Determination of quadrupole strengths in the gamma*p-->Delta(1232) transition at Q2= 0.20 (GeV/c)2 (CROSBI ID 134855)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Sparveris, N.F. ; Achenbach, P. ; Ayerbe Gayoso, C. ; Baumann, D. ; Bernauer, J. ; Bernstein, A.M. ; Bohm, R. ; Bosnar, Damir ; Botto, T. ; Christopoulou, A. ; Dale, D. ; Ding, M. ; Distler, M.O. ; Doria, L. ; Friedrich, J. ; Karabarbounis, A. ; Makek, Mihael ; Merkel, H. ; Muller, U. ; Nakagawa, I. ; Neuhausen, R. ; Nungesser, L. ; Papanicolas, C.N. ; Piegsa, A. ; Pochodzalla, J. ; Potokar, M. ; Seimetz, M. ; Sirca, S. ; Stave, S. ; Stiliaris, S. ; Walcher, Th. ; Weis, M.
engleski
Determination of quadrupole strengths in the gamma*p-->Delta(1232) transition at Q2= 0.20 (GeV/c)2
We report new precise Click to view the MathML source measurements at the peak of the Δ +(1232) resonance at Click to view the MathML source performed at the Mainz Microtron (MAMI). The new data are sensitive to both the electric (E2) and the Coulomb (C2) quadrupole amplitudes of the γ *N→ Δ transition. They yield precise quadrupole to dipole amplitude ratios: CMR=(− 5.09± 0.28stat+sys± 0.30model)% and EMR=(− 1.96± 0.68stat+sys± 0.41model)% for Click to view the MathML source. The new results are in disagreement with Constituent Quark Model predictions and in qualitative agreement with models that account for mesonic contributions, including recent Lattice calculations. They thus give further credence to the conjecture of deformation in hadronic systems favoring the attribution of the origin of deformation to the dominance of mesonic effects.
EMR; CMR; Electro-pion production; Nucleon deformation
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
nije evidentirano
