124083721
SOME ASPECTS OF TARGETING SYSTEMS FOR A SLOW EXTRACTED BEAM AT THE AGS.
126003037
The Meson Area at 1000-GeV
123415460
Rationale for a Choice of Secondary Particle Beams at NAL
118824183
Study of lepton pairs from proton-nuclear interactions: search for intermediate bosons and lee-wick structure
The authors propose to observe lepton pairs emerging from high energy proton-nuclear collisions. Large effective mass pairs probe the hadronic electromagnetic structure. The continuum mass spectrum will be measured and any resonant structures in the mass range up to {approx}28 GeV will be detected with great sensitivity. The data provides a prediction, via Conserved Vector Current theory, for the production cross section for weak vector bosons and these are also sought in the mass range {approx} 8-28 GeV. They also propose an initial photon-electron beam survey at high transverse momentum which is also a W-search with good sensitivity.
122179155
Comparison of spin asymmetries and cross sections in π0 production by 200 GeV polarized antiprotons and protons
125702680
Some Highlights in Elementary Particle Physics in 1969
110956273
A silicon pad shower maximum detector for a shashlik calorimeter
The new luminosity monitor of the DELPHI detector, STIC (Small angle TIle Calorimeter), was built using a Shashlik technique. This technique does not provide longitudinal sampling of the showers, which limits the measurement of the direction of the incident particles and the e — π separation. For these reasons STIC was equipped with a Silicon Pad Shower Maximum Detector (SPSMD). In order to match the silicon detectors to the Shashlik read out by wavelength shifter (WLS) fibers, the silicon wafers had to be drilled with a precision better than 10 μ m without damaging the active area of the detectors. This paper describes the SPSMD with emphasis on the fabrication techniques and on the components used. Some preliminary results of the detector performance from data taken with a 45 GeV electron beam at CERN are presented.
12181544
PROTOTYPE TESTS FOR A VERTEX CHAMBER
We describe the design parameters for a pressurized drift chamber under construction for use with the MAC detector at PEP to operate within 3 cm of the beam line. The chamber is constructed of 7 mm diameter tubes of aluminized mylar with wall thickness of 0.10 mm. The tracking device incorporating these tubes is particularly simple to construct and can be configured so that any malfunctioning tube cau be remotely disconnected without affecting overall og erations. Resolution studies made in a SLAC test beam with a prototype over a wide range of gases and operating conditions are reported. The resolutions obtained were in the 10-40 micron range. It was found that the chamber could be operated satisfactorily, using heavily quenched gases, at high pressures (~4 atm) and operating voltages of ~4 kV in a mode for which saturated streamers were initiated with high efficiency by single electrons. Single electron gains for this mode were -108. The streamers were confined to a region of the wire with dimension of the order of a few hundred microns and count rates in excess of lo4 Hz/cm could be sustained with low dead-times. Further studies are in progress on chamber lifetimes with a variety of gas Elliogs. For our specific application this is of particular importance as the vertex chamber is expected to run in regions of high radiation backgrounds. As was expected for a chamber with extended cathodes, lifetimes were good. Actual lifetimes observed to date with our tube configurations have ranged from 0.05 coul/cm integrated current on the anode for 50:50 argon-isobutane to ~1 coul/cm for a mix of 49% A: 50% CO2: 1% C&. The results of these tests show our design goals to be achievable. Additionally they provide a basis on which to design high precision tracking devices particularly in applications where the device is to be operated in regions of difficult physical access or high ambient radiation levels.
117135799
Physics with the MAC detector
New results, obtained during the previous year at the PEP colliding beam rings with the MAC detector at a center of mass energy of 29 GeV, are presented.
108962738
Performance of the new high precision luminosity monitor of DELPHI
The STIC calorimeter was installed in the DELPHI detector in 1994. The main goal is to measure the luminosity with an accuracy better than 0.1%. The calorimeter was built using the “Shashlik” technique. The light is collected by wavelength shifting fibers and readout by phototetrodes that can operate inside the magnetic field. The detector performance during the 1994–1995 data taking is presented. The different contributions to the systematic error on the luminosity measurement are discussed.
121789189
The silicon shower maximum detector for the STIC
The structure of a shashlik calorimeter allows the insertion of tracking detectors within the longitudinal sampling to improve the accuracy in the determination of the direction of the showering particle and the eπ separation ability. The new forward calorimeter of the DELPHI detector has been equipped with two planes of silicon pad detectors respectively after 4 and 7.4 radiation lengths. The novelty of these silicon detectors is that to cope with the shashlik readout fibers, they had to incorporate 1.4 mm holes every cm2. The detector consists of circular strips with a radial pitch of 1.7 mm and an angular granularity of 22.5°, read out by means of the MX4 preamplifier. The preamplifier is located at 35 cm from the silicon detector and the signal is carried by Kapton cables bonded to the detector. The matching to the MX4 input pitch of 44 μm was made by a specially developed fanin hybrid.