相关论文: Revealing Color Forces with Transverse Polarized E…
Two kinds of asymmetry arise from the interference of the Born amplitude and the box-type amplitude corresponding to two virtual photons exchange, namely charge-odd and one spin asymmetries. In case of unpolarized particles the charge-odd…
An internal polarized hydrogen storage cell gas target is proposed for the AD--ring to determine for the first time the two total spin--dependent cross sections $\sigma_1$ and $\sigma_2$ at antiproton beam energies in the range from 50 to…
Coincidence reactions of the type $\svec{A}(\svec{e},e'N)B$ involving the scattering of polarized electrons from deformed polarized targets are discussed within the context of the plane--wave impulse approximation. A general expression for…
An analysis of all experimental data of 50's - 90's on elastic gamma-p scattering at photon energies below 150 MeV (10 experimental works) is performed in order to determine the electric (alpha_p) and magnetic (beta_p) polarizabilities of…
Experiment E950 at AGS, BNL has provided data with high statistics for the left-right asymmetry of proton-carbon elastic scattering in the Coulomb-nuclear interference region of momentum transfer. It allows to access information about spin…
We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < Q^2 < 1.0 GeV^2. These asymmetries, arising from interference of the electromagnetic and neutral weak…
The polarization of the secondary protons in the (p,2p) reaction with the S - shell protons of nuclei 4He, 6Li, 12C, 28Si, 40Ca was measured at 1 GeV unpolarized proton beam. The spin correlation parameters Cij for the 4He and 12C targets…
We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q$^2$) up to 15.75~\gevsq. Combined with existing data, these provide an improved extraction of the proton magnetic form…
Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton $\vec{e}\vec{p} \to e' p'\gamma$ are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally…
The analysis of semi-inclusive deep inelastic electron scattering off polarized $^3$He at finite momentum transfers, aimed at the extraction of the quark transverse-momentum distributions in the neutron, requires the use of a distorted…
Excitation functions of the spin correlation coefficients A_{NN}(p_{lab},theta_{c.m.}), A_{SS}(p_{lab},theta_{c.m.}), and A_{SL}(p_{lab},theta_{c.m.}) have been measured with the polarized proton beam of the Cooler Synchrotron COSY and an…
The transverse beam spin induced asymmetry is calculated for the scattering of transversally polarized electrons on a proton target within a realistic model. Such asymmetry is due to the interference between the Born amplitude and the…
Measuring Compton scattered photons and recoil neutrons in coincidence, quasi-free Compton scattering by the neutron has been investigated at MAMI (Mainz) at $theta^{lab}_\gamma=136^o$ in an energy range from 200 to 400 MeV. From the data a…
We report on the first measurement of double-spin asymmetry, A_LL, of electrons from the decays of hadrons containing heavy flavor in longitudinally polarized p+p collisions at sqrt(s)=200 GeV for p_T= 0.5 to 3.0 GeV/c. The asymmetry was…
We present a precise measurement of the cross section, proton and $\rm ^3He$ analyzing powers, and spin correlation coefficient $C_{y,y}$ for $p$-$\rm ^3He$ elastic scattering near 65 MeV, and a comparison with rigorous four-nucleon…
The ratio of the elastic $e^+ p$ to $e^- p$ scattering cross sections has been measured precisely, allowing the determination of the two-photon exchange contribution to these processes. This neglected contribution is believed to be the…
Proton-3He scattering is one of the good probes to study the T=3/2 channel of three--nucleon forces. We have measured 3He analyzing powers for p-3He elastic scattering with the polarized 3He target at 70 and 100 MeV. The data are compared…
Scattering of protons with transversal polarization $p_y^p$ on deuterons with tensor polarization $P_{xz}$ provides a null-test signal for time-reversal (T) invariance violating but parity (P) conserving effects. We calculate the…
The data from the last seven experiments performed on polarized deep--inelastic scattering on proton and neutron (or deuteron) targets have been analyzed in search of a precise determination of the spin fraction carried by the quarks in the…
We study $pp$ scattering at high energies and moderately large momentum transfer using a QCD--based model in which the proton is viewed as being composed of a quark and a diquark. This model leads to spin asymmetries which are neither small…