25 research outputs found
Transverse Spin Asymmetries in Drell-Yan Processes: }
We consider two different spin asymmetries in Drell-Yan processes generated
by the collisions of an unpolarized proton beam on transversely polarized
protons: the muon helicity asymmetry and the left-right asymmetry. We calculate
the asymmetries in the framework of the QCD improved parton model, taking into
account the parton transverse momentum and considering the first order QCD
corrections. The muon helicity asymmetry is sensitive to the quark transversity
distribution and is nonvanishing even at zero order. On the contrary the
left-right asymmetry vanishes at zero order but not at first order in the QCD
coupling constant, as a result of gluon contribution
Phenomenological Analysis of the Decay $B^{\pm}\to K^{\pm} p {\bar p}
We propose a parametrization for intepreting some of the presently available
data of the decay, in particular those by LHCb
and Belle collaborations. The model is inspired by the well-known current and
transition contributions, usually assumed in this kind of decay. However, in
the light of considerations about the dominant graphs and about final state
interactions, we modify some parameters of the model, determining them by means
of a best fit to data. We show the results, which we discuss in some detail.
Moreover we give some predictions on other observables relative to the decays.Comment: 19 pages, 5 figures in EPJC 201
T-odd Observables in Elastic Scattering, in Deep Inelastic Processes and in Weak Decays
We give a unitary description of T-odd effects in various sectors of atomic,
nuclear and particle physics, like elastic scattering, deep inelastic processes
and weak decays. This we get thanks to a particular transformation, which leads
us to defining two T-odd observables. This approach allows to revise in quite a
natural way various azimuthal asymmetries and normal polarizations already
predicted or even observed in deep inelastic processes and in weak decays. In
the latter case, useful suggestions for phenomenological analyses and an
interesting result for normal and transverse polarization are derived
Searching for New Physics by means of Relative Phases and Moduli of Decay Amplitudes
We illustrate some tests which may shed light on physics beyond the Standard
Model. Some of them are especially sensitive to possible signals of new
physics.Comment: 16 page