SwePub - search: WFRF:(Christensen Anders)

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1.	Bridel, Claire, et al. (author) Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology : A Systematic Review and Meta-analysis 2019 In: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:9, s. 1035-1048 Research review (peer-reviewed)abstract Importance Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date.Objectives To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions.Data Sources PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC.Study Selection Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex.Data Extraction and Synthesis Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept.Main Outcome and Measure The cNfL levels adjusted for age and sex across diagnoses.Results Data were collected for 10 059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes.Conclusions and Relevance These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.
2.	Grubb, Anders, et al. (author) Generation of a new cystatin C-based estimating equation for glomerular filtration rate by use of 7 assays standardized to the international calibrator 2014 In: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 60:7, s. 974-986 Journal article (peer-reviewed)abstract BACKGROUND:Many different cystatin C-based equations exist for estimating glomerular filtration rate. Major reasons for this are the previous lack of an international cystatin C calibrator and the nonequivalence of results from different cystatin C assays.METHODS:Use of the recently introduced certified reference material, ERM-DA471/IFCC, and further work to achieve high agreement and equivalence of 7 commercially available cystatin C assays allowed a substantial decrease of the CV of the assays, as defined by their performance in an external quality assessment for clinical laboratory investigations. By use of 2 of these assays and a population of 4690 subjects, with large subpopulations of children and Asian and Caucasian adults, with their GFR determined by either renal or plasma inulin clearance or plasma iohexol clearance, we attempted to produce a virtually assay-independent simple cystatin C-based equation for estimation of GFR.RESULTS:We developed a simple cystatin C-based equation for estimation of GFR comprising only 2 variables, cystatin C concentration and age. No terms for race and sex are required for optimal diagnostic performance. The equation, [Formula: see text] is also biologically oriented, with 1 term for the theoretical renal clearance of small molecules and 1 constant for extrarenal clearance of cystatin C.CONCLUSIONS:A virtually assay-independent simple cystatin C-based and biologically oriented equation for estimation of GFR, without terms for sex and race, was produced.
3.	Guillemain, Matthieu, et al. (author) Effects of climate change on European ducks : what do we know and what do we need to know? 2013 In: Wildlife Biology. - : Nordic Council of Wildlife Research. - 0909-6396 .- 1903-220X. ; 19:4, s. 404-419 Journal article (peer-reviewed)abstract The consequences of climate change for bird populations have received much attention in recent decades, especially amongst cavity-nesting songbirds, yet little has been written on ducks (Anatidae) despite these being major elements of wetland diversity and important quarry species. This paper reviews the major known consequences of climate change for birds in general, and relates these to the limited information available specifically for ducks. Climate change can influence migration distance and phenology, potentially affecting patterns of mortality, as well as distribution and reproductive success in ducks. Studies addressing effects of climate change are, however, restricted to very few duck species, including mallardAnas platyrhynchos and common eider Somateria mollissima. Shifts in winter duck distributions have been observed, whereas the mismatch hypothesis (mistiming between the periods of peak energy requirements for young and the peak of seasonal food availability) has received limited support with regard to ducks. We propose a range of monitoring initiatives, including population surveys, breeding success monitoring schemes and individual duck marking, which should later be integrated through population modelling and adaptive management to fill these gaps.
4.	Abelev, Betty, et al. (author) Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV 2013 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41 Journal article (peer-reviewed)abstract Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
5.	Abelev, Betty, et al. (author) Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV 2012 In: Journal of High Energy Physics. - 1029-8479. ; :11 Journal article (peer-reviewed)abstract The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
6.	Cassel, Anders, et al. (author) On Perception Safety Requirements and Multi Sensor Systems for Automated Driving Systems 2020 In: SAE technical paper series. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191. ; 2020-April:April Journal article (peer-reviewed)abstract One major challenge in designing SAE level 3-5 Automated Driving Systems (ADS) is to define requirements for the perception system that would enable argumentation for safe operation. The safety requirements on the perception system can only be fulfilled through redundancy in the sensor hardware. It is, however, a challenge to specify the redundancy that is required in the sensor system. Safe operation for an ADS is significantly more difficult compared to advanced driver assistance systems (ADAS). The safety argumentation for ADAS typically argues that in case of a failure in the sensor array a fail-silent behavior is acceptable because the human driver can take control of the vehicle back. This argumentation however is not possible when developing level 4 or higher automation. This paper investigates prerequisites for applying a systematic methodology for analyzing redundancy in a multi-sensor system and the relation to a conceptual ADS functional architecture. This analysis must address the complexity that comes with partially overlapping sensor data from different sensors and considers variations in performance and characteristics due to changes in the environmental conditions. The paper introduces the term incomplete redundancy and presents a systematic methodology for analyzing redundancy. The aim is to provide arguments for how several sensors in a system, when appropriately combined, meet an assigned safety requirement on a higher level. Each sensor will then be assigned a certain responsibility and contributes with a sub-set of information. A set of questions of importance to address as a foundation for such a methodology are defined and discussed. The definitions of redundancy and independence between sensors are discussed as well as contract-based functional safety to adapt to different environmental and operating conditions.
