F2gamma

F2gamma is a term used in particle physics to describe the interaction of a photon with a photon to produce a fermion-antifermion pair, often denoted as $\gamma \gamma \to f \bar{f}$. This process is a fundamental quantum electrodynamics (QED) process and can be observed in high-energy collisions. The specific fermions produced can vary, but common examples include electron-positron pairs ($e^+ e^-$) or muon-antimuon pairs ($\mu^+ \mu^-$).

The process of F2gamma is mediated by virtual particles in the intermediate state. Typically, this involves two virtual photons, which then annihilate and produce the fermion-antifermion pair. The probability of this interaction is governed by QED and depends on the energy of the colliding photons. Experiments at facilities like the Large Electron-Positron Collider (LEP) and the SuperKEKB collider have provided data that allows for precise measurements of these cross-sections.

Studying F2gamma interactions is important for several reasons. It provides a direct test of QED at high energies and allows physicists to probe the structure of photons. Furthermore, it can be a source of background in experiments searching for new physics phenomena. Understanding the precise rates and characteristics of F2gamma events is crucial for interpreting experimental results accurately. The theoretical framework for F2gamma is well-established within the Standard Model of particle physics.