Beyond the Standard Model for Hillwalkers

In the first lecture, the Standard Model is reviewed, with the aim of seeing how its successes constrain possible extensions, the significance of the apparently low Higgs mass indicated by precision electroweak experiments is discussed, and defects of the Standard Model are examined. The second lecture includes a general discussion of the electroweak vacuum and an introduction to supersymmetry, motivated by the gauge hierarchy problem. In the third lecture, the phenomenology of supersymmetric models is discussed in more detail, with emphasis on the information provided by LEP data. The fourth lecture introduces Grand Unified Theories, with emphases on general principles and on neutrino masses and mixing. Finally, the last lecture contains short discussions of some further topics, including supersymmetry breaking, gauge-mediated messenger models, supergravity, strings and $M$ phenomenology.Comment: Lectures presented at 1998 European School of High-Energy Physics, 64 pages LaTeX, 37 eps figures, uses cernrep.cl

From HERA to the LHC

Some personal comments are given on some of the exciting interfaces between the physics of HERA and the LHC. These include the quantitative understanding of perturbative QCD, the possible emergence of saturation phenomena and the Colour-Glass Condensate at small x and large Q^2, the link between forward physics and ultra-high-energy cosmic rays, and new LHC opportunities opened up by the discovery of rapidity-gap events at HERA, including the search for new physics such as Higgs bosons in double-diffraction events.Comment: 14 pages and 9 figures latex using cernrep.cls and mcite.sty, Individual Contribution to the HERA-LHC Worksho

Possible Accelerators @ CERN Beyond the LHC

The physics and world-wide accelerator context for possible accelerator projects at CERN after the LHC are reviewed, including the expectation that an e+ e- linear collider in the TeV energy range will be built elsewhere. Emphasis is laid on the Higgs boson, supersymmetry and neutrino oscillations as benchmarks for physics after the LHC. The default option for CERN's next major project may be the CLIC multi-TeV e+ e- collider project. Also interesting is the option of a three-step scenario for muon storage rings, starting with a neutrino factory, continuing with one or more Higgs factories, and culminating in a mu+ mu- collider at the high-energy frontier.Comment: 23 pages LaTeX, 16 figures, to appear in the Proceedings of the Workshop on the Development of Future Linear Electron-Positron Colliders for Particle Physics Studies and for Research using Free-Electron Lasers, Lund, 23 - 26 September 1999, misprints concerning Fig. 8 correcte

Cosmic Connections

A National Research Council study on connecting quarks with the cosmos has recently posed a number of the more important open questions at the interface between particle physics and cosmology. These questions include the nature of dark matter and dark energy, how the Universe began, modifications to gravity, the effects of neutrinos on the Universe, how cosmic accelerators work, and whether there are new states of matter at high density and pressure. These questions are discussed in the context of the talks presented at this Summer Institute.Comment: Closing Lecture at the 31st SLAC Summer Institute, July 2003: PSN TF07, 18 pages latex, uses ssi.sty (included

Summary of the Nobel Symposium on LHC Results

This is a personal summary of points made during, and arising from the symposium, drawing largely from the talks presented there. The Standard Model is doing fine, including QCD, the electroweak sector and flavour physics. The good news is that a Standard-Model-like Higgs boson has appeared with the predicted mass, but the bad news is that the LHC has provided no hint of other new physics. On the other hand, physics beyond the Standard Model is needed to explain neutrino masses and mixing, and we look forward to experiments revealing their mass hierarchy and CP violation. Cosmology and astrophysics also require new physics to explain the origin of matter, dark matter, dark energy and the CMB fluctuations. I still think that supersymmetry is the best-motivated extension of the Standard Model, and look forward to the next phases of LHC operation at higher energy and luminosity. In the mean time, ideas abound for a new accelerator to study the Higgs boson in detail and/or whatever else the LHC may reveal in its next run.Comment: 18 pages, 6 figures, Nobel Symposium on LHC Result

Physics at Future Colliders

After a brief review of the Big Issues in particle physics, we discuss the contributions to resolving that could be made by various planned and proposed future colliders. These include future runs of LEP and the Fermilab Tevatron collider, B factories, RHIC, the LHC, a linear electron-positron collider, an electron-proton collider in the LEP/LHC tunnel, a muon collider and a future larger hadron collider (FLHC). The Higgs boson and supersymmetry are used as benchmarks for assessing their capabilities. The LHC has great capacities for precision measurements as well as exploration, but also shortcomings where the complementary strengths of a linear electron-positron collider would be invaluable. It is not too soon to study seriously possible subsequent colliders.Comment: Latex with 16 eps figures, Plenary Talk presented at the Europhysics Conference on High Energy Physics, Jerusalem, August 199

Summary of Neutrino 2000

Aspects of neutrino physics beyond the Standard Model are emphasized, including the emerging default options for atmospheric and solar neutrino oscillations, namely nu_mu to nu_tau and nu_e to nu_{mu,tau} respectively, and the need to check them, the prospects opened up by the successful starts of SNO and K2K, the opportunities for future long-baseline neutrino experiments and high-energy astrophysical neutrinos. Finally, comments are made on the road map for realizing the exciting physics potential of neutrino factories.Comment: 15 pages, 12 eps figures, uses espcrc2.st