7.	Christensen, Kjeld, et al. (author) Inflammatory reactions following percutaneous coronary intervention and stent implantation in acute coronary syndrome. Other publication (other academic/artistic)
8.	Christensen, Kjeld, et al. (author) Platelet activation following percutaneous coronary intervention and stent implantation in acute coronary syndrome-a flow cytometry study. Other publication (other academic/artistic)
9.	Christensen, Torben, et al. (author) Quality Indicators for Social Science Teaching in Nordic classrooms 2019 Conference paper (other academic/artistic)
10.	Elberling, Bo, et al. (author) Soil and Plant Community Characteristics and Dynamics at Zackenberg 2008 In: High-arctic ecosystem dynamics in a changing climate - Ten years of monitoring and research at Zackenberg Research Station, Northeast Greenland (Advances in Ecological Research). - 0065-2504. - 9780123736659 ; 40, s. 223-248 Book chapter (other academic/artistic)abstract Arctic soils hold large amounts of nutrients in the weatherable minerals and the soil organic matter, which slowly decompose. The decomposition processes release nutrients to the plant-available nutrient pool as well as greenhouse gases to the atmosphere. Changes in climatic conditions, for example, changes in the distribution of snow, water balance and the length of the growing season, are likely to affect the complex interactions between plants, abiotic and biotic soil processes as well as the composition of soil micro- and macro-fauna and thereby the overall decomposition rates. These interactions, in turn, will influence soil-plant functioning and vegetation composition in the short as well as in the long term. In this chapter, we report on soils and. plant communities and their distribution patterns in the valley Zackenbergdalen and focus on the detailed investigations within five dominating plant communities. These five communities are located along an ecological gradient in the landscape and are closely related to differences in water availability. They are therefore indirectly formed as a result of the distribution of landforms, redistribution of snow and drainage conditions. Each of the plant communities is closely related to specific nutrient levels and degree of soil development including soil element accumulation and translocation, for example, organic carbon. Results presented here show that different parts of the landscape have responded quite differently to the same overall climate changes the last 10 years and thus, most likely in the future too. Fens represent the wettest sites holding large reactive buried carbon stocks. A warmer climate will cause a permafrost degradation, which most likely will result in anoxic decomposition and increasing methane emissions. However, the net gas emissions at fen sites are sensitive to long-term changes in the water table level. Indeed, increasing maximum active layer depth at fen sites has been recorded together with a decreasing water level at Zackenberg. This is in line with the first signs of increasing extension of grasslands at the expense of fens. In contrast, the most exposed and dry areas have less soil carbon, and decomposition processes are periodically water limited. Here, an increase in air temperatures may increase active layer depth more than at fen sites, but water availability will be critical in determining nutrient cycling and plant production. Field manipulation experiments of increasing temperature, water supply and nutrient addition show that soil-plant interactions are sensitive to these variables. However, additional plant-specific investigations are needed before net effects of climate changes on different landscape and plant communities can be integrated in a landscape context and used to assess the net ecosystem effect of future climate scenarios.
11.	Guillemain, Matthieu, et al. (author) Effects of climate change on European ducks: what do we know and what do we need to know? 2013 In: Wildlife Biology. - : Wiley. - 0909-6396 .- 1903-220X. ; 19:4, s. 404-419 Research review (peer-reviewed)abstract The consequences of climate change for bird populations have received much attention in recent decades, especially amongst cavity-nesting songbirds, yet little has been written on ducks (Anatidae) despite these being major elements of wetland diversity and important quarry species. This paper reviews the major known consequences of climate change for birds in general, and relates these to the limited information available specifically for ducks. Climate change can influence migration distance and phenology, potentially affecting patterns of mortality, as well as distribution and reproductive success in ducks. Studies addressing effects of climate change are, however, restricted to very few duck species, including mallard Anas platyrhynchos and common eider Somateria mollissima. Shifts in winter duck distributions have been observed, whereas the mismatch hypothesis (mistiming between the periods of peak energy requirements for young and the peak of seasonal food availability) has received limited sup-port with regard to ducks. We propose a range of monitoring initiatives, including population surveys, breeding success monitoring schemes and individual duck marking, which should later be integrated through population modelling and adaptive management to fill these gaps.
12.	Hansen, Torben Frostrup, et al. (author) The predictive value of single nucleotide polymorphisms in the VEGF system to the efficacy of first-line treatment with bevacizumab plus chemotherapy in patients with metastatic colorectal cancer Results from the Nordic ACT trial 2012 In: International Journal of Colorectal Disease. - : Springer Science and Business Media LLC. - 1432-1262 .- 0179-1958. ; 27:6, s. 715-720 Journal article (peer-reviewed)abstract Bevacizumab and chemotherapy is a common choice for first-line treatment of metastatic colorectal cancer (mCRC). So far, no predictive markers have been identified. The aim was to investigate the possible predictive value of single nucleotide polymorphisms (SNPs) in the vascular endothelial growth factor (VEGF) system in this setting. Pre-treatment blood samples and response evaluations were available from 218 of the 249 included patients. All patients received bevacizumab and chemotherapy comprising fluorouracil and leucovorin or capecitabine combined with either oxaliplatin (FOLFOX or XELOX, n = 183) or irinotecan (FOLFIRI or XELIRI, n = 66). Germline DNA was isolated from whole blood, and five SNPs in the VEGF-A gene, one SNP in the VEGF receptor 1 (VEGFR-1) gene and three SNPs in the VEGFR-2 gene were analysed by polymerase chain reaction. Response was evaluated according to RECIST version 1.0, and the association to genotypes was analysed using Fisher's exact test. The VEGFR-1 319 C/A SNP was significantly associated with response. Objective response was observed in 36% of the patients with CC genotype, 40% with CA and 56% with AA, p = 0.048. The response rates also differed significantly between patients with C-allele containing genotypes (CC + CA) (39%) and patients homozygous for the A-allele (AA) (56%), p = 0.015. There was no correlation between response rates and the remaining SNPs. The VEGFR-1 319 C/A SNP is a potential predictive marker for bevacizumab plus chemotherapy in patients with mCRC. Patients with the A allele appeared to have increased response rates. The results call for validation.
13.	Holmstrup, Martin, et al. (author) Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland 2017 In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7 Journal article (peer-reviewed)abstract In a dry heathland ecosystem we manipulated temperature (warming), precipitation (drought) and atmospheric concentration of CO2 in a full-factorial experiment in order to investigate changes in below-ground biodiversity as a result of future climate change. We investigated the responses in community diversity of nematodes, enchytraeids, collembolans and oribatid mites at two and eight years of manipulations. We used a structural equation modelling (SEM) approach analyzing the three manipulations, soil moisture and temperature, and seven soil biological and chemical ariables. The analysis revealed a persistent and positive effect of elevated CO2 on litter C:N ratio. After two years of treatment, the fungi to bacteria ratio was increased by warming, and the diversities within oribatid mites, collembolans and nematode groups were all affected by elevated CO2 mediated through increased litter C:N ratio. After eight years of treatment, however, the CO2-increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two and eight years, respectively. These results suggest a remarkable resilience within the soil biota against global climate change treatments in the long term.
