When linearly polarised light is transmitted through a spinning window, the plane of polarisation is rotated. This rotation arises through a phase change that is applied to the circularly polarised states corresponding to the spin angular momentum (SAM). Here we show an analogous effect for the orbital angular momentum (OAM), where a differential phase between the positive and negative modes (±...

Deep Inelastic Scattering (DIS) experiments, such as eN → eX or νN → μ−X form an important basis for our knowledge of the structure of hadrons. In these processes the current probe (either a neutral current, γ/Z, or charged current, W+/W−) with large space-like momentum −q2 ≡ Q breaks-up the nucleon. The (inclusive) cross section is then determined by the structure functions F1, F2 when summing...

We find that single spin asymmetries in NRQCD are non-vanishing in general. They are proportional to the imaginary parts of some nonperturbative matrix elements. With statistics of about 10 identified J/ψ’s, or 10 identified χ2, it is possible to measure these imaginary parts even if they are an order of magnitude smaller than the real parts. Such statistics are quite reasonable at polarised HE...

The ability to controllably rotate, align, or freely spin microparticles in optical tweezers greatly enhances the manipulation possible. A variety of different techniques for achieving alignment or rotation have been suggested and demonstrated. Although these methods are diverse, employing specially shaped particles, birefringent particles, multiple trapping beams, complex beam profiles, vortex...

We review the present data on high-energy, spin-dependent photoabsorption. We find a strong isotriplet term in (σA − σP ) which persists from Q2 ∼ 0.25GeV2 to high Q2 polarised deep inelastic scattering. For Q2 ∼ 4GeV2 and x between 0.01 and 0.12 the isotriplet part of g1 behaves as g (p−n) 1 ∼ x 1 2 , in contrast to soft Regge theory which predicts that g (p−n) 1 should converge as x → 0. The ...

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...