves. This allows us to estimate the unknown complete matched cross section from an inverse-error-weighted average. The method is simple and provides an evaluation of the theoretical uncertainty of the matched cross section associated with the uncertainties from the power corrections to the factorization theorems (additional uncertainties, such as the nonperturbative ones, should be added for a proper comparison with experimental data). Its usage is illustrated with several basic examples, such as Z boson, W boson, H0 boson and Drell–Yan lepton-pair production in hadronic collisions, and compared to the state-of-the-art Collins–Soper–Sterman subtraction scheme. It is also not limited to the transverse-momentum spectrum, and can straightforwardly be extended to match any (un)polarized cross section differential in other variables, including multi-differential measurements

Microbial diversity and community structure across environmental gradients in Bransfield Strait, Western Antarctic Peninsula

© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Microbiology 5 (2014): 647, doi:10.3389/fmicb.2014.00647.The Southern Ocean is currently subject to intense investigations, mainly related to its importance for global biogeochemical cycles and its alarming rate of warming in response to climate change. Microbes play an essential role in the functioning of this ecosystem and are the main drivers of the biogeochemical cycling of elements. Yet, the diversity and abundance of microorganisms in this system remain poorly studied, in particular with regards to changes along environmental gradients. Here, we used amplicon sequencing of 16S rRNA gene tags using primers covering both Bacteria and Archaea to assess the composition and diversity of the microbial communities from four sampling depths (surface, the maximum and minimum of the oxygen concentration, and near the seafloor) at 10 oceanographic stations located in Bransfield Strait [northwest of the Antarctic Peninsula (AP)] and near the sea ice edge (north of the AP). Samples collected near the seafloor and at the oxygen minimum exhibited a higher diversity than those from the surface and oxygen maximum for both bacterial and archaeal communities. The main taxonomic groups identified below 100 m were Thaumarchaeota, Euryarchaeota and Proteobacteria (Gamma-, Delta-, Beta-, and Alphaproteobacteria), whereas in the mixed layer above 100 m Bacteroidetes and Proteobacteria (mainly Alpha- and Gammaproteobacteria) were found to be dominant. A combination of environmental factors seems to influence the microbial community composition. Our results help to understand how the dynamic seascape of the Southern Ocean shapes the microbial community composition and set a baseline for upcoming studies to evaluate the response of this ecosystem to future changes.This work was supported by the Brazilian National Counsel of Technological and Scientific Development (Polar Canion CNPq 556848/2009-8, ProOasis CNPq 565040/2010-3, Interbiota CNPq 407889/2013-2 and INCT-MAR-COI). Alex Enrich-Prast received a CNPq Productivity fellowship. Camila N. Signori was supported by a WHOI Mary Sears Visitor Award (for the microbial community analyses) and by the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES) for the “Doctorate Sandwich” scholarship (n. 18835/12-0)

Feasibility Studies for Single Transverse-Spin Asymmetry Measurements at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC)

The measurement of Single Transverse-Spin Asymmetries, A_N, for various quarkonium states and Drell–Yan lepton pairs can shed light on the orbital angular momentum of quarks and gluons, a fundamental ingredient of the proton-spin puzzle. The AFTER@LHC proposal combines a unique kinematic coverage and large luminosities thanks to the Large Hadron Collider beams to deliver precise measurements, complementary to the knowledge provided by collider experiments such as at RHIC. In this paper, we report on sensitivity studies for J/ ψ, Υ and Drell–Yan A_N done using the performance of LHCb-like or ALICE-like detectors, combined with polarised gaseous hydrogen and helium-3 targets. In particular, such analyses will provide us with new insights and knowledge about transverse-momentum-dependent parton distribution functions for quarks and gluons and on twist-3 collinear matrix elements in the proton and the neutron

Sistema de gerenciamento dos Bancos Ativos de Germoplasma da Embrapa Trigo.

bitstream/CNPT-2010/40598/1/p-co233.pd

Unpolarized transverse momentum distributions from a global fit of Drell-Yan and semi-inclusive deep-inelastic scattering data

