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arXiv · 2207.03012

gamma-UPC: Automated generation of exclusive photon-photon processes in ultraperipheral proton and nuclear collisions with varying form factors

Hua-Sheng Shao·David d'Enterria
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Abstract

The automated generation of arbitrary exclusive final states produced via photon fusion in ultraperipheral high-energy collisions of protons and/or nuclei is implemented in the MadGraph5_aMC@NLO and HelacOnia Monte Carlo codes. Cross sections are calculated in the equivalent photon approximation using $\gamma$ fluxes derived from electric dipole and charge form factors, and incorporating hadronic survival probabilities. Multiple examples of $\gamma\gamma$ cross sections computed with this setup, named gamma-UPC, are presented for proton-proton, proton-nucleus, and nucleus-nucleus ultraperipheral collisions (UPCs) at the Large Hadron Collider and Future Circular Collider. Total photon-fusion cross sections for the exclusive production of spin-0,2 resonances (quarkonia, ditauonium, and Higgs boson; as well as axions and gravitons), and for pairs of particles ($J/\psi J/\psi$, WW, ZZ, Z$\gamma$, $t\bar{t}$, HH) are presented. Differential cross sections for exclusive dileptons and light-by-light scattering are compared to LHC data. This development paves the way for the upcoming automatic event generation of any UPC final state with electroweak corrections at next-to-leading-order accuracy and beyond.

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Hua-Sheng Shao, David d'Enterria. 2022-07-06. gamma-UPC: Automated generation of exclusive photon-photon processes in ultraperipheral proton and nuclear collisions with varying form factors. https://doi.org/10.1007/jhep09(2022)248

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