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We present the state-of-the-art of the light-cone sum rule approach to Baryon form factors. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations. [ABSTRACT FROM AUTHOR]

The true muonium $${(\mu\bar{\mu})}$$ bound state presents an interesting test of light-cone quantization techniques. In addition to exhibiting the standard problems of handling non-perturbative calculations, true muonium requires correct treatment of $${e\bar{e}}$$ Fock-state contributions. Having previously produced a crude model of true muonium using the method of iterated resolvents, our current work has focused on the inclusion of the box diagrams to improve the cutoff-dependent issues of the model. Further, a parallel computer code, TMSWIFT, allowing for smaller numerical uncertainties, has been developed. This work focuses on the current state of these efforts to develop a model of true muonium that is testable at near-term experiments. [ABSTRACT FROM AUTHOR]

The large momentum effective field theory (LaMET) is aiming to calculate parton distributions directly on lattice. In this approach a class of so-called quasi distributions are defined as pure spatial correlations in a finite momentum frame and they are directly calculated on lattice. The light-cone distributions are extracted from the quasi distributions by perturbative matching conditions. We present the application of LaMET on parton distribution functions and generalized parton distributions. Besides, heavy meson's quasi and light-cone distribution amplitudes are studied under nonrelativistic QCD (NRQCD) factorization framework. [ABSTRACT FROM AUTHOR]

The relevance of Radon transform for generalized and transverse momentum dependent parton distributions is discussed. The new application for conditional (fracture) parton distributions and dihadron fragmentation functions is suggested. [ABSTRACT FROM AUTHOR]

An approximate light-cone wave function for the pion effective quark-antiquark Fock sector corresponding to a small value of the renormalization group parameter is presented. The approximate wave function is motivated by the LF-holography and the quadratic confinement potential in the front form of Hamiltonian dynamics, which is in harmony with the linear confining potential in the instant form. The pion radius, decay constant and form-factor are also presented. [ABSTRACT FROM AUTHOR]

We show how the double parton distributions may be obtained consistently from the many-body light-cone wave functions. We illustrate the method on the example of the pion with two Fock components. The procedure, by construction, satisfies the Gaunt-Stirling sum rules. The resulting single parton distributions of valence quarks and gluons are consistent with a phenomenological parametrization at a low scale. [ABSTRACT FROM AUTHOR]

We discuss the relation between the trivial light-front vacuum and the non-trivial Heisenberg vacuum. [ABSTRACT FROM AUTHOR]

Constrained systems in quantum field theories call for a careful study of diverse classes of constraints and consistency checks over their temporal evolution. Here we study the functional structure of the free electromagnetic and pure Yang-Mills fields on the front-form coordinates with the null-plane gauge condition. It is seen that in this framework, we can deal with strictu sensu physical fields. [ABSTRACT FROM AUTHOR]

Light-cone quantization always involves the solution of differential constraint equations. The solutions to these equations include integration constants (fields independent ofx-). These fields are unphysical but when they are consistently removed from the dynamics, additional operators (induced operators), which would not be present if the integration constants were simply set to zero, are included in the dynamics. These induced operators can be taken to act in the usual light-cone subspace, for instance, the space used for DLCQ. Here, I shall give a derivation of two such operators. The operators are derived starting from the QCD Lagrangian but the derivation involves some guesses. The operators will provide for the linear growth of the pion mass squared with the quark bare mass and for the splitting of the pi and the rho at zero quark mass. [ABSTRACT FROM AUTHOR]

Highlights the international workshop Light-Cone 2004, QCD on and off the Light Cone, held at the Vrije Universiteit in Amsterdam, Netherlands. Activities and programs; Topics discussed during the workshop; Attendees.