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Related papers: Isospin-Violating Contributions to $\epsilon'/\eps…

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We study both CP conserving and violating contributions to the decay $K_L\to\pi^+\pi^-\nu\bar{\nu}$. We find that the decay branching ratio is dominated by the CP conserving part. In the standard CKM model, we estimate that for $m_t\sim…

High Energy Physics - Phenomenology · Physics 2010-11-01 C. Q. Geng , I. J. Hsu , Y. C. Lin

In the first part of the talk, I review what we know (or rather do not know) about the structure of the QCD vacuum in the presence of strange quarks. Chiral perturbation theory allows to study reactions of pions and kaons and to further…

High Energy Physics - Phenomenology · Physics 2009-11-10 Ulf-G. Meißner

We discuss the RBC & UKQCD collaboration's progress towards a first-principles calculation of direct CP-violation in the Standard Model via K ->pi pi decays. In particular we focus upon the calculation of the I=0 channel amplitude A_0, for…

High Energy Physics - Lattice · Physics 2013-10-02 Christopher Kelly

We calculate the new contribution to the direct CP-violation parameter $\epsilon'$ in $K\to \pi\pi$ decay in the minimal left-right symmetric model with the recently-obtained right-handed quark Cabibbo-Kobayashi-Maskawa mixing. We pay…

High Energy Physics - Phenomenology · Physics 2010-04-23 Panying Chen , Hongwei Ke , Xiangdong Ji

The experimental data on pi N scattering in the elastic energy region T_pi < 250 MeV are analyzed within the multichannel K-matrix approach with effective Lagrangians. Isospin invariance is not assumed in this analysis and the physical…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. B. Gridnev , I. Horn , W. J. Briscoe , I. I. Strakovsky

Present precision measurements of the neutron life time lead to a CKM matrix element $|V_{ud}|$ which is three standard deviations off the value inferred from heavy quark decays etc. We investigate the possibility whether isospin-breaking…

Nuclear Theory · Physics 2009-11-07 N. Kaiser

Isospin symmetry is explicitly broken in the Standard Model by the non-zero differences of mass and electric charge between the up and down quarks. Both of these corrections are expected to have a comparable size of the order of one percent…

High Energy Physics - Lattice · Physics 2013-09-11 Antonin Portelli

We present a general analysis on charmless B-meson decays $B\to \pi\pi$ and $\pi K$. It is noticed that the final state interactions and inelastic rescattering effects must be significant in order to understand the consistency of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Y. F. Zhou , Y. L. Wu , J. N. Ng , C. Q. Geng

We investigate the isospin-violating mixing of the light scalar mesons a0(980) and f0(980) within the unitarized chiral approach. Isospin-violating effects are considered to leading order in the quark mass difference and electromagnetism.…

High Energy Physics - Phenomenology · Physics 2013-01-16 C. Hanhart , B. Kubis , J. R. Pelaez

We investigate the $\epsilon^{\prime} /\epsilon$ for $K\to \pi\pi$ in a sequential fourth generation model. By giving the basic formulae for $\epsilon^{\prime}/\epsilon$ in this model, we analyze the numerical results which are dependent of…

High Energy Physics - Phenomenology · Physics 2019-08-17 Chao-Shang Huang , Wu-Jun Huo , Yue-Liang Wu

We use the observed $SU(3)$ breaking in the mass spectrum of mesons containing a single heavy quark to place restrictions on the light quark current masses. A crucial ingredient in this analysis is our recent first-principles calculation of…

High Energy Physics - Phenomenology · Physics 2016-09-01 Markus A. Luty , Raman Sundrum

Data on Ke4 decays allow one to extract experimental information on the elastic pi pi scattering amplitude near threshold, and to confront the outcome of the analysis with predictions made in the framework of QCD. These predictions concern…

High Energy Physics - Phenomenology · Physics 2009-05-20 Gilberto Colangelo , Juerg Gasser , Akaki Rusetsky

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

We present the results of the effects of various mechanisms on the quark level, including QED-QCD interference effect, on isospin violation in ${}1S_0$ NN scatterings with the new sets of strength parameters obtained by fitting to mass…

Nuclear Theory · Physics 2007-05-23 Chung Wen Kao , Shin Nan Yang

The LHCb Collaboration has recently reported the discovery of direct CP violation in combined $D^0 \to K^+ K^-$ and $D^0 \to \pi^+ \pi^-$ decay modes at the $5.3 \sigma$ level. Assuming U-spin symmetry (i.e., $d \leftrightarrow s$…

High Energy Physics - Phenomenology · Physics 2019-10-23 Zhi-zhong Xing

We calculate the isospin symmetry violating effects to the reactions $pp\rightarrow d\pi ^+$ and $np\rightarrow d\pi ^0$ arising from the different hadron masses and from the Coulomb interaction between the positive pion and the deuteron.…

Nuclear Theory · Physics 2009-10-30 J. A. Niskanen , M. Vestama

In this Ph.D. Thesis we analyze some CP-violating observables in Kaon decays. In Chapters 1-3 we describe the framework in which this Thesis has been developed and establish the definitions and notation. In Chapter 4 we study CP-violating…

High Energy Physics - Phenomenology · Physics 2007-05-23 Elvira Gamiz

We present theoretical results for the indirect CP violation parameter, $ |\varepsilon_K| $, evaluated directly within the Standard Model using lattice QCD inputs including $ B_K $, $ |V_{cb}| $, $ |V_{us}| $, $ |V_{ud}| $, $ \xi_0 $, $…

High Energy Physics - Lattice · Physics 2025-07-16 Seungyeob Jwa , Jeehun Kim , Sunghee Kim , Sunkyu Lee , Weonjong Lee , Sungwoo Park

The cusp effect in K \to 3\pi and data on K_e4 decays allow one to extract experimental information on the elastic \pi\pi scattering amplitude near threshold, and to confront the outcome of the analyses with predictions made in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Gasser

Isospin analysis has been used to constrain the CP-asymmetries in B -> pi pi decays. In particular correlation between a weak phase \theta and a strong phase \delta is obtained. Further using the experimental values for the CP-average…

High Energy Physics - Phenomenology · Physics 2007-05-23 Fayyazuddin