Light-front approach to axial-vector quarkonium $\gamma^* \gamma^*$ form factors
| Autor: | Babiarz, Izabela, Pasechnik, Roman, Schäfer, Wolfgang, Szczurek, Antoni |
|---|---|
| Rok vydání: | 2022 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1007/JHEP09(2022)170 |
| Popis: | In this work, we perform a detailed study of transition form factors for axial-vector meson production via the two-photon fusion process $\gamma^* \gamma^* \to 1^{++}$, with space-like virtual photons in the initial state and a $P$-wave axial-vector quarkonium in the final state. In this analysis, we employ the formalism of light-front quarkonium wave functions obtained from a solution of the Schr\"odinger equation for a selection of interquark potentials for $Q \bar Q$ interaction. We found the helicity structure and covariant decomposition of the matrix elements that can be generically applied for any $q \bar q$ axial-vector meson $\gamma^* \gamma^* \to 1^{++}$ transition, while our numerical results are given for the phenomenologically relevant charmonium $\chi_{c1}$ state. We present the helicity form factors as functions of both photon virtualities. We also obtain, that $Q F_{\rm LT}(Q^2,0)/F_{\rm TT}(Q^2,0) = {\rm const.}$ Comment: 25 pages, 7 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|