2016/06/30 by A1 Collaboration, I. Friščić, P. Achenbach +23 · 6 citations
Engineering · Physics and Astronomy · #Asymmetry #Atomic physics #Cross section (physics) #Engineering #High-Energy Particle Collisions Research #Invariant (physics) #Invariant mass #Momentum transfer #Nuclear physics #Optics #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Scattering #Spectrometer #Transverse plane #nucl-ex
paper · pdf · doi:10.1016/j.physletb.2017.01.033
published in Physics Letters B 766, 301-305 (Elsevier BV) · version accepted for publishing
openalex created_date 2016/06/24 · openalex publication_date 2017/01/20 · arxiv created 2017/01/23 · arxiv updated 2017/02/01 · openalex updated_date 2026/08/05
The cross section of the p(e,e′π+)n reaction has been measured for five kinematic settings at an invariant mass of W=1094MeV and for a four-momentum transfer of Q2=0.078(GeV/c)2. The measurement has been performed at MAMI using a new short-orbit spectrometer (SOS) of the A1 collaboration, intended for detection of low-energy pions. The transverse and longitudinal cross section terms were separated using the Rosenbluth method and the transverse-longitudinal interference term has been determined from the left-right asymmetry. The experimental cross section terms are compared with the calculations of three models: DMT2001, MAID2007 and χMAID. The results show that we do not yet understand the dynamics of the fundamental pion.