Neutral Pion Electroproduction in the Δ Resonance Region

Thesis/Dissertation · Thu Nov 01 00:00:00 EDT 2007

DOI:https://doi.org/10.2172/989189· OSTI ID:989189

Villano, Anthony ^[1]

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1. Rensselaer Polytechnic Inst., Troy, NY (United States)

The electroproduction of baryon resonances at high Q² is examined. Analysis focuses on the Δ(1232) resonance via exclusive pseudoscalar meson production of π⁰ particles. Differential cross sections are extracted for exclusive π⁰ electroproduction. In the central invariant mass (W) region the cross sections are used to extract resonant multipole amplitudes. In particular, the ratio of the electric quadrupole to magnetic dipole amplitudes (E2/M1) will be discussed for the Δ(1232) resonance. The transition to pQCD is discussed in terms of E2/M1 and other multipoles. The helicity amplitude A_3/2 can be used as a baryon helicity conservation meter in this context and will be discussed. The fast shrinking of the resonant contribution in the Δ region is observed at this high momentum transfer. Apart from the observables related to pQCD scaling, the transition form factor G$$*\atop{M}$$ is extracted along with the scalar to magnetic dipole ratio C2/M1.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 989189
• Report Number(s): JLAB-PHY-09-1006; DOE/OR/23177-0756; TRN: US1007091
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
BARYONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ELECTROPRODUCTION
FORM FACTORS
HELICITY
MAGNETIC DIPOLES
MOMENTUM TRANSFER
MULTIPOLES
PIONS
PRODUCTION
PSEUDOSCALAR MESONS
QUADRUPOLES
RESONANCE
SCALARS