We present the alternative way of derivation of the Wandzura-Wilczek relations between the kinematical twist-3 and twist-2 functions, parameterizing hadronic matrix element in two-photon processes γπ → γπ and γγ → ππ. The new equations, providing the independence of the physical cross-sections on the choice of the light-cone direction, are suggested and explored. The amplitude of γγ → ππ up to ...

Sutural growth depends on maintenance of a balance between proliferation of osteogenic stem cells and their differentiation to form new bone, so that the stem cell population is maintained until growth of the skull is complete. The identification of heterozygous mutations in FGFR1, -2 and -3 and TWIST as well as microdeletions of TWIST in human craniosynostosis syndromes has highlighted these g...

The nucleon mass corrections are calculated to all polarized structure functions for neutral and charged current deep inelastic scattering in lowest order in the coupling constant. The impact of the target mass corrections on the general relations between the twist–2 and twist–3 parts of the structure functions is studied and three new relations between the twist–3 contributions are derived. Th...

We show that electromagnetic gauge invariance requires a “spin rotation” of the quarks in the usual twist–2 contribution to the amplitude for Deeply Virtual Compton Scattering. This rotation is equivalent to the inclusion of certain kinematical twist–3 (“Wandzura–Wilczek type”) terms, which have been derived previously using other methods. The new representation of the twist–3 terms is very com...

We have compared the existing experimental data on the leading power corrections to the structure functions F 2 (x, Q 2), F 3 (x, Q 2), and F L (x, Q 2) with the IR-renormalon model predictions for higher-twist contributions. Our analysis shows that the model properly describes the x-dependence, but typically falls short by a factor 2 or 3 as far as the magnitude of higher twist corrections is ...

Tao Huang1,2∗ and Xing-Gang Wu2† CCAST(World Laboratory), P.O.Box 8730, Beijing 100080, P.R.China, Institute of High Energy Physics, Chinese Academy of Sciences, P.O.Box 918(4), Beijing 100049, China.‡ Abstract A model for the twist-3 wave function ψp(x,k⊥) of the pion has been constructed based on the moment calculation by applying the QCD sum rules, whose distribution amplitude has a better e...

ab initio calculation at hf/6-31g* level of theory for geometry optimization and mp2/6-31g*//hf/6-31g* for a single point total energy calculation are reported for the important energyminimumconformations and transition-state geometries of of cyclodeca-1,2,3-triene (1). the mostfavorable conformation of 1 is a unsymmetrical twist-chair (1-tc) structure. degenerateinterconversion of 1-tc with it...

background: metastasis is one the most leading cause of death from cancer. the chemokine receptor of cxcr4 has an important role in cell migration and cancer metastasis. additionally, metastasis is always associated with the process of epithelial-mesenchymal transition (emt). in this study the correlation between expression of cxcr4 and emt-tfs has been examined. methods: the expression of cxcr...

Sum rules for twist-3 distributions are reexamined. Integral relations between twist-3 and twist-2 parton distributions suggest the possibility for a δ-function at x = 0. We confirm and clarify this result by constructing hL and h 3 L (quark-gluon interaction dependent part of hL) explicitly from their moments for a one-loop dressed massive quark. The physics of these results is illustrated by ...