We present an extraction of unpolarized transverse-momentum-dependent parton distribution and fragmentation functions based on more than two thousand data points from several experiments for two different processes: semi-inclusive deep-inelastic scattering and Drell-Yan production. The baseline analysis is performed using the Monte Carlo replica method and resumming large logarithms at (NLL)-L-3 accuracy. The resulting description of the data is very good (chi(2)/N-dat = 1.06). For semi-inclusive deep-inelastic scattering, predictions for multiplicities are normalized by factors that cure the discrepancy with data introduced by higher-order perturbative corrections

Gap-filling carbon dioxide, water, energy, and methane fluxes in challenging ecosystems : comparing between methods, drivers, and gap-lengths

Acknowledgements The authors thank the FLUXNET-CH4 research groups for providing the CC-BY-4.0 (Tier one) open-access eddy covariance data (https://fluxnet.org/data/fluxnet-ch4-community-product/) and ERA5 (https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5) for providing meteorology reanalysis data. They also thank the ReddyProc (https://cran.r-project.org/web/packages/R EddyProc/index.html) team, scikit-learn (https://scikit-learn.org/s table/install.html) team, and Xgboost team (https://xgboost.readthedocs.io/en/stable/python/python_api.html) for the packages that help the implementation and validation for gap-filling approaches. SZ and TH would like to acknowledge funding from Shell to support the PhD studentship. Rothamsted thanks BBSRC grants BBS/E/C/000I0320 and BBS/E/C/000J0100. The Eddy Covariance equipment deployed in this work was funded by CIEL (https://www.cielivestock.co.uk/) and the raw data is available on the Farm Platform Portal (https://nwfp.rothamsted.ac.uk/).Peer reviewedPublisher PD

High Prevalence of Gammaproteobacteria in the Sediments of Admiralty Bay and North Bransfield Basin, Northwestern Antarctic Peninsula

Microorganisms dominate most Antarctic marine ecosystems, in terms of biomass and taxonomic diversity, and play crucial role in ecosystem functioning due to their high metabolic plasticity. Admiralty Bay is the largest bay on King George Island (South Shetland Islands, Antarctic Peninsula) and a combination of hydro-oceanographic characteristics (bathymetry, sea ice and glacier melting, seasonal entrance of water masses, turbidity, vertical fluxes) create conditions favoring organic carbon deposition on the seafloor and microbial activities. We sampled surface sediments from 15 sites across Admiralty Bay (100502 m total depth) and the adjacent North Bransfield Basin (6931147 m), and used the amplicon 454-sequencing of 16S rRNA gene tags to compare the bacterial composition, diversity, and microbial community structure across environmental parameters (sediment grain size, pigments and organic nutrients) between the two areas. Marine sediments had a high abundance of heterotrophic Gammaproteobacteria (92.4% and 83.8% inside and outside the bay, respectively), followed by Alphaproteobacteria (2.5 and 5.5%), Firmicutes (1.5 and 1.6%), Bacteroidetes (1.1 and 1.7%), Deltaproteobacteria (0.8 and 2.5%) and Actinobacteria (0.7 and 1.3%). Differences in alpha-diversity and bacterial community structure were found between the two areas, reflecting the physical and chemical differences in the sediments, and the organic matter input.Brazilian National Council for Scientific and Technological Development - CNPq (MABIREH/IPY/CAML)CAPES-Master's fellowshipUniv Sao Paulo, Inst Oceanog, Dept Oceanog Biol, Sao Paulo, BrazilUniv Fed Santa Catarina, Ctr Ciencias Biol, Florianopolis, SC, BrazilUniv Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Dept Ciencias Ambientais, Diadema, BrazilUniv Fed Rio de Janeiro, Inst Biol, Dept Zool, Rio De Janeiro, BrazilUniv Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Dept Ciencias Ambientais, Diadema, BrazilCNPq (MABIREH/IPY/CAML): 520293/2006-1Web of Scienc