98 research outputs found

    Studies of correlations between D and Dˉ{\bar D} mesons in high energy photoproduction

    Get PDF
    Studies of DDˉD{\bar D} correlations for a large sample of events containing fully and partially reconstructed pairs of charmed DD mesons recorded by the Fermilab photoproduction experiment FOCUS (FNAL-E831) are presented. Correlations between DD and Dˉ{\bar D} mesons are used to study heavy quark production dynamics. We present results for fully and partially reconstructed charm pairs and comparisons to a recent version of \textsc{Pythia} with default parameter settings. We also comment on the production of ψ(3770)\psi(3770) in our data.Comment: 14 pages, 4 figure

    Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

    Get PDF
    The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

    Get PDF
    Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M > 70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 < e ≀ 0.3 at 16.9 Gpc−3 yr−1 at the 90% confidence level

    Vertical takeoff lift augmentation - The 'sculptured deck' concept

    No full text

    Interactions between genome-wide genetic factors and smoking influencing risk of systemic lupus erythematosus

    No full text
    Objective To identify interactions between genetic factors and current or recent smoking in relation to risk of developing systemic lupus erythematosus (SLE). Methods For the study, 673 patients with SLE (diagnosed according to the American College of Rheumatology 1997 updated classification criteria) were matched by age, sex, and race (first 3 genetic principal components) to 3,272 control subjects without a history of connective tissue disease. Smoking status was classified as current smoking/having recently quit smoking within 4 years before diagnosis (or matched index date for controls) versus distant past/never smoking. In total, 86 single-nucleotide polymorphisms and 10 classicHLAalleles previously associated with SLE were included in a weighted genetic risk score (wGRS), with scores dichotomized as either low or high based on the median value in control subjects (low wGRS being defined as less than or equal to the control median; high wGRS being defined as greater than the control median). Conditional logistic regression models were used to estimate both the risk of SLE and risk of anti-double-stranded DNA autoantibody-positive (dsDNA+) SLE. Additive interactions were assessed using the attributable proportion (AP) due to interaction, and multiplicative interactions were assessed using a chi-square test (with 1 degree of freedom) for the wGRS and for individual risk alleles. Separate repeated analyses were carried out among subjects of European ancestry only. Results The mean +/- SD age of the SLE patients at the time of diagnosis was 36.4 +/- 15.3 years. Among the 673 SLE patients included, 92.3% were female and 59.3% were dsDNA+. Ethnic distributions were as follows: 75.6% of European ancestry, 4.5% of Asian ancestry, 11.7% of African ancestry, and 8.2% classified as other ancestry. A high wGRS (odds ratio [OR] 2.0,P= 1.0 x 10(-51)versus low wGRS) and a status of current/recent smoking (OR 1.5,P= 0.0003 versus distant past/never smoking) were strongly associated with SLE risk, with significant additive interaction (AP 0.33,P= 0.0012), and associations with the risk of anti-dsDNA+ SLE were even stronger. No significant multiplicative interactions with the total wGRS (P= 0.58) or with theHLA-only wGRS (P= 0.06) were found. Findings were similar in analyses restricted to only subjects of European ancestry. Conclusion The strong additive interaction between an updated SLE genetic risk score and current/recent smoking suggests that smoking may influence specific genes in the pathogenesis of SLE.Pathophysiology and treatment of rheumatic disease
    • 

    corecore