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Related papers: Forward virtual Compton scattering and the Lamb sh…

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We calculate the electromagnetic polarizabilities of the spin-$\frac{1}{2}$ singly heavy baryons in the heavy baryon chiral perturbation theory up to $\mathcal{O}(p^3)$. We estimate the low-energy constants using the magnetic moments of…

High Energy Physics - Phenomenology · Physics 2025-04-15 Yan-Ke Chen , Liang-Zhen Wen , Lu Meng , Shi-Lin Zhu

We present our studies of the forward unpolarised doubly-virtual Compton scattering (VVCS) off the deuteron and the closely related two-photon-exchange ($2\gamma$-exchange) corrections to the Lamb shift of muonic deuterium. The deuteron…

Nuclear Theory · Physics 2022-07-05 Vadim Lensky , Franziska Hagelstein , Astrid Hiller Blin , Vladimir Pascalutsa

We study low-energy virtual Compton scattering off the proton within the framework of a nonrelativistic constituent quark model. The Compton tensor is divided into two separately gauge-invariant contributions. The first consists of the…

Nuclear Theory · Physics 2011-07-19 B. Pasquini , S. Scherer , D. Drechsel

The contribution of the $\alpha^3$ single electron-loop vacuum-polarization diagrams to the Lamb shift of the muonic hydrogen has been evaluated recently by two independent methods. One uses the exact parametric representation of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 T. Kinoshita , M. Nio

The radiative muon capture(RMC) on a proton is analyzed by means of heavy baryon chiral perturbation theory. The emitted photon energy spectrum is calculated and compared with the experimental data by taking the spin sum on the muonic atom…

High Energy Physics - Phenomenology · Physics 2009-10-30 Shung-ichi Ando , Dong-Pil Min

The Gerasimov-Drell-Hearn sum rule and related dispersive integrals connect real and virtual Compton scattering to inclusive photo- and electroproduction. Being based on universal principles as causality, unitarity, and gauge invariance,…

Nuclear Theory · Physics 2009-12-17 D. Drechsel

The low-energy theorem for the forward Compton scattering is generalized to the case of an arbitrary target spin. The generalization is used to calculate the corresponding contribution to the deuterium hyperfine structure. The…

Nuclear Theory · Physics 2009-10-28 I. B. Khriplovich , A. I. Milstein , S. S. Petrosyan

Based on a generalized side-jump formalism for massless chiral fermions, which naturally takes into account the spin-orbit coupling in the scattering of two chiral fermions and the chiral vortical effect in a rotating chiral fermion matter,…

Nuclear Theory · Physics 2021-02-03 Shuai Y. F. Liu , Yifeng Sun , Che Ming Ko

A unique feature of generalised parton distributions is their relation to the QCD energy-momentum tensor. In particular, they provide access to the mechanical properties of the proton i.e. the distributions of pressure and shear stress…

High Energy Physics - Phenomenology · Physics 2021-04-28 H. Dutrieux , C. Lorcé , H. Moutarde , P. Sznajder , A. Trawiński , J. Wagner

We compare the predictions of different variants of chiral effective field theory for the gamma-p elastic scattering differential cross section. We pay particular attention to the role of pion loops, and the impact that a heavy-baryon…

Nuclear Theory · Physics 2012-12-12 Vadim Lensky , Judith A. McGovern , Daniel R. Phillips , Vladimir Pascalutsa

The two photon exchange amplitude is investigated in frame of analytic properties of the virtual Compton scattering amplitude as a function of the invariant mass squared of the intermediate hadronic state. A sum rule is built, based on…

High Energy Physics - Phenomenology · Physics 2007-11-21 E. A. Kuraev , S. Bakmaev , E. Tomasi-Gustafsson , V. V. Bytev

A measurement of parity-violating spin-dependent gamma proton Compton scattering will provide a theoretically clean determination of the parity-violating pion-nucleon coupling constant $h_{\pi NN}^{(1)}$. We calculate the leading…

Nuclear Theory · Physics 2009-10-31 Paulo F. Bedaque , Martin J. Savage

We calculate in chiral perturbation theory the dominant next-to-leading order correction to the $\pi\gamma$-exchange NN-potential proportional to the large isovector magnetic moment $\kappa_v = 4.7$ of the nucleon. The corresponding…

Nuclear Theory · Physics 2008-11-26 N. Kaiser

We analyse deeply-virtual Compton scattering on a proton target, gamma* P -> P' gamma in the backward region and in the scaling regime. We define the transition distribution amplitudes which describe the proton to photon transition.…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. P. Lansberg , B. Pire , L. Szymanowski

The Lamb shift measurement and theory are now both a dynamically developing field and we give a review of the current data. Critical comparison of theory and experiment can be done using a value of the proton charge radius and we pay…

High Energy Physics - Phenomenology · Physics 2007-05-23 Savely G. Karshenboim

Based on analyticity, unitarity, and Lorentz invariance the contribution from hadronic vacuum polarization to the anomalous magnetic moment of the muon is directly related to the cross section of e^+e^- --> hadrons. We review the main…

High Energy Physics - Phenomenology · Physics 2015-06-17 Martin Hoferichter , Gilberto Colangelo , Massimiliano Procura , Peter Stoffer

Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton $\vec{e}\vec{p} \to e' p'\gamma$ are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally…

High Energy Physics - Experiment · Physics 2015-03-25 S. Pisano , A. Biselli , S. Niccolai , E. Seder , M. Guidal , M. Mirazita , the CLAS Collaboration

The leading order contributions of processes involving anomalous pion-photon vertices to forward spin-dependent Compton scattering from nucleons are considered in heavy-baryon chiral perturbation theory. These all involve the exchange of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Judith A. McGovern , Michael C. Birse

We study the hydrogen and muonic hydrogen within an effective field theory framework. We perform the matching between heavy baryon effective theory coupled to photons and leptons and the relevant effective field theory at atomic scales.…

High Energy Physics - Phenomenology · Physics 2009-11-07 Antonio Pineda

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…