14.	Larsen, Lars Bruun, et al. (author) Digital Recruitment and Acceptance of a Stepwise Model to Prevent Chronic Disease in the Danish Primary Care Sector : Cross-Sectional Study 2019 In: Journal of Medical Internet Research. - : JMIR Publications Inc.. - 1438-8871. ; 21:1 Journal article (peer-reviewed)abstract BACKGROUND: During recent years, stepwise approaches to health checks have been advanced as an alternative to general health checks. In 2013, we set up the Early Detection and Prevention project (Tidlig Opsporing og Forebyggelse, TOF) to develop a stepwise approach aimed at patients at high or moderate risk of a chronic disease. A novel feature was the use of a personal digital mailbox for recruiting participants. A personal digital mailbox is a secure digital mailbox provided by the Danish public authorities. Apart from being both safe and secure, it is a low-cost, quick, and easy way to reach Danish residents. OBJECTIVE: In this study we analyze the association between the rates of acceptance of 2 digital invitations sent to a personal digital mailbox and the sociodemographic determinants, medical treatment, and health care usage in a stepwise primary care model for the prevention of chronic diseases. METHODS: We conducted a cross-sectional analysis of the rates of acceptance of 2 digital invitations sent to randomly selected residents born between 1957 and 1986 and residing in 2 Danish municipalities. The outcome was acceptance of the 2 digital invitations. Statistical associations were determined by Poisson regression. Data-driven chi-square automatic interaction detection method was used to generate a decision tree analysis, predicting acceptance of the digital invitations. RESULTS: A total of 8814 patients received an invitation in their digital mailbox from 47 general practitioners. A total of 40.22% (3545/8814) accepted the first digital invitation, and 30.19 % (2661/8814) accepted both digital invitations. The rates of acceptance of both digital invitations were higher among women, older patients, patients of higher socioeconomic status, and patients not diagnosed with or being treated for diabetes mellitus, chronic obstructive pulmonary disease, or cardiovascular disease. CONCLUSIONS: To our knowledge, this is the first study to report on the rates of acceptance of digital invitations to participate in a stepwise model for prevention of chronic diseases. More studies of digital invitations are needed to determine if the acceptance rates seen in this study should be expected from future studies as well. Similarly, more research is needed to determine whether a multimodal recruitment approach, including digital invitations to personal digital mailboxes will reach hard-to-reach subpopulations more effectively than digital invitations only.
15.	Larsen, Lars Bruun, et al. (author) Step-wise approach to prevention of chronic diseases in the Danish primary care sector with the use of a personal digital health profile and targeted follow-up- A n assessment of attendance 2019 In: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 19 Journal article (peer-reviewed)abstract Background: Current evidence on chronic disease prevention suggests that interventions targeted at high-risk individuals represents the best way forward. We implemented a step-wise approach in the Danish primary care sector, designed for the systematic and targeted prevention of chronic disease. The intervention centered on a personal digital health profile for all participants, followed by targeted preventive programs for high-risk patients. The present paper examines individual characteristics and health-care usage of patients who took up the targeted preventive programs in response to their personal digital health profile. Methods: A sample of patients born between 1957 and 1986 was randomly selected from the patient-list system of participating general practitioners in two Danish municipalities. The selected patients received a digital invitation to participate. Consenting patients received a second digital invitation for a personal digital health profile based on questionnaire and electronic patient record data. The personal digital health profile contained individualized information on risk profile and personalized recommendations on further actions. If at-risk or presenting with health-risk behaviour a patient would be advised to contact either their general practitioner or municipal health centre for targeted preventive programs. Attendance at the targeted preventive programs was examined using Poisson regression and chi-squared automatic interaction detection methods. Results: A total of 9400 patients were invited. Of those who participated (30%), 22% were advised to get a health check at their general practitioner. Of these, 19% did so. Another 23% were advised to schedule an appointment for behaviour-change counselling at their municipal health centre. A total of 21% took the advice. Patients who had fair or poor self-rated health, a body mass index above 30, low self-efficacy, were female, non-smokers, or lead a sedentary lifestyle, were most likely to attend the targeted preventive programs. Conclusions: A personal digital health profile shows some promise in a step-wise approach to prevention in the Danish primary care sector and seems to motivate people with low self-efficacy to attend targeted preventive programs.
16.	Skotte, Line, et al. (author) Genome-wide association study of febrile seizures implicates fever response and neuronal excitability genes 2022 In: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 145:2, s. 555-568 Journal article (peer-reviewed)abstract Febrile seizures represent the most common type of pathological brain activity in young children and are influenced by genetic, environmental and developmental factors. In a minority of cases, febrile seizures precede later development of epilepsy. We conducted a genome-wide association study of febrile seizures in 7635 cases and 83 966 controls identifying and replicating seven new loci, all with P < 5 × 10-10. Variants at two loci were functionally related to altered expression of the fever response genes PTGER3 and IL10, and four other loci harboured genes (BSN, ERC2, GABRG2, HERC1) influencing neuronal excitability by regulating neurotransmitter release and binding, vesicular transport or membrane trafficking at the synapse. Four previously reported loci (SCN1A, SCN2A, ANO3 and 12q21.33) were all confirmed. Collectively, the seven novel and four previously reported loci explained 2.8% of the variance in liability to febrile seizures, and the single nucleotide polymorphism heritability based on all common autosomal single nucleotide polymorphisms was 10.8%. GABRG2, SCN1A and SCN2A are well-established epilepsy genes and, overall, we found positive genetic correlations with epilepsies (rg = 0.39, P = 1.68 × 10-4). Further, we found that higher polygenic risk scores for febrile seizures were associated with epilepsy and with history of hospital admission for febrile seizures. Finally, we found that polygenic risk of febrile seizures was lower in febrile seizure patients with neuropsychiatric disease compared to febrile seizure patients in a general population sample. In conclusion, this largest genetic investigation of febrile seizures to date implicates central fever response genes as well as genes affecting neuronal excitability, including several known epilepsy genes. Further functional and genetic studies based on these findings will provide important insights into the complex pathophysiological processes of seizures with and without fever.
17.	Ståhl, Göran, et al. (author) National inventory of landscapes in Sweden (NILS) : scope, design, and experiences from establishing a multi-scale biodiversity monitoring system 2011 In: Environmental Monitoring & Assessment. - : Springer Science and Business Media LLC. - 0167-6369 .- 1573-2959. ; 173:1-4, s. 579-595 Journal article (peer-reviewed)abstract The landscape-level and multiscale biodiversity monitoring program National Inventory of Landscapes in Sweden (NILS) was launched in 2003. NILS is conducted as a sample-based stratified inventory that acquires data across several spatial scales, which is accomplished by combining aerial photo interpretation with field inventory. A total of 631 sample units are distributed across the land base of Sweden, of which 20% are surveyed each year. By 2007 NILS completed the first 5-year inventory phase. As the reinventory in the second 5-year phase (2008-2012) proceeds, experiences and insights accumulate and reflections are made on the setup and accomplishment of the monitoring scheme. In this article, the emphasis is placed on background, scope, objectives, design, and experiences of the NILS program. The main objective to collect data for and perform analyses of natural landscape changes, degree of anthropogenic impact, prerequisites for natural biological diversity and ecological processes at landscape scale. Different environmental conditions that can have direct or indirect effects on biological diversity are monitored. The program provides data for national and international policy and offers an infrastructure for other monitoring program and research projects. NILS has attracted significant national and international interest during its relatively short time of existence; the number of stakeholders and cooperation partners steadily increases. This is constructive and strengthens the incentive for the multiscale monitoring approach.
18.	Aamodt, K., et al. (author) Alignment of the ALICE Inner Tracking System with cosmic-ray tracks 2010 In: Journal of Instrumentation. - 1748-0221. ; 5 Conference paper (peer-reviewed)abstract ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 mu m in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10(5) charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.
19.	Aamodt, K., et al. (author) Centrality Dependence of the Charged-Particle Multiplicity Density at Midrapidity in Pb-Pb Collisions at root s(NN)=2.76 TeV 2011 In: Physical Review Letters. - 1079-7114. ; 106:3 Journal article (peer-reviewed)abstract The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at root s(NN) = 2: 76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.
20.	Aamodt, K., et al. (author) Charged-Particle Multiplicity Density at Midrapidity in Central Pb-Pb Collisions at root s(NN)=2.76 TeV 2010 In: Physical Review Letters. - 1079-7114. ; 105:25 Journal article (peer-reviewed)abstract The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair root s(NN) = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 +/- 4(stat) +/- 76(syst), which corresponds to 8.3 +/- 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at root s(NN) = 0.2 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.
21.	Aamodt, K., et al. (author) Charged-particle multiplicity measurement in proton-proton collisions at root s=0.9 and 2.36 TeV with ALICE at LHC 2010 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 68:1-2, s. 89-108 Journal article (peer-reviewed)abstract Charged-particle production was studied in proton-proton collisions collected at the LHC with the ALICE detector at centre-of-mass energies 0.9 TeV and 2.36 TeV in the pseudorapidity range vertical bar eta vertical bar < 1.4. In the central region (vertical bar eta vertical bar < 0.5), at 0.9 TeV, we measure charged-particle pseudo-rapidity density dN(ch)/d eta = 3.02 +/- 0.01(stat.)(-0.05)(+0.08)(syst.) for inelastic interactions, and dN(ch)/d eta = 3.58 +/- 0.01 (stat.)(-0.12)(+0.12)(syst.) for non-single-diffractive interactions. At 2.36 TeV, we find dN(ch)/d eta = 3.77 +/- 0.01(stat.)(-0.12)(+0.25)(syst.) for inelastic, and dN(ch)/d eta = 4.43 +/- 0.01(stat.)(-0.12)(+0.17)(syst.) for non-single-diffractive collisions. The relative increase in charged-particle multiplicity from the lower to higher energy is 24.7% +/- 0.5%(stat.)(-2.8)(+5.7)%(syst.) for inelastic and 23.7% +/- 0.5%(stat.)(-1.1)(+4.6)%(syst.) for non-single-diffractive interactions. This increase is consistent with that reported by the CMS collaboration for non-single-diffractive events and larger than that found by a number of commonly used models. The multiplicity distribution was measured in different pseudorapidity intervals and studied in terms of KNO variables at both energies. The results are compared to proton-antiproton data and to model predictions.
22.	Aamodt, K., et al. (author) Charged-particle multiplicity measurement in proton-proton collisions at root s=7 TeV with ALICE at LHC 2010 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 68:3-4, s. 345-354 Journal article (peer-reviewed)abstract The pseudorapidity density and multiplicity distribution of charged particles produced in proton-proton collisions at the LHC, at a centre-of-mass energy root s = 7 TeV, were measured in the central pseudorapidity region vertical bar eta vertical bar < 1. Comparisons are made with previous measurements at root s = 0.9 TeV and 2.36 TeV. At root s = 7 TeV, for events with at least one charged particle in \|eta vertical bar\| < 1, we obtain dN(ch)/d eta = 6.01 +/- 0.01(stat.)(-0.12)(+0.20) (syst.). This corresponds to an increase of 57.6%+/-0.4%(stat.)(-1.8%)(+3.6) (syst.) relative to collisions at 0.9 TeV, significantly higher than calculations from commonly used models. The multiplicity distribution at 7 TeV is described fairly well by the negative binomial distribution.
23.	Aamodt, K., et al. (author) Elliptic Flow of Charged Particles in Pb-Pb Collisions at root s(NN)=2.76 TeV 2010 In: Physical Review Letters. - 1079-7114. ; 105:25 Journal article (peer-reviewed)abstract We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at root s(NN) p = 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (vertical bar eta vertical bar < 0.8) and transverse momentum range 0.2 < p(t) < 5.0 GeV/c. The elliptic flow signal v(2), measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 +/- 0.002(stat) +/- 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v(2)(p(t)) reaches a maximum of 0.2 near p(t) = 3 GeV/c. Compared to RHIC Au-Au collisions at root s(NN) = 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.
24.	Aamodt, K., et al. (author) Femtoscopy of pp collisions at root s=0.9 and 7 TeV at the LHC with two-pion Bose-Einstein correlations 2011 In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 84:11 Journal article (peer-reviewed)abstract We report on the high statistics two-pion correlation functions from pp collisions at root s = 0.9 TeV and root s = 7 TeV, measured by the ALICE experiment at the Large Hadron Collider. The correlation functions as well as the extracted source radii scale with event multiplicity and pair momentum. When analyzed in the same multiplicity and pair transverse momentum range, the correlation is similar at the two collision energies. A three-dimensional femtoscopic analysis shows an increase of the emission zone with increasing event multiplicity as well as decreasing homogeneity lengths with increasing transverse momentum. The latter trend gets more pronounced as multiplicity increases. This suggests the development of space-momentum correlations, at least for collisions producing a high multiplicity of particles. We consider these trends in the context of previous femtoscopic studies in high-energy hadron and heavy-ion collisions and discuss possible underlying physics mechanisms. Detailed analysis of the correlation reveals an exponential shape in the outward and longitudinal directions, while the sideward remains a Gaussian. This is interpreted as a result of a significant contribution of strongly decaying resonances to the emission region shape. Significant nonfemtoscopic correlations are observed, and are argued to be the consequence of "mini-jet"-like structures extending to low p(t). They are well reproduced by the Monte-Carlo generators and seen also in pi(+)pi(-) correlations.
