2018/06/13 by Hong-Yu Chen, Hongyu Chen, Hai-Qing Zhou · 7 citations
Mathematics · Physics and Astronomy · #Amplitude #Asymmetry #Geometry #High-Energy Particle Collisions Research #Mathematics #Momentum (technical analysis) #Momentum transfer #Nuclear physics #Order (exchange) #Particle physics #Particle physics theoretical and experimental studies #Perturbative QCD #Photon #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #Scattering #Twist #Virtual particle #hep-ex #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.98.054003
published in Physical review. D/Physical review. D. 98(5) (American Physical Society)
arxiv created 2018/06/13 · openalex created_date 2018/06/21 · openalex publication_date 2018/09/05 · arxiv updated 2018/09/12 · openalex updated_date 2026/08/05
The two-photon-exchange (TPE) effects in the process e+e^\ensuremath-\ensuremath→\ensuremathπ+\ensuremathπ^\ensuremath- at large momentum transfer are discussed within the perturbative QCD (pQCD). The contributions from the twist-2 and twist-3 distribution amplitudes (DAs) of the pion are considered in the estimation. Different from the results under the one-photon-exchange (OPE) approximation, the TPE effects result in an asymmetry of the differential cross section on the scattering angle. The precise measurement of this asymmetry by the further experiment is a precise test of pQCD at large momentum transfer. The timelike electromagnetic form factor of the pion at the leading order (LO) of pQCD is rediscussed, and the comparison of our results with those in the references is presented. Our results show that the contributions from the twist-2 and twist-3 DAs in the LO of pQCD are much smaller than the experimental data at Q2=14.2, 17.4 GeV2, which is very different from the conclusion given in the references.