Simulation of Bose-Einstein effect using space-time aspects of Lund string fragmentation model

The experimentally observed enhancement of number of close boson pairs in e+e- collisions is reproduced by local weighting according to the quantum mechanical prescriptions for production of identical bosons. The space-time picture of the process, inherently present in the Lund fragmentation model, is explicitly used. The model is used to check systematic errors in the W mass measurements due to the Bose-Einstein effect. The possibility of direct implementation of the Bose-Einstein effect into string fragmentation is discussed.Comment: 26 pages, Latex, 17 figures in PS format attache

Standard Model physics results

SM physics results for Moriond QCD session 202

Helix string fragmentation and charged particle correlations

Correlations between charged particles provide important insight about hadronization process. The analysis of the momentum difference between charged hadrons in pp, p-lead, and lead-lead collisions of various energies is performed in order to study the dynamics of hadron formation. The spectra of correlated hadron chains are explored and compared to the predictions based on the quantized fragmentation of a three dimensional QCD helix string. This provides an alternative view of the two-particle correlation phenomenon typically attributed to the Bose-Einstein correlation, which will also be presented

Mesure de la masse des bosons W±\pm au LEP à l'aide du détecteur Delphi

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Modeling of quantum effects in the hadronization

International audienceA recent observation of a threshold momentum difference in the production of adjacent hadrons is implemented in the fragmentation model of a three-dimensional QCD string, with the aim to investigate the common origin of the azimuthal ordering of hadrons and of the correlations commonly attributed to the Bose-Einstein effect. The role of particle decays and their polarization in the measurement of two-particle correlations is evaluated. A comparison with the available data is presented and further measurements suggested. The impact of the hadronization on the long range angular correlations is discussed

Modeling of quantum effects in the hadronization

International audienceA recent observation of a threshold momentum difference in the production of adjacent hadrons is implemented in the fragmentation model of a three-dimensional QCD string, with the aim to investigate the common origin of the azimuthal ordering of hadrons and of the correlations commonly attributed to the Bose-Einstein effect. The role of particle decays and their polarization in the measurement of two-particle correlations is evaluated. A comparison with the available data is presented and further measurements suggested. The impact of the hadronization on the long range angular correlations is discussed

Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13 TeV with the ATLAS Detector

International audienceThis Letter reports the observation of $WWW$ production and a measurement of its cross section using 139 fb$^{-1}$ of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from $WWW$ production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive $WWW$ production cross section is measured to be $820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)}$ fb, approximately 2.6 standard deviations from the predicted cross section of $511 \pm 18$ fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy