I discuss the importance of the O(g4m2t/M 2 W ) corrections to the effective electroweak angle and MW in the indirect determination of the Higgs mass. I emphasize the rôle of a very preciseMW measurement on the MH estimate. ∗ Talk presented at the Zeuthen Workshop on Elementary Particle Theory ”Loops and Legs in Gauge Theories” Rheinsberg, Germany, April 19-24, 1998

We derive compact analytical formulae of the Bonneau-Martin type for the reaction e + e − → ¯ f f γ with cuts on minimal energy and acollinearity of the fermions, where the photons may be emitted both from the initial or final states. Soft photon exponentiation is also taken into account. One of the cleanest scattering processes at elementary particle accelerators is fermion-pair production in ...

One of the major goals of the Large Hadron Collider is to probe the electroweak symmetry breaking mechanism and the generation of the masses of the elementary particles. We review the physics of the Higgs sector in the Standard Model and some of its extensions such as supersymmetric theories and models of extra dimensions. The prospects for discovering the Higgs particles at the LHC and the stu...

INTRODUCTION Protons, electrons, neutrons, neutrinos and even quarks are often featured in news of scientific discoveries. All of these, and a whole "zoo" of others, are tiny sub-atomic particles too small to be seen even with the microscopes. While molecules and atoms are the basic elements of familiar substances that we can see and feel, we have to "look" within atoms in order to learn about ...

It has often been suggested that observed symmetries among elementary particles may well reflect symmetries of some fundamental dynamical equation or system of equations. The suggestion has gained credence with the recent successes of gauge theories, the WeinbergSalam (W-S) model in particular. However, in current theories no definite connection has yet been established between the so-called in...

J. D. Bjorken Stanford Linear Accelerator Center Stanford University, Stanford, California 94305 To a remarkable degree, gauge principles now permeate the description of almost all of the basic interactions of elementary particles. The proceedings of this Conference make it rather clear why this is so, and why it is hard to find any theorist (including myself) working actively and continuously ...

Our present understanding of neutrino masses and mixing comes from the interpretation of data on solar and atmospheric neutrinos as well as the results from the LSND experiment in terms of neutrino oscillations [1]. If neutrinos have masses, flavour is mixed in the CC interactions of the leptons, and a leptonic mixing matrix will appear analogous to the CKM [2] matrix for the quarks. The possib...

The purpose cif this note is to investigate consequences of the three-dimensional unitary group (denoted as U 3 hereafter), which is a certain generalization of the usual isotopic space group. Though many authors1>'2J,aJ have examined this problem, our procedure is simpler and some new results have been obtained. Also, we can treat different schemes of U3 such as Sakata's1>' 2J or Gell-Mann's3>...

A shadow of a numerical solution to a chaotic system is an exact solution to the equations of motion that remains close to the numerical solution for a long time. In a collisionless n-body system, we know that particle motion is governed by the global potential rather than by interparticle interactions. As a result, the trajectory of each individual particle in the system is independently shado...