Measurement of the polarized structure function {sigma}{sub LT{sup '}} for pion electroproduction in the Roper-resonance region

Journal Article · Tue Nov 01 04:00:00 EST 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.72.058202· OSTI ID:20699156

Joo, K; Ungaro, M ^[1]; Smith, L C; Minehart, R; Crabb, D; Fatemi, R; Pierce, J; Pocanic, D; Wang, K ^[2]; Aznauryan, I G; Asryan, G; Egiyan, K S ^[3]; Burkert, V D; Brooks, W K; Cords, D; Degtyarenko, P V; Deur, A; Guo, L; Gyurjyan, V; Ito, M M ^[4]

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1. University of Connecticut, Storrs, Connecticut 06269 (United States)
2. University of Virginia, Charlottesville, Virginia 22901 (United States)
3. Yerevan Physics Institute, 375036 Yerevan (Armenia)
4. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); and others

The polarized longitudinal-transverse structure function {sigma}{sub LT{sup '}} measures the interference between real and imaginary amplitudes in pion electroproduction and can be used to probe the coupling between resonant and nonresonant processes. We report new measurements of {sigma}{sub LT{sup '}} in the N(1440)(1/2){sup +} (Roper) resonance region at Q{sup 2}=0.40 and 0.65GeV{sup 2} for both the {pi}{sup 0}p and {pi}{sup +}n channels. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) using longitudinally polarized electrons at a beam energy of 1.515 GeV. Complete angular distributions were obtained and are compared to recent phenomenological models. The {sigma}{sub LT{sup '}}({pi}{sup +}n) channel shows a large sensitivity to the Roper-resonance multipoles M{sub 1-} and S{sub 1-} and provides new constraints on models of resonance formation.

• OSTI ID: 20699156
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 5 Vol. 72; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMPLITUDES
ANGULAR DISTRIBUTION
CEBAF ACCELERATOR
COUPLING
ELECTRON BEAMS
ELECTRON REACTIONS
ELECTROPRODUCTION
FOUR MOMENTUM TRANSFER
GEV RANGE
INTERFERENCE
MULTIPOLES
N-1440 BARYONS
PARITY
PIONS NEUTRAL
PIONS PLUS
POLARIZATION
POLARIZED BEAMS
SENSITIVITY
SPIN
STRUCTURE FUNCTIONS