120572228
First operation of a 72 k element hybrid silicon micropattern pixel detector array
Abstract We have constructed and tested silicon pixel detector arrays of 96 × 378 (36 288) sensor elements with 75 μm × 500 μm area. The low-noise signal processing circuit associated with each element occupies an identical area on a bump-bonded readout chip. The pixel cell response for ionizing particles is binary with an adjustable threshold between 4000 e − and 15 000 e − . Single chips, the array of 6 ladders and a double array have been characterized in particle test beams and in the Omega experiment WA97 at CERN. The two arrays together, staggered by ∼ 4 mm cover hermetically a 53 mm × 55 mm area with 72 576 pixels. The proportion of properly functioning pixels was 98% in the first 36 k pixel array and 80% in the second one. The ∼ 1% “always-on” pixels could be masked electronically. After masking the rate of “spurious noise hits” was −8 of the identified particle hits while with beam off no hits at all were recorded With a beam trigger most events consisted of a single cluster with a single hit. At the 8000 e − threshold an efficiency > 99% was measured. Tracks were reconstructed with a precision of 22 μm. The proportion of double hits (∼ 11%) depends only slightly on threshold and detector bias voltage, and for these double hits a precision of 10 μm on the particle position was obtained.
136042277
RD19: status report and addendum. Development of hybrid and monolithic silicon micropattern detectors
124110052
Parton-cluster model of hadrons and impact parameter structure of non-diffractive collisions
A model of hadron structure and hadron collisions is proposed for interpreting experimental data. It starts from the assumption that a hadron consists of a number of partons with very large masses which are grouped inside hadrons into clusters with quantum numbers of the known hadrons. In hadron collisions the most peripheral clusters behave as spectators and represent leading particles; non-diffractive hadron collisions can then be interpreted mostly as stripping-like reactions. It is shown on a sample of annihilation and non-annihilation pp collisions at 5·7 GeV/c that experimental data for several different leading particles are in good qualitative agreement with the basic requirement of the model which concerns the strong impact parameter angular dependence of the leading particles.
186674866
The First Three TILECAL Submodule Assembly in Prague
136300702
RD19: status report on 1993 development of hybrid and monolithic silicon micropattern detectors
110037616
The results of mass testing of the plastic streamer tubes for the DELPHI hadron calorimeter
Abstract The procedure and results of mass testing of plastic streamer tubes for the DELPHI hadron calorimeter are described in detail. The mass testing includes three stages: high voltage test and conditioning, X-ray test on radiation load capability and wire tension control in ready detectors. The productivity of the test workshop was 240 detectors per day at maximum. After testing of about 25 000 streamer tubes, 8% have been rejected on the ground of severe rejection criteria which exceed significantly the working conditions in the DELPHI experiment.
120862082
Remarks on double poles and non-exponential decays
The model of an unstable particle with two internal states, which are able to change from one into the other, is analyzed with the help of the formalism outlined generally in the papers by J. Jersák: Jader fiz. (in press) and M. Lokajíček: Czech. J. Phys.B 19 (1969), 925. This formalism is developed further.
15615074
Locality problem, Bell's inequalities and EPR experiments
The question has been solved whether Bell's inequalities cover all possible kinds of hidden-variable theories. It has been shown that the given nequalities can be hardly derived when the changing space position of photon-pair source together with the microscopic space structure of measuring devices are taken into account; and when corresponding impact parameters (i.e., exact impact points) of photons in individual measuring devices (polarizers) influence measured values, in addition to usually considered characteristics.
121451892
Physical meaning of the phase of high energy elastic scattering amplitude
The influence of the phaset-dependence on the profiles of high energy elastic hadron scattering in the impact-parameter plane are discussed. The analysis of interference experimental data concerning pp, ¯pp and p4He scattering is summarized. It is shown that in all these cases the high-energy elastic scattering can be interpreted as a peripheral process.
115828864
Contemporary models of elastic nucleon scattering and their predictions for LHC
The analyses of elastic collisions of charged nucleons have been based standardly on West and Yennie formula. However, this approach has been shown recently to be inadequate from experimental as well as theoretical points of view. The eikonal model seems to be more pertinent as it enables to determine physical characteristics in impact parameter space. The contemporary phenomenological models cannot give, of course, any definite answer as the elastic collisions may be interpreted differently, as central or peripheral processes. Nevertheless, the predictions for the planned LHC energy have been given on their basis and the possibility of exact determination of luminosity has been considered.
17100968
Realistic theory of microscopic phenomena; a new solution of hidden-variable problem
It has been shown that quantum paradoxes have followed from one special assumption, i.e., from attributing basic physical meaning to Hamiltonian eigenfunctions and representing all physical states by vectors of the Hilbert space spanned on these eigenfunctions. However, any paradoxical properties disappear if the physical states are represented by vectors from the extended Hilbert space on which the scattering theory of Lax and Phillips has been based. On the other side, all stationary characteristics and experimentally verified quantum-mechanical predictions remain the same. The extended mathematical model is also in full agreement with results of EPR experiments, if one takes into account that a further assumption (in addition to locality condition) is involved in derivation of Bell's inequalities as shown recently (see: quant-ph/9808005).