We calculate the single spin asymmetry in the inclusive pion production in protonproton collisions. We generate the asymmetry at the level of fragmentation function (Collins effect) by the Lundâ€¦ (More)

We review the density matrix formalism and the positivity conditions for general multiple spin asymmetries, taking as an example the case Â¯ p + p â†’ Î› + Î› in which one, two or three spins areâ€¦ (More)

Model-independent identities and inequalities which relate the various spin observables of collisions in nuclear and particle physics are reviewed in a unified formalism. Their physicalâ€¦ (More)

For a monopole, the analogue of the Lorentz equation in matter is shown to be f = g (H âˆ’ v Ã— D). Dual-symmetric Maxwell equations, for matter containing hidden magnetic charges in addition toâ€¦ (More)

Positivity constraints have been widely studied in hadron p hysics to determine the allowed domain of physical observab les. They can be used to test the consistency of various available measurementsâ€¦ (More)

We discuss model-independent inequalities for the spin observables in the reaction pÌ„p â†’ Î›Î›, which have been measured at CERN with a polarised proton target.

We present the principles of the measurement of the quark transversity distributions in semi-inclusive deep inelastic electron scattering, which form the basis of HELP and one of the ELFE proposals.â€¦ (More)

A new kind of positron sources for future linear colliders, where the converter is an aligned tungsten crystal, oriented on the ã€ˆ111ã€‰ axis, has been studied at CERN in the WA103 experiment withâ€¦ (More)

The spatial resolution power of Optical Transition Radiation (OTR), applied to beam proÂ®le measurements at high Lorentz factor c, is studied taking into account diÂ€raction and self-diÂ€raction eÂ€ects.â€¦ (More)