Geometry of Multihadron Production

Summary talk given at the 24th International Symposium on Multiparticle Dynamics, Italy, September 1994 -- This summary talk only reviews a small sample of topics featured at this symposium: 1. Introduction 2. The Geometry and Geography of Phase space 3. Space-Time Geometry and HBT 4. Multiplicities, Intermittency, Correlations 5. Disoriented Chiral Condensate 6. Deep Inelastic Scattering at HERA 7. Other ContributionsComment: 18 pages, 4 figures, uuencode

Standard Model Parameters and the Cosmological Constant

Simple functional relations amongst standard model couplings, including gravitional, are conjectured. Possible implications for cosmology and future theory are discussed.Comment: submitted to Physical Review

The Future of Particle Physics

After a very brief review of twentieth century elementary particle physics, prospects for the next century are discussed. First and most important are technological limits of opportunities; next, the future experimental program, and finally the status of the theory, in particular its limitations as well as its opportunities.Comment: Invited talk given at the International Conference on Fundamental Sciences: Mathematics and Theoretical Physics, Singapore, 13-17 March 200

Electron-positron annihilation: some remarks on the theory

We review some topics in e+e- annihilation, including high-quality QCD tests, jet production, production of old and new leptons and quarks, gluonium, Higgs-bosons, and unconfined quarks

Possible multiparticle ridge-like correlations in very high multiplicity proton-proton collisions

The CMS collaboration at the LHC has reported a remarkable and unexpected phenomenon in very high-multiplicity high energy proton-proton collisions: a positive correlation between two particles produced at similar azimuthal angles, spanning a large range in rapidity. We suggest that this "ridge"-like correlation may be a reflection of the rare events generated by the collision of aligned flux tubes connecting the valence quarks in the wave functions of the colliding protons. The "spray" of particles resulting from the approximate line source produced in such inelastic collisions then gives rise to events with a strong correlation between particles produced over a large range of both positive and negative rapidity. We suggest an additional variable that is sensitive to such a line source which is related to a commonly used measure, ellipticity.Comment: Updated figure. Version to be published in Physics Letters

New Fixed-Target Experiments to Search for Dark Gauge Forces

Fixed-target experiments are ideally suited for discovering new MeV-GeV mass U(1) gauge bosons through their kinetic mixing with the photon. In this paper, we identify the production and decay properties of new light gauge bosons that dictate fixed-target search strategies. We summarize existing limits and suggest five new experimental approaches that we anticipate can cover most of the natural parameter space, using currently operating GeV-energy beams and well-established detection methods. Such experiments are particularly timely in light of recent terrestrial and astrophysical anomalies (PAMELA, FERMI, DAMA/LIBRA, etc.) consistent with dark matter charged under a new gauge force.Comment: 14 pages + 6 page appendix and refs, 11 figure

Lifetime of a Disoriented Chiral Condensate

The lifetime of a disoriented chiral condensate formed within a heat bath of pions is calculated assuming temperatures and densities attainable at present and future heavy-ion colliders. A generalization of the reduction formula to include coherent states allows us to derive a formula for the decay rate. We predict the half-life to be between 4 and 7 fm/c, depending on the assumed pion density. We also calculate the lifetime in the presence of higher resonances and baryons, which shortens the lifetime by at most 20%.Comment: 9 pages, 3 figures, REVTeX, Eq. (3) modifie

Cosmology and the Standard Model

We consider the properties of an ensemble of universes as function of size, where size is defined in terms of the asymptotic value of the Hubble constant (or, equivalently, the value of the cosmological constant). We assume that standard model parameters depend upon size in a manner that we have previously suggested, and provide additional motivation for that choice. Given these assumptions, it follows that universes with different sizes will have different physical properties, and we estimate, very roughly, that only if a universe has a size within a factor of a square root of two or so of our own will it support life as we know it. We discuss implications of this picture for some of the basic problems of cosmology and particle physics, as well as the difficulties this point of view creates.Comment: 49 page