SLAC Today is available online at:
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In this issue:
SLAC Hosts Extremely Large Databases Workshop
Science Today: BaBar in Search for Exotica
Longtime SLAC Employee Magellan Starks Passes Away
SLAC to Update Employee Records
SLAC to Begin Blocking Emails by IP Address

SLAC Today

Thursday - October 25, 2007

SLAC Hosts Extremely Large Databases Workshop

Data collections at SLAC aren't just pretty big—the experts call them "Extremely Large Databases." BaBar's two petabytes of data will seem paltry when the Large Synoptic Survey Telescope (LSST), which is expected to collect 100 petabytes over 10 years, comes online in 2014. SLAC is leading the effort to build the LSST's database system.

Companies such as Google, eBay, AT&T and AOL depend on large databases too. But no commercial enterprise makes the kind of software needed to manage all the petabytes that some users require. "Almost all of [these companies] make their own homegrown systems," says SLAC Information Systems Specialist Jacek Becla.

Becla aims to confront that issue, starting with a workshop today at SLAC. Becla invited commercial database vendors, industry and academic users of large databases and what he calls "the world's best database gurus" to the Extremely Large Databases Workshop. Kian-Tat Lim and Andrew Hanushevsky, both of SLAC, also helped to organize the meeting.

The meeting is an opportunity for users to tell the vendors what they need from database systems. "Vendors should go home with the ideas of what they should be adding to their systems," Becla says.

SLAC, Becla says, provides a "neutral ground" for these diverse and competing groups to meet. For example, he says, Yahoo! would be reluctant to attend such a conference if it was held at Google, but both will come to SLAC.

"Perhaps we will be able to build a longer-term relationship among cutting-edge database users from industry, the scientific community and the database vendors," Becla says.

(Daily Column - Science Today)

In Search of Exotica

A famous character once said, "Life is like a box of chocolates… You never know what you're gonna get." In particle physics, we do not follow this principle often. Experiments are designed and data analyses are developed with the help of theoretical predictions and powerful simulation tools, to make sure that the experiments operate optimally. If new effects are discovered, they can be quickly compared to theories and identified. The Standard Model, a well-established theory of particles and interactions, has been very successful in predicting the outcomes of the experiments over the last 25 years. New theories, developed on the basis of these measurements and building on the success of the Standard Model, typically predict new phenomena to show up at high energies. According to conventional wisdom, new discoveries would be made at the energy frontier: at the most energetic colliders such as Fermilab's Tevatron, or the Large Hadron Collider (LHC) at CERN, the new machine to be commissioned next year. Yet, BaBar physicists are attempting to bend this conventional wisdom ever so slightly.

The SLAC PEP-II storage ring and the BaBar detector are collectively known as the "B-Factory," which implies the main purpose of the experiment: precision study of charge-parity (CP) violation in the decays of B mesons (Bs). The Bs are heavy equivalents of pions, particles commonly produced in cosmic rays, and contain a heavy b-quark. The accelerator produces about 20 Bs each second, and the BaBar researches look for subtle differences in the time evolution and decay of the Bs  and their anti-particles (B-bars). PEP-II has produced nearly 500 million B/B-bar pairs, and the BaBar Collaboration has written over 300 scientific papers since the start of the experiment in 1999.

But just like a GM factory may churn out Chevy, GMC, or Isuzu cars, and even an occasional Saab, electron-positron annihilations at the SLAC B-Factory produce more than just B mesons. Lighter quark flavors, from up/down to charm, are produced in even larger quantities, as well as muons, tau-leptons, and even undetectable neutrinos. BaBar physicists look at those processes too, and in fact some of the more unexpected discoveries have come out from these studies: the discoveries of several new charm mesons, the discovery of the D0-D0bar mixing, to name a few.

