The experimental value for the isospin amplitude ReA2 in K → ππ decays has been successfully explained within the standard model (SM), both within the large N approach to QCD and by QCD lattice calculations. On the other hand within the large N approach the value of ReA0 is by at least 30% below the data. While this deficit could be the result of theoretical uncertainties in this approach and c...

In this paper, we investigate the bi-objective multiperiod one-dimensional cutting stock problem that seeks to minimize cost of production associated with total length cut objects (waste) and inventory costs related items. A mathematical model is presented heuristically solved by a column generation method. Computational tests were performed using Weighted Sum method, ε-Constraint method variat...

During the epidemic outbreak period, number of infected people increased explosively. In order to effectively contain further spread and treat people, it is necessary make reasonable planning for treatment distribution materials. this paper, a multi-objective mixed-integer programming model integrated design emergency medical material networks developed, in which location points, allocation mat...

Strong final state interaction (FSI) effects can play a central role in the Standard Model prediction of weak K → 2π matrix elements. Here, I discuss how FSI's affect the direct CP violation parameter ε ′ /ε by solving the Omnès problem for the necessary K → 2π amplitudes. The main results of this analysis have been reported in a previous paper 1 and are further discussed in Refs. 2,3. The resu...

We discuss a new estimate of ε/ε in the kaon system. The present approach is based on the evaluation of the hadronic matrix elements of the ∆S = 1 effective quark lagrangian by means of the chiral quark model, with the inclusion of meson one-loop renormalization and NLO Wilson coefficients. The estimate here reviewed is fully consistent with the ∆I = 1/2 selection rule in K → ππ decays, which i...

We present a recent analysis of ε′/ε in the 1/Nc expansion. We show that the 1/Nc corrections to the matrix element of Q6 are large and positive, indicating a ∆I = 1/2 enhancement similar to the one of Q1 and Q2 which dominate the CP conserving amplitude. This enhances the CP ratio and can bring the standard model prediction close to the measured value for central values of the parameters. Seve...

providing clear evidence for a non-zero ε/ε value. The theoretical status is instead more debated (see ref. [2] for a brief review). One of the problems that had to be faced during the past years has been that, while CP violation is born at a scale say O(MW ), the observables that enter in the game have to be estimated at a scale of O(MK) (see fig. 1). Changing the order of magnitude of the sca...