5,820 research outputs found

    Bose-Einstein correlations in WW events at LEP

    Get PDF
    The current status of the LEP results on Bose-Einstein correlations is discussed. Emphasis is given to the measurement of Bose-Einstein correlations between decay products from different W's, in an energy range between 172 and 209 GeV, dependent on the experiment. For the first time all four LEP experiments conclude that no evidence for correlations between pions from different W's is seen at the current level of precision.Comment: 6 pages, 4 figures, Talk given at XXXVI Rencontres de Moriond, Les Arcs, France, March 17-24 200

    Bose-Einstein correlations in WW pair production at LEP

    Full text link
    This paper presents an overview of the latest results from the L3 and DELPHI collaborations concerning the measurement of Bose-Einstein correlations between identical bosons coming from different W's in fully hadronic WW decays. Using the same method, L3 sees no indication of any inter-W BEC effect, while DELPHI reports an indication of inter-W BEC between like-charged particles of the order of three standard deviations.Comment: 5 pages, 4 figures, Talk given at the XXXVIIIth Rencontres de Moriond (QCD), Les Arcs, France, March 22-29 200

    Investigation of Bose-Einstein Correlations in 3 jet events with the DELPHI detector

    Get PDF
    A preliminary investigation of Bose-Einstein correlations in 3 jet events has been made by analysing the collected data at the Z0Z^0 peak from '94 and '95 and the calibration runs during the LEP2 period from '97 to 2000. Three methods were used to extract two-particle correlation functions. No significant difference was found between quark and gluon jets for all three methods.Comment: 6 pages, 2 figures in ps and 1 in eps, talk given at XXXI International Symposium on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. see http://ismd31.ccnu.edu.cn

    Particle production in pp collisions at the LHC as studied by CMS

    Get PDF
    This is a report on the study of hadron production in non-singlediffractive events by using minimum bias and jet triggered data collected with the CMS experiment in the first year of LHC running. The importance of these measurements lies in the understanding of the dynamics of multi-hadron production which is described by non-perturbative QCD. The modeling via Monte Carlo generators, and their respective re-tuning, is necessary to describe the underlying event and pileup, having impact on many measurements that rely on an accurate measurement of hadron jets or missing transverse energy. I present an overview of the inclusive single particle spectra, the yields of strange hadrons and the charged hadron multiplicity distributions measured at several center-of-mass energies that show a fast growth of particle densities at the highest energies, especially for low transverse momenta, and a strong violation of KNO scaling in large pseudorapidity intervals

    SoLid : Search for Oscillations with Lithium-6 Detector at the SCK-CEN BR2 reactor

    Get PDF
    Sterile neutrinos have been considered as a possible explanation for the recent reactor and Gallium anomalies arising from reanalysis of reactor flux and calibration data of previous neutrino experiments. A way to test this hypothesis is to look for distortions of the anti-neutrino energy caused by oscillation from active to sterile neutrino at close stand-off (similar to 6-8m) of a compact reactor core. Due to the low rate of anti-neutrino interactions the main challenge in such measurement is to control the high level of gamma rays and neutron background. The SoLid experiment is a proposal to search for active-to-sterile anti-neutrino oscillation at very short baseline of the SCK center dot CEN BR2 research reactor. This experiment uses a novel approach to detect anti-neutrino with a highly segmented detector based on Lithium-6. With the combination of high granularity, high neutron-gamma discrimination using 6LiF:ZnS(Ag) and precise localization of the Inverse Beta Decay products, a better experimental sensitivity can be achieved compared to other state-of-the-art technology. This compact system requires minimum passive shielding allowing for very close stand off to the reactor. The experimental set up of the SoLid experiment and the BR2 reactor will be presented. The new principle of neutrino detection and the detector design with expected performance will be described. The expected sensitivity to new oscillations of the SoLid detector as well as the first measurements made with the 8 kg prototype detector deployed at the BR2 reactor in 2013-2014 will be reported

    Validating module network learning algorithms using simulated data

    Get PDF
    In recent years, several authors have used probabilistic graphical models to learn expression modules and their regulatory programs from gene expression data. Here, we demonstrate the use of the synthetic data generator SynTReN for the purpose of testing and comparing module network learning algorithms. We introduce a software package for learning module networks, called LeMoNe, which incorporates a novel strategy for learning regulatory programs. Novelties include the use of a bottom-up Bayesian hierarchical clustering to construct the regulatory programs, and the use of a conditional entropy measure to assign regulators to the regulation program nodes. Using SynTReN data, we test the performance of LeMoNe in a completely controlled situation and assess the effect of the methodological changes we made with respect to an existing software package, namely Genomica. Additionally, we assess the effect of various parameters, such as the size of the data set and the amount of noise, on the inference performance. Overall, application of Genomica and LeMoNe to simulated data sets gave comparable results. However, LeMoNe offers some advantages, one of them being that the learning process is considerably faster for larger data sets. Additionally, we show that the location of the regulators in the LeMoNe regulation programs and their conditional entropy may be used to prioritize regulators for functional validation, and that the combination of the bottom-up clustering strategy with the conditional entropy-based assignment of regulators improves the handling of missing or hidden regulators.Comment: 13 pages, 6 figures + 2 pages, 2 figures supplementary informatio