A theoretical prediction is given for the spin and orbital angular momentum distribution functions of the nucleon within the framework of an effective quark model of QCD, i.e. the chiral quark soliton model. An outstanding feature of the model is that it predicts fairly small quark spin fraction of the nucleon ∆Σ ≃ 0.35, which in turn dictates that the remaining 65% of the nucleon spin is carri...

We developed a new and unified scheme for describing both quark spin and orbital angular momenta in symmetry-breaking chiral quark model. The loss of quark spin in the chiral splitting processes is compensated by the gain of the orbital angular momentum carried by quarks and antiquarks. The sum of both spin and orbital angular momenta carried by quarks and antiquarks is 1/2. The analytic and nu...

Mode division multiplexing (MDM) is mooted as a technology to address future bandwidth issues, and has been successfully demonstrated in free space using spatial modes with orbital angular momentum (OAM). To further increase the data transmission rate, more degrees of freedom are required to form a densely packed mode space. Here we move beyond OAM and demonstrate multiplexing and demultiplexin...

Electromagnetic fields can carry, besides energy, linear and angular momentum. The exchange of linear momentum with matter produces forces due to radiation pressure. That comet tails point away from the Sun because light carries linear momentum was first suggested by Kepler. A complete account of radiation pressure was developed by Poynting in 1905 in terms of electromagnetic linear momentum de...

We experimentally demonstrated that infrared light imprinted with orbital angular momentum (OAM) was linearly converted into visible light using four-wave mixing (FWM) via a ladder-type configuration in 85Rb atoms. Simultaneously, we theoretically simulated this linear conversion process, and the theoretical analysis was in reasonable agreement with the experimental results. A large single-phot...

In Notes 13, we worked out the general theory of the representations of the angular momentum operators J and the corresponding rotation operators. That theory did not make any assumptions about the kind of system upon which the angular momentum and rotation operators act, for example, whether it is a spin system or has spatial degrees of freedom, whether single particle or multiparticle, whethe...

Abstract Photons carrying an orbital angular momentum (OAM) are present in the off-axis radiation of higher harmonics of helical undulators. Usually, the purity and visibility of OAM carrying photons is blurred by the electron beam emittance. However, high brightness OAM beams are expected in Ultimate Storage Rings (USRs) and FELs, and they may trigger a new class of experiments utilizing the v...

We derive a generalized counting rule for hard exclusive processes involving parton orbital angular momentum and hadron helicity flip. We start with a systematic way to enumerate the Fock components of a hadronic light-cone wave function with n partons and orbital angular momentum projection l(z). We show that the wave-function amplitude psi(n)(x(i),k(i perpendicular ),l(zi)) has a leading beha...