CLAS Physics Database

JLab | Search | Overview | Register | Login

E99-105

Spokespersons
M. Garçon, M. Guidal, E. S. Smith
Year
2002
Abstract
The exclusive omega electroproduction off the proton was studied in a large kinematical domain above the nucleon resonance region and for the highest possible photon virtuality (Q2) with the 5.75 GeV beam at CEBAF and the CLAS spectrometer. Cross sections were measured up to large set abstract = of the four-momentum transfer (-t < 2.7 GeV2) to the proton. The contributions of the interference terms sigma_TT and sigma_TL to the cross sections, as well as an analysis of the omega spin density matrix, indicate that helicity is not conserved in this process. The t-channel pi0 exchange, or more generally the exchange of the associated Regge trajectory, seems to dominate the reaction gamma* p -> omega p, evenfor Q2 as large as 5 GeV2. Contributions of handbag diagrams, related to Generalized Parton Distributions in the nucleon, are therefore difficult to extract for this process. Remarkably, the high-t behaviour of the cross sections is nearly Q2-independent, which may be interpreted as a coupling of the photon to a point-like object in this kinematical limit.
Publication
  1. L. Morand, D. Dore, M. Garçon, M. Guidal, J.-M. Laget, S. Morrow, F. Sabatie, E. Smith, and CLAS collaboration Deeply virtual and exclusive electroproduction of omega mesons // hep-ex/0504057
Quantities
σ   σTT   σTL   dσ/dt   r   Re r1004   r001   r111   Re r101   r1-11   Im r102   Im r1-12   r005   r115   Re r105   r1-15   Im r106   dσ/dφ   Im r1-16   r0004   r1-104

Measurements

ID Quantity Beam Target Final state Q2min,
GeV2 		Q2max,
GeV2 		Wmin,
GeV 		Wmax,
GeV
E15M1 σ e p ω p 1.725 4.85 1.85 2.77
E15M2 σTT e p ω p 1.725 4.85 1.85 2.77
E15M3 σTL e p ω p 1.725 4.85 1.85 2.77
E15M4 dσ/dt e p ω p 1.725 1.725 2.77 2.77
E15M5 dσ/dt e p ω p 1.752 1.752 2.48 2.48
E15M6 dσ/dt e p ω p 2.042 2.042 2.63 2.63
E15M7 dσ/dt e p ω p 2.32 2.32 2.7 2.7
E15M8 dσ/dt e p ω p 1.785 1.785 2.21 2.21
E15M9 dσ/dt e p ω p 2.05 2.05 2.33 2.33
E15M10 dσ/dt e p ω p 2.35 2.35 2.47 2.47
E15M11 dσ/dt e p ω p 2.639 2.639 2.58 2.58
E15M12 dσ/dt e p ω p 2.914 2.914 2.62 2.62
E15M13 dσ/dt e p ω p 2.05 2.05 2.09 2.09
E15M14 dσ/dt e p ω p 2.35 2.35 2.21 2.21
E15M15 dσ/dt e p ω p 2.65 2.65 2.32 2.32
E15M16 dσ/dt e p ω p 2.95 2.95 2.43 2.43
E15M17 dσ/dt e p ω p 3.295 3.295 2.51 2.51
E15M18 dσ/dt e p ω p 2.055 2.055 1.9 1.9
E15M19 dσ/dt e p ω p 2.35 2.35 2.0 2.0
E15M20 dσ/dt e p ω p 2.65 2.65 2.1 2.1
E15M21 dσ/dt e p ω p 2.95 2.95 2.19 2.19
E15M22 dσ/dt e p ω p 3.35 3.35 2.31 2.31
E15M23 dσ/dt e p ω p 3.807 3.807 2.41 2.41
E15M24 dσ/dt e p ω p 2.371 2.371 1.85 1.85
E15M25 dσ/dt e p ω p 2.651 2.651 1.91 1.91
E15M26 dσ/dt e p ω p 2.95 2.95 1.99 1.99
E15M27 dσ/dt e p ω p 3.35 3.35 2.09 2.09
E15M28 dσ/dt e p ω p 3.85 3.85 2.21 2.21
E15M29 dσ/dt e p ω p 4.307 4.307 2.3 2.3
E15M30 dσ/dt e p ω p 2.968 2.968 1.85 1.85
E15M31 dσ/dt e p ω p 3.357 3.357 1.91 1.91
E15M32 dσ/dt e p ω p 3.85 3.85 2.01 2.01
E15M33 dσ/dt e p ω p 4.35 4.35 2.11 2.11
E15M34 dσ/dt e p ω p 4.765 4.765 2.16 2.16
E15M35 dσ/dt e p ω p 3.882 3.882 1.86 1.86
E15M36 dσ/dt e p ω p 4.352 4.352 1.91 1.91
E15M37 dσ/dt e p ω p 4.85 4.85 2.0 2.0
E15M38 dσ/dφ e p ω p 1.725 1.725 2.77 2.77
E15M39 dσ/dφ e p ω p 1.752 1.752 2.48 2.48
E15M40 dσ/dφ e p ω p 2.042 2.042 2.63 2.63
E15M41 dσ/dφ e p ω p 2.32 2.32 2.7 2.7
E15M42 dσ/dφ e p ω p 1.785 1.785 2.21 2.21
E15M43 dσ/dφ e p ω p 2.05 2.05 2.33 2.33
E15M44 dσ/dφ e p ω p 2.35 2.35 2.47 2.47
E15M45 dσ/dφ e p ω p 2.639 2.639 2.58 2.58
E15M46 dσ/dφ e p ω p 2.914 2.914 2.62 2.62
E15M47 dσ/dφ e p ω p 2.05 2.05 2.09 2.09
E15M48 dσ/dφ e p ω p 2.35 2.35 2.21 2.21
E15M49 dσ/dφ e p ω p 2.65 2.65 2.32 2.32
E15M50 dσ/dφ e p ω p 2.95 2.95 2.43 2.43
E15M51 dσ/dφ e p ω p 3.295 3.295 2.51 2.51
E15M52 dσ/dφ e p ω p 2.055 2.055 1.9 1.9
E15M53 dσ/dφ e p ω p 2.35 2.35 2.0 2.0
E15M54 dσ/dφ e p ω p 2.65 2.65 2.1 2.1
E15M55 dσ/dφ e p ω p 2.95 2.95 2.19 2.19
E15M56 dσ/dφ e p ω p 3.35 3.35 2.31 2.31
E15M57 dσ/dφ e p ω p 3.807 3.807 2.41 2.41
E15M58 dσ/dφ e p ω p 2.371 2.371 1.85 1.85
E15M59 dσ/dφ e p ω p 2.651 2.651 1.91 1.91
E15M60 dσ/dφ e p ω p 2.95 2.95 1.99 1.99
E15M61 dσ/dφ e p ω p 3.35 3.35 2.09 2.09
E15M62 dσ/dφ e p ω p 3.85 3.85 2.21 2.21
E15M63 dσ/dφ e p ω p 4.307 4.307 2.3 2.3
E15M64 dσ/dφ e p ω p 2.968 2.968 1.85 1.85
E15M65 dσ/dφ e p ω p 3.357 3.357 1.91 1.91
E15M66 dσ/dφ e p ω p 3.85 3.85 2.01 2.01
E15M67 dσ/dφ e p ω p 4.35 4.35 2.11 2.11
E15M68 dσ/dφ e p ω p 4.765 4.765 2.16 2.16
E15M69 dσ/dφ e p ω p 3.882 3.882 1.86 1.86
E15M70 dσ/dφ e p ω p 4.352 4.352 1.91 1.91
E15M71 dσ/dφ e p ω p 4.85 4.85 2.0 2.0
E15M72 r0004 e p ω p 1.94 3.9 1.87 2.52
E15M73 r1-104 e p ω p 1.94 3.9 1.87 2.52
E15M74 r e p ω p 1.89 1.89 2.469 2.469
E15M75 r e p ω p 2.532 2.532 2.3 2.3
E15M76 r e p ω p 2.028 2.028 2.171 2.171
E15M77 r e p ω p 3.18 3.18 2.114 2.114
E15M78 r e p ω p 2.534 2.534 1.957 1.957
E15M79 r e p ω p 2.11 2.11 1.89 1.89
E15M80 r e p ω p 3.818 3.818 1.914 1.914
E15M81 r e p ω p 3.007 3.007 1.855 1.855
E15M82 r0004 e p ω p 1.89 3.818 1.855 2.469
E15M83 Re r1004 e p ω p 1.89 3.818 1.855 2.469
E15M84 r1-104 e p ω p 1.89 3.818 1.855 2.469
E15M85 r001 e p ω p 1.89 3.818 1.855 2.469
E15M86 r111 e p ω p 1.89 3.818 1.855 2.469
E15M87 Re r101 e p ω p 1.89 3.818 1.855 2.469
E15M88 r1-11 e p ω p 1.89 3.818 1.855 2.469
E15M89 Im r102 e p ω p 1.89 3.818 1.855 2.469
E15M90 Im r1-12 e p ω p 1.89 3.818 1.855 2.469
E15M91 r005 e p ω p 1.89 3.818 1.855 2.469
E15M92 r115 e p ω p 1.89 3.818 1.855 2.469
E15M93 Re r105 e p ω p 1.89 3.818 1.855 2.469
E15M94 r1-15 e p ω p 1.89 3.818 1.855 2.469
E15M95 Im r106 e p ω p 1.89 3.818 1.855 2.469
E15M96 Im r1-16 e p ω p 1.89 3.818 1.855 2.469
Created in SINP MSU, CLAS Collaboration