Baryons with many colors and flavors
May, 199423 pages
Published in:
- Phys.Rev.D 51 (1995) 2322-2331
e-Print:
- hep-ph/9405271 [hep-ph]
Report number:
- LBL-35539,
- NSF-ITP-94-42
Citations per year
Abstract:
Using recently-developed diagrammatic techniques, I derive some general results concerning baryons in the expansion, where is the number of QCD colors. I show that the spin-flavor relations which hold for baryons in the large- limit, as well as the form of the corrections to these relations at higher orders in , hold even if , where is the number of light quark flavors. I also show that the amplitude for a baryon to emit mesons is , and that meson loops attached to baryon lines are unsupressed in the large- limit, independent of . For , there are ambiguities in the extrapolation away from because the baryon flavor multiplets for a given spin grow with . I argue that the expansion is valid for baryons with spin and {\it arbitrary} flavor quantum numbers, including e.g. baryons with isospin and/or strangeness . This allows the formulation of a large- expansion in which it is not necessary to identify the physical baryons with particular large- states. symmetry can be made manifest to all orders in , yet group theory factors must be evaluated explicitly only for . To illustrate this expansion, I consider the non-singlet axial currents, baryon mass splittings, and matrix elements of \mybar ss and \mybar s \gam_\mu \gam_5 s in the nucleon.- baryon: color
- baryon: flavor
- spin: flavor
- flavor: spin
- symmetry: SU(N)
- current: axial
- baryon: mass difference
- mass difference: baryon
- meson baryon: interaction
- interaction: meson baryon
References(28)
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