What does CHY mean in UNCLASSIFIED

CHY is a theoretical framework that combines elements of string theory and gauge theory to describe the scattering of particles in high-energy physics. It provides a powerful tool to calculate scattering amplitudes, which are key objects for understanding the interactions between fundamental particles.

CHY uses a technique called "on-shell recursion" to construct scattering amplitudes. It starts with the simplest scattering process, involving only two particles, and iteratively adds more particles to the calculation. This approach allows for the efficient computation of amplitudes for complex scattering processes involving many particles.

CHY offers several advantages over traditional methods for calculating scattering amplitudes. It is:

• Efficient: CHY can compute amplitudes for complex processes much faster than other methods.
• Generalizable: CHY can be applied to a wide range of scattering processes, including those involving gluons, quarks, and other particles.
• Analytically solvable: CHY provides explicit formulas for amplitudes, which can be used to study their properties and identify symmetries.

CHY is a perturbative approach, which means it can only describe scattering processes at high energies. It also becomes less efficient for processes involving a large number of particles or particles with large spins.

CHY is widely used in high-energy physics research, particularly in the study of:

• Particle scattering processes at the Large Hadron Collider (LHC)
• The properties of the Higgs boson
• Quantum gravity and string theory