In quantum field theory, and especially asymptotically free quantum field theories, an observable is infrared safe if it does not depend on the low energy/long distance physics of the theory. Such observables can therefore be calculated reliably using perturbative methods and then compared to experiment.[1][2] An example of an observable which is infrared safe is the total scattering cross-section for the collision of an electron and a positron to produce hadrons.[3]

See also edit

References edit

  1. ^ Botje, Michiel. "Quantum Chromo Dynamics, Section 7. Soft and Collinear Singularities" (PDF). Retrieved May 30, 2014.
  2. ^ Soper, Davison. "Jet Definitions" (PDF). Retrieved May 30, 2014.
  3. ^ Chris, Sachrajda. "Standard Model of Particle Physics" (PDF). Retrieved May 30, 2014.