0000000000548017
AUTHOR
Nikolai Kivel
showing 4 related works from this author
QCD radiative corrections to the soft spectator contribution in the wide angle Compton scattering
2014
We derive the complete factorization formula for the leading power contribution in wide angle Compton scattering. It consists of the soft- and hard-spectator contributions. The hard-spectator contribution is well known and defined in the form of the convolution of a hard kernel with the nucleon distribution amplitudes. The soft-spectator contribution describes the scattering which involves the soft modes. We use the soft collinear effective theory in order to define this term in a field theoretical approach. Using the SCET framework we provide the proof of the factorization formula. We also compute the next-to-leading QCD corrections to the hard coefficient function of the soft spectator co…
Two-photon exchange in elastic electron-proton scattering: a QCD factorization approach.
2009
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer $Q^2$. It is shown that the leading two-photon exchange amplitude behaves as $1/Q^4$ relative to the one-photon amplitude, and can be expressed in a model independent way in terms of the leading twist nucleon distribution amplitudes. Using several models for the nucleon distribution amplitudes, we provide estimates for existing data and for ongoing experiments.
Radiative decays χcJ→Vγ within the QCD factorization framework
2017
We present a discussion of radiative decays ${\ensuremath{\chi}}_{cJ}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\rho}(\ensuremath{\omega},\ensuremath{\phi})$. The decay amplitudes are computed within the QCD factorization framework. NRQCD has been used in the heavy meson sector as well as a collinear expansion in order to describe the overlap with light mesons in the final state. The color-singlet contributions to all helicity amplitudes have been computed using the light-cone distribution amplitudes of twist-2 and twist-3. All obtained expressions are well defined at least in the leading-order approximation. The color-octet contributions have also been studied in the Coulomb li…
Production of a tensor glueball in the reaction γγ → G2π0 at large momentum transfer
2018
Abstract We study the production of a tensor glueball in the reaction γ γ → G 2 π 0 . We compute the cross section at higher momentum transfer using the collinear factorisation approach. We find that for a value of the tensor gluon coupling of f g T ∼ 100 MeV, the cross section can be measured in the near future by the Belle II experiment.