25.	Aamodt, K., et al. (author) First proton-proton collisions at the LHC as observed with the ALICE detector: measurement of the charged-particle pseudorapidity density at root s=900 GeV 2010 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 65:1-2, s. 111-125 Journal article (peer-reviewed)abstract On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range vertical bar eta vertical bar < 0.5, we obtain dN(ch)/d eta = 3.10 +/- 0.13(stat.) +/- 0.22(syst.) for all inelastic interactions, and dN(ch)/d eta = 3.51 +/- 0.15(stat.) +/- 0.25(syst.) for nonsingle diffractive interactions. These results are consistent with previous measurements in proton-antiproton interactions at the same centre-of-mass energy at the CERN Sp<(p)over bar>S collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase.
26.	Aamodt, K., et al. (author) Harmonic decomposition of two particle angular correlations in Pb-Pb collisions at root s(NN)=2.76 TeV 2012 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 708:3-5, s. 249-264 Journal article (peer-reviewed)abstract Angular correlations between unidentified charged trigger (t) and associated (a) particles are measured by the ALICE experiment in Pb-Pb collisions at root s(NN) = 2.76 TeV for transverse momenta 0.25 < p(T)(t,a) < 15 GeV/c, where p(T)(t) > p(T)(a). The shapes of the pair correlation distributions are studied in a variety of collision centrality classes between 0 and 50% of the total hadronic cross section for particles in the pseudorapidity interval \|eta\| < 1.0. Distributions in relative azimuth Delta phi equivalent to phi(t) - phi(a) are analyzed for \|Delta eta\| equivalent to \|eta(t) - eta(a)\| > 0.8, and are referred to as "long-range correlations". Fourier components V-n Delta equivalent to < cos(n Delta phi)> are extracted from the long-range azimuthal correlation functions. If particle pairs are correlated to one another through their individual correlation to a common symmetry plane, then the pair anisotropy V-n Delta (p(T)(t), p(T)(a)) is fully described in terms of single-particle anisotropies v(n)(p(T)) as V-n Delta(p(T)(t), p(T)(a)) = v(n)(p(T)(t))v(n)(p(T)(a)). This expectation is tested for 1 <= n <= 5 by applying a global fit of all V-n Delta(p(T)(t), p(T)(a)) to obtain the best values v(n){GF}(p(T)). It is found that for 2 <= n <= 5, the fit agrees well with data up to p(T)(a) similar to 3-4 GeV/c, with a trend of increasing deviation as p(T)(t) and p(T)(a) are increased or as collisions become more peripheral. This suggests that no pair correlation harmonic can be described over the full 0.25 < p(T) < 15 GeV/c range using a single v(n)(p(T)) curve: such a description is however approximately possible for 2 <= n <= 5 when p(T)(a) < 4 GeV/c. For the n = 1 harmonic, however, a single v(1)(p(T)) curve is not obtained even within the reduced range p(T)(a) < 4 GeV/c. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.
27.	Aamodt, K., et al. (author) Higher Harmonic Anisotropic Flow Measurements of Charged Particles in Pb-Pb Collisions at root s(NN)=2.76 TeV 2011 In: Physical Review Letters. - 1079-7114. ; 107:3 Journal article (peer-reviewed)abstract We report on the first measurement of the triangular nu(3), quadrangular nu(4), and pentagonal nu(5) charged particle flow in Pb-Pb collisions at root s(NN) = 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow nu(2) and nu(3) have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.
28.	Aamodt, K., et al. (author) Midrapidity Antiproton-to-Proton Ratio in pp Collisons root s=0.9 and 7 TeV Measured by the ALICE Experiment 2010 In: Physical Review Letters. - 1079-7114. ; 105:7 Journal article (peer-reviewed)abstract The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at root s = 0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45 < p(t) < 1.05 GeV/c and rapidity vertical bar y vertical bar < 0.5. The ratio is measured to be R-vertical bar y vertical bar<0.5 = 0.957 +/- 0.006(stat) +/- 0.0014(syst) at 0.9 Tev and R-vertical bar y vertical bar<0.5 = 0.991 +/- 0.005 +/- 0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.
29.	Aamodt, K., et al. (author) Particle-Yield Modification in Jetlike Azimuthal Dihadron Correlations in Pb-Pb Collisions at root S-NN=2.76 TeV 2012 In: Physical Review Letters. - 1079-7114. ; 108:9 Journal article (peer-reviewed)abstract The yield of charged particles associated with high-pt trigger particles (8 < p(t) < 15 GeV/c) is measured with the ALICE detector in Pb-Pb collisions at root S-NN = 2.76 TeV relative to proton-proton collisions at the same energy. The conditional per-trigger yields are extracted from the narrow jetlike correlation peaks in azimuthal dihadron correlations. In the 5% most central collisions, we observe that the yield of associated charged particles with transverse momenta p(t) > 3 GeV/c on the away side drops to about 60% of that observed in pp collisions, while on the near side a moderate enhancement of 20%-30% is found.
30.	Aamodt, K., et al. (author) Production of pions, kaons and protons in pp collisions at root s=900 GeV with ALICE at the LHC 2011 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 71:6 Journal article (peer-reviewed)abstract The production of pi(+), pi(-), K+, K-, p, and (p) over bar at mid-rapidity has been measured in proton-proton collisions at root s = 900 GeV with the ALICE detector. Particle identification is performed using the specific energy loss in the inner tracking silicon detector and the time projection chamber. In addition, time-of-flight information is used to identify hadrons at higher momenta. Finally, the distinctive kink topology of the weak decay of charged kaons is used for an alternative measurement of the kaon transverse momentum (p(t)) spectra. Since these various particle identification tools give the best separation capabilities over different momentum ranges, the results are combined to extract spectra from p(t) = 100 MeV/c to 2.5 GeV/c. The measured spectra are further compared with QCD-inspired models which yield a poor description. The total yields and the mean pt are compared with previous measurements, and the trends as a function of collision energy are discussed.
