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

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We present results on the pseudoscalar meson masses from a fully dynamical simulation of QCD+QED. We concentrate particularly on violations of isospin symmetry. We calculate the $\pi^+$-$\pi^0$ splitting and also look at other isospin…

High Energy Physics - Lattice · Physics 2016-05-04 R. Horsley , Y. Nakamura , H. Perlt , D. Pleiter , P. E. L. Rakow , G. Schierholz , A. Schiller , R. Stokes , H. Stüben , R. D. Young , J. M. Zanotti

Using isospin relations, we predict the Standard-Model correlation between S_{pi^0 K_S}=(sin 2beta)_{pi^0 K_S} and A_{pi^0 K_S}, the mixing-induced and direct CP asymmetries of B^0-> pi^0 K_S. The calculation uses flavour SU(3) only to fix…

High Energy Physics - Phenomenology · Physics 2008-12-30 Robert Fleischer , Sebastian Jager , Dan Pirjol , Jure Zupan

Following the recent analysis done in collaboration with Jason Aebischer and Christoph Bobeth, I summarize the optimal, in our view, strategy for the present evaluation of the ratio $\varepsilon'/\varepsilon$ in the Standard Model (SM). In…

High Energy Physics - Phenomenology · Physics 2020-08-26 Andrzej J. Buras

Data indicate that $\Delta I=1/2$ transitions account for 4.5-4.7% of both CP conserving and CP violating $K \to 2\pi$ decays, as well as CP conserving radiative $K \to \pi\pi\gamma$ processes. Observed $K \to \pi\pi\gamma/\pi\pi$ branching…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michael D. Scadron , George Rupp , Eef van Beveren

The branching ratio of the \eta->3\pi decay is an important source of information on the value of the quark mass ratio 1/R=(m_d-m_u)/(m_s-\hat m). Furthermore, isospin breaking effects in the decays K->3\pi provide information on the pion…

High Energy Physics - Phenomenology · Physics 2011-03-07 M. Zdrahal , K. Kampf , M. Knecht , J. Novotny

We evaluate the branching ratios for the decays $K\rightarrow \pi\pi\pi e\nu$ at leading order in chiral perturbation theory and give an isospin relation for the decay rates.

High Energy Physics - Phenomenology · Physics 2009-10-28 Stefan Blaser

This is a pedagogical review of some selected topics of CP and T violation in the decays of K mesons. Diagonalization of the quark mass matrix and the emergence of the complex phase in both the standard and the left--right symmetric models…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. N. Rogalyov

I discuss the estimate of the CP-violating ratio eps'/eps by stressing the role played by the chiral quark model in predicting the experiment and in showing that the same dynamical mechanism at work in the Delta I=1/2 rule also explains the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Marco Fabbrichesi

We present an update on the ongoing computation of the isospin-breaking effects in the Pion Decay Constant from the BMW Collaboration. The calculation is carried out with N$_f$=2+1+1 staggered quarks with a near-physical pion mass and…

High Energy Physics - Lattice · Physics 2026-04-22 Alessandro Cotellucci , Davide Giusti

Two aspects of isospin breaking in the decay $K^\pm \to \pi^0 \pi^0 e^\pm \stackrel{_{(-)}}{\nu_e}$ are studied and discussed. The first addresses the possible influence of the phenomenological description of the unitarity cusp on the…

High Energy Physics - Phenomenology · Physics 2015-01-29 Véronique Bernard , Sébastien Descotes-Genon , Marc Knecht

CP violation due to interference between $K_L$ and $K_S$ decays into $\pi ^+\pi^-\gamma$ is analyzed in the Standard Model. The CP-violating parameter $\epsilon'_{+- \gamma}$, which is the difference between $\eta_{+-\gamma}$ and…

High Energy Physics - Phenomenology · Physics 2010-11-01 Hai-Yang Cheng

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

We consider strong and electromagnetic isospin violation in near-threshold pion-kaon scattering. At tree level, such effects are small for all physical channels. We work out the complete one-loop corrections to the process pi^- K^+ -> pi^0…

High Energy Physics - Phenomenology · Physics 2009-11-07 Bastian Kubis , Ulf-G. Meißner

We systematically calculate the isospin violating decay, $D_s^*\to D_s\pi^0$, with the heavy meson chiral perturbation theory up to $\mathcal{O}(p^3)$ including the loop diagrams. The $\mathcal{O}(p^3)$ tree level amplitudes contain four…

High Energy Physics - Phenomenology · Physics 2020-03-25 Bin Yang , Bo Wang , Lu Meng , Shi-Lin Zhu

We complete here our work on isospin violation in the $K\to3\pi$ system. We first calculate $K\to2\pi$ to the same order as we did $K\to3\pi$ in papers I and II of this series. This adds effects of order $G_{27} p^2 (m_u-m_d)$ and $G_{27}…

High Energy Physics - Phenomenology · Physics 2011-09-13 Johan Bijnens , Fredrik Borg

A reliable determination of the isospin breaking double quark mass ratio from precise experimental data on $\eta\to 3\pi$ decays should be based on the chiral expansion of the amplitude supplemented with a Khuri-Treiman type dispersive…

High Energy Physics - Phenomenology · Physics 2015-10-23 M. Albaladejo , B. Moussallam

The recently measured direct CP asymmetries in the processes $D^0\to \pi^+\pi^-$ and $D^0\to K^+K^-$ show a significant deviation from the naive Standard Model expectation. Using a general parameterization of the decay amplitudes, we show…

High Energy Physics - Phenomenology · Physics 2015-06-04 Enrico Franco , Satoshi Mishima , Luca Silvestrini

We have compared the decay rates of K_L and K_S to \pi^+ \pi^- and \pi^0 \pi^0 final states using a subset of the data from the KTeV experiment (E832) at Fermilab. We find that the direct-CP-violation parameter Re(\epsilon'/\epsilon) is…

High Energy Physics - Experiment · Physics 2012-08-27 KTeV Collaboration

Because of their small electromagnetic corrections, the isospin-breaking decays $\eta\to3\pi$ seem to be good candidates for extracting isospin-breaking parameters $ (m_d-m_u)$. This task is unfortunately complicated by large chiral…

High Energy Physics - Phenomenology · Physics 2011-12-21 Karol Kampf , Marc Knecht , Jiří Novotný , Martin Zdráhal

We present a new measurement of the time-dependent CP-violating parameters in B0 --> pi+ pi- decays with 275 x 10^6 BB-bar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider operating at the Upsilon(4S)…

High Energy Physics - Experiment · Physics 2008-11-26 Belle Collaboration , K. Abe
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