Mesonic Content of the Nucleon and the Roper Resonance

Abstract

We investigate colorless (mesonic) 3q-q qbar components in the nucleon and the Roper resonance N*(1440). Starting from constituent quarks and gluons we estimate the excitation of quark-antiquark pairs in a gluon exchange model with the strong coupling constant extracted from a comparison with a non-perturbative resonating group calculation of the pi, eta, rho and omega content of the nucleon. Applying the same model to the Roper resonance, we find as the most striking result a very strong scalar-isoscalar sigma content of the N*(1440) with a strength of the 3q-q qbar configurations comparable to the 3q component itself.

9 pages, 3 figures, 1 table; modified text, new figures

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Cited by in corpus (12)

• Electroexcitation of nucleon resonances
• The $N^{\ast }(1710)$ as a resonance in the $\pi \pi N$ system
• Electroexcitation of the Roper resonance for 1.7 < Q2 < 4.5 GeV2 in ep -> enpi+
• Valence quark contributions for the gamma N -> P11(1440) form factors
• Electromagnetic Transition Form Factors of Baryon Resonances
• Experimental and theoretical evidences for an intermediate $\sigma$-dressed dibaryon in the NN interaction
• Roper resonances in chiral quark models
• Possible $D^{(\ast )}{\bar{D}}^{(\ast )}$ and $B^{(\ast )}{\bar{B}}^{(\ast )}$ molecular states in the extended constituent quark models
• Baryon Resonances
• Dynamically generated resonances
• Opposite parity fermion mixing and baryons $1/2^{\pm }$
• Mechanism of Pion Production in $alpha$p Scattering at 1 GeV/nucleon