Meson production in two-photon interaction in pp and pA ultraperipheral collisions at the LHC and FCC

Meson cross-sections are evaluated in two-photon interaction in hadron–hadron ultraperipheral collisions at the CERN Large Hadron Collider (LHC) and Future Circular Collider (FCC). Two models of the equivalent photon flux are employed in the calculations. Cross-sections of meson production in proton–proton and proton-lead ultraperipheral collisions are presented in this paper. These meson cross-sections in two-photon interaction can be applied to predict cross-sections in the experiments at the LHC and FCC.

Equivalent photons at the LHC: pp(γγ) → ppl+l-, Pb Pb (γγ) → Pb Pb l+l-

The Large Hadron Collider is considered as a photon-photon collider with the photons produced in ultraperipheral collisions of protons or heavy ions. The equivalent photon approximation is applied to derive analytical formulae for the fiducial cross sections of reactions pp(γγ) → pp μ+μ- and Pb Pb (γγ) → Pb Pb μ+μ-. The results are compared to the measurements reported by the ATLAS collaboration.

EXCLUSIVE PRODUCTION OF ρ0ρ0 PAIRS IN ULTRARELATIVISTIC HEAVY ION COLLISIONS

We disuss exclusive electromagnetic production of two neutral ρ0 mesons and show the predictions for the AA → AAρ0ρ0 reactions for gold-gold collisions at the energy of [Formula: see text] and for lead-lead collisions at the energy of [Formula: see text]. The elementary cross section is calculated with the help of the vector-dominance-model (VDM)-Regge approach which usually very well describes the experimental data at large γγ energy. The low-energy γγ → ρ0ρ0 cross section is parametrized. The cross section for nuclear process is calculated by means of the equivalent photon approximation (EPA). We compare the results with realistic charge density with the results for monopole form factor.

Photon equivalent charge in a two-electron temperature Fermi plasma

The equivalent photon charge in a two-electron temperature Fermi plasma is determined through the plasma physics method. The Fermi plasma has distinct populations of hot and cold electrons that are described by a quantum hydrodynamic model which accounts for the quantum statistical pressure of the hot electrons and the quantum force acting on the two electron fluids. Relations for the coupling between the electron plasma density fluctuations and the radiation fields are derived, and the effective photon charge is then calculated.