Two Nucleon-States in a Chiral Quark-Diquark Model

Abstract

We study the ground and first excited states of nucleons in a chiral quark-diquark model. We include two quark-diquark channels of the scalar-isoscalar and axial-vector-isovector types for the nucleon states. The diquark correlation violating the spin-flavor SU(4)${}_{SF}$ symmetry allows to treat the two quark-diquark channels independently. Hence the two states appear as the superpositions of the two quark-diquark channels; one is the nucleon and the other is a state which does not appear in the SU(4)${}_{SF}$ quark models. With a reasonable choice of model parameters, the mass of the excited state appears at around 1.5 GeV, which we identify with the Roper resonance N(1440).

11 pages, 5 figures. Errors are corrected. Conclusions are not affected

References in corpus (8)

• Diquarks and Exotic Spectroscopy
• Roper Resonance and S_{11}(1535) from Lattice QCD
• Spectral Analysis of Excited Nucleons in Lattice QCD with Maximum Entropy Method
• Spatially improved operators for excited hadrons on the lattice
• Extracting excited states from lattice QCD: the Roper resonance
• Structure of the nuclear force in a chiral quark-diquark model
• Role of quark-quark correlation in baryon structure and non-leptonic weak transitions of hyperons
• The mass of the nucleon in a chiral quark-diquark model

Cited by in corpus (4)

• Emergent Hadrons and Diquarks
• The volume dependence of the long-range two-body potentials in various color channels by lattice QCD
• Structure of the Nucleon and Roper Resonance with Diquark Correlations
• Quartet of spin-3/2 baryons in chiral multiplet $(1,1/2)\oplus (1/2,1)$ with mirror assignment