Exotic baryons in two-dimensional QCD and the generalized sine-Gordon solitons

Abstract

The solitons and kinks of the SU (3) generalized sine-Gordon model (GSG) are shown to describe the baryonic spectrum of two-dimensional quantum chromodynamics (QCD 2 ). The GSG model arises in the low-energy effective action of bosonized QCD 2 with unequal quark mass parameters. The GSG potential for N f = 3 flavors resembles the potential of the effective chiral lagrangian proposed by Witten to describe low-energy behavior of four dimensional QCD. Among the attractive features of the GSG model are the variety of soliton and kink type solutions for QCD 2 unequal quark mass parameters [JHEP(0701)(2007)(027)]. Exotic baryons in QCD 2 [J. Ellis et al JHEP0508(2005)081] are discussed in the context of the GSG model. Various semi-classical computations are performed improving the results of this reference and clarifying the role of unequal quark masses. The remarkable double sine Gordon model also arises as a reduced GSG model bearing a kink(K) type solution describing a multi-baryon; so, the description of some resonances in QCD 2 may take advantage of the properties of the KK system.

Solitary oscillations and multiple antikink-kink pairs in the double sine-Gordon model

“…Then, the DSG spectrum and kink-antikink system can be useful for the description of multiflavor spectrum and some resonances in QCD 2 [54]. The DSG model also appears in the effective action describing exotic baryons in QCD 2 [56,57].…”

A scattering theory of ultrarelativistic solitons

“…4) 12 We thank Erick Weinberg for alerting us to this possibility. 13 If the potential is not periodic, we have to subtract a "reference" ∆φ, i.e.…”

Renormalization of QCD2

“…The difference between the bosonized models appears when N f > 2 and N c > 2. We note that the low energy multi-flavor QCD 2 with unequal masses can also be bosonized giving a so called generalized SG model [10,26] but its investigation is out of the scope of this paper.…”

“…For example the 2-dimensional quantum electrodynamics (QED 2 ) proved to be a good toy model for treating the soft mechanism of the quark confinement [2][3][4][5]. The confining properties, the large-N c expansion [6] or the baryon structure [7][8][9][10] of QCD can also be studied in the 2-dimensional version of the model and then one can get even analytical results for the non-perturbative domain. One usually takes the bosonized version of these models which are local selfinteracting scalar theories, and can be investigated in an easier way [11,12].…”