Quarkonium production at ATLAS

The production of quarkonium is an important testing ground for QCD calculations. The J/\psi\ and \Upsilon\ production cross-sections are measured in proton-proton collisions at a centre-of-mass energy of 7~TeV with the ATLAS detector at the LHC. Differential cross-sections are presented as a function of transverse momentum and rapidity. The fraction of J/\psi\ produced in B-hadron decays is also measured and the differential cross-sections of prompt and non-prompt J/\psi\ production determined separately. Measurements of the fiducial production cross-section of the \Upsilon(1S) and observation of the \chi_{c,bJ} states are also discussed.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 3 pages, 8 figure

W/Z properties and V+jets at the Tevatron

We present a summary of recent measurements of $W$ and $Z$ properties and $W/Z$ production in association with jets in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV with the CDF and D\O\ detectors. Latest measurements of $Z/\gamma^*$ transverse momentum and are presented along with new measurements of the angular distributions of final state electrons from Drell Yan events as a way to probe $Z$ boson production mechanisms. The mass dependence of the forward-backward asymmetry in $p\bar{p} \rightarrow Z/\gamma^{*} \rightarrow e^+e^-$ interactions is measured, the effective weak mixing angle extracted, and the most precise direct measurement of the vector and axial-vector couplings of $u$ and $d$ quarks to the $Z$ boson presented. New measurements of jets produced in association with $Z$ and $W$ bosons for inclusive, beauty and charm jets are also discussed.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 4 pages, 13 figure

Production of charm and charmonium with the ATLAS detector at 7 TeV

We report on the observation of the charm mesons D^\ast \pm, D^\pm and D_s ^\pm with 1.4 nb^-1 of data, and of the J/psi-->mu+mu- resonance with 78 nb-1 of data from the ATLAS detector in 7 TeV proton-proton collisions at the LHC. The resultant signals support the high performance of the ATLAS detector as predicted from simulation and prospects for future measurements in the charm and charmonium sector.Comment: 4 pages, 11 figure

Isospin-violating dark matter at liquid noble detectors: new constraints, future projections, and an exploration of target complementarity

There is no known reason that dark matter interactions with the Standard Model should couple to neutrons and protons in the same way. This isospin violation can have large consequences, modifying the sensitivity of existing and future direct detection experimental constraints by orders of magnitude. Previous works in the literature have focused on the zero-momentum limit which has its limitations when extending the analysis to the Non-Relativistic Effective Field Theory basis (NREFT). In this paper, we study isospin violation in a detailed manner, paying specific attention to the experimental setups of liquid noble detectors. We analyse two effective Standard Model gauge invariant models as interesting case studies as well as the more model-independent NREFT operators. This work demonstrates the high degree of complementarity between the target nuclei xenon and argon. Most notably, we show that the Standard Model gauge-invariant formulation of the standard spin-dependent interaction often generates a sizeable response from argon, a target nuclei with zero spin. This work is meant as an update and a useful reference to model builders and experimentalists.Comment: 22 pages in total, 13 figures, 1 table, 3 appendices. Data from the main results of this paper is available at https://doi.org/10.1140/epjc/s10052-023-11826-

Predicting Maximum Tree Heights and Other Traits from Allometric Scaling and Resource Limitations

Terrestrial vegetation plays a central role in regulating the carbon and water cycles, and adjusting planetary albedo. As such, a clear understanding and accurate characterization of vegetation dynamics is critical to understanding and modeling the broader climate system. Maximum tree height is an important feature of forest vegetation because it is directly related to the overall scale of many ecological and environmental quantities and is an important indicator for understanding several properties of plant communities, including total standing biomass and resource use. We present a model that predicts local maximal tree height across the entire continental United States, in good agreement with data. The model combines scaling laws, which encode the average, base-line behavior of many tree characteristics, with energy budgets constrained by local resource limitations, such as precipitation, temperature and solar radiation. In addition to predicting maximum tree height in an environment, our framework can be extended to predict how other tree traits, such as stomatal density, depend on these resource constraints. Furthermore, it offers predictions for the relationship between height and whole canopy albedo, which is important for understanding the Earth's radiative budget, a critical component of the climate system. Because our model focuses on dominant features, which are represented by a small set of mechanisms, it can be easily integrated into more complicated ecological or climate models.National Science Foundation (U.S.) (Research Experience for Undergraduates stipend)Gordon and Betty Moore FoundationNational Science Foundation (U.S.) (Graduate Research Fellowship Program)Massachusetts Institute of Technology. Presidential FellowshipEugene V. and Clare Thaw Charitable TrustEngineering and Physical Sciences Research CouncilNational Science Foundation (U.S.) (PHY0202180)Colorado College (Venture Grant Program

Molecular epidemiology of methicillin-resistant Staphylococcus aureus isolated from Australian veterinarians

This work investigated the molecular epidemiology and antimicrobial resistance of methicillinresistant Staphylococcus aureus (MRSA) isolated from veterinarians in Australia in 2009. The collection (n = 44) was subjected to extensive molecular typing (MLST, spa, SCCmec, dru, PFGE, virulence and antimicrobial resistance genotyping) and antimicrobial resistance phenotyping by disk diffusion. MRSA was isolated from Australian veterinarians representing various occupational emphases. The isolate collection was dominated by MRSA strains belonging to clonal complex (CC) 8 and multilocus sequence type (ST) 22. CC8 MRSA (ST8-IV [2B], spa t064; and ST612-IV [2B] , spa variable,) were strongly associated with equine practice veterinarians (OR = 17.5, 95% CI = 3.3-92.5, P < 0.001) and were often resistant to gentamicin and rifampicin. ST22-IV [2B], spa variable, were strongly associated with companion animal practice veterinarians (OR = 52.5, 95% CI = 5.2-532.7, P < 0.001) and were resistant to ciprofloxacin. A single pig practice veterinarian carried ST398-V [5C2], spa t1451. Equine practice and companion animal practice veterinarians frequently carried multiresistant-CC8 and ST22 MRSA, respectively, whereas only a single swine specialist carried MRSA ST398. The presence of these strains in veterinarians may be associated with specific antimicrobial administration practices in each animal species

Phylogenetic and Phyletic Studies of Informational Genes in Genomes Highlight Existence of a 4th Domain of Life Including Giant Viruses

The discovery of Mimivirus, with its very large genome content, made it possible to identify genes common to the three domains of life (Eukarya, Bacteria and Archaea) and to generate controversial phylogenomic trees congruent with that of ribosomal genes, branching Mimivirus at its root. Here we used sequences from metagenomic databases, Marseillevirus and three new viruses extending the Mimiviridae family to generate the phylogenetic trees of eight proteins involved in different steps of DNA processing. Compared to the three ribosomal defined domains, we report a single common origin for Nucleocytoplasmic Large DNA Viruses (NCLDV), DNA processing genes rooted between Archaea and Eukarya, with a topology congruent with that of the ribosomal tree. As for translation, we found in our new viruses, together with Mimivirus, five proteins rooted deeply in the eukaryotic clade. In addition, comparison of informational genes repertoire based on phyletic pattern analysis supports existence of a clade containing NCLDVs clearly distinct from that of Eukarya, Bacteria and Archaea. We hypothesize that the core genome of NCLDV is as ancient as the three currently accepted domains of life