Prompt Jpsi and b->Jpsi X production in pp collisions

International audienceThe LHCb measurement of the J/ψ production cross-section is presented. The double differential cross-section is measured as a function of the J/ψ transverse momentum pT and of the J/ψ rapidity y in the fiducial region pT∈[0;14],GeV/c and y∈[2.0;4.5]. The analysis is based on a sample of 5.2 pb−1 collected in September 2010 at the pp Large Hadron Collider at CERN, at a centre-of-mass energy of s = 7TeV. The contributions from prompt J/ψ and J/ψ from b are separated using the J/ψ pseudo-proper time

AMBER on the VLTI: data processing and calibration issues

We present here the current performances of the AMBER / VLTI instrument for standard use and compare these with the offered modes of the instrument. We show that the instrument is able to reach its specified precision only for medium and high spectral resolution modes, differential observables and bright objects. For absolute observables, the current achievable accuracy is strongly limited by the vibrations of the Unit Telescopes, and also by the observing procedure which does not take into account the night-long transfer function monitoring. For low-resolution mode, the current limitation is more in the data reduction side, since several effects negligible at medium spectral resolution are not taken into account in the current pipeline. Finally, for faint objects (SNR around 1 per spectral channel), electromagnetic interferences in the VLTI interferometric laboratory with the detector electronics prevents currently to get unbiased measurements. Ideas are under study to correct in the data processing side this effect, but a hardware fix should be investigated seriously since it limits seriously the effective limiting magnitude of the instrument.Comment: 10 page

Nonleptonic charmless B_c decays and their search at LHCb

International audienceWe discuss the decay of B_c mesons into two light (pseudoscalar and vector) mesons. All these decay channels come from a single type of diagram, namely tree annihilation which allows us to derive simple relations among these processes. The size of annihilation contributions is an important issue in B physics, and we provide two different estimates in the case of non-leptonic charmless B_c decays, either a comparison with annihilation decays of heavy-light mesons or a perturbative model inspired by QCD factorisation. We finally discuss a possible search for these channels at LHCb

Genomics reveals historic and contemporary transmission dynamics of a bacterial disease among wildlife and livestock

Whole-genome sequencing has provided fundamental insights into infectious disease epidemiology, but has rarely been used for examining transmission dynamics of a bacterial pathogen in wildlife. In the Greater Yellowstone Ecosystem (GYE), outbreaks of brucellosis have increased in cattle along with rising seroprevalence in elk. Here we use a genomic approach to examine Brucella abortus evolution, cross-species transmission and spatial spread in the GYE. We find that brucellosis was introduced into wildlife in this region at least five times. The diffusion rate varies among Brucella lineages (∼3 to 8 km per year) and over time. We also estimate 12 host transitions from bison to elk, and 5 from elk to bison. Our results support the notion that free-ranging elk are currently a self-sustaining brucellosis reservoir and the source of livestock infections, and that control measures in bison are unlikely to affect the dynamics of unrelated strains circulating in nearby elk populations

Genetic profiling of Mycobacterium bovis strains from slaughtered cattle in Eritrea

<div><p><i>Mycobacterium bovis</i> (<i>M</i>.<i>bovis</i>) is the main causative agent for bovine tuberculosis (BTB) and can also be the cause of zoonotic tuberculosis in humans. In view of its zoonotic nature, slaughterhouse surveillance, potentially resulting in total or partial condemnation of the carcasses and organs, is conducted routinely. Spoligotyping, VNTR profiling, and whole genome sequencing (WGS) of <i>M</i>. <i>bovis</i> isolated from tissues with tuberculosis-like lesions collected from 14 cattle at Eritrea’s largest slaughterhouse in the capital Asmara, were conducted.The 14 <i>M</i>. <i>bovis</i> isolates were classified into three different spoligotype patterns (SB0120, SB0134 and SB0948) and six VNTR profiles. WGS results matched those of the conventional genotyping methods and further discriminated the six VNTR profiles into 14 strains. Furthermore, phylogenetic analysis of the <i>M</i>. <i>bovis</i> isolates suggests two independent introductions of BTB into Eritrea possibly evolving from a common ancestral strain in Europe.This molecular study revealed the most important strains of <i>M</i>. <i>bovis</i> in Eritrea and their (dis)similarities with the strains generally present in East Africa and Europe, as well as potential routes of introduction of <i>M</i>. <i>bovis</i>. Though the sample size is small, the current study provides important information as well as platform for future in-depth molecular studies on isolates from both the dairy and the traditional livestock sectors in Eritrea and the region. This study provides information onthe origin of some of the <i>M</i>. <i>bovis</i> strains in Eritrea, its genetic diversity, evolution and patterns of spread between dairy herds. Such information is essential in the development and implementation of future BTB control strategy for Eritrea.</p></div

Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions

This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photo-production in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7th Framework Programme

Modelling knowledge in Electronic Study Books

Knowledge graphs are a new form of knowledge representation. They are closely related to semantic networks and can be looked upon as in line with Schank's conceptual dependency theory and Sowa's conceptual graphs. The special feature of knowledge graphs is the use of a very restricted set of types of relations, that is considered to be the basic set of primitive relations. The theory of knowledge graphs is outlined in the first part of the paper. In the second part the possibilities of knowledge graphs for solving problems posed by Electronic (Study) Books will be discussed