368 research outputs found
Possible hadronic molecule structure of the Y(3940) and Y(4140)
In the present article we report on evidence for hadronic molecule structures
in the charmonium sector. In particular we discuss the Y(3940) and the recently
observed Y(4140) as heavy hadron molecule states with quantum numbers or . The Y(3940) state is considered to be a superposition of
and , while the
Y(4140) is a bound state of and mesons. We give
predictions for both the strong Y(3940) to J/psi omega, Y(4140) to J/psi phi
and radiative Y(3940)/Y(4140) to gamma gamma decay widths in a phenomenological
Lagrangian approach. The results for the strong hidden charm decay modes
clearly support the molecular interpretation of the Y(3940) and Y(4140), while
our estimates for the radiative decays provide a sensitive test for the
underlying meson structure of the two Y mesons discussed here. The alternative
assignment of is also tested, giving similar results for the
strong decay widths.Comment: 5 pages, 2 figures. To appear in the Proceedings of XIII
International Conference on Hadron Spectroscopy, November 29 - December 4,
2009, Florida State Universit
Nucleon parton distributions in a light-front quark model
Continuing with our analysis of parton distributions in the nucleon, we
extend our light-front quark model in order to obtain both the helicity
independent and helicity dependent parton distributions, analytically matching
the results of global fits at the initial scale GeV, and which
also contain the correct Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution.
We also calculate the transverse parton, Wigner and Husimi distributions from a
unified point of view, using our light-front wave functions and expressing them
in terms of the parton distributions and . Our results
are very relevant for the current and future program of the COMPASS experiment
at SPS (CERN)
Generalized parton distributions in an AdS/QCD hard-wall model
We use a matching procedure of sum rules relating the electromagnetic form
factors to generalized parton distributions (GPDs) and AdS modes. In this way,
in the framework of an AdS/QCD hard-wall model, the helicity-independent GPDs
of quarks for the nucleon in the zero skewness case are calculated
Light-front quark model consistent with Drell-Yan-West duality and quark counting rules
We propose a phenomenological light-front wave function for hadrons with
arbitrary twist-dimension (mesons, baryons and multiquark states), which gives
the correct scaling behavior of structure functions (parton distributions) and
form factors for pions and nucleons. For other hadronic states the proposed
wave function produces form factors consistent with quark counting rules, and
gives predictions for structure functions (parton distributions). As an
application we build a light-front quark model for nucleons based on the
proposed wave function.Comment: 5 page
Some Hadronic Properties from Light Front Holography
Using ideas from Light Front Holography, we discuss the calculation of
hadronic properties. In this talk I will pay special attention to hadronic
masses and the nucleon helicity-independent generalized parton distributions of
quarks in the zero skewness caseComment: Prepared for NSTAR2011. The 8th International Workshop on the Physics
of Excited Nucleons. May 17-20, 2011. Thomas Jefferson National Accelerator
Facility. Newport News, Virginia, US
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