相关论文: Polarized Protons in HERA
Coupled electron-nuclear spins represent a promising quantum system, where the optically induced electron spin polarization can be dynamically transferred to nuclear spins via the hyperfine interaction. Most experiments on dynamic nuclear…
Intense positron beams can be prepared via electro production with the reaction $e^{-} + e^{-} \rightarrow e^{-}+e^{+}+e^{-}+e^{-}$ due to the availability of high current electron beams. Head on collisions inside of a magnetic field of a…
The acceleration of charged particles, producing collimated mono-energetic beams, over short distances holds the promise to offer new tools in medicine and diagnostics. Here, we consider a possible mechanism for accelerating protons to high…
The recent proposals concerning the usage of the real polarized gamma beam, obtained by the Compton backscattering of the laser photons off the electron beams from either the linear or circular accelerators were considered. The heavy quark…
Results on elastic vector meson production at HERA are presented in the framework of perturbative QCD. The energy dependence of the cross section for J/Psi photoproduction and for rho electroproduction is studied. A full polarisation…
Results of our next-to-leading order analytic calculation for longitudinally polarized photoproduction of heavy quarks are presented. Certain differential cross sections and the corresponding asymmetries are computed for energy ranges…
We discuss heavy quark and quarkonium production in various kinematic regions at the HERA ep collider. In contrast to fixed target experiments, collider kinematics allows the possibility of detailed measurements of particle production in…
A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field,…
We demonstrate in this research the quasi-monoenergetic electron and proton acceleration through three dimensional particle-in-cell simulations of short petawatt circular polarized laser pulse interactions with near critical density…
The effects of Scalar Leptoquarks in various channels have been analysed for the HERA collider and also for an eventual new $ep$ machine running at higher energies. We emphasize the relevance of polarized beams.
The phenomenon of polarization of nuclei in the process of stimulated recombination of atoms in the field of circularly polarized laser radiation is considered. This effect is considered for the case of the proton-electron beams used in the…
Many sets of polarization evolution equations have been suggested to describe the method of polarization buildup by spin filtering in storage rings. In this paper a generic system of polarization evolution equations describing spin…
Physics from the polarized electron or positron beam colliding with the unpolarized proton beam at HERA-II as well as from the unpolarized ep collisions at HERA-I is discussed. Results shown include (i) inclusive neutral and charged current…
The equations of classical spin-orbit motion can be extended to a Hamiltonian system in 9-dimensional phase space by introducing a coupled spin-orbit Poisson bracket and a Hamiltonian function. After this extension and by establishing…
The production of polarized proton beams with multi-GeV energies in ultra-intense laser interaction with targets is studied with three-dimensional Particle-In-Cell simulations. A near-critical density plasma target with pre-polarized proton…
SABRE (Signal Amplification By Reversible Exchange) has become a widely used method for hyper-polarizing nuclear spins, thereby enhancing their Nuclear Magnetic Resonance (NMR) signals by orders of magnitude. In SABRE experiments,…
In order to measure the mass of the eta meson with high accuracy using the d+p -> 3He+eta reaction, the momentum of the circulating deuteron beam in the Cooler Synchrotron COSY of the Forschungszentrum Juelich has to be determined with…
Precision measurements in storage rings are increasingly limited by the ability to monitor collective spin dynamics coherently over long time scales. Existing polarimetry techniques rely on destructive scattering processes that preclude…
An efficient technique to generate ensembles of spins that are highly polarized by external magnetic fields is the Holy Grail in Nuclear Magnetic Resonance (NMR) spectroscopy. Since spin-half nuclei have steady-state polarization biases…
Controlling non-linear effects in the transverse dynamics of charged particle beams in circular accelerators opens new possibilities for controlling some of the beam properties. Beam splitting by crossing a stable 1D non-linear resonance is…