119 research outputs found
Charm rescattering contribution in rare decay
Following the experimental results from LHCb on the rare decay , we investigate the possibility where this process is dominated by
a double charm rescattering. The decay to double charm channels have a
weak topology that is favoured in comparison with the direct production of
in the final state, suppressed by quark annihilation. The decay
amplitude for with decaying first to double charm
channels is described by a charm penguin diagram, represented by charm hadronic
triangle loops, which reach the final state of interest after or transitions. We show that these
processes give rise to non-resonant amplitudes with a clear signature in the
Dalitz plot. In a near future, the new data from LHCb run II will be able to
confirme if the main hypotheses of this work is correct and the dominant
mechanism to produce from the decay of is through charm
rescattering
Renormalization of an effective model Hamiltonian by a counter term
An ill-defined integral equation for modeling the mass-spectrum of mesons is
regulated with an additional but unphysical parameter. This parameter
dependance is removed by renormalization. Illustrative graphical examples are
given.Comment: 3 pages, 3 figures, 1 reference. to be published in Nucl. Phys. B
(Proc. Suppl.) Talk presented at the Workshop "Light-cone Physics: Particles
and Strings" at ECT* in Trento, Sep 3-11, 200
Linear meson and baryon trajectories in AdS/QCD
An approximate holographic dual of QCD is constructed and shown to reproduce
the empirical linear trajectories of universal slope on which the square masses
of radially and orbitally excited hadrons join. Conformal symmetry breaking and
other IR effects are described exclusively by deformations of the anti-de
Sitter background metric. The predictions for the light hadron spectrum include
new relations between ground state masses and trajectory slopes and are in good
overall agreement with experimental data.Comment: 4 page
Fractal structure of hadrons and non-extensive statistics
The role played by non-extensive thermodynamics in physical systems has been
under intense debate for the last decades. Some possible mechanisms that could
give rise to non-extensive statistics have been formulated along the last few
years, in particular the existence of a fractal structure in thermodynamic
functions for hadronic systems. We investigate the properties of such fractal
thermodynamical systems, in particular the fractal scale invariance is
discussed in terms of the Callan-Symanzik~equation. Finally, we propose a
diagrammatic method for calculations of relevant quantities.Comment: 5 pages, 2 figures. Presented by E.Megias at the QCD@Work:
International Workshop on QCD, 25-28 June 2018, Matera, Ital
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