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The SLAC's experiment failed to find any millicharges but were able to leave out a substantial part of the parameter plane, according to Alyssa Prinz, member of the research team. She added that they recorded nearly 300 mil machine pulses during 14 weeks of running.

The DIRC, a new type of ring-imaging Cherenkov detector that images internally reflected Cherenkov light, is being constructed as the main hadronic particle identification component of the BABAR detector at SLAC. The device makes use of 5 meter long fused silica (colloquially called quartz) bars, which serve both as the Cherenkov radiators and as light pipes for transmitting the light to an array of photo-multiplier tubes. This paper describes a program of research and development aimed at determining whether bars that meet the stringent requirements of the DIRC can be obtained from commercial sources. The results of studies of bulk absorption of fused silica, surface finish, radiation damage and bulk inhomogeneities are discussed.

This paper describes the radiation testing of CCDs for the vertex detector now installed at the SLAC linear collider. In addition to data from the batch qualification, results are also presented on the effect of biasing the CCDs during irradiation. A comparison between Co60 and Sr90 irradiation is made and initial results for radiation effects in the vertex detector during operation are presented.

The charge limit phenomena in different p-type GaAs photocathodes was studied. A linear collider designed at Stanford Linear Accelerator Center was used to illuminate cathode samples and obtain measurements of the structures'beam intensity, temporal pulse structure and transverse spatial profile. Results indicate that the charge limit in photocathodes is caused by an increase in the cathode work function brought about by high carrier densities.

Since May 1999 the BABAR detector has been taking data at the PEP-II asymmetric electron-positron collider at the Stanford Linear Accelerator Center, CA. This experiment requires a very large data sample and the PEP-II accelerator uses intense beams to deliver the high collision rates needed. This poses a severe challenge to the BABAR trigger system, which must reject the large rate of background signals resulting from the high beam currents whilst accepting the collisions of interest with very high efficiency. One of the systems that performs this task is the Level 1 Calorimeter Trigger, which identifies energy deposits left by particles in the BABAR calorimeter. It is a digital, custom, fixed latency system which makes heavy use of high-speed FPGA devices to allow flexibility in the choice of data filtering algorithms. Results from several intermediate processing stages are read out, allowing the selection algorithm to be fully analyzed and optimized offline. In addition, the trigger is monitored in real time by sampling these data and cross-checking each stage of the trigger calculation against a software model. The design, implementation, construction and performance of the Level 1 Calorimeter Trigger during the first year of BABAR operation are presented. Index Terms--Calorimetry, data acquisition, elementary particles, field-programmable gate arrays (FPGAs), triggering.

SAN FRANCISCO--Humanity--and everything else in the universe--exists because matter and antimatter forged in equal amounts during the big bang may have decayed into slightly different sets of particles, giving matter [...]

Throughout 1995, there was a steady drip in the comer of a graduate student office at the Stanford Linear Accelerator Center (SLAC). o one called the plumbers, however, because physicists [...]

On the cult television hit The X-Files, FBI Agent Fox Mulder investigates reports of everything from attacks by vampires to visits from UFOs. Living by the motto 'The truth is [...]

The US Energy Department awarded the development of the unique electron collider to the Stanford Linear Accelerator Center (SLAC), near Menlo, California, US, at the beginning of Oct 1993. The electron collider will be able to help physicists anlayse why the world is composed of matter. The other tender was put forward by Cornell University whose project was $100 million cheaper than that of the SLAC. Cornell was rejected as scientists claimed that it was technically more of a risk. SLAC's B-factory project will be undertaken at a cost of $177 million.