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arXiv · 2406.04668

The distribution amplitude of the $\eta_c$-meson at leading twist from Lattice QCD

Benoît Blossier·Mariane Mangin-Brinet·José Manuel Morgado Chávez·Teseo San José
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Abstract

Distribution amplitudes are functions of non-perturbative matrix elements describing the hadronization of quarks and gluons. Thanks to factorization theorems, they can be used to compute the scattering amplitude of high-energy processes. Recently, new ideas have allowed their computation using lattice QCD, which should provide us with a general, fully relativistic determination. We present the first lattice calculation of the $\eta_c$-meson distribution amplitude at leading twist. Starting from the relevant matrix element in discrete Euclidean space on a set of $N_f=2$ CLS ensembles, we explain the method to connect to continuum Minkowski spacetime. After addressing several sources of systematic uncertainty, we compare to Dyson-Schwinger and non-relativistic QCD determinations of this quantity. We find significant deviations between the latter and our result even at small Ioffe times.

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Benoît Blossier, Mariane Mangin-Brinet, José Manuel Morgado Chávez, Teseo San José. 2024-06-07. The distribution amplitude of the $\eta_c$-meson at leading twist from Lattice QCD. https://doi.org/10.1007/jhep09(2024)079

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