CLAS Physics Database

E-89-039

Spokespersons
S. Dytman, K. Giovanetti
Year
2007
Abstract
New cross sections for the reaction ep to e eta p are reported for total center of mass energy W=1.5-2.3 GeV and invariant squared momentum transfer Q2=0.13-3.3 GeV2. This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta-N coupling strengths of baryon resonances. A sharp structure is seen at W ~ 1.7 GeV. The shape of the differential cross section is indicative of the presence of a P-wave resonance which persists to high Q2. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance. This is the first consistent interpretation over a large range of Q2.
Publication
  1. H. Denizli, J. Mueller, S. Dytman, M.L. Leber, R.D. Levine, J. Miles, K.Y. Kim, and CLAS Collaboration Q2 dependence of the S11(1535) Photocoupling and Evidence for a P-wave resonance in η electroproduction //
Quantities
σ dσ/dΩ dσ/dΩT+ε·dσ/dΩL AsymLT AsymTT

Measurements

ID Quantity Beam Target Final state Q2min,
GeV2
Q2max,
GeV2
Wmin,
GeV
Wmax,
GeV
E102M301 AsymTT e p η p 1.3 2.1 1.53 1.55
E102M302 AsymTT e p η p 1.3 2.1 1.55 1.57
E102M303 AsymTT e p η p 1.3 2.1 1.57 1.59
E102M304 AsymTT e p η p 1.3 2.1 1.59 1.61
E102M305 AsymTT e p η p 1.3 2.1 1.61 1.63
E102M306 AsymTT e p η p 1.3 2.1 1.63 1.65
E102M307 AsymTT e p η p 1.3 2.1 1.65 1.67
E102M308 AsymTT e p η p 1.3 2.1 1.67 1.69
E102M309 AsymTT e p η p 1.3 2.1 1.69 1.71
E102M310 AsymTT e p η p 1.3 2.1 1.71 1.73
E102M311 AsymTT e p η p 1.3 2.1 1.73 1.75
E102M312 AsymTT e p η p 1.3 2.1 1.75 1.77
E102M313 AsymTT e p η p 1.3 2.1 1.77 1.79
E102M314 AsymTT e p η p 1.3 2.1 1.79 1.81
E102M315 AsymTT e p η p 1.3 2.1 1.81 1.83
E102M316 AsymTT e p η p 1.3 2.1 1.83 1.85
E102M317 AsymTT e p η p 1.3 2.1 1.85 1.87
E102M318 AsymTT e p η p 1.3 2.1 1.87 1.89
E102M319 AsymTT e p η p 1.3 2.1 1.89 1.91
E102M320 AsymTT e p η p 1.3 2.1 1.91 1.93
E102M321 AsymTT e p η p 1.3 2.1 1.93 1.95
E102M322 AsymTT e p η p 1.3 2.1 1.95 1.97
E102M323 AsymTT e p η p 1.3 2.1 1.97 1.99
E102M324 AsymTT e p η p 1.3 2.1 1.99 2.01
E102M325 AsymTT e p η p 2.1 2.9 1.49 1.51
E102M326 AsymTT e p η p 2.1 2.9 1.51 1.53
E102M327 AsymTT e p η p 2.1 2.9 1.53 1.55
E102M328 AsymTT e p η p 2.1 2.9 1.55 1.57
E102M329 AsymTT e p η p 2.1 2.9 1.57 1.59
E102M330 AsymTT e p η p 2.1 2.9 1.59 1.61
E102M331 AsymTT e p η p 2.1 2.9 1.61 1.63
E102M332 AsymTT e p η p 2.1 2.9 1.63 1.65
E102M333 AsymTT e p η p 2.1 2.9 1.65 1.67
E102M334 AsymTT e p η p 2.1 2.9 1.65 1.69
E102M335 AsymTT e p η p 2.1 2.9 1.67 1.71
E102M336 AsymTT e p η p 2.1 2.9 1.69 1.73
E102M337 AsymTT e p η p 2.1 2.9 1.71 1.75
E102M338 AsymTT e p η p 2.1 2.9 1.73 1.77
E102M339 AsymTT e p η p 2.1 2.9 1.75 1.79
E102M340 AsymTT e p η p 2.1 2.9 1.77 1.81
E102M341 AsymTT e p η p 2.1 2.9 1.79 1.83
E102M342 AsymTT e p η p 2.1 2.9 1.81 1.85
E102M343 AsymTT e p η p 2.1 2.9 1.83 1.87
E102M344 AsymTT e p η p 2.1 2.9 1.85 1.89
E102M345 AsymTT e p η p 2.1 2.9 1.87 1.91
E102M346 AsymTT e p η p 2.1 2.9 1.89 1.93