83 research outputs found
On Breaking through Final State Interactions and CP Asymmetries in Decays
We analyse decays to two pseudoscalars assuming the dominant
source of breaking lies in final state interactions. We
obtain an excellent agreement with experimental data and are able to predict CP
violation in several channels based on current data on branching ratios and
. We also make predictions for and the
branching fraction for the decay .Comment: 21 pages. Updated with the 2019 measurement of from LHC
The statistical model for parton distributions
The phenomenological motivations, the expressions and the comparison with
experiment of the parton distributions inspired by the quantum statistics are
described. The Fermi-Dirac expressions for the quarks and their antiparticles
automatically account for the correlation between the shape and the first
moments of the valence partons, as well as the flavor and spin asymmetries of
the sea. One is able to describe with a small number of parameters both
unpolarized and polarized structure functions.Comment: 7 pages, 3 figures, Invited talk at XX International Workshop on
"`Deep-Inelastic Scattering and related subjects"', University of Bonn,
Germany, March 26-30 2012, presented by F. Buccella, to appear in the
conference proceeding
How large is the gluon polarization in the statistical parton distributions approach?
We review the theoretical foundations of the quantum statistical approach to
parton distributions and we show that by using some recent experimental results
from Deep Inelastic Scattering, we are able to improve the description of the
data by means of a new determination of the parton distributions. We will see
that a large gluon polarization emerges, giving a significant contribution to
the proton spin.Comment: 4 pages, 3 figures, Invited talk presented by Jacques Soffer at "
DIFFRACTION 2014 ",May 10 - 15, 2014, Primosten (Croatia) (to be published in
the AIP Conference Proceedings{\deg
Hints for the existence of hexaquark states in the baryon-antibaryon sector
The discovery of some baryon-antibaryon resonances has led us to consider
3q~3\bar{q} systems as possible candidates. We predict their spectrum in the
framework of a constituent model, where the chromo-magnetic interaction plays
the main role. The relevant parameters are fixed by the present knowledge on
tetraquarks. The emerging scenario complies well with experiment. Besides the
description of the baryon-antibaryon resonances, we find evidence for new
tetraquark states, namely the a0(Y) in the hidden strangeness sector and, in
the cs\bar{c}\bar{s} sector, the Y(4140) and the X(4350). A detailed account of
the spectra and the decay channels is provided for future comparisons with
data.Comment: 17 page
CP violation in D meson decays: would it be a sign of new physics ?
Ascribing the large SU(3) violations in the Cabibbo forbidden decays of
neutral D mesons to the final state interactions, one gets large strong phase
differences, necessary for substantial direct CP violation. While the absolute
value of the CP violating asymmetries depend on the uncertain strength of the
penguin contribution, we predict an asymmetry for the decays into charged pions
more than twice as large and having opposite sign with respect to that for
charged kaons.Comment: 9 pages, added references, minor changes in the text, results
unchanged. Accepted for publication in Physical Review
Chromomagnetism, flavour symmetry breaking and S-wave tetraquarks
The chromomagnetic interaction, with full account for flavour-symmetry
breaking, is applied to S-wave configurations containing two quarks and two
antiquarks. Phenomenological implications are discussed for light, charmed,
charmed and strange, hidden-charm and double-charm mesons, and extended to
their analogues with beauty.Comment: 16 pages, 2 figures, RevTeX, Refs. updated, further typos corrected,
to appear in EPJ
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