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Related papers: Study of K^0 \to pi^- e^+ nu_e e^+ e^- in chiral p…

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We study the decay $D^0\rightarrow \bar K^{*0} \pi^- e^+ \nu_e$, using $SU(2)_L \otimes SU(2)_R$ chiral perturbation theory for heavy charmed mesons and vector mesons, in the kinematic regime where $p_M \cdot p_\pi/m_M$ (here $M = D^0$ or…

High Energy Physics - Phenomenology · Physics 2014-11-17 Hooman Davoudiasl

It is shown that the low energy coefficients of the next-to-leading order (NLO) chiral perturbation theory needed to determine $\Delta I=1/2$, $K\to\pi\pi$ decay amplitudes can be fixed by calculating $K\pi\to\pi$ amplitudes on lattice.…

High Energy Physics - Lattice · Physics 2009-09-02 Changhoan Kim

We investigate the rare radiative eta decay modes $\eta\to\pi^+\pi^-\gamma\gamma$ and $\eta\to\pi^0\pi^0\gamma\gamma$ within the framework of chiral perturbation theory at $O(p^4)$. We present photon spectra and partial decay rates for both…

High Energy Physics - Phenomenology · Physics 2009-10-28 G. Kn"ochlein , S. Scherer , D. Drechsel

We propose an approach for calculating $K\to\pi\pi$ decays to the next-to-leading order in chiral expansion. A detailed numerical study of this approach is being performed.

High Energy Physics - Lattice · Physics 2016-08-16 Ph. Boucaud , V. Giménez , C. -J. D. Lin , V. Lubicz , G. Martinelli , M. Papinutto , F. Rapuano , C. T. Sachrajda

The dominant decay mode of the eta-prime, eta-prime -> eta pi pi, is investigated within the framework of infrared regularized U(3) chiral perturbation theory up to fourth chiral order and including one-loop corrections. We find reasonable…

High Energy Physics - Phenomenology · Physics 2011-03-23 N. Beisert , B. Borasoy

The double lepton pair decay modes of the K_L meson are analyzed including all contributions of order p^6 in Chiral Perturbation Theory. The experimentally established e^+ e^- e^+ e^- mode and the recently observed e^+ e^- mu^+ mu^- mode…

High Energy Physics - Phenomenology · Physics 2014-11-17 Longzhe Zhang , J. L. Goity

We evaluate the matrix elements for the radiative kaon decays $K^+ \to l^+\nu_l\gamma$, $l^+ \nu_l l'^+ l'^-$ and $K \to \pi l \nu_l\gamma$ \ ($l,\ l' = e,\mu$) to next-to-leading order in chiral perturbation theory. We calculate total…

High Energy Physics - Phenomenology · Physics 2011-09-29 J. Bijnens , G. Ecker , J. Gasser

Pionic beta decay \pi^+ to \pi^0 e^+ \nu_e is analyzed in chiral perturbation theory with virtual photons and leptons. All electromagnetic corrections up to order e^2 p^2 are taken into account. Theoretical results are confronted with…

High Energy Physics - Phenomenology · Physics 2010-11-23 Hannes Pichl

It is proposed to compute matrix elements for the (unphysical) $K^0\pi^-\to \pi^-$ transition to determine the next-to-leading order low energy constants of the weak chiral Lagrangian. This allows us to evaluate $K\to(\pi\pi)_{I=0}$ decay…

High Energy Physics - Lattice · Physics 2009-10-09 Changhoan Kim , Christopher Sachrajda

An investigation is performed of all non-leptonic kaon decays sensitive to the chiral anomaly. Within the framework of chiral perturbation theory, there are two classes of anomalous amplitudes at $O(p^4)$: reducible and direct…

High Energy Physics - Phenomenology · Physics 2009-10-22 G. Ecker , H. Neufeld , A. Pich

A phenomenological analysis of $K\to \pi\pi\gamma$ ($K_L\to\pi^+\pi^-\gamma$ and $K^+\to\pi^+\pi^0\gamma$) with the direct emission photon is carried out beyond the leading order in the chiral perturbation theory. We show that the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Giancarlo D'Ambrosio , Dao-Neng Gao

We present a complete analysis of K -> 3 pi gamma decays to O(p^4) in the low-energy expansion of the Standard Model. We employ the notion of "generalized bremsstrahlung" to take full advantage of experimental information on the…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. D'Ambrosio , G. Ecker , G. Isidori , H. Neufeld

The NA48/2 experiment at the CERN SPS collected in 2003 and 2004 large samples of the decays K+- -> pi+ pi- e+- nu (Ke4+-), K+- -> pi0 pi0 e+- nu (Ke400) and K+- -> pi0 pi0 pi+-. From the Ke4+- form factors and from the cusp in the M00^2…

High Energy Physics - Experiment · Physics 2017-08-23 L. Masetti

The long distance contribution to $K^+ \to \pi^+ \nu {\bar \nu} $ is calculated using chiral perturbation theory. The leading contribution comes from $O(p^4)$ tree terms. The branching ratio of the $O(p^4)$ long distance contribution is…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Fajfer

A brief survey of applications of chiral perturbation theory to both semileptonic and nonleptonic kaon decays is presented. Special emphasis is given to recent theoretical advances related to semileptonic decays, in particular pion pion…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Ecker

We calculate the forward spin-dependent photon-nucleon Compton amplitude as a function of photon energy at the next-to-leading (${\cal O}(p^4)$) order in chiral perturbation theory, from which we extract the contribution to nucleon spin…

High Energy Physics - Phenomenology · Physics 2009-10-31 Xiangdong Ji , Chung-Wen Kao , Jonathan Osborne

We calculate all of the form factors for the one-photon, $K_L \rightarrow \pi^+ \pi^- \gamma^* \rightarrow \pi^+ \pi^- e^+e^-$ contribution to the $K_L \rightarrow \pi^+ \pi^- e^+e^-$ decay amplitude at leading order in chiral perturbation…

High Energy Physics - Phenomenology · Physics 2014-11-17 John K. Elwood , Mark B. Wise , Martin J. Savage

We calculate the $T$-matrices of elastic pion-nucleon ($\pi N$) scattering up to fourth order in SU(3) heavy baryon chiral perturbation theory. The pertinent low-energy constants are determined by fitting to $\pi N$ phase shifts below 200…

Nuclear Theory · Physics 2020-12-03 Bo-Lin Huang

We use one-loop chiral perturbation theory (ChPT) to compare lattice results for the K+ to pi+ pi0 decay amplitude with the experimental value. Three systematic effects: quenching, finite-volume effects, and the use of unphysical values of…

High Energy Physics - Lattice · Physics 2009-10-30 Maarten Golterman , Ka Chun Leung

The decays $K \to \pi l^{+} l^{-}$, $K \to \pi \gamma \gamma $ and $K \to \pi \nu {\bar \nu}$ are investigated using the higher order terms of the chiral perturbation theory. The counterterms induced by strong, weak and electromagnetic…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Fajfer