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In this issue:
From the Director: Please Join Me in Welcoming Steve Chu
Hats Off for Top Off
BaBar Celebrates 400th Paper
Word of the Week: Quark

SLAC Today

Friday - June 26, 2009

From the Director:
Please Join Me in Welcoming Steve Chu

(Photo - Persis Drell)

Secretary of Energy Dr. Steven Chu visits SLAC today. In an all-hands presentation this morning, Steve will share his vision for our energy future. I strongly encourage everyone at the lab to attend this special event. Steve is a strong supporter of science, and this is our opportunity to hear his plans.

The Secretary's visit caps a very special week. Earlier in the week the BaBar collaboration announced the publication of its 400th scientific paper, and yesterday the Stanford Synchrotron Radiation Lightsource achieved top off injection, an accomplishment years in the making. I was impressed to watch top off injection turn on with the flip of a switch (but as we know there is always a lot of preparation and planning behind the simple flip of a switch!). My congratulations to all involved in these successes.

The Secretary's presentation begins at 10:00 a.m. on the main SLAC green. I look forward to seeing you there!

Britt Hedman flipped the switch to begin top off injection at SSRL on Thursday afternoon. (Photo by Brad Plummer.)

Hats Off for Top Off

Yesterday, the Stanford Synchrotron Radiation Lightsource reached a milestone years in the making. At 2:00 p.m. on Thursday afternoon, SSRL engineers and physicists achieved "top off injection," whereby they replenished the current within the SPEAR3 storage ring without blocking the X-ray beam headed for selected SSRL beamlines.  Read more...

BaBar Celebrates 400th Paper

BaBarians celebrated the publication of the collaboration's 400th paper with a toast at this week's collaboration meeting in Valencia. (Photo by Neus Lopez-March.)

A champagne toast in Valencia, Spain, on Monday marked a tremendous accomplishment for the BaBar collaboration: the group has submitted its 400th paper for publication.

"BaBar's rate of publication is the highest in the world," said Spokesman Francois LeDiberder. "I do not know of any collaboration in our field that has reached such a publication rate. The secret of this incredible success lies in the fact that BaBar is a fully international collaboration."

LeDiberder and Physics Analysis Coordinator Owen Long took a moment to celebrate during the collaboration meeting, where they are busy preparing material to be presented at summer conferences. Long said the collaboration has been so busy that he almost missed this important mile marker. In addition, BaBar recently had its 300th Ph.D. thesis defended.

SLAC physicist Mark Convery and Ph.D. student Kevin Yarritu authored the 400th paper, "Measurement of Branching Fractions and CP and Isospin Asymmetries in B → K*(892)γ Decays."

(Image - building blocks)
(Image: Symmetry magazine)

Word of the Week: Quark

Along with leptons, quarks are the smallest and most fundamental constituents of matter known. Quarks carry electric charges, so they interact electrically, and they also carry something called "color charge," which means they interact strongly, combining to form the composite particles known as hadrons.

Quarks play a big role in SLAC's history. The first evidence supporting the existence of quarks came from SLAC experiments conducted in 1968, a discovery for which SLAC physicist Richard Taylor shared the 1990 Nobel Prize in physics. Taylor's prize wasn't the first for SLAC, though; SLAC physicist Burton Richter received the 1976 Nobel Prize in physics for his research team's 1974 discovery of the J/psi particle, which was evidence for the charm quark.


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