Search results for " dependence"
showing 10 items of 2018 documents
Winkelverteilung von elastisch und mit 6,7 eV-Energieverlust an freien Hg-Atomen gestreuten Elektronen
1970
The angular dependence of electrons scattered elastically and inelastically at free mercury atoms have been measured for electron energies between 20 and 300 eV (angular range from 20 to 155°).
Winkelverteilungen elastisch an Edelgas-Atomstrahlen gestreuter Elektronen; Spinpolarisation eines an Argon gestreuten 40 eV-Elektronenstrahls
1967
The angular distribution of electrons scattered elastically by rare-gas atomic beams (He, Ne, Ar, Kr, Xe) has been investigated over the angular range from 20° to 155° and with electron energies between 5 eV and 1000 eV. The results are compared with theory. Only for energies above 300 eV the agreement is good. The angular dependence of polarization P(Θ) of electrons, elastically scattered by a beam of argon atoms, is measured in a double scattering experiment for an electron energy of 40 eV. Maximum degree of polarization measured isP=12.5% ± 2.5%.
Velocity distribution of ion beams from the RIKEN IGISOL
1992
Abstract A direct measurement of the velocity distribution of ion beams from an ion-guide isotope separator on-line (IGISOL) was carried out at RIKEN with a technique of laser spectroscopy. The skimmer-potential and gas-cell pressure dependence of the velocity distribution were also measured. The velocity distribution was found to be about two times narrower than that estimated from the mass resolving power (MRP). It is pointed out that the velocity spread deduced from MRP is considerably overestimated at various conditions. The way of improvement to make the velocity distribution of the ion beam from the IGISOL narrower and the feasibility of fast atomic-beam collinear laser spectroscopy a…
Elektronenpolarisation im Energiebereich unterhalb 50 eV durch Streuung an freien Hg-Atomen
1966
The angular dependence of spin polarizationP(Θ) of electrons elastically scattered by a beam of mercury atoms is measured in a double scattering experiment for electron energies of 45±1 eV; 23±1 eV; 7±1 eV; and 3,5±1 eV. Maximum degree of polarization obtained isP(100°)=0,39±0,07; electron energy 7±1 eV; electron current 10−12–10−11 A.
Systematic Comparison of Jet Energy-Loss Schemes in a realistic hydrodynamic medium
2009
We perform a systematic comparison of three different jet energy-loss approaches. These include the Armesto-Salgado-Wiedemann scheme based on the approach of Baier-Dokshitzer-Mueller-Peigne-Schiff and Zakharov (BDMPS-Z/ASW), the Higher Twist approach (HT) and a scheme based on the approach of Arnold-Moore-Yaffe (AMY). In this comparison, an identical medium evolution will be utilized for all three approaches: not only does this entail the use of the same realistic three-dimensional relativistic fluid dynamics (RFD) simulation, but also includes the use of identical initial parton-distribution functions and final fragmentation functions. We are, thus, in a unique position, not only to isolat…
Messung der Spinpolarisation langsamer Elektronen nach elastischer Streuung an festen Hg-Targets
1967
SpinpolarizationP(Θ) of slow electrons elastically scattered by a solid Hg-target has been studied in a double-scattering experiment for electron energies between 300 eV and 900 eV. For the same energy range the angular dependence of the scattered intensity has been measured. Maximum degree of polarization found isP=−0.23±0.04 (E=900 eV,Θ=105°).
Generalized parton distributions and hard exclusive reactions
2003
Abstract We discuss how generalized parton distributions (GPDs) enter in a variety of hard exclusive processes such as deeply virtual Compton scattering (DVCS) and hard meson electroproduction reactions on the nucleon. We discuss the links between GPDs and elastic nucleon form factors as well as the information contained in the second moment of GPDs. We subsequently show some key observables which are sensitive to the various hadron structure aspects of the GPDs, and discuss their experimental status.
Polarization effects in exclusive semi-leptonic Λc and Λb charm and bottom baryon decays
1992
Abstract We discuss polarization effects in semi-leptonic decays of polarized and unpolarized heavy Λ-type baryons into heavy and into light Λ-type baryons. We use the non-leptonic decay of the daughter baryon and the leptonic decay of the Woff-shell into a lepton pair as polarization analyzers to analyze the polarization of the daughter baryon and the Woff-shell. Technically this is done by writing down joint angular decay distributions. We calculate the values of the various asymmetry parameters that characterize the angular dependence of the angular decay distributions where we use the predictions of the heavy quark effective theory (HQET) supplemented by simple ansatze for the q2-depend…
Global analysis of nuclear PDFs – latest developments
2013
Abstract In this review talk I discuss the latest developments in the DGLAP-based global analysis of nuclear parton distribution functions (nPDFs), focusing on the recent EPS09, nCTEQ and DSSZ global fits. I also briefly review the recent analysis for assigning a spatial dependence to the globally analysed nPDFs, resulting in the new sets EPS09s and EKS98s (“s” for spatial). With these, one can now compute nuclear hard-process cross sections and estimate their nPDF-originating uncertainties in different centrality classes for the first time consistently with the global nPDF fits.
Polarized photon measurements of the12C(γ→,pp)and12C(γ→,pn)reactions forEγ=160−350MeV
2001
The ${}^{12}\mathrm{C}(\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}},pp)$ and ${}^{12}\mathrm{C}(\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}},pn)$ reactions have been studied for ${E}_{\ensuremath{\gamma}}=160\ensuremath{-}350$ MeV using linearly polarized photons from the Glasgow tagged photon spectrometer at the Mainz microtron MAMI. Both reaction channels show a negative photon asymmetry $\ensuremath{\Sigma}$ for missing energies ${E}_{m}$ below 70 MeV, where direct emission nucleon pairs is expected. A strong peak at low ${E}_{m}$ is observed in ${\ensuremath{\Sigma}}_{(\ensuremath{\gamma},pp)},$ but not in ${\ensuremath{\Sigma}}_{(\ensuremath{\gamma},pn)}.$ Furth…