相关论文: Constraints on spin observables in pbar p --> Lamb…
Measurements of transverse polarization of Lambda hyperons produced in high energy pp collisions may help to address several open issues about Lambda production and polarization mechanisms, such as the amount of SU(3) breaking, the…
It is shown that single and double spin asymmetries in polarized diffractive $Q \bar Q$ production depend strongly on the spin structure of the quark-pomeron vertex. They can be studied in future spin experiments at HERA.
The reaction $e^+e^- \to \bar \Lambda \Lambda$ is investigated for energies close to the threshold. Specific emphasis is put on the role played by the interaction in the final $\bar \Lambda \Lambda$ system which is taken into account…
We discuss supplementary (or hidden) variables in spin-measuring equipments in EPR-Bell experiment. This theme was considered in a Bell's later work. We generalize it. First, we show why the original supplementary variable $\lambda$ is not…
The Lambda polarization in muon neutrino charged current interactions has been measured in the NOMAD experiment. We observe negative polarization along the W - boson direction which is enhanced in the target fragmentation region: Px (xF <…
A general formalism is developed to calculate the cross section and the polarization observables for the reaction $\bar N+N\to \pi +\ell^++\ell^-$. The matrix element and the observables are expressed in terms of six scalar amplitudes…
We investigate polarization observables in hyperon-nucleon scattering by decomposing scattering amplitudes into spin-space tensors, where each component describes scattering by corresponding spin-dependent interactions, so that…
We present results for a complete set of polarization observables for jet production in lepton proton collision, where the final state lepton is not observed. The calculations are carried out in collinear factorization at the level of Born…
This contribution reports on a proof-of-principle measurement of the longitudinal spin transfer $D_{LL}$ in inclusive $\Lambda$ and $\bar \Lambda$ production in polarized proton-proton collisions at a center of mass energy $\sqrt{s}$ = 200…
Double spin asymmetries in the diffractive $Q \bar Q$ and $J/\Psi$ leptoproduction are discussed. It is shown that the asymmetries for longitudinally polarized lepton and longitudinally or transversely polarized proton can be used to study…
The transverse spin transfer from polarized protons to $\Lambda$ and $\bar{\Lambda}$ hyperons is expected to provide sensitivity to the transversity distribution of the nucleon and to the transversely polarized fragmentation functions. We…
The measurements of reactions $\pi^- p \to \pi^- \pi^+ n$ and $\pi^+ n \to \pi^+ \pi^- p$ on polarized targets at CERN found a strong dependence of pion production amplitudes on nucleon spin. Analyses of recent measurements of $\pi^- p \to…
The polarization observables in the elastic scattering of polarized deuterons on a polarized hydrogen target, with measurement of the recoil proton polarization, are considered. The observables are calculated in the one-neutron exchange…
We explore the discovery and analysis potentials of the HERA collider, with and without polarized beams, in search for electron-quark contact interactions in the neutral current channel. We find that the sensitivity to contact interactions…
Previously, in an effective field theory formulated by us, we have carried out parameter-free calculations of a large number of low-energy two-nucleon properties. An experiment at the Institut Laue-Langevin is currently measuring…
After a brief introduction into the general importance of polarization observables for the analysis of a reaction, the basic density matrix formalism for the description of polarization phenomena is outlined and illustrated by explicit…
In CMS data at the CERN Large Hadron Collider, the ratio $\sigma(pp \to \bar \Lambda_b X)/\sigma(p p \to \Lambda_b X)$ appears to fall as the baryons become more forward. Mechanisms which could give rise to this effect are discussed. It is…
For any inclusive reaction of the type $A_1({spin} 1/2)+ A_2({spin} 1/2) \to B + X$, we derive new positivity constraints on spin observables and study their implications for theoretical models in view, in particular, of accounting for…
Calculations of the polarization of $\Lambda$ and $\bar{\Lambda}$ particles after fragmentation of a polarized quark produced in processes like $Z$-decay and deep inelastic polarized lepton scattering must include $\Lambda$ and…
With the aim to study spin dependence of pion production near threshold, an internal target facility and a forward detector have been installed in the Cooler synchrotron ring at IUCF. The detector system comprises scintillators and wire…