Handedness of direct photons

The azimuthal asymmetry of direct photons originating from primary hard scatterings between partons is calculated. This can be accounted for by the inclusion of the color dipole orientation, which is sensitive to the rapid variation of the nuclear profile. To this end we introduce the dipole orientation within the saturation model of Golec-Biernat and W\"usthoff, while preserving all its features at the cross-section level. We show that the direct photon elliptic anisotropy v2 coming from this mechanism changes sign and becomes negative for peripheral collisions, albeit it is quite small for nuclear collisions at the RHIC energy.Comment: 6 pages, 6 figures, Based on talk given by A.H.R. at II LAWHEP, Sao Miguel das Missoes, Brazil, December 3-7, 200

Applied QCD

These lectures stress the theoretical elements that underlie a wide range of phenomenological studies of high-energy QCD, which include both soft and hard processes. After a brief introduction to the basics of QCD, various aspects of QCD-based phenomenology are covered: colour transparency, hadronization of colour charges, Regge phenomenology, parton model, Bjorken scaling and its violation, DGLAP evolution equation, BFKL formalism, GLRMQ evolution equation and saturation. In the last part of the lecture, we employ the lightcone dipole formalism to describe deep inelastic lepton scattering, DrellYan processes, direct photon production, diffraction, quark and gluon shadowing in nuclei, the Cronin effect and nuclear broadening

Hadron multiplicity in pp and AA collisions at LHC from the Color Glass Condensate

We provide quantitative predictions for the rapidity, centrality and energy dependencies of inclusive charged-hadron productions for the forthcoming LHC measurements in nucleus-nucleus collisions based on the idea of gluon saturation in the color-glass condensate framework. Our formulation gives very good descriptions of the first data from the LHC for the inclusive charged-hadron production in proton-proton collisions, the deep inelastic scattering at HERA at small Bjorken-x, and the hadron multiplicities in nucleus-nucleus collisions at RHIC.Comment: 7 pages, 8 figures; v3: minor changes, one reference added, results unchanged, the version to appear in Phys. Rev.

The mechanical behaviour of compacted Lambeth-group clays with and without fibre reinforcement

This study investigated the effect of fibre reinforcement on the large strain behaviour of compacted clay samples tested using large triaxial test equipment. A novel specimen preparation method was proposed where peds of clay are compacted to closely simulate the in-situ compaction. A large number of 100 × 200 mm triaxial tests and one-dimensional compression tests were performed using reinforced and unreinforced samples. The behaviour of unreinforced samples was observed to be similar to highly fissured clays; ped compaction generated a random fissure pattern due to the contact between peds. The addition of fibres to the compacted samples created fissures with higher mobility at lower friction than those in the unreinforced samples; hence, the state boundary surface of reinforced clay was below that of the unreinforced clay. With the addition of fibres, the failure mechanism changed from the formation of a shear plane to barrelling, demonstrating that the fibres transferred stresses further away from the shear plane, producing a more homogeneous stress distribution. The preparation method proposed here produced a fissure pattern in the clay that introduced transitional behaviour, which was drastically reduced with addition of the fibres, allowing better normalisation and the definition of a unique boundary surface