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Title: Charge-conjugation symmetric complete impulse approximation for the pion electromagnetic form factor in the covariant spectator theory

The pion form factor is calculated in the framework of the charge-conjugation invariant covariant spectator theory. This formalism is established in Minkowski space, and the calculation is set up in momentum space. In a previous calculation we included only the leading pole coming from the spectator quark (referred to as the relativistic impulse approximation). In this study we also include the contributions from the poles of the quark which interacts with the photon and average over all poles in both the upper and lower half-planes in order to preserve charge conjugation invariance (referred to as the C-symmetric complete impulse approximation). We find that for small pion mass these contributions are significant at all values of the four-momentum transfer Q2 but, surprisingly, do not alter the shape obtained from the spectator poles alone.
Authors:
 [1] ;  [1] ;  [2] ;  [3]
  1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  2. Univ. de Lisboa, Lisboa (Portugal)
  3. Univ. de Evora, Evora (Portugal)
Publication Date:
OSTI Identifier:
1224196
Report Number(s):
JLAB-THY--15-2125; DOE/OR/23177--3517
Journal ID: ISSN 1550-7998; PRVDAQ; TRN: US1600894
Grant/Contract Number:
UID/FIS/00777/2013; CERN/FP/123580/2011; SFRH/BPD/100578/2014; AC05-06OR23177
Type:
Accepted Manuscript
Journal Name:
Physical Review. D, Particles, Fields, Gravitation and Cosmology
Additional Journal Information:
Journal Volume: 92; Journal Issue: 7; Journal ID: ISSN 1550-7998
Publisher:
American Physical Society (APS)
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS