Measurement of the transverse-longitudinal cross sections in the p(e→,e'p)π0 reaction in the Δ region
Creators
- Kunz, C.
- Kaloskamis, N.I.
- Distler, M.O.
- Zhou, Z.-L.
- Alarcon, R.
- Barkhuff, D.
- Bernstein, A.M.
- Bertozzi, W.
- Calarco, J.
- Casagrande, F.
- Chen, J.
- Comfort, J.
- Dodson, G.
- Dooley, A.
- Dow, K.
- Farkhondeh, M.
- Georgakopoulos, S.
- Gilad, S.
- Hicks, R.
- Hotta, A.
- Jiang, X.
- Karabarbounis, A.
- Kowalski, S.
- Margaziotis, D.J.
- Mertz, C.
- Miskimen, R.
- Nakagawa, I.
- Papanicolas, C.N.
- Pavan, M.M.
- Peterson, G.
- Ramirez, A.
- Rowntree, D.
- Sarty, A.J.
- Shaw, J.
- Six, E.
- Sparveris, N.
- Soong, S.-B.
- Stiliaris, S.
- Tamae, T.
- Tieger, D.
- Tschalaer, C.
- Tsentalovich, G.
- Turchinetz, W.
- Vellidis, C.E.
- Warren, G.A.
- Williamson, S.
- Young, A.
- Zhao, J.
- Zwart, T.
Description
Accurate measurements of the p(e→,e'p)π0 reaction were performed at Q2=0.127 (GeV/c)2 in the Δ resonance energy region. The experiments at the MIT-Bates Linear Accelerator used an 820 MeV polarized electron beam with the out-of-plane magnetic spectrometer system (OOPS). In this Letter we report the first simultaneous determination of both the TL and TL' ('fifth' or polarized) cross sections at low Q2 where the pion cloud contribution is predicted to dominate the quadrupole amplitudes (E2 and C2). These are the real and imaginary parts of the transverse-longitudinal interference amplitudes and provide a sensitive determination of the Coulomb quadrupole amplitude and a test of reaction calculations. Comparisons with model calculations are presented. The empirical MAID calculation gives the best overall agreement with this accurate data. The parameters of this model for the values of the resonant multipoles are vertical bar M1+(I=3/2) vertical bar =(40.9±0.3)x10-3/mπ, CMR=C2/M1=-6.5±0.3%, EMR=E2/M1=-2.2±0.9%, where the errors are due to the experimental uncertainties
Additional details
Identifiers
- DOI
- 10.1016/S0370-2693;
- PII
- S0370269303006750;
Publishing Information
- Journal Title
- Physics Letters. Section B
- Journal Volume
- 564
- Journal Issue
- 1-2
- Journal Page Range
- p. 21-26
- ISSN
- 0370-2693
- CODEN
- PYLBAJ
INIS
- Country of Publication
- Netherlands
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 37103848
- Subject category
- S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
- Descriptors DEI
- AMPLITUDES; CROSS SECTIONS; ELECTRON BEAMS; ERRORS; INTERFERENCE; LINEAR ACCELERATORS; MAGNETIC SPECTROMETERS; MEV RANGE 100-1000; PARTICLE PRODUCTION; PIONS NEUTRAL; QUADRUPOLES; RESONANCE
- Descriptors DEC
- ACCELERATORS; BEAMS; BOSONS; ELEMENTARY PARTICLES; ENERGY RANGE; HADRONS; LEPTON BEAMS; MEASURING INSTRUMENTS; MESONS; MEV RANGE; MULTIPOLES; PARTICLE BEAMS; PIONS; PSEUDOSCALAR MESONS; SPECTROMETERS
Optional Information
- Copyright
- Copyright (c) 2003 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.