31.	Aamodt, K., et al. (author) Rapidity and transverse momentum dependence of inclusive J/psi production in pp collisions at root s=7 TeV 2011 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 704:5, s. 442-455 Journal article (peer-reviewed)abstract The ALICE experiment at the LHC has studied inclusive J/psi production at central and forward rapidities in pp collisions at root s = 7 TeV. In this Letter, we report on the first results obtained detecting the J/psi through the dilepton decay into e(+)e(-) and mu(+)mu(-) pairs in the rapidity ranges vertical bar y vertical bar < 0.9 and 2.5 < y < 4, respectively, and with acceptance down to zero PT. In the dielectron channel the analysis was carried Out on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1) and the number of signal events is N-J/psi = 352 +/- 32 (stat.) +/- 28 (syst.): the corresponding figures in the dimuon channel are L-int = 15.6 nb(-1) and N-J/psi = 1924 +/- 77 (stat.) +/- 144 (syst.). The measured production cross sections are sigma(J/psi) (vertical bar y vertical bar < 0.9) = 10.7 +/- 1.0 (stat.) +/- 1.6 (syst.)(-2.3)(+1.6) (syst.pol.) mu b and sigma(J/psi) (2.5 < y < 4) = 6.31 +/- 0.25 (stat.) +/- 0.76 (syst.)(-1.96)(+0.95) (syst.pol.) mu b. The differential cross sections, in transverse momentum and rapidity, of the J/psi were also measured. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.
32.	Aamodt, K., et al. (author) Strange particle production in proton-proton collisions at root s=0.9 TeV with ALICE at the LHC 2011 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 71:3 Journal article (peer-reviewed)abstract The production of mesons containing strange quarks (K-S(0), phi) and both singly and doubly strange baryons (Lambda, (Lambda) over bar, and Xi(-) + (Xi) over bar (+)) are measured at mid-rapidity in pp collisions at root s = 0.9 TeV with the ALICE experiment at the LHC. The results are obtained from the analysis of about 250 k minimum bias events recorded in 2009. Measurements of yields (dN/dy) and transverse momentum spectra at mid-rapidity for inelastic pp collisions are presented. For mesons, we report yields (< dN/dy >) of 0.184 +/- 0.002(stat.) +/- 0.006(syst.) for K-S(0) and 0.021 +/- 0.004(stat.) +/- 0.003(syst.) for phi. For baryons, we find < dN/dy > = 0.048 +/- 0.001(stat.) +/- 0.004(syst.) for Lambda, 0.047 +/- 0.002(stat.) +/- 0.005(syst.) for (Lambda) over bar and 0.0101 +/- 0.0020(stat.) +/- 0.0009(syst.) for Xi(-) + (Xi) over bar (+). The results are also compared with predictions for identified particle spectra from QCD-inspired models and provide a baseline for comparisons with both future pp measurements at higher energies and heavy-ion collisions.
33.	Aamodt, K., et al. (author) Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at root s(NN)=2.76 TeV 2011 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 696:1-2, s. 30-39 Journal article (peer-reviewed)abstract Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at root s(NN) = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in \|eta\| < 0.8 and 0.3 < p(T) < 20 GeV/c are compared to the expectation in pp collisions at the same root s(NN), scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor R-AA. The result indicates only weak medium effects (R-AA approximate to 0.7) in peripheral collisions. In central collisions, R-AA reaches a minimum of about 0.14 at p(T) = 6-7 GeV/c and increases significantly at larger p(T). The measured suppression of high-p(T) particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC. (C) 2010 CERN. Published by Elsevier B.V. All rights reserved.
34.	Aamodt, K., et al. (author) The ALICE experiment at the CERN LHC 2008 In: Journal of Instrumentation. - 1748-0221. ; 3:S08002 Research review (peer-reviewed)abstract ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
35.	Aamodt, K., et al. (author) Transverse momentum spectra of charged particles in proton-proton collisions at root s=900 GeV with ALICE at the LHC 2010 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 693:2, s. 53-68 Journal article (peer-reviewed)abstract The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at root s = 900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (vertical bar eta vertical bar < 0.8) over the transverse momentum range 0.15 < p(T) < 10 GeV/c. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for vertical bar eta vertical bar < 0.8 is < p(T)>(INEL) = 0.483 +/- 0.001 (stat.) +/- 0.007 (syst.) GeV/c and < p(T)>(NSD) = 0.489 +/- 0.001 (stat.) +/- 0.007 (syst.) GeV/c, respectively. The data exhibit a slightly larger < p(T)> than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET. (C) 2010 Published by Elsevier B.V.
36.	Aamodt, K., et al. (author) Two-pion Bose-Einstein correlations in central Pb-Pb collisions at root(NN)-N-S=2.76 TeV 2011 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 696:4, s. 328-337 Journal article (peer-reviewed)abstract The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at root(NN)-N-S = 2.76 TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC. (C) 2010 CERN. Published by Elsevier B.V. All rights reserved.
37.	Aamodt, K., et al. (author) Two-pion Bose-Einstein correlations in pp collisions at root s=900 GeV 2010 In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 82:5 Journal article (peer-reviewed)abstract We report on the measurement of two-pion correlation functions from pp collisions at root s = 900 GeV performed by the ALICE experiment at the Large Hadron Collider. Our analysis shows an increase of the Hanbury Brown-Twiss radius with increasing event multiplicity, in line with other measurements done in particle- and nuclear collisions. Conversely, the strong decrease of the radius with increasing transverse momentum, as observed at the Relativistic Heavy Ion Collider and at Tevatron, is not manifest in our data.
38.	Abbafati, C, et al. (author) Five insights from the Global Burden of Disease Study 2019 2020 In: Lancet (London, England). - 1474-547X .- 0140-6736. ; 396:10258, s. 1135-1159 Journal article (peer-reviewed)
39.	Abbas, E., et al. (author) Centrality dependence of the pseudorapidity density distribution for charged particles in Pb-Pb collisions at root s(NN)=2.76 TeV 2013 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 726:4-5, s. 610-622 Journal article (peer-reviewed)abstract We present the first wide-range measurement of the charged-particle pseudorapidity density distribution, for different centralities (the 0-5%, 5-10%, 10-20%, and 20-30% most central events) in Pb-Pb collisions at root s(NN) = 2.76 TeV at the LHC. The measurement is performed using the full coverage of the ALICE detectors, -5.0 < eta < 5.5, and employing a special analysis technique based on collisions arising from LHC 'satellite' bunches. We present the pseudorapidity density as a function of the number of participating nucleons as well as an extrapolation to the total number of produced charged particles (N-ch = 17165 +/- 772 for the 0-5% most central collisions). From the measured dN(ch)/d eta distribution we derive the rapidity density distribution, dN(ch)/dy, under simple assumptions. The rapidity density distribution is found to be significantly wider than the predictions of the Landau model. We assess the validity of longitudinal scaling by comparing to lower energy results from RHIC. Finally the mechanisms of the underlying particle production are discussed based on a comparison with various theoretical models. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.
