321 research outputs found
Jantzen coefficients and simplicity of generalized Verma modules
The main purpose of the paper is to establish new tools in the study of
. We introduce the Jantzen coefficients of
generalized Verma modules. It comes from the Jantzen's simplicity criteria for
generalized Verma modules and has a deep relation with the structure of
. We develop a reduction process to compute those
coefficients. For which we need to consider generalized Verma modules induced
from maximal parabolic subalgebras having maximal nontrivial singularity, so
called basic generalized Verma modules. The classification of such modules is
obtained in this paper. As the first application of our results, we give a
refinement of Jantzen's simplicity criteria.Comment: 43 pages, 4 figure
Analysis of Exotic Hybrid eta pion, eta-prime pion Decays
Investigations of the mass and decays of the exotic hybrid are reviewed,
including calculation of the pion1 to eta pion, eta-prime pion decay widths
within the QCD sum rules technique. In this calculation, the recently-proposed
eta, eta-prime quark mixing scheme is employed. The results indicate that the
decay width Gamma(pion1 to eta pion) around 250 MeV is large compared with the
decay width Gamma(pion1 to eta-prime pion) around 20 MeV. Inspired by these
results, some phenomenological approaches are suggested to gain an
understanding of the underlying mechanism of eta pion and eta-prime pion hybrid
decays.Comment: 4 pages, talk presented at the 10th International Symposium on
Meson-Nucleon Physics and the Structure of the Nucleon(MENU2004), Beijing,
China, August 29 to September 4, 200
Light Four-quark States and New Observations by BES
Four-quark states are discussed within the constituent quark model.
Incompleteness of existed studies of four-quark state with QCD sum rule is
analyzed. The masses of diquark cluster were determined by QCD sum rules, and
light four-quark states masses were obtained in terms of the diquark. The
four-quark state possibility of the newly observed near-threshold p\bar p
enhancement, X(1835), X(1812) and X(1576) by BES is discussed.Comment: 4pages, no figure, PTPTEX, talk at the Yukawa International Seminar
(YKIS2006), "New frontiers in QCD", Kyoto, Japa
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