The Sivers effect in single hadron semi-inclusive deep inelastic scattering on a transversely polarized nucleon describes the modulation of the cross section with the sine of the azimuthal angle between the produced hadron's transverse momentum and the nucleon spin (P(h) and φ(S), respectively). This effect is attributed to the so-called Sivers parton distribution function of the nucleon. We em...

Some general remarks on parton transverse spin distributions and transverse motions are presented. The issue of accessing experimental information on the transversity distributions hq1 is discussed. In particular direct information could be obtained from Drell-Yan processes with polarized protons and antiprotons (planned at GSI), while indirect information, coupling hq1 to the Collins fragmenta...

Many of the key issues in understanding quantum chromodynamics involves processes at intermediate energies. We discuss a range of hadronic and nuclear . . _-. phenomena-exclusive processes, color transparency, hidden color degrees of freedom in nuclei, reduced nuclear amplitudes, jet coalescence, formation zone effects, hadron helicity selection rules, spin correlations, higher twist effects, a...

One of the key objectives of the COMPASS experiment at CERN is the determination of the gluon contribution to the nucleon spin. The gluon polarization is measured via photon-gluon fusion in deep-inelastic scattering of 160 GeV/c polarized muons on a polarized LiD solid-state target. Photon-gluon fusion is tagged by the observation of charmed mesons or the production of hadron pairs with large t...

We present the results of an O(αs) calculation of the transverse polarization of top quarks produced in e+e−-annihilation. In a first step we determine the transverse polarization of the top with regard to the hadron plane spanned by the (q, q, g) system. We then rotate the transverse components of the polarization to the lepton plane spanned by the (q, e, e−) system. After azimuthal averaging ...

simulation of gamma and hadron showers in the energy range 100gev- 25tev has been carried out. for a big ideal cherenkov light array, characteristics of lateral distribution of cherenkov photon density have been studied. results from this ideal detector are compared with those simulated for a real tunka- like array to investigate experimental potential of using existence of a hump in lateral di...

Abstract—Complete one-loop electroweak corrections to neutral current Drell–Yan process $$pp \to {{\ell }^{ + }}{{\ell - }}X$$ are presented for the case of longitudinal polarization initial particles. The single- and double-spin asymmetries under study allow us extract information about polarized parton distribution functions. Numerical impact next-order as function vector boson rapidity lepto...

To properly discover a charged Higgs Boson (H±) requires its spin and couplings to be determined. We investigate how to utilize tt̄ spin correlations to analyze the H± couplings in the decay t → bH → bτντ . Within the framework of a general TwoHiggs-Doublet Model, we obtain results on the spin analyzing coefficients for this decay and study in detail its spin phenomenology, focusing on the limit...