Light Front Wave Functions and γ∗γ∗−Quarkonium transition form factors

par Izabela Babiarz (IFJ PAN Cracow)

jeudi 27 juin 2024, 14:00 → 16:00 Europe/Paris

100/2-A201 - Salle A201 (IJCLab)

The internal structure of meson can be investigated by studying the electromagnetic form factor and the ${\gamma }^{\ast }{\gamma }^{\ast }-Quarkonium$ transition form factor. Recently, there has been a lot of interest in the exclusive production of mesons by photon fusion processes, especially in the $e^{+}{e}^{-}$ colliders. This study is strongly motivated by the expectation that the cross-section measurement will give strong constraints on the parton structure of the meson. We will introduce a formalism of light-front quarkonium wave functions obtained from a solution of the Schrödinger equation for a selection of interquark potentials for $Q\overline{Q}$ interaction. We will present the helicity structure and covariant decomposition of the matrix elements that can be generically applied for any $Q\overline{Q}$ pseudo-scalar, scalar, axial-vector and vector photon-meson transition. We will discuss the light-front wave function representation of the helicity form factors as functions of photon virtualities. We will discuss ${\eta }_c$, ${\chi }_{c0}$, ${\chi }_{c1}$, ${\chi }_{c2}$, and exotic state ${\chi }_{c1}(3872)$.