We discuss theoretical predictions for W -pair production and decay at LEP2 and higher energies in a form suitable for comparison with raw data. We present a practical framework for calculating uncertainties of predictions given by the KORALW and grc4f Monte Carlo programs. As an example we use observables in the sscc decay channel: the total four-quark (four-jet) cross section and two-quark/jet invariant-mass distribution and cross section, in the case when the other two may escape detection.Effects of QED bremsstrahlung, effective couplings, running W and Z widths, Coulomb interaction and the complete tree level set of diagrams are discussed.We also revisit the question of technical precision of the new version 1.21 of the KORALW Monte Carlo code as well as of version 1.2(26) of the grc4f one.Finally we find predictions of the two programs to have an overall physical uncertainty of 2%.As a side result we show, on the example of an ss invariant mass distribution, the strong interplay of spin correlations and detector cut-offs in the case of four-fermion final states.

We discuss the allowed parameter regime in the coupling-mass plane implied by the existing LEP2 data on e + e − → hadrons at 172.3 GeV for the leptoquark interpretation of the anomalous DESY positron-jet events for four different models of the leptoquark charges and chiral couplings to quarks, for both a loose cut on s ′ /s and a tight cut on s ′ /s. We find that this interpretation of the DESY phenomenon is still consistent with the LEP2 data although, for vector leptoquarks, a significant regime of the relevant parameter space is already excluded.

IR-improvement based on amplitude-level resummation allows one to control unintegrable results in quantum field theory with arbitrary precision in principle. We illustrate such resummation in specific examples in precision LHC and FCC physics and in quantum gravity.

Selected experimental results related to heavy-ion physics, obtained using the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC), are presented. Measurements have been performed for lead-lead (PbPb), proton-lead (pPb) and proton-proton (pp) data samples collected in the years 2010-2012. The jet-quenching phenomenon has been studied by looking at the production of the so-called "hard probes", such as high transverse momentum charged particles, isolated photons, Z and W bosons, and jets. In addition, the suppression of quarkonium states and long-range two-particle correlations have been investigated.

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