40.	Abbas, E., et al. (author) Charmonium and e(+)e(-) pair photoproduction at mid-rapidity in ultra-peripheral Pb-Pb collisions at root s(NN)=2.76 TeV 2013 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 73:11 Journal article (peer-reviewed)abstract The ALICE Collaboration at the LHC has measured the J/psi and psi' photoproduction at mid-rapidity in ultra-peripheral Pb-Pb collisions at root s(NN) = 2.76 TeV. The charmonium is identified via its leptonic decay for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 23 mu b(-1). The cross section for coherent and incoherent J/psi production in the rapidity interval -0.9 < y < 0.9, are d sigma(coh)(J/psi)/dy = 2.38(-0.24)(+0.34)(sta + sys) mb and d sigma(inc)(J/psi)/dy = 0.98(-0.17)(+0.19)(sta + sys) mb and , respectively. The results are compared to theoretical models for J/psi production and the coherent cross section is found to be in good agreement with those models incorporating moderate nuclear gluon shadowing at Bjorken-x around 10(-3), such as EPS09 parametrization. In addition the cross section for the process gamma gamma -> e(+)e(-) has been measured and found to be in agreement with models implementing QED at leading order.
41.	Abbas, E., et al. (author) J/psi Elliptic Flow in Pb-Pb Collisions at root s(NN)=2.76 TeV 2013 In: Physical Review Letters. - 1079-7114. ; 111:16 Journal article (peer-reviewed)abstract We report on the first measurement of inclusive J/psi elliptic flow v(2) in heavy-ion collisions at the LHC. The measurement is performed with the ALICE detector in Pb-Pb collisions at root s(NN) = 2.76 TeV in the rapidity range 2.5 < y < 4.0. The dependence of the J/psi v(2) on the collision centrality and on the J/psi transverse momentum is studied in the range 0 <= p(T) < 10 GeV/c. For semicentral Pb-Pb collisions at root s(NN) = 2.76 TeV, an indication of nonzero v(2) is observed with a largest measured value of v(2) = 0.116 +/-0.046(stat) +/- 0.029(syst) for J/psi in the transverse momentum range 2 <= p(T) < 4 GeV/c. The elliptic flow measurement complements the previously reported ALICE results on the inclusive J/psi nuclear modification factor and favors the scenario of a significant fraction of J/psi production from charm quarks in a deconfined partonic phase.
42.	Abbas, E., et al. (author) Mid-rapidity anti-baryon to baryon ratios in pp collisions at root s=0.9, 2.76 and 7 TeV measured by ALICE 2013 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 73:7 Journal article (peer-reviewed)abstract The ratios of yields of anti-baryons to baryons probes the mechanisms of baryon-number transport. Results for (p) over bar /p, (Lambda) over bar/Lambda, (Xi) over bar (+)/(Xi) over bar (-) and (Omega) over bar (+)/(Omega) over bar (-) in pp collisions at root s = 0.9, 2.76 and 7 TeV, measured with the ALICE detector at the LHC, are reported. Within the experimental uncertainties and ranges covered by our measurement, these ratios are independent of rapidity, transverse momentum and multiplicity for all measured energies. The results are compared to expectations from event generators, such as PYTHIA and HIJING/B, that are used to model the particle production in pp collisions. The energy dependence of (p) over bar /p, (Lambda) over bar/(Lambda) over bar, (Xi) over bar (+)/(Xi) over bar (-) and (Omega) over bar (+)/(Omega) over bar (-), reaching values compatible with unity for root s = 7 TeV, complement the earlier (p) over bar /p measurement of ALICE. These dependencies can be described by exchanges with the Regge-trajectory intercept of alpha(J) approximate to 0.5, which are suppressed with increasing rapidity interval Delta y. Any significant contribution of an exchange not suppressed at large Delta y (reached at LHC energies) is disfavoured.
43.	Abbas, E., et al. (author) Performance of the ALICE VZERO system 2013 In: Journal of Instrumentation. - 1748-0221. ; 8 Journal article (peer-reviewed)abstract ALICE is an LHC experiment devoted to the study of strongly interacting matter in proton-proton, proton-nucleus and nucleus-nucleus collisions at ultra-relativistic energies. The ALICE VZERO system, made of two scintillator arrays at asymmetric positions, one on each side of the interaction point, plays a central role in ALICE. In addition to its core function as a trigger source, the VZERO system is used to monitor LHC beam conditions, to reject beam-induced backgrounds and to measure basic physics quantities such as luminosity, particle multiplicity, centrality and event plane direction in nucleus-nucleus collisions. After describing the VZERO system, this publication presents its performance over more than four years of operation at the LHC.
44.	Abelev, B., et al. (author) Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at root S-NN=2.76 TeV 2013 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 18-28 Journal article (peer-reviewed)abstract The elliptic, v(2), triangular, v(3), and quadrangular, v(4), azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions, and (anti-)protons in Pb-Pb collisions at root S-NN = 2.76 TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range vertical bar eta vertical bar < 0.8 at different collision centralities and as a function of transverse momentum, p(T), out to p(T) = 20 GeV/c. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for p(T) > 8 GeV/c. The small p(T) dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to p(T) = 8 GeV/c. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least p(T) = 8 GeV/c indicating that the particle type dependence persists out to high p(T). (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
45.	Abelev, B., et al. (author) Beauty production in pp collisions at root s=2.76 TeV measured via semi-electronic decays 2014 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 738, s. 97-108 Journal article (peer-reviewed)abstract The ALICE Collaboration at the LHC reports measurement of the inclusive production cross section of electrons from semi-leptonic decays of beauty hadrons with rapidity \|y\| < 0.8 and transverse momentum 1 < p(T)< 10 GeV/c, in pp collisions at root s = 2.76 TeV. Electrons not originating from semi-electronic decay of beauty hadrons are suppressed using the impact parameter of the corresponding tracks. The production cross section of beauty decay electrons is compared to the result obtained with an alternative method which uses the distribution of the azimuthal angle between heavy-flavour decay electrons and charged hadrons. Perturbative QCD predictions agree with the measured cross section within the experimental and theoretical uncertainties. The integrated visible cross section, sigma(b -> e) = 3.47 +/- 0.40(stat)(+1.12)(-1.33)(sys) +/- 0.07(norm) mu b, was extrapolated to full phase space using Fixed Order plus Next-to-Leading Log (FONLL) calculations to obtain the total b (b) over bar production cross section, sigma(b (b) over bar) = 130 +/- 15.1(stat)(+42.1)(-49.8)(sys)(+3.4)(-3.1)(extr) +/- 2.5(norm) +/- 4.4(BR) mu b. (C) 2014 The Authors. Published by Elsevier B.V.
