We calculate the next-to-leading corrections to the jet vertex which is relevant for the Mueller-Navelet-jets production in pp̄ collisions and for the forward jet cross section in ep collisions. In this first part we present the results of the vertex for an incoming quark. Particular emphasis is given to the separation of the collinear divergent part and the central region of the produced gluon.

The implications of the positivity constraint, |g γ(P 2) 1 (x,Q 2)| ≤ F γ(P 2) 1 (x,Q 2), on the presently unknown spin–dependent structure function g γ(P 2) 1 (x,Q 2) of real and virtual photons are studied at scales Q2 ≫ P 2 where longitudinally polarized photons dominate physically relevant cross sections. In particular it is shown how to implement the physical constraints of positivity and ...

Recent development of the universal seesaw mass matrix model is reviewed. The model was proposed in order to explain why quark and lepton masses are so small compared with the electroweak scale ΛL = 〈φL〉 = 174 GeV. However, the recently observed top-quark mass mt ≃ 180 GeV seems to make an objection against the seesaw mass picture. For this problem, it has recently pointed out that the seesaw m...

We compute the inclusive decay rates b → D − s (D * − s)c including lowest order QCD corrections on the quark legs, and compare with existing CLEO data. Unlike the short distance QCD corrections, that are of higher order, these corrections are of order α s. In the on-shell renormalization scheme and for α s (m b) ∼ = 0.2 we find a correction of −10 % to the inclusive rate computed using factori...

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...