The complete knowledge of the nucleon spin structure at leading twist requires also addressing the transverse spin distribution of quarks, or transversity, which is yet unexplored because of its chiral-odd nature. Elaborating strategies to extract it from (spin) asymmetry data represents a unique opportunity to explore more generally the transverse spin structure of the nucleon and the transver...

We present an approach for the calculation of spin density distributions for molecules that require very large active spaces for a qualitatively correct description of their electronic structure. Our approach is based on the density-matrix renormalization group (DMRG) algorithm to calculate the spin density matrix elements as a basic quantity for the spatially resolved spin density distribution...

We perform a quenched lattice calculation of the first moment of twist-two generalized parton distribution functions of the proton, and assess the total quark (spin and orbital angular momentum) contribution to the spin of the proton.

in this paper we investigate the effect of a random transverse field, distributed according to a trimodal distribution, on the phase diagram and magnetic properties of a two-dimensional lattice (square with z=4),  ferromagnetic ising system consisting of magnetic atoms with spin-1. this study is done using the effectivefield theory (eft) with correlations method. the equations are derived using...

Hard processes with polarized nucleon beams enable us to study spin-dependent dynamics of QCD and the spin structure of nucleon. The helicity distribution ∆q(x) of quarks within nucleon has been measured in polarized DIS experiments, and ∆G(x) of gluons has also been estimated from the scaling violations of them. On the other hand, the transversity distribution δq(x), i.e. the distribution of t...

We calculate the Bethe–Heitler cross section for the production of lepton pairs in the field of a longitudinally polarized nucleon, taking into account the lepton masses and the target mass. This process is a dominant background to the detection of open charm from semi-leptonic decay modes, which is a potential probe of the polarized gluon distribution in the nucleon. The knowledge on the spin ...