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Related papers: Isospin Breaking Effects in $K_{\ell4}$ Decays

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We construct the general Lagrangian for relativistic and heavy baryon chiral perturbation theory with virtual photons to fourth order. We work out the electromagnetic and strong isospin violating contributions to the nucleon self-energy,…

High Energy Physics - Phenomenology · Physics 2009-10-31 Guido Müller , Ulf-G. Meißner

We present an extension of chiral perturbation theory that explicitly includes an isosinglet scalar in the Lagrangian. The dynamical effects from the scalar state is of phenomenological relevance in theories where the mass of the isosinglet…

High Energy Physics - Phenomenology · Physics 2019-06-04 Martin Hansen , Kasper Langæble , Francesco Sannino

We provide an overview of the current state of lattice calculations concerning isospin-breaking corrections in weak decays, focusing in particular on leptonic decays of light pseudoscalar mesons. We examine the two currently existing…

High Energy Physics - Lattice · Physics 2024-01-17 Matteo Di Carlo

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

The combined use of chiral $SU(3)$ and heavy quark symmetries allows one to relate the hadronic form factors for the decay $\bar B\to \bar K\e^+\e^-$ to those for $\bar B\to\pi\e^-\bar\nu$. We investigate departures from the symmetry limit…

High Energy Physics - Phenomenology · Physics 2009-10-22 Adam F. Falk , Benjamin Grinstein

The data on the form factors of the $K_{e4}$ decay permit to fix a value of the non-specified in the theory parameter entering in the lagrangian of the system of $0^+$ and $0^-$ mesons . Then, for a mass of the lightest $\sigma$-meson we…

High Energy Physics - Phenomenology · Physics 2013-12-03 E. Shabalin

We investigate the problem of the extraction of the isovector and isoscalar spectral functions from data on $e^+e^-\to hadrons$, in the presence of non-zero isospin breaking. It is shown that the conventional approach to extracting the…

Nuclear Theory · Physics 2009-10-30 Kim Maltman

The effects of isospin violation on the neutral weak magnetic form factor of the proton are studied using two-flavour chiral perturbation theory. The first nonzero contributions appear at O(p^4) in the small-momentum expansion, and the…

High Energy Physics - Phenomenology · Physics 2009-12-30 Randy Lewis , Nader Mobed

The masses and decays of the scalar D_{s0}^*(2317) and axial-vector D_{s1}^*(2460) charmed strange mesons are calculated consistently in the hadrogenesis conjecture. These mesons decay either strongly into the isospin-violating pi^0 D_s and…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. F. M. Lutz , M. Soyeur

The isospin-breaking decay eta {\to} 3pi is an ideal tool to extract information on light quark mass ratios from experiment. For a precise determination, however, a detailed description of the Dalitz plot distribution is necessary. In that…

High Energy Physics - Phenomenology · Physics 2011-02-17 Sebastian P. Schneider , Bastian Kubis , Christoph Ditsche

We discuss radiative corrections to K_{e3} and pi_{e3} decays within chiral perturbation theory with virtual photons and leptons. We then present the extraction of the CKM elements V_{us} and V_{ud} using the presently available…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. Cirigliano

We present a study of the isospin-breaking (IB) corrections to pseudoscalar (PS) meson masses using the gauge configurations produced by the ETM Collaboration with $N_f=2+1+1$ dynamical quarks at three lattice spacings varying from 0.089 to…

High Energy Physics - Lattice · Physics 2018-04-18 D. Giusti , V. Lubicz , G. Martinelli , F. Sanfilippo , S. Simula , N. Tantalo , C. Tarantino

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

To one-loop order and $O(\alpha_{em})$, the electromagnetic mass splittings of $\pi$, $a_1$, $K$, $K_1(1400)$, and $K^*(892)$ are calculated in the framework of $U(3)_L\times U(3)_R$ chiral field theory. The logarithmic divergences emerging…

High Energy Physics - Phenomenology · Physics 2008-11-26 Dao-Neng Gao , Bing An Li , Mu-Lin Yan

We compute the electromagnetic mass difference for the $B$-, $D$- and $K$-mesons using QCD sum rules with double dispersion relations. For the $B$- and $D$-mesons we also compute the linear quark mass correction, whereas for the $K$ the…

High Energy Physics - Phenomenology · Physics 2023-07-05 Matthew Rowe , Roman Zwicky

In a recent paper we used chiral perturbation theory to determine the phase diagram and pion spectrum for Wilson and twisted-mass fermions at non-zero lattice spacing with non-degenerate up and down quarks. Here we extend this work to…

High Energy Physics - Lattice · Physics 2015-10-14 Derek P. Horkel , Stephen R. Sharpe

The infinite mass effective theory, when a heavy quark mass tends to infinity, and Chiral perturbation theory at the quark level, based on the extended Nambu -- Jona -- Lasinio model with linear realization of chiral $U(3)\times U(3)$…

High Energy Physics - Phenomenology · Physics 2016-09-01 F. Hussain , A. N. Ivanov , N. I. Troitskaya

We report on the physical-point RBC/UKQCD calculation of the leading isospin-breaking corrections to light-meson leptonic decays. This is highly relevant for future precision tests in the flavour physics sector, in particular the first-row…

In this work, we study the isospin-violating decay of $\phi\to \omega\pi^0$ and quantify the electromagnetic (EM) transitions and intermediate meson exchanges as two major sources of the decay mechanisms. In the EM decays, the present datum…

High Energy Physics - Phenomenology · Physics 2008-11-26 Gang Li , Qiang Zhao , Bing-Song Zou

The pion mass difference generates a pronounced cusp in the pi0 pi0 invariant mass distribution of K+ --> pi0 pi0 pi+ decays. As originally pointed out by Cabibbo, an accurate measurement of the cusp may allow one to pin down the S-wave…

High Energy Physics - Phenomenology · Physics 2014-11-20 Bastian Kubis