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Related papers: Epsilon'/Epsilon in the Standard Model: Theoretica…

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We review the present theoretical status of the CP violating ratio epsilon'/epsilon in the Standard Model (SM) and confront its estimates with the most recent data. In particular we review the present status of the most important parameters…

High Energy Physics - Phenomenology · Physics 2007-05-23 Andrzej J. Buras

Isospin breaking correction to the $\Delta I = {1/2}$ decay of $K\to\pi\pi$ generates a large enough contribution to $\epsilon'$ through an induced $\Delta I = {3/2}$ amplitude in $K_L$ decay. Aside from the $\pi$-$\eta$ and $\pi$-$\eta'$…

High Energy Physics - Phenomenology · Physics 2007-05-23 Mahiko Suzuki

We briefly overview the historical controversy around Standard Model predictions of $\varepsilon'/\varepsilon$ and clarify the underlying physics. A full update of this important observable is presented, with all known short- and…

High Energy Physics - Phenomenology · Physics 2020-08-26 V. Cirigliano , H. Gisbert , A. Pich , A. Rodríguez-Sánchez

We present a detailed analysis of epsilon'/epsilon 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…

High Energy Physics - Phenomenology · Physics 2014-11-17 E. Pallante , A. Pich , I. Scimemi

In the chiral limit of QCD, the pion decay constant F can be extracted from lattice gauge theory by means of a coupling to isospin chemical potential. Here we compute the leading correction due to finite volume in the epsilon-expansion of…

High Energy Physics - Lattice · Physics 2008-11-26 Poul H. Damgaard , Thomas DeGrand , Hidenori Fukaya

We discuss the theoretical and experimental status of the CP violating ratio eps'/eps. We revise our 1997 standard-model estimate-based on hadronic matrix elements computed in the chiral quark model up to O(p^4) in the chiral expansion-by…

High Energy Physics - Phenomenology · Physics 2014-11-17 Stefano Bertolini , Jan O. Eeg , Marco Fabbrichesi

The electromagnetic corrections to the masses of the pseudoscalar mesons $\pi$ and $K$ are considered. We calculate in chiral perturbation theory the contributions which arise from resonances within a photon loop at order $O(e^2 m_q)$.…

High Energy Physics - Phenomenology · Physics 2009-10-28 Robert Baur , Res Urech

I give a short presentation of the theoretical prediction of epsilon-prime/epsilon. Short distance and especially long distance aspects of the computation is discussed. I consentrate on the general framework and the chiral quark model…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. O. Eeg

We analyze the CP violating ratio epsilon'/epsilon and rare K and B decays in the MSSM with minimal flavour and CP violation, including NLO QCD corrections and imposing constraints on the supersymmetric parameters coming from epsilon,…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. J. Buras , P. Gambino , M. Gorbahn , S. Jager , L. Silvestrini

Nature might be kinder than previously thought as far as epsilon'/epsilon is concerned. We show that the recently obtained experimental value for epsilon'/epsilon does not require sizeable 1/N and isospin-breaking corrections. We propose to…

High Energy Physics - Phenomenology · Physics 2014-11-17 Andrzej J. Buras , Jean-Marc Gérard

The measurement of epsilon'/epsilon has left open several theoretical problems, the most important of which is an accurate calculation of the relevant hadronic matrix elements. Here we study the possibility of relating epsilon' to CP…

High Energy Physics - Phenomenology · Physics 2007-05-23 I. Scimemi , E. Gamiz , J. Prades

The CP violating parameter epsilon'/epsilon is computed using the low-energy dynamics of a chiral theory supplemented by vector resonances. The divergent contributions coming from strong pi-pi scattering are tamed by vector-meson exchange…

High Energy Physics - Phenomenology · Physics 2014-11-17 Anirban Kundu , Emmanuel A. Paschos , Yu-Feng Zhou

The CP-violating parameter eps'/eps is estimated in a novel way by including the explicit computation of eps in the ratio as opposed to the usual procedure of taking its value from the experiments. This approach has the advantage of being…

High Energy Physics - Phenomenology · Physics 2011-08-17 Marco Fabbrichesi

We have combined a new systematic calculation of mesonic matrix elements at O(p^6) from an effective chiral lagrangian approach with Wilson coefficients taken from paper by G.Buchalla et al. Rev.Mod.Phys. 68 (1996) 1125, derived in the…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. A. Bel'kov , G. Bohm , A. V. Lanyov , A. A. Moshkin

We report on a calculation of epsilon'/epsilon at next-to-leading in the 1/N_c expansion and to lowest order in Chiral Perturbation Theory. We also discuss the chiral corrections to our results and give the result of including the two known…

High Energy Physics - Phenomenology · Physics 2007-05-23 Johan Bijnens , Joaquim Prades

We discuss direct $CP$ violation in the standard model by giving a new estimate of $\varepsilon'/\varepsilon$ in kaon decays. Our analysis is based on the evaluation of the hadronic matrix elements of the \mbox{$\Delta S =1$} effective…

High Energy Physics - Phenomenology · Physics 2014-11-17 S. Bertolini , J. O. Eeg , M. Fabbrichesi

We present a status report on our study of long-distance contributions to the decay amplitudes A(K^0 --> pi pi, I) in the framework of the 1/N expansion. We argue that a modified prescription for the identification of meson momenta in the…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. H. Soldan

I discuss recent progress made in calculating electromagnetic corrections in the framework of the effective field theory of QCD. In the case of elastic pion-pion scattering, strong interaction predictions have been worked out to two loop…

High Energy Physics - Phenomenology · Physics 2009-10-30 Ulf-G. Meißner

It is shown that isospin-breaking corrections to the pion-deuteron scattering length can be very large, because of the vanishing of the isospin-symmetric contribution to this scattering length at leading order in chiral perturbation theory.…

Nuclear Theory · Physics 2008-11-26 Ulf-G. Meißner , Udit Raha , Akaki Rusetsky

After presenting an optimistic prediction for the CP-violating parameter $\epsilon'/\epsilon$ in the standard model, we provide an analysis on new physics effects in $\epsilon'/\epsilon$.

High Energy Physics - Phenomenology · Physics 2007-05-23 Yue-Liang Wu