46.	Abelev, B., et al. (author) Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at root s(NN)=2.76 TeV 2013 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 720:1-3, s. 52-62 Journal article (peer-reviewed)abstract The inclusive transverse momentum (p(T)) distributions of primary charged particles are measured in the pseudo-rapidity range vertical bar eta vertical bar <0.8 as a function of event centrality in Pb-Pb collisions at root S-NN = 2.76 TeV with ALICE at the LHC. The data are presented in the p(T) range 0.15 < p(T) <50 GeV/c for nine centrality intervals from 70-80% to 0-5%. The results in Pb-Pb are presented in terms of the nuclear modification factor R-AA using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-p(T) particles strongly depends on event centrality. The yield is most suppressed in central collisions (0-5%) with R-AA approximate to 0.13 at p(T) = 6-7 GeV/c. Above p(T) = 7 GeV/c, there is a significant rise in the nuclear modification factor, which reaches R-AA approximate to 0.4 for p(T) > 30 GeV/c. In peripheral collisions (70-80%), only moderate suppression (R-AA approximate to 0.6-0.7) and a weak p(T) dependence is observed. The measured nuclear modification factors are compared to other measurements and model calculations. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.
47.	Abelev, B., et al. (author) Centrality dependence of pi, K, and p production in Pb-Pb collisions at root s(NN)=2.76 TeV 2013 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 88:4 Journal article (peer-reviewed)abstract In this paper measurements are presented of pi(+/-), K-+/-, p, and (p) over bar production at midrapidity (vertical bar y vertical bar < 0.5), in Pb-Pb collisions at root s(NN) = 2.76 TeV as a function of centrality. The measurement covers the transverse-momentum (p(T)) range from 100, 200, and 300 MeV/c up to 3, 3, and 4.6 GeV/c for pi, K, and p, respectively. The measured p(T) distributions and yields are compared to expectations based on hydrodynamic, thermal and recombination models. The spectral shapes of central collisions show a stronger radial flow than measured at lower energies, which can be described in hydrodynamic models. In peripheral collisions, the p(T) distributions are not well reproduced by hydrodynamic models. Ratios of integrated particle yields are found to be nearly independent of centrality. The yield of protons normalized to pions is a factor similar to 1.5 lower than the expectation from thermal models.
48.	Abelev, B., et al. (author) Centrality determination of Pb-Pb collisions at root s(NN)=2.76 TeV with ALICE 2013 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 88:4 Journal article (peer-reviewed)abstract This publication describes the methods used to measure the centrality of inelastic Pb-Pb collisions at a center-of-mass energy of 2.76 TeV per colliding nucleon pair with ALICE. The centrality is a key parameter in the study of the properties of QCD matter at extreme temperature and energy density, because it is directly related to the initial overlap region of the colliding nuclei. Geometrical properties of the collision, such as the number of participating nucleons and the number of binary nucleon-nucleon collisions, are deduced from a Glauber model with a sharp impact parameter selection and shown to be consistent with those extracted from the data. The centrality determination provides a tool to compare ALICE measurements with those of other experiments and with theoretical calculations.
49.	Abelev, B., et al. (author) Centrality, rapidity and transverse momentum dependence of J/Psi suppression in Pb-Pb collisions at root(NN)-N-S=2.76TeV 2014 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 734, s. 314-327 Journal article (peer-reviewed)abstract The inclusive J/.nuclear modification factor (R-AA) in Pb-Pb collisions at root(NN)-N-S = 2.76TeVhas been measured by ALICE as a function of centrality in the e+ e-decay channel at mid-rapidity (\| y\| < 0.8) and as a function of centrality, transverse momentum and rapidity in the + -decay channel at forward-rapidity (2.5 < y < 4). The J/.yields measured in Pb-Pb are suppressed compared to those in ppcollisions scaled by the number of binary collisions. The RAAintegrated over a centrality range corresponding to 90% of the inelastic Pb-Pb cross section is 0.72 - 0.06(stat.) - 0.10(syst.) at mid-rapidity and 0.58 - 0.01(stat.) - 0.09(syst.) at forward-rapidity. At low transverse momentum, significantly larger values of RAAare measured at forward-rapidity compared to measurements at lower energy. These features suggest that a contribution to the J/.yield originates from charm quark (re) combination in the deconfined partonic medium. (C) 2014 The Authors. Published by Elsevier B. V.
50.	Abelev, B., et al. (author) Charge correlations using the balance function in Pb-Pb collisions at root s(NN)=2.76 TeV 2013 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 723:4-5, s. 267-279 Journal article (peer-reviewed)abstract In high-energy heavy-ion collisions, the correlations between the emitted particles can be used as a probe to gain insight into the charge creation mechanisms. In this Letter, we report the first results of such studies using the electric charge balance function in the relative pseudorapidity (Delta eta) and azimuthal angle (Delta phi) in Pb-Pb collisions at root s(NN) = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The width of the balance function decreases with growing centrality (i.e. for more central collisions) in both projections. This centrality dependence is not reproduced by HIJING, while AMPT, a model which incorporates strings and parton rescattering, exhibits qualitative agreement with the measured correlations in Delta phi but fails to describe the correlations in Delta eta. A thermal blast-wave model incorporating local charge conservation and tuned to describe the p(T) spectra and v(2) measurements reported by ALICE, is used to fit the centrality dependence of the width of the balance function and to extract the average separation of balancing charges at freeze-out. The comparison of our results with measurements at lower energies reveals an ordering with root s(NN): the balance functions become narrower with increasing energy for all centralities. This is consistent with the effect of larger radial flow at the LHC energies but also with the late stage creation scenario of balancing charges. However, the relative decrease of the balance function widths in Delta eta and Delta phi, with centrality from the highest SPS to the LHC energy exhibits only small differences. This observation cannot be interpreted solely within the framework where the majority of the charge is produced at a later stage in the evolution of the heavy-ion collision. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.

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