Diffractive two-meson electroproduction with a nucleon and deuteron target

Autor: Wim Cosyn, Bernard Pire, Lech Szymanowski
Přispěvatelé: Dept of Physics and Astronomy, Ghent University, Florida International University [Miami] (FIU), Centre de Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), National Center for Nuclear Research [Warsaw] (NCBJ), National Center for Nuclear Research (NCBJ)
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Physical Review
Physical Review D
PHYSICAL REVIEW D
ISSN: 2470-0010
2470-0029
0038-5646
0038-5506
Popis: The diffractive electro- or photo-production of two mesons separated by a large rapidity gap gives access to generalized parton distributions (GPDs) in a very specific way. First, these reactions allow to easily access the chiral-odd transversity quark GPDs by selecting one of the produced vector meson to be transversely polarized. Second, they are only sensitive to the so-called ERBL region where GPDs are not much constrained by forward quark distributions. Third, the skewness parameter $\xi$ is not related to the Bjorken $x_\text{Bj}$ variable, but to the size of the rapidity gap. We analyze different channels ($\rho_L^0\,\rho_{L/T}, \rho^0_L\,\omega_{L/T}$ and $\rho^0_L\,\pi$ production) on nucleon and deuteron targets. The analysis is performed in the kinematical domain where a large momentum transfer from the photon to the diffractively produced vector meson introduces a hard scale (the virtuality of the exchanged hard Pomeron). This enables the description of the hadronic part of the process in the framework of collinear factorization of GPDs. We show that the unpolarized cross sections depend very much on the parameterizations of both chiral-even and chiral-odd quark distributions of the nucleon, as well as on the shape of the meson distribution amplitudes. The rates are shown to be in the range of the capacities of a future electron-ion collider.
Comment: 20 pages, 15 figures
Databáze: OpenAIRE