204 research outputs found
Heavy quark skyrmions
The description of the heavy baryons as heavy-meson--soliton bound systems is
reviewed. We outline how such bound systems arise from effective lagrangians
that respect both chiral symmetry and heavy quark symmetry. Effects due to
finite heavy quark masses are also discussed, and the resulting heavy baryon
spectra are compared with existing quark model and empirical results. Finally,
we address some issues related to a possible connection between the usual bound
state approach to strange hyperons and that for heavier baryons.Comment: To appear in "The Multifaceted Skyrmion" (World Scientific) ed. G.E.
Brown and M. Rh
Multibaryons in the Skyrme model
Low-lying multibaryon configurations are studied within the bound state
approach to the SU(3) Skyrme model. We use approximate ansaetze for the static
background fields based on rational maps which have the same symmetries of the
exact solutions. To determine the explicit form of the collective Hamiltonians
and wave functions we only make use of these symmetries. Thus, the expressions
obtained are also valid in the exact case. On the other hand, the meson
bindings, inertia parameters and hyperfine splitting constants we calculate do
depend on the detailed form of the ansaetze and are, therefore, approximate.
Using these values we compute the low-lying spectra of multibaryons with B =< 9
and strangeness 0 and -B. With these results the stability of some multilambda
configurations is discussed.Comment: 7 pages. To be published in the Proc. of "Hadron Physics 99".
Coimbra, Portugal. September 10- 15, 199
Decays of Non-Strange Positive Parity Excited Baryons in the 1/Nc Expansion
The decays of non-strange positive parity excited baryons via emission of a
pseudo-scalar meson are studied in the framework of the 1/Nc expansion to order
1/Nc. In particular, the pionic decays of the l=0 Roper baryons and of the l=2
baryons in the mass interval 1680-1950 MeV are analyzed using the available
partial decay widths. Decay widths by emission of an eta meson are shown to be
suppressed by a factor 1/Nc^2 with respect to the pionic ones.Comment: 16 pages, 8 table
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