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Related papers: Rescattering effects in eta {\to} 3pi decays

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The recently developed 'Resummed' ChPT is illustrated on the case of pseudoscalar meson decay constants. We try to get an estimate of the eta decay constant, which is not well known from experiments, while using several ways including the…

High Energy Physics - Phenomenology · Physics 2009-02-20 M. Kolesar , J. Novotny

We analyse the radiative decay $\eta \to \pi^+\pi^- \pi^0\gamma$ in the low--energy expansion of the Standard Model. We employ the notion of ``generalized bremsstrahlung'' to take full advantage of the theoretical and experimental…

High Energy Physics - Phenomenology · Physics 2009-10-31 G. D'Ambrosio , G. Ecker , G. Isidori , H. Neufeld

We perform a complete analysis of isospin breaking in K -> Pi Pi amplitudes in chiral perturbation theory, including both strong isospin violation and electromagnetic corrections to next-to-leading order in the low-energy expansion. The…

High Energy Physics - Phenomenology · Physics 2014-11-17 V. Cirigliano , G. Ecker , H. Neufeld , A. Pich

We obtain a model-independent expression for the complete Dalitz plot of semileptonic decays of polarized hyperons, which includes both the three-body and the four-body regions. We calculate radiative corrections to order alpha, neglecting…

High Energy Physics - Phenomenology · Physics 2014-11-17 Ruben Flores-Mendieta , A. Garcia , A. Martinez , J. J. Torres

Using psi(2S) --> pi+ pi- J/psi, J/psi --> gamma eta' events acquired with the CLEO-c detector at the CESR e+e- collider, we make the first observations of the decays eta' --> pi+ pi- pi0 and eta' --> pi+ pi- e+ e-, measuring absolute…

High Energy Physics - Experiment · Physics 2010-04-08 CLEO Collaboration , P. Naik

The estimation of rare K decay matrix-elements from Kl3 experimental data is extended beyond LO in Chiral Perturbation Theory. Isospin-breaking effects at NLO (and partially NNLO) in the ChPT expansion, as well as QED radiative corrections…

High Energy Physics - Phenomenology · Physics 2008-11-26 Federico Mescia , Christopher Smith

Results from the Belle and BaBar experiments on measurement of the weak angle phi_3 using a Dalitz plot analysis of the KSpi+pi- decay of the neutral D meson from the B+=>D(*)K(*)+ process are presented. The method employs the interference…

High Energy Physics - Experiment · Physics 2008-11-26 Alexei Garmash

We analyze the spectrum of two- and three-pion states of maximal isospin obtained recently for isosymmetric QCD with pion mass $M\approx 200\;$MeV in Ref. [1]. Using the relativistic three-particle quantization condition, we find $\sim 2…

High Energy Physics - Lattice · Physics 2021-03-16 Tyler D. Blanton , Fernando Romero-López , Stephen R. Sharpe

We calculate the radiative corrections to the angular correlation between the polarization of the decaying baryon and the direction of the emitted charged lepton in the semileptonic decays of spin one-half baryons to order…

High Energy Physics - Phenomenology · Physics 2014-11-18 M. Neri , A. Martinez , Ruben Flores-Mendieta , J. J. Torres , A. Garcia

Dynamical correlations of the spin and the energy density are investigated in the critical region of the random transverse-field Ising chain by numerically exact calculations in large finite systems (L<=128). The spin-spin autocorrelation…

Disordered Systems and Neural Networks · Physics 2016-08-31 H. Rieger , F. Igloi

We discuss the application of an effective field theory (EFT) which incorporates the chiral symmetry of QCD to Compton scattering from the proton and deuteron. We describe the chiral EFT analysis of the proton Compton scattering database…

Nuclear Theory · Physics 2015-06-11 Daniel R. Phillips , Judith A. McGovern , Harald W. Griesshammer

Using non relativistic effective Lagrangian techniques, we analyze the hadronic decay of the pi+pi- atom and the strong energy-level shift of pionic hydrogen in the ground state. We derive general formulae for the width and level shift,…

High Energy Physics - Phenomenology · Physics 2011-04-15 J. Gasser , V. E. Lyubovitskij , A. Rusetsky

We briefly summarize current experimental and theoretical results on the $\pi^0$ Dalitz decay, including the new value for the ratio $R={\Gamma(\pi^0\to e^+e^-\gamma(\gamma))}/{\Gamma(\pi^0\to\gamma\gamma)}=11.978(6)\times10^{-3}$, which is…

High Energy Physics - Phenomenology · Physics 2019-11-19 Tomáš Husek

Interpreting measurements requires a physical theory, but the theory's accuracy may vary across the experimental domain. To optimize experimental design, and so to ensure that the substantial resources necessary for modern experiments are…

We calculate the electromagnetic corrections to the decays $\eta \rightarrow 3\pi$ in next to leading order in the chiral expansion. We find that the corrections are small in accordance with Sutherland's theorem and modify neither rate nor…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. Baur , J. Kambor , D. Wyler

We construct an effective non-relativistic quantum field theory that describes bound states of pi+ pi- pairs and their hadronic decays. We then derive a general expression for the lifetime of the ground state at next-to-leading order in…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Gasser , V. E. Lyubovitskij , A. Rusetsky , A. Gall

We investigate isospin breaking in low-energy pion-nucleon scattering in the framework of chiral perturbation theory. This work extends the systematic analysis of [1] to the energy range above threshold. Various relations, which identically…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner

A calculational scheme for obtaining the electric polarizability of the neutron in lattice QCD with dynamical quarks is developed, using the background field approach. The scheme differs substantially from methods previously used in the…

High Energy Physics - Lattice · Physics 2008-11-26 Michael Engelhardt

We study the Dalitz plot of the decay D^+ --> K^- pi^+ pi^+ with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known K pi resonances and a uniform nonresonant term, we do not…

High Energy Physics - Experiment · Physics 2012-08-27 E791 Collaboration

This Letter provides a new determination of the ten real coefficients that describe the structure of the $K \to \pi\pi\pi$ amplitudes in the limit where isospin is conserved and complex phases, due to either CP violation or final-state…

High Energy Physics - Phenomenology · Physics 2022-11-28 G. D'Ambrosio , M. Knecht , S. Neshatpour