Towers of positive parity excited baryons and their mixing in the large Nc limit

We consider configuration mixing for the nonstrange positive parity excited baryons in the [56′,0+], [56,2+], [70,0+], and [70,2+] quark model SU(6)×O(3) multiplets contained in the N=2 band. Starting from the effective mass operator for these states, we show by an explicit calculation that in the l...

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Autores principales: Willemyns, C., Schat, C.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_24700010_v95_n9_p_Willemyns
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spelling todo:paper_24700010_v95_n9_p_Willemyns2023-10-03T16:42:05Z Towers of positive parity excited baryons and their mixing in the large Nc limit Willemyns, C. Schat, C. We consider configuration mixing for the nonstrange positive parity excited baryons in the [56′,0+], [56,2+], [70,0+], and [70,2+] quark model SU(6)×O(3) multiplets contained in the N=2 band. Starting from the effective mass operator for these states, we show by an explicit calculation that in the large Nc limit they fall into six towers of degenerate states labeled by K=0,1,1′,2,2′,3. We find that the mixing of the spin-flavor states is much simpler than what is naively expected in the quark model. To leading order in Nc, only states carrying the same K label can mix, which implies that, for the spin-flavor states we started with, configuration mixing can be parameterized by just two constants: μK=1 and μK=2. The obtained mass degeneracies and mixing pattern constitute a signature of the contracted spin-flavor symmetry for baryons in the large Nc limit. © 2017 American Physical Society. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_24700010_v95_n9_p_Willemyns
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description We consider configuration mixing for the nonstrange positive parity excited baryons in the [56′,0+], [56,2+], [70,0+], and [70,2+] quark model SU(6)×O(3) multiplets contained in the N=2 band. Starting from the effective mass operator for these states, we show by an explicit calculation that in the large Nc limit they fall into six towers of degenerate states labeled by K=0,1,1′,2,2′,3. We find that the mixing of the spin-flavor states is much simpler than what is naively expected in the quark model. To leading order in Nc, only states carrying the same K label can mix, which implies that, for the spin-flavor states we started with, configuration mixing can be parameterized by just two constants: μK=1 and μK=2. The obtained mass degeneracies and mixing pattern constitute a signature of the contracted spin-flavor symmetry for baryons in the large Nc limit. © 2017 American Physical Society.
format JOUR
author Willemyns, C.
Schat, C.
spellingShingle Willemyns, C.
Schat, C.
Towers of positive parity excited baryons and their mixing in the large Nc limit
author_facet Willemyns, C.
Schat, C.
author_sort Willemyns, C.
title Towers of positive parity excited baryons and their mixing in the large Nc limit
title_short Towers of positive parity excited baryons and their mixing in the large Nc limit
title_full Towers of positive parity excited baryons and their mixing in the large Nc limit
title_fullStr Towers of positive parity excited baryons and their mixing in the large Nc limit
title_full_unstemmed Towers of positive parity excited baryons and their mixing in the large Nc limit
title_sort towers of positive parity excited baryons and their mixing in the large nc limit
url http://hdl.handle.net/20.500.12110/paper_24700010_v95_n9_p_Willemyns
work_keys_str_mv AT willemynsc towersofpositiveparityexcitedbaryonsandtheirmixinginthelargenclimit
AT schatc towersofpositiveparityexcitedbaryonsandtheirmixinginthelargenclimit
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