125171490
CROSS-SECTIONS, AVERAGE MULTIPLICITIES AND ENERGY FRACTIONS OF NEUTRAL pi- AND K MESONS IN anti-p p ANNIHILATIONS AT 22.4-GeV/c
186674866
The First Three TILECAL Submodule Assembly in Prague
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.
136300702
RD19: status report on 1993 development of hybrid and monolithic silicon micropattern detectors
136042277
RD19: status report and addendum. Development of hybrid and monolithic silicon micropattern detectors
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.
117874201
First Results from the TOTEM Experiment
Visitor from an external Institution.The ﬁrst physics results from the TOTEM experiment are here reported,concerning the measurements of the total, diﬀerential elastic, elastic and in-elastic pp cross-section at the LHC energy of√s = 7 TeV, obtained using theluminosity measurement from CMS. A preliminary measurement of the forwardcharged particle η distribution is also shown.PRESENTED AT
67834315
Luminosity-independent measurements of total, elastic and inelastic cross-sections at $\sqrt{s}$ = 7 TeV
The TOTEM experiment at the LHC has performed the first luminosity-independent determination of the total proton-proton cross-section at . This technique is based on the optical theorem and requires simultaneous measurements of the inelastic rate – accomplished with the forward charged-particle telescopes T1 and T2 in the range 3.1 < |η| < 6.5 – and of the elastic rate by detecting the outcoming protons with Roman Pot detectors. The data presented here were collected in a dedicated run in 2011 with special beam optics (β* = 90 m) and Roman Pots approaching the beam close enough to register elastic events with squared four-momentum transfers |t| as low as 5·10−3 GeV2. The luminosity-independent results for the elastic, inelastic and total cross-sections are σel = (25.1 ± 1.1) mb, σinel = (72.9 ± 1.5) mb and σtot = (98.0 ± 2.5) mb, respectively. At the same time this method yields the integrated luminosity, in agreement with measurements by CMS. TOTEM has also determined the total cross-section in two complementary ways, both using the CMS luminosity measurement as an input. The first method sums the elastic and inelastic cross-sections and thus does not depend on the ρ parameter. The second applies the optical theorem to the elastic-scattering measurements only and therefore is free of the T1 and T2 measurement uncertainties. The methods, having very different systematic dependences, give results in excellent agreement. Moreover, the ρ-independent measurement makes a first estimate for the ρ parameter at possible: |ρ| = 0.145 ± 0.091.
116951283
Problems related to description of particle decay
115913744
To the theory of high-energy elastic nucleon collisions
The commonly used West and Yennie integral formula for the relative phase between the Coulomb and elastic hadronic amplitudes requires for the phase of the elastic hadronic amplitude to be constant at all kinematically allowed values of t. More general interference formula based on the eikonal model approach does not exhibit such limitation. The corresponding differences will be demonstrated and some predictions of different phenomenological models for elastic pp scattering at energy of 14 TeV at the LHC will be given. Special attention will be devoted to determination of luminosity from elastic scattering data; it will be shown that the systematic error might reach till 5 % if the luminosity is derived from the values in the center of the interference region with the help of West and Yennie formula.
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.