In this talk I summarize a recently proposed mechanism to understand ππ scattering to 1 GeV. The model is motivated by the 1/NC expansion to QCD, and includes a current algebra contact term and resonant pole exchanges. Chiral symmetry plays an important role in restricting the form of the interactions. The existence of a broad low energy scalar (σ) is indicated.

the omega polynomial(x) was recently proposed by diudea, based on the length of stripsin given graph g. the sadhana polynomial has been defined to evaluate the sadhana index ofa molecular graph. the pi polynomial is another molecular descriptor. in this paper wecompute these three polynomials for some infinite classes of nanostructures.

π-calculus is a framework that aims to describe concurrent calculations through a formal definition of processes. Originally, π-calculus is defined by a formal language and a set of reduction rules, much in the spirit of λ-calculus. Our aim is to provide a graphical representation of π-calculus using multi-wired interaction nets, in the spirit this time of proof-nets of linear logic. 1 π-calcul...

Recent work by J. Prades and myself on K ! is described. The rst part describes our method to connect in a systematic fashion the short-distance evolution with long-distance matrix-element calculations taking the scheme dependence of the short-distance evolution into account correctly. In the second part I show the results we obtain for the I = 1=2 rule in the chiral limit.