/ 97 08 47 1 v 1 2 7 A ug 1 99 7 String derivation of two - loop Feynman diagrams ∗

he p - ph / 9 70 84 71 27 A ug 1 99 7 String derivation of two - loop

We brieey review the technology involved in extracting the eld{ theory limit of multiloop bosonic string amplitudes, and we apply it to the evaluation of simple two-loop diagrams involving scalars and gauge bosons.

ar X iv : h ep - p h / 97 08 47 0 v 1 2 7 A ug 1 99 7 Toward Loop Level Study of Supersymmetric Model at Future e + e − Linear Collider

In the case with a large splitting between the squark and slepton masses, the supersymmetric identities which enforce the equality of the gauge and gaugino couplings are violated in the effective theory below the squark mass threshold. We compute the full one-loop (s)quark corrected slepton production cross-sections. We find that the one-loop corrected slepton production cross-sections can depe...

ep - p h / 99 08 28 8 v 1 6 A ug 1 99 9 CompHEP - a package for evaluation of Feynman diagrams and integration over multi - particle phase space

ar X iv : h ep - t h / 97 08 14 2 v 1 2 7 A ug 1 99 7 BLACK HOLES IN STRING THEORY

The black hole solutions to Einstein's vacuum field equations are also solutions to the equations of motion of the low energy limit of superstring theory. At the same time, string theory boasts a much broader and richer collection of black hole solutions. Fortunately, string theories also possess a remarkable set of duality symmetries relating states within and between different string theories...

ar X iv : h ep - p h / 97 08 47 8 v 1 2 7 A ug 1 99 7 RAL - 97 - 042 hep - ph / 9708478 Two photon physics at LEP 2

The working group on two photon physics concentrated on three main subtopics: modelling the hadronic final state of deep inelastic scattering on a photon; unfolding the deep inelastic scattering data to obtain the photon structure function; and resonant production of exclusive final states, particularly of glueball candidates. In all three areas, new results were presented.