[en] I reconsider the Yokoya-Chen approximate evolution equation for beamstrahlung and modify it slightly to generate simple, consistent analytical approximations for the electron and photon energy spectra. I compare these approximations to previous ones, and to simulation data.I reconsider the Yokoya-Chen approximate evolution equation for beamstrahlung and modify it slightly to generate simple, consistent analytical approximations for the electron and photon energy spectra. I compare these approximations to previous ones, and to simulation data

No abstract available

[en] A vector-dominance two-photon exchange model is proposed to explain the recently observed production of ρ⁰ρ⁰ and ρ⁰φ pairs in e⁺e^- annihilation at 10.58 GeV with the BaBar detector. All the observed features of the data--angular and decay distributions, rates--are in agreement with the model. Predictions are made for yet-unobserved final states

[en] One of the major currents of physics in the twentieth century has been the unfolding of structure, the successive analysis of atoms, nuclei, and nucleons into constituent particles with more fundamental equations of motion. It is, then, natural to ask whether quarks and leptons can also be decomposed into simpler constituents. At one time, this idea could be viewed as a casual speculation. But in the past few years, the proliferation of quarks and leptons has become one of the central puzzles of particle physics, and the problem of computing the mass spectrum of quark and leptons has become one of its most difficult challenges. Models in which quarks and leptons are composite have provided a major approach to the resolution of these questions. It is thus important to search for experimental signs of the composite nature of quarks and leptons. In this paper, the authors compare the abilities of various proposed accelerators to probe for indications of this structure

[en] The upper bound on the number of relativistic species present at nucleosynthesis has been used to constrain particles with electric charge εe(10^-8<ε<1). We correct the bound previously calculated for millicharged particles that interact with a shadow photon. We also discuss the additional constraints from the properties of red giants and of Supernova 1987A

[en] To aid phenomenological studies of Beyond-the-Standard-Model (BSM) physics scenarios, a web repository for BSM calculational tools has been created. We here present brief overviews of the relevant codes, ordered by topic as well as by alphabet

[en] Several proposals are being developed around the world for an e⁺e^- linear collider with an initial center of mass energy of 500 GeV. In this paper, we will discuss why a project of this type deserves priority as the next major initiative in high energy physics

[en] A comprehensive review of physics at an e⁺e^- linear collider in the energy range of √(s) = 92 GeV-3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focusses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well. (orig.)