Pole masses of quarks in dimensional reduction

Pole masses of quarks in the quantum chromodynamics are calculated to the two-loop order in the framework of the regularization by dimensional reduction. For the diagram with a light quark loop, the non-Euclidean asymptotic expansion is constructed with the external momentum on the mass shell of a heavy quark.Comment: the version accepted for publication in Nucl.Phys.B. The new references are added, new Appendix are presented, little misprints fixed in eqs. (2), (14), (17). LaTex, 23 pages, including 1 eps-figur

Reflection Matrices for Integrable N=1N=1 Supersymmetric Theories

We study two-dimensional integrable $N=1$ supersymmetric theories (without topological charges) in the presence of a boundary. We find a universal ratio between the reflection amplitudes for particles that are related by supersymmetry and we propose exact reflection matrices for the supersymmetric extensions of the multi-component Yang-Lee models and for the breather multiplets of the supersymmetric sine-Gordon theory. We point out the connection between our reflection matrices and the classical boundary actions for the supersymmetric sine-Gordon theory as constructed by Inami, Odake and Zhang \cite{IOZ}.Comment: 29 pages, Revtex, 4 figure

Highest weight representations of Uq(sl^(2∣1))U_q(\hat{sl}(2|1)) and correlation functions of the q-deformed supersymmetric t-J model

We re-examine the level-one irreducible highest weight representations of the quantum affine superalgebra $U_q(\hat{sl}(2|1))$ and derive the characters and supercharacters associated with these representations. We calculate the exchange relations of the vertex operators and find that these vertex operators satisfy the graded Faddeev-Zamolodchikov algebra. We give an integral expression of the correlation functions of the q-deformed supersymmetric t-J model and derive the difference equations which they satisfy.Comment: Some misprints corrected; RevTex 18 page