1,462 research outputs found
Quasi-exotic open-flavor mesons
Meson states with exotic quantum numbers arise naturally in a covariant
bound-state framework in QCD. We investigate the consequences of shifting quark
masses such that the states are no longer restricted to certain C-parities, but
only by J^P. Then, a priori, one can no longer distinguish exotic or
conventional states. In order to identify signatures of the different states to
look for experimentally, we provide the behavior of masses, leptonic decay
constants, and orbital-angular-momentum decomposition of such mesons, as well
as the constellations in which they could be found. Most prominently, we
consider the case of charged quasi-exotic excitations of the pion.Comment: 10 pages, 5 figures, 2 tables, revised version incorporating reviewer
comment
Impact of Four-Quark Condensates on In-Medium Effects of Hadrons
Spectral properties of hadrons in nuclear matter are treated in the framework
of QCD sum rules. The influence of the ambient strongly interacting medium is
encoded in various condensates. Especially, the structure of different
four-quark condensates and their density dependencies in light quark systems
are exemplified for the omega meson and the nucleon.Comment: Contribution to Quark Confinement and the Hadron Spectrum VII,
02.-07.09.2006, Ponta Delgada, Portuga
Aspects of open-flavour mesons in a comprehensive DSBSE study
Open-flavour meson studies are the necessary completion to any comprehensive
investigation of quarkonia. We extend recent studies of quarkonia in the
Dyson-Schwinger-Bethe-Salpeter-equation approach to explore their results for
all possible flavour combinations. Within the inherent limitations of the
setup, we present the most comprehensive results for meson masses and leptonic
decay constants currently available and put them in perspective with respect to
experiment and other approaches.Comment: 38 pages, 26 figures, 2 tables, revised according to reviewer
comment
Chiral QCD sum rules for open charm mesons
QCD sum rules for chiral partners in the open-charm meson sector are
presented at nonzero baryon net density or temperature. We focus on the
differences between pseudo-scalar and scalar as well as vector and axial-vector
D mesons and derive the corresponding Weinberg type sum rules. This allows for
the identification of such QCD condensates which drive the non-degeneracy of
chiral partners in lowest order of the strong coupling alpha_s and which
therefore may serve as "order parameters" for chiral restoration (or elements
thereof).Comment: 24 pages, 4 figure
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