The dual standard model and the 750 GeV events at the LHC

The aim of this short paper is to discuss the recently observed excess at 750 GeV by both CMS and ATLAS in the light of the dual standard model. Within this framework it is natural to introduce neutral spin 0 and/or spin 2 SU(2) glue mesons which could easily account for this observation if it is confirmed. The model predicts that these glue mesons would be part of SU(2) triplets and that there must thus be charged counterparts of these glue mesons carrying a QED charge of _1 with a spin 0 and/or 2 as well

Three loop MSbar renormalization of QED in the 't~Hooft-Veltman gauge

Quantum electrodynamics (QED) fixed in the 't~Hooft-Veltman gauge is renormalized to three loops in the MSbar scheme. The beta-functions and anomalous dimensions are computed as functions of the usual QED coupling and the additional coupling, xi, which is introduced as part of the nonlinear gauge fixing condition. Similar to the maximal abelian gauge of quantum chromodynamics, the renormalization of the gauge parameter is singular.Comment: 8 latex page

Z Boson Pair-Production at LEP

Events stemming from the pair-production of Z bosons in e^+e^- collisions are studied using 217.4 pb^-1 of data collected with the L3 detector at centre-of-mass energies from 200 GeV up to 209 GeV. The special case of events with b quarks is also investigated. Combining these events with those collected at lower centre-of-mass energies, the Standard Model predictions for the production mechanism are verified. In addition, limits are set on anomalous couplings of neutral gauge bosons and on effects of extra space dimensions

Study of the W+W-gamma Process and Limits on Anomalous Quartic Gauge Boson Couplings at LEP

The process e+e- -> W+ W- gamma is studied using the data collected by the L3 detector at LEP. New results, corresponding to an integrated luminosity of 427.4 pb-1 at centre-of-mass energies from 192 GeV to 207 GeV, are presented. The W+W- gamma cross sections are measured to be in agreement with Standard Model expectations. No hints of anomalous quartic gauge boson couplings are observed. Limits at 95% confidence level are derived using also the process e+e- --> nu nubar gamma gamma

Production of Single W Bosons at LEP and Measurement of WWgamma Gauge Coupling Parameters

Single W boson production in electron-positron collisions is studied with the L3 detector at centre-of-mass energies between 192 GeV and 209 GeV. Events with two acoplanar hadronic jets or a single energetic lepton are selected, and the single W cross section is measured. Combining the results with measurements at lower centre-of-mass energies, the ratio of the measured cross section to the Standard Model expectation is found to be 1.12^{+0.11}_{-0.10}+/-0.03. From all single W data, the WWgamma gauge coupling parameter kappa_gamma is measured to be 1.116^{+0.082}_{-0.086}+/-0.068

Studies of Hadronic Event Structure in e+e- Annihilation from 30 GeV to 209 GeV with the L3 Detector

In this Report, QCD results obtained from a study of hadronic event structure in high energy e^+e^- interactions with the L3 detector are presented. The operation of the LEP collider at many different collision energies from 91 GeV to 209 GeV offers a unique opportunity to test QCD by measuring the energy dependence of different observables. The main results concern the measurement of the strong coupling constant, \alpha_s, from hadronic event shapes and the study of effects of soft gluon coherence through charged particle multiplicity and momentum distributions.Comment: To appear in Physics Report

Measurement of Ks0K^0_s, Λ\Lambda, Λ−\Lambda^{-} Production at HERA

The production of the neutral strange hadrons $K^{0}_{S}$, $\Lambda$ and $\bar{\Lambda}$ has been measured in $ep$ collisions at HERA using the ZEUS detector. Cross sections, baryon-to-meson ratios, relative yields of strange and charged light hadrons, $\Lambda$ ($\bar{\Lambda}$) asymmetry and polarization have been measured in three kinematic regions: Q^2 > 25 \gev^2; 5 < Q^2 < 25 \gev^2; and in photoproduction ($Q^2 \simeq 0$). In photoproduction the presence of two hadronic jets, each with at least 5 \gev transverse energy, was required. The measurements agree in general with Monte Carlo models and are consistent with measurements made at $e^+ e^-$ colliders, except for an enhancement of baryon relative to meson production in photoproduction.Comment: 40 pages, 20 figures, 1 table, minor revisions, accepted by European Physical Journal