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In this issue:
BaBar Steadies Omega-minus Spin
Dorfan Today will return next week
Photo of the Day: OIO
Rare Transit of Mercury
Safety Firsts

SLAC Today

Monday - November 6, 2006

BaBar Steadies Omega-minus Spin

The first evidence of the omega-minus particle in a bubble chamber. (Image courtesy of Brookhaven National Laboratory. Click on image for larger version.)

If you snatch a copy of the Particle Data Book from your colleague's back pocket and flip to the entry for the Omega-minus particle, you'll see that the very first line says its spin is "not yet measured." That entry may soon be changed. The BaBar collaboration has established that the spin of the Omega-minus, a particle that was discovered more than 40 years ago, is 3/2.

"The Omega-minus has been around for a long time and it's got a very interesting history," says BaBar collaborator Bill Dunwoodie. "It was a confirmation of Murray Gell-Mann's ideas about broken symmetry that led eventually to the quark model."

The analysis of BaBar data was primarily conducted by Veronique Ziegler, a graduate student from the University of Iowa, with Dunwoodie. The findings are published in the Sept. 15 issue of Physical Review Letters. Read more...

(Director's Column - Dorfan Today)

Jonathan is currently traveling. His Director's Column will return next week.

Photo of the Day:

(Photo - OIO)
Photo courtesy of John Shepardson. (Click on image for larger version.)

Eleven members of the Office of Independent Oversight (OIO) began evaluating SLAC's Integrated Safety and Environmental Management System (ISEMS) last Monday.  In the above image, OIO Inspector Jim Lockridge (right) speaks with Acting Division Head for the Klystron Department Chris Pearson (left) and Michael Benes of the Klystron Machine Shop (center).

The OIO evaluation is quite extensive. The team is spending eleven days assessing the effectiveness of the lab's ISEMS and its systems and practices in order to identify areas in need of strengthening. In this process, the team is interviewing SLAC employees and users, observing work being accomplished, and evaluating documents and records.

Any SLAC employee or user approached by the OIO is asked to please be forthright and cooperative in their conversations with the OIO team.

The team's final report will be presented in the last week of November.

Rare Transit of Mercury

In this image of Mercury's 1986 transit of the sun, Mercury is visible as a black dot in the upper left of the image. Mercury also transited the sun in 2003. (Image courtesy of Planetarium Smolyan).

Usually you expect to see planets at night. But in broad daylight on Wednesday, November 8th, the planet Mercury will cross the face of the sun.

It will be visible in silhouette through a telescope with a safe solar filter placed securely over the front. Mercury will "transit" the sun for about five hours, looking like a tiny round sunspot creeping westward across the enormous surface of our home star.

Transits of Mercury don't happen very often. The last was on May 7, 2003, and the next doesn't come until May 9, 2016.

Well-prepared observers will see Mercury edge onto the sun's face around 11:12 a.m. Pacific Standard Time. Watchers in western North America can see the entire transit, which ends when Mercury slips off the sun's edge at 4:10 p.m. Pacific time. Read more...

Safety Firsts

If you look at all the injuries suffered by SLAC staff members, you find at least two common patterns. The first is that almost all were engaged in activities that they understood and were quite familiar with. Can you guess the other?

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