We propose an extended Nambu–Jona-Lasinio model to include the heavy mesons with the heavy quark symmetry. The quark current-current interaction is generalized to include the heavy quark currents. In order to comply with the heavy quark spin symmetry at the heavy quark limit, the quark mass dependence of the interaction strength is introduced. The light and heavy pseudo-scalar and vector meson,...

We study the dynamics of a ‘composite’ or ‘dressed’ quark in stronglycoupled large-Nc N = 4 super-Yang-Mills, making use of the AdS/CFT correspondence. We show that the standard string dynamics nicely captures the physics of the quark and its surrounding non-Abelian field configuration, making it possible to derive a relativistic equation of motion that incorporates the effects of radiation dam...

This paper presents an overview of the physics program of the 15-30 GeV continuous beam electron facility proposed by the European community of nuclear physicists to study the quark and gluon structure of hadrons. The goal of this new facility is to explore the quark structure of matter by exclusive and semi-inclusive electron scattering from nuclear targets.

Inclusive and semi-inclusive deep inelastic leptoproduction offers possibilities to study details of the quark and gluon structure of the hadrons involved. In many of these experiments polarization is an essential ingredient. We also emphasize the dependence on transverse momenta of the quarks, which leads to azimuthal asymmetries in the produced hadrons.

We evaluate the long distance weak contribution to the neutron and proton electric dipole moments using an effective Lagrangian framework. We estimate the coefficients needed by a factorization hypothesis and additional assumptions on γ5 terms in the baryon lagrangian. We obtain |de | ≈ 5 × 10−32 e·cm and |de | ≈ 4 × 10−32 e·cm. The former estimate is similar to the quark model estimates done p...

It is shown that the number of independent weak form factors collapses if the heavy diquark exists inside the baryons containing a single heavy quark. The relations between the weak form factors are quite different in the case of light diquark. So a careful analysis on the future data of the weak form factors would clarify that in those baryons the correlation between the heavy quark and a ligh...

Due to its high mass and short lifetime, the top quark plays an important role in checking the Standard Model of particle physics. In this report, we present a variety of searches for physics beyond the Standard Model, involving top quarks, at the D0 detector at the Fermilab Tevatron collider. Specifically, we present searches in top quark pair production, single top quark production and top qu...

We investigate the effect of non-degenerate quarks on BK . This effect is noticeably large for BK (significantly larger than statistical uncertainty). Hence, it is important to include this effect in order to determine BK with higher precision. We also observe that the quality of fitting for BK gets better when we include non-degenerate combinations to fit to the prediction by Van de Water and ...

We show how identification of absolutely flat directions allows the construction of a new class of compactified string theories with reduced gauge symmetry that may or may not be continuously connected to the original theory. We use this technique to construct a class of 3 generation models with just the Standard Model gauge group after compactification. We discuss the low-energy symmetries nec...

The experimental data of the past decade suggests that the quantum gravity vacuum should possess two key ingredients. The existence of three generations and their embedding in SO(10) representations. The Z2 × Z2 orbifold of the heterotic string provides examples of vacua that accommodate these properties. The utilization of string dualities to explore these models is discussed. Classification o...