Next-to-Next-to-Leading-Order QCD Prediction for the Photon-Pion Form Factor
J. Gao, Tobias Huber, Yao Ji, Yu-Ming Wang
Abstract
We accomplish the complete two-loop computation of the leading-twist contribution to the photon-pion transition form factor γγ^{*}→π^{0} by applying the hard-collinear factorization theorem together with modern multiloop techniques. The resulting predictions for the form factor indicate that the two-loop perturbative correction is numerically important. We also demonstrate that our results will play a key role in disentangling various models of the twist-two pion distribution amplitude thanks to the envisaged precision at Belle II.
Topics & Concepts
PionFactorizationPhysicsForm factor (electronics)Particle physicsTwistQuantum chromodynamicsLoop (graph theory)PhotonOrder (exchange)ComputationPerturbative QCDAmplitudeDistribution (mathematics)Quantum electrodynamicsQuantum mechanicsComputer scienceAlgorithmMathematicsMathematical analysisGeometryFinanceEconomicsCombinatoricsParticle physics theoretical and experimental studiesQuantum Chromodynamics and Particle InteractionsHigh-Energy Particle Collisions Research