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Related papers: K_{l 3} and \pi_{e 3} transition form factors

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The form factor $F_{3\pi}(s,t,u)$ for the anomalous process $\gamma^\ast \pi \rightarrow \pi \pi$ is calculated in the isospin limit for several values of the light current-quark mass (i.e., the pion mass) using Dyson-Schwinger and…

High Energy Physics - Phenomenology · Physics 2025-06-23 Angel S. Miramontes , Gernot Eichmann , Reinhard Alkofer

In treating the relativistic three-quark problem, a dressed-quark propagator parameterization is used which is compatible with recent lattice data and pion observables. Furthermore two-quark correlations are modeled as a series of quark…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Oettel , R. Alkofer

We describe the calculation of the three-loop QCD corrections to quark and gluon form factors. The relevant three-loop Feynman diagrams are evaluated and the resulting three-loop Feynman integrals are reduced to a small set of known master…

High Energy Physics - Phenomenology · Physics 2023-11-15 T. Gehrmann , E. W. N. Glover , T. Huber , N. Ikizlerli , C. Studerus

We present results from a calculation of the electromagnetic transition form factors between ground-state octet and decuplet baryons as well as the octet-only $\Sigma^0$ to $\Lambda$ transition. We work in the combined framework of…

High Energy Physics - Phenomenology · Physics 2018-03-09 Helios Sanchis-Alepuz , Reinhard Alkofer , Christian S. Fischer

We obtain stringent bounds in the < r^2 >_S^{K pi}-c plane where these are the scalar radius and the curvature parameters of the scalar pi K form factor respectively using analyticity and dispersion relation constraints, the knowledge of…

High Energy Physics - Phenomenology · Physics 2009-07-22 Gauhar Abbas , B. Ananthanarayan

We calculate the form factors for the heavy-to-light transitions $B\rightarrow \pi,K $ by means of QCD sum rules using $\pi$ and $K$ light-cone wave functions. Higher twist contributions as well as gluonic corrections are taken into…

High Energy Physics - Phenomenology · Physics 2019-08-15 V. M. Belyaev , A. Khodjamirian , R. Rückl

We report the calculation of electromagnetic form factors of nucleons within a relativistic three-quark model with Gaussian shape for the nucleon-quark vertex. The allowed region for two adjustable parameters, the range parameter…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. A. Ivanov , M. P. Locher , V. E. Lyubovitskij

We study the form factors of the low energy anomalous pion-2-photon and photon-3-pion processes in the nonlocal chiral quark model which incorporates the momentum dependence of the dynamical quark mass and realizes correctly the chiral…

High Energy Physics - Phenomenology · Physics 2009-11-07 Xiaoyuan Li , Yi Liao

The elastic and $\gamma \to \pi$ transition form factors of the pion along with its usual static observables are calculated within a light-front field approach to the constituent quark model. The focus of this exercise in a simple model is…

Nuclear Theory · Physics 2015-06-18 J. P. B. C. de Melo , B. El-Bennich , T. Frederico

Using dispersion theory, the electromagnetic Sigma-to-Lambda transition form factors are expressed as the product of the pion electromagnetic form factor and the $\Sigma\bar{\Lambda}\to\pi\pi$ scattering amplitudes with the latter estimated…

High Energy Physics - Phenomenology · Physics 2023-04-05 Yong-Hui Lin , Hans-Werner Hammer , Ulf-G. Meißner

Bounds on the expansion coefficients of the strangeness changing $K\pi$ form factors were derived recently from analyticity and unitarity, using as input suitable correlation functions calculated by perturbative QCD in the Euclidian region.…

High Energy Physics - Phenomenology · Physics 2011-07-15 Irinel Caprini , Elena-Mirela Babalic

We compute the Kl3 and pion form factors using partially twisted boundary conditions. The twists are chosen so that the Kl3 form factors are calculated directly at zero momentum transfer (q^2=0), removing the need for a q^2 interpolation,…

High Energy Physics - Lattice · Physics 2010-01-21 P. A. Boyle , J. M. Flynn , A. Jüttner , C. Kelly , H. Pedroso de Lima , C. M. Maynard , C. T. Sachrajda , J. M. Zanotti

The slope and curvature parameters of the $K\pi$ vector form factor, $F_+^{K\pi}$, are fitted to the data on $\tauKpi$ and $K_{l3}$ decays yielding $\lambda_+'=(25.49 \pm 0.31) \times 10^{-3}$ and $\lambda_+"= (12.22 \pm 0.14) \times…

High Energy Physics - Phenomenology · Physics 2011-01-17 Diogo R. Boito , Rafel Escribano , Matthias Jamin

I briefly summarize the application of the Dyson-Schwinger/Faddeev approach to baryon form factors. Recent results for nucleon electromagnetic and axial form factors as well as N-Delta-Gamma electromagnetic transition form factors are…

High Energy Physics - Phenomenology · Physics 2011-12-22 Gernot Eichmann

We compute the electromagnetic form factors of the nucleon in the Poincare-covariant Faddeev framework based on the Dyson-Schwinger equations of QCD. The general expression for a baryon's electromagnetic current in terms of three…

High Energy Physics - Phenomenology · Physics 2011-08-08 Gernot Eichmann

A short review is given of calculations of the pion electromagnetic and transition form factors within the framework of quantum chromodynamics. It is argued that both the perturbative and nonperturbative aspects of the Q^2 dependence of…

High Energy Physics - Phenomenology · Physics 2017-08-23 A. V. Radyushkin

We compute the axial and pseudoscalar form factors of the nucleon in the Dyson-Schwinger approach. To this end, we solve a covariant three-body Faddeev equation for the nucleon wave function and determine the matrix elements of the…

High Energy Physics - Phenomenology · Physics 2015-06-03 Gernot Eichmann , Christian S. Fischer

Elastic and semileptonic transition form factors for the kaon and pion are calculated using the leading-order in a global-symmetry-preserving truncation of the Dyson-Schwinger equations and a momentum-independent form for the associated…

Nuclear Theory · Physics 2014-08-06 Chen Chen , Lei Chang , Craig D. Roberts , Sebastian M. Schmidt , Shaolong Wan , David J. Wilson

This work studies the $\phi \to 3\pi$ decay and the $\phi \to \pi^0 \gamma^\ast$ transition form factor, utilizing the Khuri-Treiman formalism to account for analyticity, crossing, and unitarity. Using once-subtracted dispersion relations,…

High Energy Physics - Phenomenology · Physics 2025-05-22 A. Garcia-Lorenzo , M. Albaladejo , S. Gonzlez-Solis , N. Hammoud , V. Mathieu , G. Montana , A. Pilloni , D. Winney , A. P. Szczepaniak

We report the calculation of electromagnetic form factors of nucleons within a relativistic three-quark model with Gaussian shape for the nucleon-quark vertex. The allowed region for two adjustable parameters, the range parameter…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. A. Ivanov , M. P. Locher , V. E. Lyubovitskij