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Central exclusive production of the scalar χc meson at the Fermilab Tevatron, BNL RHIC, and CERN LHC energies

We calculate several differential distributions for exclusive double-diffractive χc(0++) production in the proton-antiproton collisions at the Tevatron and in proton-proton collisions at RHIC and LHC. We use unintegrated gluon distributions (UGDFs) within the kt-factorization approach. The g*g*→χc(0++) transition vertex is calculated as a function of gluon virtualities via the standard perturbativ

Bjorken sum rule and perturbative QCD frontier on the move

The reasonableness of the use of perturbative QCD notions in the region close to the scale of hadronization, i.e., below 1GeV is under study. First, the interplay between higher orders of pQCD expansion and higher-twist contributions in the analysis of recent Jefferson Lab (JLab) data on the generalized Bjorken sum rule function Γ1p-n(Q2) at 0.1

Diagonalization of the neutralino mass matrix and boson-neutralino interaction

We analyze a connection between the neutralino mass sign, parity and structure of the neutralino-boson interaction. Correct calculation of spin-dependent and spin-independent contributions to neutralino-nuclear scattering should consider this connection. A convenient diagonalization procedure, based on the exponential parametrization of unitary matrix, is suggested.

pp→ppη′ reaction at high energies

We discuss double-diffractive (double-elastic) production of the η′-meson in the pp→pη′p reaction within the formalism of unintegrated gluon distribution functions (UGDF). We estimate also the contribution of γ*γ*→η′ fusion. The distributions in the Feynman xF (or rapidity), transferred four-momenta squared between initial and final protons (t1,t2) and azimuthal angle difference between outgoing p

Scalar Higgs boson production in fusion of two off-shell gluons

The amplitude for scalar Higgs boson production in the fusion of two off-shell gluons is calculated including finite (not infinite) masses of quarks in the triangle loop. In comparison to the effective Lagrangian approach, we have found a new term in the amplitude. The matrix element found can be used in the k⊥-factorization approach to the Higgs boson production. The results are compared with the

Dispersive approach to the axial anomaly and nonrenormalization theorem

Anomalous triangle graphs for the divergence of the axial-vector current are studied using the dispersive approach generalized for the case of higher orders of perturbation theory. The validity of this procedure is proved up to the two-loop level. By direct calculation in the framework of dispersive approach we have obtained that the two-loop axial-vector-vector (AVV) amplitude is equal to zero. A