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...

“I’ve never touched the hard stuff, only smoked grass a few times with the boys to be polite, and that’s all, though ten is the age when the big guys come around teaching you all sorts to things. But happiness doesn’t mean much to me, I still think life is better. Happiness is a mean son of a bitch and needs to be put in his place. Him and me aren’t on the same team, and I’m cutting him dead. I...

CP violation in the neutral kaon system is known to be dominated by the mixing of K 0 and K 0. Direct CP violation in the 2 pion decays of neutral kaons has been a controversial subject over the last decade. A strong experimental effort has been devoted to the precise measurement of the direct CP violation parameter ℜe (ε ′ /ε). After 10 years of detector development, data collection and analys...

We present a detailed analysis of ε/ε within the Standard Model, taking into account the strong enhancement through final–state interactions identified in refs. [1] and [2]. The relevant hadronic matrix elements are fixed at leading order in the 1/NC expansion, through a matching procedure between the effective short–distance Lagrangian and its corresponding low–energy description in Chiral Per...

I discuss the comparison of the current theoretical calculations of ε/ε with the experimental data. Lacking reliable “first principle” calculations, phenomenological approaches may help in understanding correlations among different contributions and available experimental data. In particular, in the chiral quark model approach the same dynamics which underlies the ∆I = 1/2 selection rule in kao...

Sensitivity measurements performed on EVLA antenna #14 show that the cold-sky zenith system temperature is about 45K for the 18 – 26 GHz band, and 60 K for the low frequency end of the 40 – 50 GHz band, rising to 95 K at the high frequency end. Efficiency measurements based on the planet Venus show the antenna efficiency to be about 50% in the 18 – 26 GHz band, and about 28% for the 40 – 50 GHz...

the geometric-arithmetic index is another topological index was defined as2 deg ( )deg ( )( )deg ( ) deg ( )g guv eg gu vga gu v  , in which degree of vertex u denoted by degg (u). wenow define a new version of ga index as 4( )2 ε ( )ε ( )( )ε ( ) ε ( )g ge uv e g g gu vga g  u v , where εg(u) isthe eccentricity of vertex u. in this paper we compute this new topological index for twogr...