Then, there are truly exotic possibilities. What if the Higgs boson, expected within the Standard Model to have the mass above 120 GeV/c2, is instead unconventionally light? Such a particle could be produced in e+e- annihilations, in association with energetic photons, but the process might be too rare to have been observed at other colliders that more energetic but less prolific in data rates. The experiments at the LHC, designed to discover the Higgs bosons, would probably miss a very light Higgs (or a Higgs-like) particle too. What if the dark matter particles, which carry about a quarter of the mass of the Universe and believed to relatively slow and heavy (several hundred GeV), are instead light and weakly interacting? There are a number of (decidedly unconventional) theoretical models that predict such light states, motivated by astrophysical observations, or simply exploring the possibilities. Very light new particles might be hard to identify at high-energy colliders, and that is where BaBar comes in.

BaBar physicists have started to explore the opportunities to look for such exotic events. Most models agree on one thing: even if collisions at the B-Factory have enough energy to produce new particles, the probability to create such a state in a given e+e- annihilation is very low. Researches need to look through a lot of data, in quantities matched only by the BaBar's sister experiment, Belle, and be able to reject copious "background" events, to have a chance for discovery. In addition, the signature for such events sometimes includes a single particle—a high-energy photon—and nothing else detectable. Such events used to be ignored by the event selection algorithms, but this fall BaBar has enabled a new "trigger": an electronic marker to record events that look interesting for further analysis. This trigger will enable new searches next year, and—if Nature proves to be sufficiently exotic—potential discoveries.

BaBar collaboration is organizing a special workshop on October 29 to jump-start these efforts, and to generate new ideas. Theorists and BaBar experimentalists alike are invited, and interesting ideas, even wild ones, are welcome. Who is to say we won't find a little exotic nugget?

Longtime SLAC Employee Magellan Starks Passes Away


Magellan Starks

Services will be held this Friday for longtime SLAC employee Magellan Starks, who died Sunday of cancer.

Starks was a fixture in the Shipping and Receiving Department, where he worked for 31 years. He started working at SLAC when he was 17 years old.

"He was definitely a role model here in the department," said coworker Alex Vega.

Colleagues remember Starks as a perennially positive and friendly person. "He was very polite," said Jim Minich, who worked with Starks for 29 years. Starks always said "you're welcome," never "yeah" or "sure," Minich said.

He was also an active member of the lab community, joining onsite basketball games and playing on the SLAC softball team.

"He was my right-hand man," said Sandra Pickrom, his supervisor. "We will miss him terribly."

Starks is survived by his wife, daughter, stepson, two grandchildren and his mother, who also worked at SLAC.

A viewing will be held today between 6:00 and 8:00 p.m. at Jones Mortuary, 660 Donohoe St., East Palo Alto, 94303. The service will be held on Friday at 11:00 a.m., also at Jones Mortuary.


SLAC to Update Employee Records

Human Resources needs your cooperation in a very important update to the lab's employee records.

Soon, every SLAC employee will receive a request via internal mail for his or her current home address, mailing address (if different) and contact telephone numbers. In addition, the Records Department is requesting emergency contact information. This information will give SLAC a way to contact the right people in the event of an accident or medical situation.

This confidential information will also be used for mailing W-2 Forms and benefits enrollment information. Please provide this information even if the current information is correct.


Lab to Begin Blocking E-mails by IP Address

A whopping 85% of the e-mail SLAC receives is spam. The computing effort needed to send this colossal amount of e-mail through spam filters and virus scanners not only uses up valuable computing resources, but can also result in delivery delays of legitimate messages.

In an effort to decrease the volume of spam SLAC needs to process, the computing division will begin using an IP port blocking service this Saturday. The service, offered by Sophos, the lab's e-mail software vendor, automatically blocks e-mails coming from IP addresses that have been verified as high-volume spam-senders. The blocking service will reduce the number of messages SLAC's filters and scanners have to process by about 50%.

Both Sophos and SLAC's computing division have tested this service carefully, and found that it is extremely unlikely that any legitimate e-mail will be blocked by the new service. To further ensure that no e-mail is lost, the sender of each blocked message will receive an e-mail explaining why the message did not make it to the intended recipient.

In the unlikely event that legitimate e-mail is blocked, please contact the SLAC e-mail administrators. More information on this new service is available on the computing website.


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