112 research outputs found
Observation of the muonic decay of the charged intermediate vector boson W+-
No full textSIGLEAvailable from the library of Aachen Technische Hochschule (DE) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
Search for massive e?? and ??? final states at the CERN super proton synchrotron collider
No full textThe observation of an apparent excess of radiative Z0 decays into e+e-γ and μ+μ-γ has prompted the search for massive eνγ and μνγ final states containing an energetic photon. No events were found other than those consistent with QED radiative effects in leptonic W decays. The data sample corresponds to an integrated luminosity of 0.136 pb-1 produced at the CERN super proton synchrotron (SPS) collider. An upper limit on the occurrence of such events is given. © 1984
Observation of muonic ZO-decay at the p̄p collider
No full textWe report the observation of five muonic Z0 decays. The mass and cross section times branching ratio is consistent with the previous measurements of Z0→e+e-. Three of the muonic decays have unexpected features. One event is of the type Z0→μ+μ-γ. Two of the Z0→μ+μ- decays are accommpanied by several (>4) energetic (ET > 10 GeV) jets which are difficult to explain within the framework of standard QCD corrections. © 1984
Recent Results On Intermediate Vector Boson Properties At the Cern Super Proton Synchrotron Collider
No full textThe properties of a sample of 172 charged intermediate vector bosons decaying in the (eve) channel and 16 neutral intermediate vector bosons decaying in the (e+e-) channel are summarized. Masses, decay widths, decay angular distributions, and production cross sections are given, and a limit is put on the number of light neutrino types Nv ≤ 10 at 90% CL. © 1986
Jet fragmentation into charged particles at the CERN proton-antiproton collider
No full textInclusive fragmentation of jets into charged particles has been studied in the UA1 experiment at the CERN Super Proton Synchrotron (SPS) pp̄ Collider at s = 540 GeV for jets having a transverse energy above 30 GeV. The observed fragmentation function is very similar to that seen in e+e-jets and is therefore indicative of similar hadronization processes for gluons and quarks. Scaling with the energy of the jet is valid to a good approximation, although slight deviations are suggested by the data. The average transverse momentum with respect to the jet axis for jets with ET > 30 GeV is 600 MeV/c for particles having z > 0.1 and increases slowly with the jet energy. © 1983
Analysis of the fragmentation properties of quark and gluon jets at the CERN SPS pp̄ collider
No full textA sample of two-jet events from the UA1 experiment at the CERN pp̄ Collider has been used to study the fragmentation of high-energy quark and gluon jets into charged hadrons. Compared with lower-energy jets observed in e+e- and pp collisions, the fragmentation function measured in the present experiment is softer (i.e. peaked to smaller values of z) and the mean internal transverse momentum is larger, mainly because of the effects of the QCD scaling violations. Using our knowledge of the quark and gluon structure functions in the proton, together with the QCD matrix elements, a statistical separation of quark and gluon jets is achieved within the present experiment. The fragmentation function for the gluon jets is found to be softer, and the angular spread of the fragmentation products larger, than is the case for quark jets. © 1986
Search for leptoquarks with the ZEUS detector
No full textA search for any resonant state coupled to an electron and a proton constituent has been performed using collisions of electron and proton beams at HERA. In a sample with integrated luminosity of 26 nb-1, no evidence has been found for production of leptoquarks with decays to e- + jet or ν + jet. Limits on the coupling strength of scalar leptoquarks to electron and quark have been determined for masses above 25 GeV. For example, scalar isosinglet leptoquarks (S0) with electroweak coupling strength to (e-u) states are ruled out at the 95% confidence level for masses below 168 GeV for left-handed couplings and below 176 GeV for right-handed couplings
Events with large missing transverse energy at the cern collider: I.W??? decay and test of ????e universality at Q2=mw2
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