Measurement of charm production at central rapidity in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV

The $p_{\rm T}$-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D$^0$, D$^+$, and D$^{*+}$ in the rapidity range $|y|<0.5$, and for transverse momentum $1< p_{\rm T} <12$ GeV/$c$, were measured in proton-proton collisions at $\sqrt{s} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D$^0 \rightarrow$K$\pi$, D$^+ \rightarrow$K$\pi\pi$, D$^{*+} \rightarrow$D$^0\pi$, and their charge conjugates, and was performed on a $L_{\rm int} = 1.1$ nb$^{-1}$ event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at $\sqrt{s} = 2.76$ TeV and at 7 TeV was evaluated by extrapolating to the full phase space the $p_{\rm T}$-differential production cross sections at $\sqrt{s} = 2.76$ TeV and our previous measurements at $\sqrt{s} = 7$ TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/307

Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

The yield of charged particles associated with high-$p_{\rm T}$ trigger particles ($8 < p_{\rm T} < 15$ GeV/$c$) is measured with the ALICE detector in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV relative to proton-proton collisions at the same energy. The conditional per-trigger yields are extracted from the narrow jet-like correlation peaks in azimuthal di-hadron correlations. In the 5% most central collisions, we observe that the yield of associated charged particles with transverse momenta $p_{\rm T}> 3$ 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.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/350

Risk Factors for Severe Pediatric Invasive Group A Streptococcal Disease

Importance: An increase in pediatric cases of invasive group A streptococcus (iGAS) disease was noted in the Netherlands starting in early 2022. GAS disease can range from mild to life-threatening invasive infections. Clinical and public health decisions rely on timely and detailed reporting of clinical data. Objective: To determine risk factors associated with severe pediatric iGAS, defined as requiring admission to an intensive care unit and/or death, and to analyze pediatric iGAS incidence, presentations, and outcome between pre-COVID-19 pandemic (January 2015 to March 2020), COVID-19 pandemic (April 2020 to December 2021), and post-COVID-19 pandemic (January 2022 to June 2024) periods.Design, Setting, and Participants: This observational, retrospective and prospective cohort study in 20 hospitals (tertiary and nontertiary) in the Netherlands was conducted from January 2015 to June 2024, with real-time reporting of data on the study website since January 2022. Children aged 0 to 17 years with iGAS (positive culture or polymerase chain reaction test and/or clinical presentation) were included. Exposure:iGAS infection. Main Outcome and Measures: The primary outcome was risk factors for severe iGAS; secondary outcomes included iGAS incidence rate and clinical phenotypes prior, during, and after the COVID-19 pandemic. Risk factors for severity and mortality were analyzed using univariable and multivariable logistic regression analyses, and incidence rate ratios (IRRs) between pre-COVID-19 and postCOVID-19 pandemic periods were calculated using Poisson regression. Results: Of 617 children included, 351 (56.9%) were aged 0 to 4 years. For the 192 participants with detailed data collection, median (IQR) age was 4.2 (1.7-7.1) years and 91 (47.4%) were male. iGAS cases decreased during the COVID-19 pandemic and increased significantly in the post-COVID-19 period (IRR, 2.93; 95%, 2.46-3.49), as compared with the pre-COVID-19 pandemic period. By late 2023, the incidence of iGAS returned to pre-COVID-19 pandemic levels. Factors associated with increased risk of severe disease included a post-COVID-19 pandemic diagnosis (odds ratio [OR], 3.49; 95% CI, 2.31-6.26), pulmonary involvement (OR, 8.64; 95% CI, 5.50-13.55), streptococcal toxic shock syndrome (STSS; OR, 11.71; 95% CI, 4.39-31.18), and meningitis or encephalitis (OR, 4.38; 95% CI, 4.39-31.18). Clinical factors associated with increased risk of severe disease were reduced consciousness (OR, 7.61; 95% CI, 1.84-34.41), dyspnea (OR, 9.89; 95% CI, 3.04-32.14), abnormal auscultation (OR, 6.32; 95% CI, 2.18-18.32), and elevated C-reactive protein (OR, 6.32; 95% CI, 2.18-18.32), while estimated glomerular filtration rate was associated with a decreased risk (OR, 0.64; 95% CI, 0.49-0.84). Disease severity increased in post-COVID-19-pandemic cases, with higher mortality (13 of 294 cases [4.4%] vs 3 of 218 cases [1.4%]) and intensive care admission rates (113 of 294 cases [38.4%] vs 34 of 218 cases [15.6%]), as compared with pre-COVID-19 pandemic cases. Severity of pulmonary iGAS was similar in both periods. In the post-COVID-19 pandemic period, there was a significant increase in the incidence of pulmonary infections (IRR, 5.04; 95% CI, 3.27-7.97) , STSS (IRR, 10.30; 95% CI, 3.88-35.60), meningitis or encephalitis (IRR, 12.30; 95% CI, 4.14-52.70), and necrotizing fasciitis (IRR, 26.10; 95% CI, 5.14-475.00). Conclusions and Relevance: In this cohort study, risk factors for a complicated course of iGAS in children included pulmonary or central nervous system involvement, STSS, reduced consciousness or pulmonary clinical signs, elevated CRP, and decreased eGFR. Awareness of these risk factors is important to improve timely recognition of at-risk cases and improve clinical outcomes.</p

The Physical Processes of CME/ICME Evolution

As observed in Thomson-scattered white light, coronal mass ejections (CMEs) are manifest as large-scale expulsions of plasma magnetically driven from the corona in the most energetic eruptions from the Sun. It remains a tantalizing mystery as to how these erupting magnetic fields evolve to form the complex structures we observe in the solar wind at Earth. Here, we strive to provide a fresh perspective on the post-eruption and interplanetary evolution of CMEs, focusing on the physical processes that define the many complex interactions of the ejected plasma with its surroundings as it departs the corona and propagates through the heliosphere. We summarize the ways CMEs and their interplanetary CMEs (ICMEs) are rotated, reconfigured, deformed, deflected, decelerated and disguised during their journey through the solar wind. This study then leads to consideration of how structures originating in coronal eruptions can be connected to their far removed interplanetary counterparts. Given that ICMEs are the drivers of most geomagnetic storms (and the sole driver of extreme storms), this work provides a guide to the processes that must be considered in making space weather forecasts from remote observations of the corona.Peer reviewe

Review of Solar Energetic Particle Prediction Models

Solar Energetic Particle (SEP) events are interesting from a scientific perspective as they are the product of a broad set of physical processes from the corona out through the extent of the heliosphere, and provide insight into processes of particle acceleration and transport that are widely applicable in astrophysics. From the operations perspective, SEP events pose a radiation hazard for aviation, electronics in space, and human space exploration, in particular for missions outside of the Earth’s protective magnetosphere including to the Moon and Mars. Thus, it is critical to improve the scientific understanding of SEP events and use this understanding to develop and improve SEP forecasting capabilities to support operations. Many SEP models exist or are in development using a wide variety of approaches and with differing goals. These include computationally intensive physics-based models, fast and light empirical models, machine learning-based models, and mixed-model approaches. The aim of this paper is to summarize all of the SEP models currently developed in the scientific community, including a description of model approach, inputs and outputs, free parameters, and any published validations or comparisons with data

Beam-energy Dependence Of Charge Balance Functions From Au + Au Collisions At Energies Available At The Bnl Relativistic Heavy Ion Collider

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Balance functions have been measured in terms of relative pseudorapidity (Δη) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at sNN=7.7GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at sNN=2.76TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at sNN=7.7 GeV implies that a QGP is still being created at this relatively low energy. © 2016 American Physical Society.942CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoMinistry of Education and Science of the Russian FederationMOE, Ministry of Education of the People's Republic of ChinaMOST, Ministry of Science and Technology of the People's Republic of ChinaNRF-2012004024, National Research FoundationNSF, National Stroke FoundationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

ϒ production in p–Pb collisions at √sNN=8.16 TeV

ϒ production in p–Pb interactions is studied at the centre-of-mass energy per nucleon–nucleon collision √sNN = 8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pb collisions at √sNN = 5.02 TeV and with theoretical calculations.publishedVersio

Long-range Angular Correlations On The Near And Away Side In P-pb Collisions At √snn=5.02 Tev

7191/Mar294

Centrality Dependence Of The Pseudorapidity Density Distribution For Charged Particles In Pb-pb Collisions At √snn=2.76tev

7264/Mai61062