Abstract
We discuss the light baryon spectrum obtained from a recent quark–diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe–Salpeter equations. We examine the orbital angular momentum content in the baryons’ rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction \(P=(-1)^L\) which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe–Salpeter equations, their possible connection with ‘anomalous’ states, and we propose a method to eliminate them from the spectrum.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
E. Klempt, J.M. Richard, Baryon spectroscopy. Rev. Mod. Phys. 82, 1095 (2010)
L. Tiator, D. Drechsel, S.S. Kamalov, M. Vanderhaeghen, Electromagnetic excitation of nucleon resonances. Eur. Phys. J. Special Top. 198, 141 (2011)
I.G. Aznauryan et al., Studies of nucleon resonance structure in exclusive meson electroproduction. Int. J. Mod. Phys. E 22, 1330015 (2013)
V. Crede, W. Roberts, Progress towards understanding baryon resonances. Rep. Prog. Phys. 76, 076301 (2013)
M. Gockeler et al., Scattering phases for meson and baryon resonances on general moving-frame lattices. Phys. Rev. D 86, 094513 (2012)
D.J. Wilson et al., Coupled \(\pi \pi \), \(K K^-\) scattering in P-wave and the \(\rho \) resonance from lattice QCD. Phys. Rev. D 92(9), 094502 (2015)
C.B. Lang, L. Leskovec, M. Padmanath, S. Prelovsek, Pion-nucleon scattering in the Roper channel from lattice QCD. ar**v:1610.01422 [hep-lat]
J.J. Wu, H. Kamano, T.-S.H. Lee, D.B. Leinweber, A.W. Thomas, Nucleon resonance structure in the finite volume of lattice QCD. ar**v:1611.05970 [hep-lat]
A. Bashir et al., Collective perspective on advances in Dyson-Schwinger Equation QCD. Commun. Theor. Phys. 58, 79 (2012)
J. Segovia et al., Completing the picture of the Roper resonance. Phys. Rev. Lett. 115(17), 171801 (2015)
G. Eichmann et al., Baryons as relativistic three-quark bound states. Prog. Part. Nucl. Phys. 91, 1 (2016)
G. Eichmann, R. Alkofer, A. Krassnigg, D. Nicmorus, Nucleon mass from a covariant three-quark Faddeev equation. Phys. Rev. Lett. 104, 201601 (2010)
M. Anselmino et al., Diquarks. Rev. Mod. Phys. 65, 1199 (1993)
S.J. Brodsky, G.F. de Teramond, H.G. Dosch, J. Erlich, Light-Front Holographic QCD and Emerging Confinement. Phys. Rep. 584, 1 (2015)
C. Patrignani et al., Review of Particle Physics. Chin. Phys. C 40(10), 100001 (2016). (PDG Collaboration)
G. Eichmann, C.S. Fischer, H. Sanchis-Alepuz, On light baryons and their excitations. Phys. Rev. D 94, 094033 (2016)
G. Eichmann, D. Nicmorus, Nucleon to Delta electromagnetic transition in the Dyson-Schwinger approach. Phys. Rev. D 85, 093004 (2012)
M. Oettel, G. Hellstern, R. Alkofer, H. Reinhardt, Octet and decuplet baryons in a covariant and confining diquark-quark model. Phys. Rev. C 58, 2459 (1998)
W.B. Kaufmann, Numerical solutions of the bethe-salpeter equation. Phys. Rev. 187, 2051 (1969)
N. Seto, I. Fukui, Scalar scalar ladder model in the unequal mass case. 1: Numerical evidence for the complex eigenvalues. Prog. Theor. Phys. 89, 205 (1993)
S. Ahlig, R. Alkofer, (In) consistencies in the relativistic description of excited states in the Bethe-Salpeter equation. Ann. Phys. 275, 113 (1999)
E. Rojas, B. El-Bennich, J.P.B.C. de Melo, Exciting flavored bound states. Phys. Rev. D 90, 074025 (2014)
B. El-Bennich, G. Krein, E. Rojas, F.E. Serna, Excited hadrons and the analytical structure of bound-state interaction kernels. Few Body Syst. 57(10), 955 (2016)
T. Hilger, A. Krassnigg, Charming quasi-exotic open-flavor mesons. ar**v:1611.04334 [hep-ph]
G.C. Wick, Properties of Bethe-Salpeter Wave Functions. Phys. Rev. 96, 1124 (1954)
R.E. Cutkosky, Solutions of a Bethe-Salpeter equations. Phys. Rev. 96, 1135 (1954)
N. Nakanishi, A General survey of the theory of the Bethe-Salpeter equation. Prog. Theor. Phys. Suppl. 43, 1 (1969)
J. Bijtebier, Bethe-Salpeter equation: 3-D reductions, heavy mass limits and abnormal solutions. Nucl. Phys. A 623, 498 (1997)
R. Alkofer, L. von Smekal, The Infrared behavior of QCD Green’s functions: Confinement dynamical symmetry breaking, and hadrons as relativistic bound states. Phys. Rep. 353, 281 (2001)
M.S. Bhagwat et al., Schwinger functions and light-quark bound states. Few Body Syst. 40, 209 (2007)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Eichmann, G. More About the Light Baryon Spectrum. Few-Body Syst 58, 81 (2017). https://doi.org/10.1007/s00601-016-1200-3
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s00601-016-1200-3