Related papers: Sum rules for light-by-light scattering
We examine the radiative $\Delta \to \gamma N$ transition at the real photon point $Q^2=0$ using the framework of light-cone QCD sum rules. In particular, the sum rules for the transition form factors $G_M(0)$ and $R_{EM}$ are determined up…
We studied the feasibility of observing light-by-light scattering in a photon-photon collider based on an existing accelerator complex and a commercially available laser system. We investigated the statistical significance of the signal…
We bound EFT coefficients appearing in $2 \to 2$ photon scattering amplitudes in four dimensions. After reviewing unitarity and positivity conditions in this context, we use dispersion relations and crossing symmetry to compute sum rules…
Light-by-light scattering is a relatively new area of experimental physics. Our recent, theoretical research shows that studying two photon measurements in regions with lower transverse momentum ($p_{t,\gamma}$) and invariant mass…
We reminde definite results related to the low-energy hadronic phenomenology, obtained using the QCD sum rules methods. We emphasize that these results can be of interest for the comparison with available and new experimental results,…
The existing calculations of the form factors describing the decay $B\to\rho e \nu$ from QCD sum rules have yielded conflicting results at small values of the invariant mass squared of the lepton pair. We demonstrate that the disagreement…
Considering very high energy peripheral electron-hadron scattering with a production of hadronic state X moving closely to the direction of initial hadron the Weizs\"acker-Williams like expression, relating the difference of q^2-dependent…
The calculations of masses and decay constants of the radial excitations of light pseudoscalar and scalar mesons within QCD sum rules method are briefly reviewed. The predictions are based on the $1/N_c$-supported model spectra, which…
Light-driven matter can exhibit qualitatively distinct electronic and optical properties from those observed at equilibrium. We introduce generalized sum rules for the optical properties of driven systems by both quantum and classical…
The aim of this article is to explore a potential usability of a photon-photon self-interaction from the noncommutative quantum electrodynamics (NCQED) in the case of light-by-light scattering ($\gamma\gamma\to\gamma\gamma$) in…
We deduce momentum sum rules for the parton structure functions of a photon target. Non-perturbative QCD contribution to the momentum sum rules follows from conservation of the energy--momentum tensor and it is calculated through the…
We consider scattering of light by light in Very Special Relativity (VSR) Quantum Electrodynamics(QED) with a non-zero photon mass. In order to preserve gauge invariance and Sim(2) symmetry we made use of a recently introduced infrared…
A unified approach to total cross-sections, based on the QCD contribution to the rise with energy, is presented for the processes $pp$, $p{\bar p}$, $\gamma p, \gamma \gamma, e^+e^- \to hadrons$. For proton processes, a discussion of the…
I extend the well-known photonuclear sum rule that relates the strength of the photoexcitation of the giant dipole resonance in a nucleus to the number of elementary scatterers-nucleons to the case of virtual photons. The new sum rule…
We use a quantum loop expansion to derive sum rule constraints on polarized photoabsorption cross sections in the Standard Model, generalizing earlier results obtained by Altarelli, Cabibbo, and Maiani. We show that the logarithmic integral…
The backward Compton scattering is a basic process at future higher energy photon colliders. To obtain a high probability of e->gamma conversion the density of laser photons in the conversion region should be so high that simultaneous…
The questions on the presense and quantitative role of the constant terms in the real part of the high-energy photon-nucleon and photon-nucleus amplitudes representing the contribution of the non-Regge (the fixed j=0-pole) singularities in…
An introduction to the method of QCD sum rules is given for those who want to learn how to use this method. Furthermore, we discuss various applications of sum rules, from the determination of quark masses to the calculation of hadronic…
The process of elastic scattering of photons (scattering of light by light) has attracted much attention in recent years. It goes through a loop where all the charged particles contribute to the cross section. To date, this $\gamma\gamma…
We investigate the transition to perturbative QCD in Compton processes, by concentrating on the specific reactions $\pi \gamma \to \pi \gamma$ and pion photoproduction at moderate energy scales. New sum rules for each of the helicities…