K + Lambda photo- and eletroproduction off proton

0532074 - ÚJF 2021 RIV US eng C - Conference Paper (international conference)
Skoupil, Dalibor - Bydžovský, Petr
K + Lambda photo- and eletroproduction off proton.
AIP Conference Proceedings. Vol. 2249. Melville: AIP Publishing, 2020, č. článku 030042. ISBN 9780735420083. ISSN 0094-243X.
[15th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU-2019). Pittsburgh (US), 02.06.2019-07.06.2019]
R&D Projects: GA ČR GA19-19640S
Institutional support: RVO:61389005
Keywords : photoproduction * nucleons * mesons
OECD category: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)

Exploiting the isobar and Regge-plus-resonance models, we study photo- and electroproduction of K+Lambda. Recently, we included to our models a new formalism for exchanges of high-spin (3/2 and 5/2) baryon fields which were found to be important for data description. Moreover, we introduced also energy-dependent widths of the nucleon resonances to the isobar model, which aim at correcting unitarity broken in our tree-level approach. In order to achieve a reliable description of K+Lambda electroproduction with the isobar model, we considered including electromagnetic form factors and longitudinal couplings of virtual photons which appeared to be a necessity at small photon virtuality. In the Regge-plus-resonance approach, we focused mainly on the issue of gauge invariance, being broken by Reggeizing the t-channel current. We use a recently proposed method for restoring gauge invariance and achieve an acceptable data description. We also discuss the changes the choice of either pseudoscalar or pseudovector coupling in the strong vertex makes for cross-section predictions in kinematic regions where data are scarce. The majority of nucleon resonances selected in the analysis with the Regge-plus-resonance models overlap with other sets chosen with the isobar models.
Permanent Link: http://hdl.handle.net/11104/0310680