1 99 4 hep - ph / 9410332 TTP 94 - 21 ON THE NEW METHOD OF COMPUTING TWO - LOOP MASSIVE DIAGRAMS

ar X iv : h ep - p h / 94 07 21 1 v 1 3 J ul 1 99 4 Semiclassical Meson - Baryon Dynamics from Large - N c QCD

The large-Nc limit of the meson-baryon effective Lagrangian is shown to reduce to a semiclassical field theory. A chiral bag structure emerges naturally in the Nc → ∞ limit. A possible connection between the chiral bag picture and the Skyrme model is discussed. The classical meson-baryon theory is used to reproduce the M π non-analytic correction to the baryon mass obtained previously as a loop...

ar X iv : h ep - p h / 94 09 38 8 v 2 1 2 O ct 1 99 4 INLO -

Motivated by the precision results in the electroweak theory studies of two-loop Feynman diagrams are performed. Specifically this paper gives a contribution to the knowledge of massive two-loop selfenergy diagrams in arbitrary and especially four dimensions. This is done in three respects: firstly results in terms of generalized, multivariable hypergeometric functions are presented giving expl...

ar X iv : h ep - p h / 99 07 47 1 v 1 2 3 Ju l 1 99 9 hep - ph / 9907471 July 1999 Problems of the Strategy of Regions

Problems that arise in the application of general prescriptions of the so-called strategy of regions for asymptotic expansions of Feynman in-tegrals in various limits of momenta and masses are discussed with the help of characteristic examples of two-loop diagrams. The strategy is also reformulated in the language of alpha parameters.

On the New Method of Computing Two-loop Massive Diagrams

ar X iv : h ep - p h / 94 07 38 9 v 1 2 7 Ju l 1 99 4 The lightest Higgs boson mass in the Minimal Supersymmetric Standard Model ∗

We compute the upper bound on the mass of the lightest Higgs boson in the Minimal Supersymmetric Standard Model in a model-independent way, including leading (one-loop) and next-to-leading order (two-loop) radiative corrections. We find that (contrary to some recent claims) the two-loop corrections are negative with respect to the one-loop result and relatively small (< ∼ 3%). After defining ph...