2004/11/12 by Haiyan Gao, Lingyan Zhu · 1 citation
Physics and Astronomy · #Center of mass (relativistic) #Classical mechanics #Degrees of freedom (physics and chemistry) #Deuterium #High-Energy Particle Collisions Research #Meson #Nuclear physics #Nucleon #Optics #Particle physics #Particle physics theoretical and experimental studies #Photon #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quark #Scaling #hep-ex #nucl-ex
paper · pdf · doi:10.1063/1.1871659
6 pages, 5 figures, Plenary talk presented at the HiX2004 Workshop, July 26-28, Marseille, France. References added
arxiv created 2004/11/12 · openalex publication_date 2005/01/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The γn → π−p and γp → π+n reactions are essential probes of the transition from meson‐nucleon degrees of freedom to quark‐gluon degrees of freedom in exclusive processes. The cross sections of these processes are also advantageous, for the investigation of oscillatory behavior around the quark counting prediction, since they decrease relatively slower with energy compared with other photon‐induced processes. In this talk, we discuss recent results on the γp → π+n and γn → π−p processes from Jefferson Lab experiment E94‐104. We also discuss a new experiment in which singles γp → π+n measurement from hydrogen, and coincidence γn → π−p measurements at the quasifree kinematics from deuterium for center‐of‐mass energies between 2.3 GeV to 3.4 GeV in fine steps at a center‐of‐mass angle of 90° are planned. The proposed measurement will allow a detailed investigation of the oscillatory scaling behavior in photopion production processes.