Azimuthal single-spin asymmetries (SSA) in semi-inclusive electroproduction of charged pions in deep-inelastic scattering (DIS) of positrons on a transversely polarised hydrogen target are presented. Azimuthal moments for both the Collins and the Sivers mechanism are extracted. In addition the subleading-twist contribution due to the transverse spin component from SSA on a longitudinally polari...

We present the results of a QCD fit to global data on deep-inelastic polarised lepton-hadron scattering. We find that it is possible to fit the data with strongly broken SU(2) flavour for the polarised sea densities. This can easily be tested in W production at polarised RHIC. The data fails to pin down polarised singlet sea quark and gluon densities. We explore the uncertainties in detail and ...

A polarised QCD condensate: νp elastic scattering as a probe of U A (1) dynamics Abstract U A (1) dynamics have the potential to induce a polarised condensate inside a nucleon. The formation of this condensate is related to the realisation of U A (1) symmetry breaking by tunneling processes such as instantons. If it is present, the polarised condensate induces a term in g 1 which has support on...

Transverse Momentum Dependent Distributions (TMDs) describe the spin structure of the proton. At leading twist spin structure of spin-1/2 hadron can be described by 8 TMDs. TMDs reveal three-dimensional distribution of partons inside polarised nucleon. Experimentally these functions can be studied in polarised experiments using Spin Asymmetries in particular Single Spin Asymmetries (SSAs). We d...

Shape-from-shadow perception fails when the contour bordering a shadowed area is reduced to a black line, and the shadow area becomes white. It might be that the polarity of the shadowed and illuminated areas has to be from dark on the shadowed side to light on the illuminated side for successful perception. Or it may be that the line, which has two contours, has one too many for shape-from-sha...

Polarised stereoscopic projection involves the polarisation of the two projected images in orthogonal directions e.g. +/45 degrees for linear polarisation, or clockwise and counter-clockwise for circular polarisation. When LCD projectors are used for polarised stereoscopic projection it is important to take into consideration the fact that the output of these types of projectors is already pola...

The HERMES experiment has studied for more than a decade deep-inelastic scattering of electrons/positrons from longitudinally and transversely polarised and also unpolarised atomic gas targets internal to the electron storage ring of HERA. The collected semi-inclusive data allowed to extract informations about various quark distribution and fragmentation functions. Examples presented in this co...

One of the missing keys in the present understanding of the spin structure of the nucleon is the contribution from the gluons: the so-called gluon polarisation. This quantity can be determined in DIS through the Photon-Gluon Fusion (PGF) process, in which two analysis methods may be used: (i) identifying open charm events or (ii) selecting events with high-p T hadrons. The data used in the pres...

Increased absorption of transverse-magnetic (TM)-polarised light by a graphene-oxide (GO) coated polymer waveguide has been observed in the presence of transverse-electric (TE)-polarised light. The GO-coated waveguide exhibits very strong photo-absorption of TE-polarised light--and acts as a TM-pass waveguide polariser. The absorbed TE-polarised light causes a significant temperature increase i...