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In this issue:
GLAST Telescope Components to be Tested at CERN
Science Today: The Rarest B Decay
Planned Isobutane Flare
Linear Collider Industrial Forum Comes to SLAC

SLAC Today

Thursday - April 27, 2006

(Image - GLAST's view of the universe)
GLAST's Large Area Telescope will view the universe in gamma ray photons, allowing researchers to create images like the simulated one shown above. In order to create these maps accurately, the telescope will need to be well-calibrated.

GLAST Telescope Components
to be Tested at CERN

When the task is to find gamma ray photons in outer space, where they are outnumbered 10,000 to 1 by charged particles, it helps to have a perfectly calibrated instrument.

The instrument charged with this challenging task is the Large Area Telescope (LAT), assembled at SLAC as part of the NASA-led multi-nation Gamma-ray Large Area Space Telescope (GLAST) project. As the LAT gets ready to go to the Naval Research Laboratory for further environmental testing, a scaled-down version of it, called a calibration unit, will undergo several weeks of testing at CERN from the end of July through mid-September.  Read more...

(Daily Column - Science Today)

The Rarest B Decay

(Photo - BaBar Detector) SLAC's BaBar detector.
(Photo by Peter Ginter.)

As the PEP-II accelerator creates ever increasing numbers of electron-positron collisions, BaBar experimenters are exploiting the large data sample to search for exceedingly rare particle reactions which could potentially reveal the existence of new spacetime dimensions and symmetries.

In a paper recently submitted to Physical Review, BaBar researchers describe the latest measurements of the rarest B meson reaction ever observed: a B meson decaying into a K meson and a pair of charged leptons (electrons or muons). The B meson, which is composed of a "bottom" quark and a light anti-quark, is prolifically produced by PEP-II, and out of the 500 million B mesons recorded by the BaBar detector, only 50 of these rare decay events were found.

BaBar researchers relied on excellent particle identification by the detector, multivariate background discrimination methods, a "blind" analysis technique, and plenty of data to accomplish this needle-in-a-haystack feat.

The motivation for their search was to study how a bottom species of quark can change into a "strange" quark species, which in the Standard Model theory can only proceed via a rare "penguin diagram" loop of virtual high-energy particles. New dimensions of spacetime, or new spacetime symmetries, such as supersymmetry, could dramatically modify this prediction, changing the decay rate or the angular orientation of the decay products. The standard theory was found to be consistent with the BaBar results, which highly constrains how supersymmetry or extra dimensions could be realized in nature. However, with only small samples currently in hand, there is plenty of room for even stronger tests of these new phenomena as BaBar plans to accumulate billions of B mesons through 2008.

Planned Isobutane Flare

(Photo - Isobutane Flare) (Click on image for larger version.)

SLAC is making way for LCLS construction. Part of this effort is the removal of a 30-foot isobutane tank located on the SLAC Large Detector gas pad near Building 750. Isobutane is a flammable gas that must be managed in a safe manner to prevent a fire hazard or even an explosion.

Working with HAAS- TCM, SLAC's chemical service provider, and two sub-contractors that specialize in this type of work, Chemical and General Safety (CGS) and Conventional and Experimental Facilities (CEF) have partnered to remove this tank. The first step was burning off any remaining Isobutane using a torch placed a safe distance away from the tank and any combustible material.

The tank will now be purged multiple times using an inert gas and then filled with water. After the tank is empty and clean it will be sent off site to a metal recycler.

Linear Collider Industrial Forum Comes to SLAC

(Photo - ILC Industrialization Forum)

The Linear Collider Forum of America (LCFOA) will hold its Spring 2006 meeting at SLAC on May 1-2. The LCFOA is an organization of manufacturers and civil construction firms that support the ILC and are interested in participating in its construction. They keep up to date with R&D developments through semi-annual meetings such as this one.

The LCFOA provides a partnership between its industry members and the government, National Laboratories, universities, the ILC Global Design Effort (GDE) and the Americas Regional Team supporting the GDE throughout all phases of the ILC program. Read more...

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