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E. M. Kabuss

Publications and source records attributed to E. M. Kabuss.

3 recordsLinked to original sources

A high power liquid hydrogen target for the Mainz A4 parity violation experiment

We present a new powerful liquid hydrogen target developed for the precise study of parity violating electron scattering on hydrogen and deuterium. This target has been designed to have minimal target density fluctuations under the heat load of a 20$μ$A CW 854.3 MeV electron beam without rastering the electron beam. The target cell has a wide aperture for scattered electrons and is axially symmetric around the beam axis. The construction is optimized to intensify heat exchange by a transverse turbulent mixing in the hydrogen stream, which is directed along the electron beam. The target is constructed as a closed loop circulating system cooled by a helium refrigerator. It is operated by a tangential mechanical pump with an optional natural convection mode. The cooling system supports up to 250 watts of the beam heating removal. Deeply subcooled liquid hydrogen is used for keeping the in-beam temperature below the boiling point. The target density fluctuations are found to be at the level 10$^{-3}$ at a beam current of 20 $μ$A.

nucl-ex

Electron Scattering with Polarized Targets at TESLA

Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA, can be directed onto a solid state target that may be either longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q^2-dependence of the experimentally totally unknown quark transversity distributions that will complete the information on the nucleon's quark spin structure as relevant for high energy processes. Comparing their Q^2-evolution to that of the corresponding helicity distributions constitutes an important precision test of the predictive power of QCD in the spin sector. Measuring transversity distributions and tensor charges allows access to the hitherto unmeasured chirally odd operators in QCD which are of great importance to understand the role of chiral symmetry. The possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics.

hep-ph

The Structure Function Ratios F2(Li)/F2(D) and F2(C)/F2(D) at small x

We present the structure function ratios F2(Li)/F2(D) and F2(C)/F2(D) measured in deep inelastic muon-nucleus scattering at a nominal incident muon energy of 200 GeV. The kinematic range 0.0001 < x < 0.7 and 0.01< Q^2 < 70 GeV^2 is covered. For values of $x$ less than $0.002$ both ratios indicate saturation of shadowing at values compatible with photoabsorption results.

hep-ex