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Related papers: Power Corrections to QCD Sum Rules for Compton Sca…

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We estimate the form factors that parametrise the hadronic matrix elements of proton-to-pion transitions with the help of light-cone sum rules. These form factors are relevant for semi-leptonic proton decay channels induced by baryon-number…

High Energy Physics - Phenomenology · Physics 2021-06-08 Ulrich Haisch , Amando Hala

Applying the method of light-cone sum rules with photon distribution amplitudes, we compute the subleading-power correction to the radiative leptonic $B \to \gamma \ell \nu$ decay, at next-to-leading order in QCD for the twist-two…

High Energy Physics - Phenomenology · Physics 2018-07-04 Yu-Ming Wang , Yue-Long Shen

In this paper we calculate the power corrections to the pion transition form factor within the framework of perturbative QCD approach on the basis of $k_T$ factorization. The power suppressed contributions from higher twist pion wave…

High Energy Physics - Phenomenology · Physics 2019-08-07 Yue-Long Shen , Zhi-Tian Zou , Ying Li

I present a unifying scheme for hadronic functions that comprises logarithmic corrections due to gluon emission in perturbative QCD, as well as power-behaved corrections of nonperturbative origin. The latter are derived by demanding that…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. G. Stefanis

We analyze the higher-twist effects and the SU(3)-flavour symmetry breaking in the correlation functions used to calculate form factors of pseudoscalar mesons in the QCD light-cone sum rule approach. It is shown that the Ward identities for…

High Energy Physics - Phenomenology · Physics 2011-09-13 Johan Bijnens , Alexander Khodjamirian

Taking the example of the most popular and well-established Borel / Laplace / Exponential sum rule (LSR), I shortly review some of its recent applications in hadron physics namely the estimates of non-perturbative condensates, the…

High Energy Physics - Phenomenology · Physics 2014-10-07 Stephan Narison

We review the DPD sum rules and establish their validity to all orders in QCD. This is done using a diagrammatic approach and light-front perturbation theory. In the process we furthermore investigate the QCD evolution of double parton…

High Energy Physics - Phenomenology · Physics 2017-04-11 Peter Plößl

We determine the values of the one- and two-loop low energy constants appearing in the SU(2) Chiral Perturbation Theory calculation of pion-pion scattering. For this we use a recent and precise sum rule determination of some scattering…

High Energy Physics - Phenomenology · Physics 2015-06-05 J. Nebreda , J. R. Pelaez , G. Rios

Higher-loop corrections to the pseudoscalar ($0^{-+}$) gluonium correlation function will be used to obtain the leading gluon condensate contributions to the subtraction-independent QCD sum-rules. The effect of these higher-loop corrections…

High Energy Physics - Phenomenology · Physics 2021-07-01 D. Asner , R. B. Mann , J. L. Murison , T. G. Steele

The description of electromagnetic reactions at intermediate energies, such as pion electroproduction or (virtual) Compton scattering, traditionally starts from covariant tree-level Feynman diagrams (Born or pole terms). Internal hadron…

Nuclear Theory · Physics 2009-11-07 J. H. Koch , V. Pascalutsa , S. Scherer

We discuss a possibility to measure the spin-dependent part of the forward Compton scattering amplitude through interference effects of the Bethe-Heitler and virtual Compton scattering mechanisms in photoproduction of e+e- pairs at small…

Nuclear Theory · Physics 2007-05-23 A. I. L'vov , S. Scopetta , D. Drechsel , S. Scherer

The transition pion-photon form factor is studied within the framework of Light-Cone QCD Sum Rules. The spectral density for the next-to-leading order corrections is calculated for any Gegenbauer harmonic. At the level of the…

High Energy Physics - Phenomenology · Physics 2011-05-13 S. V. Mikhailov , N. G. Stefanis

In these lectures, I describe the techniques used within the QCD sum rule approach. The basic concepts of the approach are introduced using a simple model of quantum-mechanical oscillator in 2+1 dimensions. Then I discuss their…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. V. Radyushkin

We analyze new QCD sum rules for the pion wave function $\phi_{\pi}(x)$, obtained recently by A.V. Radyushkin in the framework of the non-local vacuum condensates method for non-diagonal correlators, and suggest a new approach for…

High Energy Physics - Phenomenology · Physics 2016-09-01 A. P. Bakulev , S. V. Mikhailov

We calculate the forward spin-dependent photon-nucleon Compton amplitudes $S_1$ and $S_2$ as functions of photon energy $\nu$ and mass $Q^2$ at the next-to-leading (${\cal O}(p^4)$) order in chiral perturbation theory, from which we extract…

High Energy Physics - Phenomenology · Physics 2008-11-26 Xiangdong Ji , Chung-Wen Kao , Jonathan Osborne

We present the estimates of the order $O(\alpha^{4}_{s})$ QCD corrections to $R(s)$, $R_{\tau}$ and to the deep-inelastic scattering sum rules, namely to the non-polarized and polarized Bjorken sum rules and to the Gross-Llewellyn Smith sum…

High Energy Physics - Phenomenology · Physics 2008-02-03 A. L. Kataev , V. V. Starshenko

We overview the issue of the power corrections to the parton model, mostly within the context of QCD sum rules. There are a few sources of the power corrections responsible for various qualitative effects. The basic idea that the power…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. I. Zakharov , MPI-Munich

It is reviewed how Compton scattering sum rules relate low-energy nucleon structure quantities to the nucleon excitation spectrum. In particular, the GDH sum rule and recently proposed extensions of it will be discussed. These extensions…

High Energy Physics - Phenomenology · Physics 2014-11-18 Marc Vanderhaeghen

We present a detailed investigation of the spacelike pion's electromagnetic form factor using three-point QCD sum rules that exclusively involve nonlocal condensates. Our main methodological tools are a spectral density which includes…

High Energy Physics - Phenomenology · Physics 2009-06-25 A. P. Bakulev , A. V. Pimikov , N. G. Stefanis

We recalculated pion virtual Compton scattering in perturbative QCD in this paper. Our calculation avoids some deficiencies in existing literatures, and treats real Compton scattering as a limit case in which the mass of the virtual photon…

High Energy Physics - Phenomenology · Physics 2015-06-25 Ding-fang Zeng , Bo-qiang Ma