Exclusive photo- and electroproduction of excited light vector mesons via holographic model

Abstract

In this paper, we study total and differential observables of electro- and photoproduction of light $\rho$, $\omega$ and $\varphi$ mesons as functions of the center-of-mass energy of the $\gamma p$ collision and momentum transfer squared $|t|$. The corresponding vector mesons wave functions have been computed in the framework of relativistic AdS/QCD holographic approach. A satisfactory description of all available data on ground-state $\rho (1S)$, $\omega (1S)$ and $\varphi (1S)$ mesons production cross sections has been achieved in the color dipole picture. Finally, the key observables of excited $\rho (2S)$, $\omega (2S)$ and $\varphi (2S)$ states production in ${\gamma }^{(\ast )}p$ collisions have been presented here using a common wave function formalism. This study reveals a large theoretical uncertainty coming from the modeling of the partial dipole amplitude in the nonperturbative kinematical domain. Hence, the latter could benefit from future measurements of photoproduction of the excited states.