HAL : in2p3-00353229, version 1
 arXiv : 0901.2055
 Reviews of Modern Physics 82 (2010) 1095-1153
 Baryon spectroscopy
 (2010)
 About 120 baryons and baryon resonances are known, from the abundant nucleon with $u$ and $d$ light-quark constituents up to the recently discovered $\Omega_b^-=bss$, and the $\Xi_b^-=bsd$ which contains one quark of each generation. In spite of this impressively large number of states, the underlying mechanisms leading to the excitation spectrum are not yet understood. Heavy-quark baryons suffer from a lack of known spin-parities. In the light-quark sector, quark-model calculations have met with considerable success in explaining the low-mass excitations spectrum but some important aspects like the mass degeneracy of positive-parity and negative-parity baryon excitations are not yet satisfactorily understood. At high masses, above 1.8 GeV, quark models predict a very high density of resonances per mass interval which is not observed. In this review, issues are identified discriminating between different views of the resonance spectrum; prospects are discussed how open questions in baryon spectroscopy may find answers from photo- and electro-production experiments which are presently carried out in various laboratories.
 équipe(s) de recherche : Theorie
 Thème(s) : Physique/Physique des Hautes Energies - Phénoménologie
 Lien vers le texte intégral : http://fr.arXiv.org/abs/0901.2055
 in2p3-00353229, version 1 http://hal.in2p3.fr/in2p3-00353229 oai:hal.in2p3.fr:in2p3-00353229 Contributeur : Emmanuelle Vernay <> Soumis le : Jeudi 15 Janvier 2009, 08:44:23 Dernière modification le : Mardi 13 Avril 2010, 13:10:49