579 research outputs found

    Constraints for nuclear gluon shadowing from DIS data

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    The Q2Q^2 dependence of the ratios of the cross sections of deep inelastic lepton--nucleus scattering is studied in the framework of leading twist, lowest order perturbative QCD. The log⁥Q2\log Q^2 slope of the ratio F2Sn/F2CF_2^{\rm Sn}/F_2^{\rm C} is computed by using the DGLAP evolution equations, and shown to be sensitive to the nuclear gluon distribution functions. Four different parametrizations for the nuclear effects of parton distributions are studied. We show that the NMC data on the Q2Q^2 dependence of F2Sn/F2CF_2^{\rm Sn}/F_2^{\rm C} rule out the case where nuclear shadowing (suppression) of gluons at x∌0.01x\sim 0.01 is much larger than the shadowing observed in the ratio F2A/F2DF_2^A/F_2^{\rm D}. We also show that the possible nonlinear correction terms due to gluon fusion in the evolution equations do not change this conclusion. Some consequences for computation of RHIC multiplicities, which probe the region x\gsim0.01, are also discussed.Comment: 11 pages, 3 eps figure

    Global DGLAP fit analyses of the nPDF: EKS98 and HKM

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    The DGLAP analyses of the nuclear parton distribution functions (nPDF) based on the global fits to the data are reviewed, and the results from EKS98 and HKM are compared. The usefulness of measuring hard probes in pApA collisions, at the LHC in particular, is demonstrated.Comment: 10 pages, 3 figures. Contribution to CERN Yellow Report on Hard Probes in Heavy Ion Collisions at the LH

    Constraints for nuclear gluon densities from DIS data

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    The Q2Q^2 dependence of the ratios of nuclear structure functions F2AF_2^A is studied by performing QCD evolution of nuclear parton distribution functions. The log Q2Q^2 slope of these ratios is very sensitive to the nuclear gluon distribution function. Taking different parametrizations, we show that the NMC data on the Q2Q^2 dependence of F2Sn/F2CF_2^{\rm Sn}/F_2^{\rm C} rule out the case where nuclear shadowing (suppression) of gluons at x∌0.01x\sim 0.01 is much larger than the shadowing observed in the ratio F2A/F2DF_2^A/F_2^{\rm D}. We also take into account modifications to the DGLAP evolution by including gluon fusion terms and see that the effect is small at present energies, and, in any case, a strong gluon shadowing is not favored. The region studied (x∌0.01x \sim 0.01) is the most relevant for RHIC multiplicities.Comment: 4 pages, 3 postscript figures. Contributed to 37th Rencontres de Moriond on QCD and Hadronic Interactions, Les Arcs, France, 16-23 Mar 200

    Nuclear parton distributions in the DGLAP approach

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    Determination of the nuclear parton distributions within the framework of perturbative QCD, the DGLAP equations in particular, is discussed. Scale and flavour dependent nuclear effects in the parton distributions are compared with the scale and flavour independent parametrizations of HIJING and of the Hard Probe Collaboration. A comparison with the data from deep inelastic lepton-nucleus scattering and the Drell-Yan process in proton-nucleus collisions is shown.Comment: 19 pages, 6 eps-figures, to appear in the Proceedings of the Hard Probe Collaboratio

    Hadron multiplicities, pT-spectra and net-baryon number in central Pb+Pb collisions at the LHC

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    We compute the initial energy density and net baryon number density in 5% most central Pb+Pb collisions at s=5.5\sqrt s=5.5 TeV from pQCD + (final state) saturation, and describe the evolution of the produced system with boost-invariant transversely expanding hydrodynamics. In addition to the total multiplicity at midrapidity, we give predictions for the multiplicity of charged hadrons, pions, kaons and (anti)protons, for the total transverse energy and net-baryon number, as well as for the pTp_T-spectrum of charged hadrons, pions and kaons. We also predict the region of applicability of hydrodynamics by comparing these results with high-pTp_T hadron spectra computed from pQCD and energy losses.Comment: 2 pages, 2 figures, to be presented at the workshop "Heavy Ion Collisions at the LHC: Last Call for Predictions" at CERN 29 May - 2 Jun

    Transverse Spectra of Hadrons in Central AAAA Collisions at RHIC and LHC from pQCD+Saturation+Hydrodynamics and from pQCD+Energy Losses

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    We study the transverse spectra of hadrons in nearly central AAAA collisions at RHIC and LHC in a broad transverse momentum range Low-pTp_T spectra are calculated by using boost-invariant hydrodynamics with initial energy and net-baryon densities from the EKRT pQCD+saturation model. High-pTp_T spectra are obtained from pQCD jet calculation including the energy loss of the parton in the matter prior to its fragmentation to final hadrons.Comment: 4 pages, 2 figures, proceedings for Quark Matter 200

    Developing LCA-based benchmarks for sustainable consumption - for and with users

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    This article presents the development process of a consumer-oriented, illustrative benchmarking tool enabling consumers to use the results of environmental life cycle assessment (LCA) to make informed decisions. Active and environmentally conscious consumers and environmental communicators were identified as key target groups for this type of information. A brochure presenting the benchmarking tool was developed as an participatory, iterative process involving consumer focus groups, stakeholder workshops and questionnaire-based feedback. In addition to learning what works and what does not, detailed suggestions on improved wording and figures were obtained, as well as a wealth of ideas for future applications

    DGLAP analyses of nPDF: constraints from data

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    We explain how the constraints from present experimental data can be used to obtain the nPDF in the framework of LO DGLAP evolution. We will also compare the only two available sets of this type and comment on the important information that neutrino factories could provide.Comment: 1 pages, 1 postscript figure. Invited talk at the NuFact'02 workshop (Neutrino Factories based on Muon Storage Rings), London, July 200

    Long term life dissatisfaction and subsequent major depressive disorder and poor mental health

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    <p>Abstract</p> <p>Background</p> <p>Poor mental health, especially due to depression, is one of the main public health problems. Early indicators of poor mental health in general population are needed. This study examined the relationship between long-term life dissatisfaction and subsequent mental health, including major depressive disorder.</p> <p>Method</p> <p>Health questionnaires were sent to a randomly selected population-based sample in 1998 and repeated in 1999 and 2001. In 2005, a clinically studied sub-sample (n = 330) was composed of subjects with (n = 161) or without (n = 169) repeatedly reported adverse mental symptoms at all three previous data collection times. Clinical symptom assessments were performed with several psychometric scales: life satisfaction (<b>LS</b>), depression (<b>HDRS, BDI</b>), hopelessness (<b>HS</b>), mental distress (<b>GHQ</b>), dissociative experiences (<b>DES</b>), and alexithymia (<b>TAS</b>). The long-term life dissatisfaction burden was calculated by summing these life satisfaction scores in 1998, 1999, 2001 and dividing the sum into tertiles. Psychiatric diagnoses were confirmed by SCID-I for DSM-IV in 2005. Logistic regression analyses were performed to assess the studied relationship.</p> <p>Results</p> <p>The previous life dissatisfaction burden associated with adverse socio-demographic, life style and clinical factors. In adjusted logistic regression analyses, it was independently and strongly associated with subsequent major depressive disorder in 2005, even when the concurrent LS score in 2005 was included in the model. Excluding those with reported major depressive disorder in 1999 did not alter this finding.</p> <p>Limitations</p> <p>MDD in 1999 was based on self-reports and not on structured interview and LS data in 2001-2005 was not available.</p> <p>Conclusions</p> <p>The life satisfaction burden is significantly related to major depressive disorder and poor mental health, both in cross-sectional and longitudinal settings.</p
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