A brief review is given of the recent developments in the analyses of supersymmetric dark matter. Chief among these is the very accurate determination of the amount of cold dark matter in the universe from analyses using WMAP data. The implications of this data for the mSUGRA parameter space are analyzed. It is shown that the data admits solutions on the hyperbolic branch of the radiative breaking of the electroweak symmetry. A part of the hyperbolic branch lies in the so-called inversion region, where the LSP neutralino χ 1 0 becomes essentially a pure Higgsino and degenerates with the next-to-the-lightest neutralino χ 2 0 and the light chargino χ 1 ± . Thus, some of the conventional signals for the observation of supersymmetry in colliders (e.g., the missing energy signals) do not operate in this region. On the other hand, the inversion region contains a high degree of degeneracy of χ 1 0 , χ 2 0 , χ 1 ± leading to coannihilations, which allow for the satisfaction of the WMAP relic density constraints deep on the hyperbolic branch. Further, an analysis of the neutralino-proton cross sections in this region reveals that this region can still be accessible to dark matter experiments in the future. Constraints from gπ−2 and from B s 0 → μ+μ− are discussed. Future prospects are also discussed.

The theoretical status of the muon anomaly is reviewed including the recent change in the light by light hadronic correction. Specific attention is given to the implications of the shift in the difference between the BNL experiment result and the standard model prediction for sparticle mass limits. The implication of the BNL data for Yukawa unification is discussed and the role of gaugino mass nonuniversalities in the satisfaction of Yukawa unification is explored. An analysis of the BNL constraint for the satisfaction of the relic density constraint and for the search for dark matter is also given.

The effects of nonuniversality of gaugino masses on dark matter are examined within supersymmetric grand unification, and in string and D-brane models with R parity invariance. In SU(5) unified models nonuniversality in the gaugino sector can be generated via the gauge kinetic energy function which may depend on the 24, 75 and 200 dimensional Higgs representations. We also consider string models which allow for nonuniversality of gaugino masses and D-brane models where nonuniversality arises from embeddings of the standard model gauge group on five-branes and nine-branes. It is found that with gaugino mass nonuniversality the range of the LSP mass can be extended much beyond the range allowed in the universal SUGRA case, up to about 600 GeV even without coannihilation effects in some regions of the parameter space. The effects of coannihilation are not considered and inclusion of these effects may further increase the allowed neutralino mass range. Similarly with the inclusion of gaugino mass nonuniversality, the neutralino-proton $(\ensuremath{\chi}\ensuremath{-}p)$ cross section can increase by as much as a factor of 10 in some regions of the parameter space. An analysis of the uncertainties in the quark density content of the nucleon is given and their effects on the $\ensuremath{\chi}\ensuremath{-}p$ cross section are discussed. The predictions of our analysis including nonuniversality are compared with the current limits from dark matter detectors and implications for future dark matter searches are discussed.

Predictions for the out-going muon fluxes from the annihilation of neutralinos in the center of the sun and the earth in mSUGRA models are given. Effects of uncertainties of the input data on the local wimp density and on the rms wimp velocity are analyzed. It is shown that the out-going muon flux measurements from the sun and the earth are complementary, with the earth providing a larger flux for low values of fine tuning and the Sun providing a larger flux for high values of fine-tuning. It is further shown that a combination of the out-going muon flux measurements from both the earth and the sun can compete favorably with the direct detection measurements. The mSUGRA predictions are compared with the recent limits from BAIKAL NT-96, MACRO, and BAKSAN.

We discuss present predictions for the total γγ and γp cross-sections, highlighting why predictions differ. We present results from the Eikonal Minijet Model and improved predictions based on soft gluon resummation.

We study the theoretical predictions for the total inelastic $\gamma \gamma$ cross-sections, with an emphasis on the eikonalised minijet model (EMM). In the context of the EMM, we discuss a new ansatz for the overlap function involving the photons. We discuss the dependence of the EMM predictions on various input parameters as well as predictions for \siggg from a simple extension of the Regge Pomeron Exchange model. We then compare both with the recent LEP data.

A model for the parton distributions of hadrons in impact parameter space has been constructed using soft gluon summation. This model incorporates the salient features of distributions obtained from the intrinsic transverse momentum behaviour of hadrons. Under the assumption that the intrinsic behaviour is dominated by soft gluon emission stimulated by the scattering process, the b-spectrum becomes softer and softer as the scattering energy increases. In minijet models for the inclusive cross-sections, this will counter the increase from σjet.

Predictions for total inelastic cross-sections for photon induced processes are discussed in the context of the QCD-inspired minijet model. Large theoretical uncertainties exist, some of them related to the parton distributions of hadrons in impact parameter space. A model for such distribution is presented, based on soft gluon summation. This model incorporates (the salient features of distributions obtained from) the intrinsic transverse momentum behaviour of hadrons. Under the assumption that the intrinsic behaviour is dominated by soft gluon emission stimulated by the scattering process, the b-spectrum becomes softer and softer as the scattering energy increases. In minijet models for the inclusive cross-sections, this will counter the increase from $\sigma_{jet}$ .

This report is an overview of the gamma-gamma physics capabilities of LEP2, and covers the following topics: structure functions, equivalent photon approximation, tagging conditions etc, soft and semihard physics, large-$p_t$ processes, heavy-quark physics, and exclusive channels.