3,436 research outputs found
Puzzles in charm spectroscopy
We briefly analyze aspects of open and hidden charm resonances, discussing in
particular the mesons and X(3872).Comment: 8 pages, 4 figures. Invited talk given at the YKIS Seminar on New
Frontiers in QCD: Exotic Hadrons and Hadronic Matter, Kyoto, Japan, 20 Nov. -
8 Dec. 200
Quarkonium dissociation in a far-from-equilibrium holographic setup
The real-time dissociation of the heavy quarkonium in a strongly coupled
boost-invariant non-Abelian plasma relaxing towards equilibrium is analyzed in
a holographic framework. The effects driving the plasma out of equilibrium are
described by boundary quenching, impulsive variations of the boundary metric.
Quarkonium is represented by a classical string with endpoints kept close to
the boundary. The evolution of the string profile is computed in the
time-dependent geometry, and the dissociation time is evaluated for different
configurations with respect to the direction of the plasma expansion.
Dissociation occurs fastly for the quarkonium placed in the transverse plane.Comment: 14 pages, 8 figures. References added. Matches the published versio
Identifying through its decay modes
We study how to assign the recently observed meson to an
appropriate level of the spectrum by the analysis of its decay modes
in final states comprising a light pseudoscalar meson. We use an effective
lagrangian approach with heavy quark and chiral symmetries, obtaining that the
measurement of the decay width would allow to distinguish between two
possible assignments.Comment: RevTex, 6 pages - references adde
New meson spectroscopy with open charm and beauty
All the available experimental information on open charm and beauty mesons is
used to classify the observed states in heavy quark doublets. The masses of
some of the still unobserved states are predicted, in particular in the beauty
sector.
Adopting an effective Lagrangian approach based on the heavy quark and chiral
symmetry, individual decay rates and ratios of branching fractions are
computed, with results useful to assign the quantum numbers to recently
observed charmed states which still need to be properly classified.
Implications and predictions for the corresponding beauty mesons are provided.
The experimental results are already copious, and are expected to grow up
thanks to the experiments at the LHC and to the future high-luminosity flavour
and facilities.Comment: RevTex, 15 pages, 1 figure. Corrected Equations (8) and (9
decays and the structure of X(3872)
It has been suggested that the radiative decay modes
are useful to shed light on the structure of the meson X(3872), since the ratio
is
expected to be small () if is a molecular state.
We compute in a description of finding that
it is tiny in a wide range of hadronic parameters governing the decay. A
discrimination between the molecular and description can be obtained
through the analysis of the photon spectrum.Comment: LaTex, 12 pages, 5 figures, version accepted for publication in PL
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