On the deformation of abelian integrals

We consider the deformation of abelian integrals which arose from the study of SG form factors. Besides the known properties they are shown to satisfy Riemann bilinear identity. The deformation of intersection number of cycles on hyperelliptic curve is introduced.Comment: 8 pages, AMSTE

Gauge-Invariant Differential Renormalization: Abelian Case

A new version of differential renormalization is presented. It is based on pulling out certain differential operators and introducing a logarithmic dependence into diagrams. It can be defined either in coordinate or momentum space, the latter being more flexible for treating tadpoles and diagrams where insertion of counterterms generates tadpoles. Within this version, gauge invariance is automatically preserved to all orders in Abelian case. Since differential renormalization is a strictly four-dimensional renormalization scheme it looks preferable for application in each situation when dimensional renormalization meets difficulties, especially, in theories with chiral and super symmetries. The calculation of the ABJ triangle anomaly is given as an example to demonstrate simplicity of calculations within the presented version of differential renormalization.Comment: 15 pages, late

Baxter equations and Deformation of Abelian Differentials

In this paper the proofs are given of important properties of deformed Abelian differentials introduced earlier in connection with quantum integrable systems. The starting point of the construction is Baxter equation. In particular, we prove Riemann bilinear relation. Duality plays important role in our consideration. Classical limit is considered in details.Comment: 28 pages, 1 figur

Geometric approach to asymptotic expansion of Feynman integrals

We present an algorithm that reveals relevant contributions in non-threshold-type asymptotic expansion of Feynman integrals about a small parameter. It is shown that the problem reduces to finding a convex hull of a set of points in a multidimensional vector space.Comment: 6 pages, 2 figure

Fermionic decays of scalar leptoquarks and scalar gluons in the minimal four color symmetry model

Fermionic decays of the scalar leptoquarks $S=S_1^{(+)}, S_1^{(-)}, S_m$ and of the scalar gluons $F=F_1, F_2$ predicted by the four color symmetry model with the Higgs mechanism of the quark-lepton mass splitting are investigated. Widths and branching ratios of these decays are calculated and analysed in dependence on coupling constants and on masses of the decaying particles. It is shown that the decays $S_1^{(+)}\to tl^+_j, S_1^{(-)}\to \nu_i\tilde b, S_m\to t\tilde \nu_j, F_1\to t\tilde b, F_2\to t\tilde t$ are dominant with the widths of order of a few GeV for $m_S, m_F<1$ TeV and with the total branching ratios close to 1. In the case of $m_S < m_t$ the dominant scalar leptoquark decays are S_1^{(+)}\to cl_j^+, S_1^{(-)}\to \nu_i\tilde b, S_m\to b\l_j^+, S_m\to c\tilde \nu_j with the total branching ratios $Br(S_1^{(+)}\to cl^+) \approx$ $Br(S_1^{(-)}\to \nu\tilde b) \approx 1$, $Br(S_m\to bl^+) \approx 0.9$ and $Br(S_m\to c\tilde \nu) \approx 0.1.$ A search for such decays at the LHC and Tevatron may be of interest.Comment: 11 pages, 1 figure, 1 table, to be published in Modern Physics Letters